Clinical Focus

  • Acute Pain Management
  • Regional Anesthesia
  • Chronic Post-Surgical Pain
  • Pediatric Anesthesia

Boards, Advisory Committees, Professional Organizations

  • Scientific Advisory Board, Association of University Anesthesiologists (2020 - Present)
  • Associate Editor, Chronic Pain Medicine, Anesthesia & Analgesia (2019 - Present)
  • Abstract Review Subcommittee on Regional Anesthesia and Acute Pain, American Society of Anesthesiologists (2018 - Present)
  • Educational Advisory Board, Association of University Anesthesiologists (2016 - 2019)
  • Active Member, Association of University Anesthesiologists (2015 - Present)
  • Member, International Anesthesia Research Society (2015 - Present)
  • Member, Society for Pediatric Anesthesia (2008 - Present)
  • Member, American Society of Anesthesiologists (2005 - Present)

Professional Education

  • Board Certification: American Board of Anesthesiology, Pediatric Anesthesia (2015)
  • Board Certification: American Board of Anesthesiology, Anesthesia (2013)
  • Fellowship: Boston Children's Hospital (2011) MA
  • Residency: UCSF Anesthesiology Residency (2010) CA
  • Internship, San Joaquin General Hospital, CA (2007)
  • Medical Education: University of Michigan School of Medicine (2006) MI
  • Ph.D., Massachusetts Institute of Technology, MA (2002)


  • Thomas Anderson. "United States Patent WO2015200712A1 Optical sensor for needle-tip tissue identification and diagnosis", Massachusetts Institute of Technology; Massachusetts General Hospital

Research Interests

  • Adolescence
  • Early Childhood
  • Poverty and Inequality
  • Race and Ethnicity

Current Research and Scholarly Interests

1. Acute and Chronic Pain Management: Focused Ultrasound for Peripheral Neuromodulation
Poorly controlled acute and chronic pain are common and significant sources of patient morbidity. Inadequate control of postoperative pain is a risk factor for worsened patient outcomes, and 5% to 80% of patients will develop chronic pain after surgery. Novel, safe, and effective methods to improve and prevent acute and chronic pain are needed. Focused ultrasound (FUS) can modulate central and peripheral nervous system structures. Most FUS research is concentrated on its utility for transcranial modulation of neural structures and ablation of tissues. However, there is evidence that it can also alter peripheral nerve conduction, including compound action potential depression in a manner similar to local anesthetics. However, no work has yet been published assessing its effects on acute or chronic pain, nor whether it is able to differentially modulate different classes of nerve fibers. We are interested in the potential of focused ultrasound to modulate peripheral nerves and improve both acute and chronic pain.

2. Pediatric Perioperative Outcomes
Chronic pain and opioid use are major public health issues in the United States and internationally. Those who use opioids chronically and patients with chronic pain are more likely to have worsened health and require more medical care. Both adults and children who undergo surgery are at increased risk of prolonged opioid use after surgery and chronic post-surgical pain. While these issues have been well-studied in adult patients, far fewer studies exist in pediatric surgical populations. As more than six million inpatient and outpatient pediatric surgical procedures take place in the U.S. each year, it is imperative to understand the risk of prolonged opioid use and chronic pain after surgery in this vulnerable and understudied population and to design and investigate interventions to decrease these risks. We are working with several healthcare datasets assessing the risk of prolonged opioid use after surgery and chronic post-surgical pain in children. Our goal is to understand how various perioperative pain management strategies affect outcomes in children who undergo surgery. We are further interested in whether disparities exist in the perioperative pain management of children of different races, ethnicities, and socioeconomic status.

2023-24 Courses

Graduate and Fellowship Programs

  • Pediatric Anesthesia (Fellowship Program)

All Publications

  • Focused ultrasound-induced inhibition of peripheral nerve fibers in an animal model of acute pain. Regional anesthesia and pain medicine Anderson, T. A., Pacharinsak, C., Vilches-Moure, J., Kantarci, H., Zuchero, J. B., Butts-Pauly, K., Yeomans, D. 2023


    Moderate-to-severe acute pain is prevalent in many healthcare settings and associated with adverse outcomes. Peripheral nerve blockade using traditional needle-based and local anesthetic-based techniques improves pain outcomes for some patient populations but has shortcomings limiting use. These limitations include its invasiveness, potential for local anesthetic systemic toxicity, risk of infection with an indwelling catheter, and relatively short duration of blockade compared with the period of pain after major injuries. Focused ultrasound is capable of inhibiting the peripheral nervous system and has potential as a pain management tool. However, investigations of its effect on peripheral nerve nociceptive fibers in animal models of acute pain are lacking. In an in vivo acute pain model, we investigated focused ultrasound's effects on behavior and peripheral nerve structure.Focused ultrasound was applied directly to the sciatic nerve of rats just prior to a hindpaw incision; three control groups (focused ultrasound sham only, hindpaw incision only, focused ultrasound sham+hindpaw incision) were also included. For all four groups (intervention and controls), behavioral testing (thermal and mechanical hyperalgesia, hindpaw extension and flexion) took place for 4 weeks. Structural changes to peripheral nerves of non-focused ultrasound controls and after focused ultrasound application were assessed on days 0 and 14 using light microscopy and transmission electron microscopy.Compared with controls, after focused ultrasound application, animals had (1) increased mechanical nociceptive thresholds for 2 weeks; (2) sustained increase in thermal nociceptive thresholds for ≥4 weeks; (3) a decrease in hindpaw motor response for 0.5 weeks; and (4) a decrease in hindpaw plantar sensation for 2 weeks. At 14 days after focused ultrasound application, alterations to myelin sheaths and nerve fiber ultrastructure were observed both by light and electron microscopy.Focused ultrasound, using a distinct parameter set, reversibly inhibits A-delta peripheral nerve nociceptive, motor, and non-nociceptive sensory fiber-mediated behaviors, has a prolonged effect on C nociceptive fiber-mediated behavior, and alters nerve structure. Focused ultrasound may have potential as a peripheral nerve blockade technique for acute pain management. However, further investigation is required to determine C fiber inhibition duration and the significance of nerve structural changes.

    View details for DOI 10.1136/rapm-2022-104060

    View details for PubMedID 36822815

  • Association of Common Pediatric Surgeries with New Onset Chronic Pain in Patients 0-21 Years of Age in the United States. The journal of pain Thapa, I., De Souza, E., Ward, A., Bambos, N., Anderson, T. A. 2022


    Chronic pain (CP) is a major public health issue. While new onset CP is known to occur frequently after some pediatric surgeries, its incidence after the most common pediatric surgeries is unknown. This retrospective cohort study used insurance claims data from 2002 to 2017 for patients 0-21 years of age. The primary outcome was CP 90-365 days after each of the 20 most frequent surgeries in five age categories (identified using CP ICD codes). Multivariable logistic regression identified surgeries and risk factors associated with CP after surgery. A total of 424,590 surgical patients aged 0-21 were included, 22,361 of whom developed CP in the 90-365 days after surgery. The incidences of CP after surgery were: 1.1% in age group 0-1 years; 3.0% in 2-5 years; 5.6% in 6-11 years; 10.1% in 12-18 years; 9.9% in 19-21 years. Some surgeries and patient variables were associated with CP. Approximately one in ten adolescents who underwent the most common surgeries developed CP, as did a striking percentage of children in other age groups. Given the long-term consequences of CP, resources should be allocated toward identification of high-risk pediatric patients and strategies to prevent CP after surgery.

    View details for DOI 10.1016/j.jpain.2022.09.015

    View details for PubMedID 36216129

  • Racial/Ethnic Variability in Use of General Anesthesia for Pediatric Magnetic Resonance Imaging Anderson, T. A., Gan, Z., Rosenbloom, J. M., De Souza, B. LIPPINCOTT WILLIAMS & WILKINS. 2022: 828
  • Health Care Burden Associated with Pediatric Prolonged Opioid Use After Surgery Anderson, T. A., Joyner, A., King, M. R., Safranek, C., Parvathinathan, G., De Souza, B. LIPPINCOTT WILLIAMS & WILKINS. 2022: 380
  • Low-dose intraoperative opioids and its association with PACU outcomes: a retrospective equivalence study Anderson, T. A., De Souza, B., King, M. R. LIPPINCOTT WILLIAMS & WILKINS. 2022: 829
  • Visualizing Opioid-Use Variation in a Pediatric Perioperative Dashboard. Applied clinical informatics Safranek, C. W., Feitzinger, L., Joyner, A. K., Woo, N., Smith, V., Souza, E. D., Vasilakis, C., Anderson, T. A., Fehr, J., Shin, A. Y., Scheinker, D., Wang, E., Xie, J. 2022; 13 (2): 370-379


    BACKGROUND: Anesthesiologists integrate numerous variables to determine an opioid dose that manages patient nociception and pain while minimizing adverse effects. Clinical dashboards that enable physicians to compare themselves to their peers can reduce unnecessary variation in patient care and improve outcomes. However, due to the complexity of anesthetic dosing decisions, comparative visualizations of opioid-use patterns are complicated by case-mix differences between providers.OBJECTIVES: This single-institution case study describes the development of a pediatric anesthesia dashboard and demonstrates how advanced computational techniques can facilitate nuanced normalization techniques, enabling meaningful comparisons of complex clinical data.METHODS: We engaged perioperative-care stakeholders at a tertiary care pediatric hospital to determine patient and surgical variables relevant to anesthesia decision-making and to identify end-user requirements for an opioid-use visualization tool. Case data were extracted, aggregated, and standardized. We performed multivariable machine learning to identify and understand key variables. We integrated interview findings and computational algorithms into an interactive dashboard with normalized comparisons, followed by an iterative process of improvement and implementation.RESULTS: The dashboard design process identified two mechanisms-interactive data filtration and machine-learning-based normalization-that enable rigorous monitoring of opioid utilization with meaningful case-mix adjustment. When deployed with real data encompassing 24,332 surgical cases, our dashboard identified both high and low opioid-use outliers with associated clinical outcomes data.CONCLUSION: A tool that gives anesthesiologists timely data on their practice patterns while adjusting for case-mix differences empowers physicians to track changes and variation in opioid administration over time. Such a tool can successfully trigger conversation amongst stakeholders in support of continuous improvement efforts. Clinical analytics dashboards can enable physicians to better understand their practice and provide motivation to change behavior, ultimately addressing unnecessary variation in high impact medication use and minimizing adverse effects.

    View details for DOI 10.1055/s-0042-1744387

    View details for PubMedID 35322398

  • Dose-dependent effects of high intensity focused ultrasound on compound action potentials in an ex vivo rodent peripheral nerve model: comparison to local anesthetics. Regional anesthesia and pain medicine Anderson, T. A., Delgado, J., Sun, S., Behzadian, N., Vilches-Moure, J., Szlavik, R. B., Butts-Pauly, K., Yeomans, D. 1800


    BACKGROUND: In animal models, focused ultrasound can reversibly or permanently inhibit nerve conduction, suggesting a potential role in managing pain. We hypothesized focused ultrasound's effects on action potential parameters may be similar to those of local anesthetics.METHODS: In an ex vivo rat sciatic nerve model, action potential amplitude, area under the curve, latency to 10% peak, latency to 100% peak, rate of rise, and half peak width changes were assessed after separately applying increasing focused ultrasound pressures or concentrations of bupivacaine and ropivacaine. Focused ultrasound's effects on nerve structure were examined histologically.RESULTS: Increasing focused ultrasound pressures decreased action potential amplitude, area under the curve, and rate of rise, increased latency to 10% peak, and did not change latency to 100% peak or half peak width. Increasing local anesthetic concentrations decreased action potential amplitude, area under the curve, and rate of rise and increased latency to 10% peak, latency to 100% peak, and half peak width. At the highest focused ultrasound pressures, nerve architecture was altered compared with controls.DISCUSSION: While some action potential parameters were altered comparably by focused ultrasound and local anesthetics, there were small but notable differences. It is not evident if these differences may lead to differences in clinical pain effects when focused ultrasound is applied in vivo or if focused ultrasound pressures that result in clinically relevant changes damage nerve structures. Given the potential advantages of a non-invasive technique for managing pain conditions, further investigation may be warranted in an in vivo pain model.

    View details for DOI 10.1136/rapm-2021-103115

    View details for PubMedID 35115412

  • Laying the First Brick: A Foundation for Medical Investigation Through Big Data. Anesthesia and analgesia Grant, M. C., Anderson, T. A. 1800; 134 (1): 5-7

    View details for DOI 10.1213/ANE.0000000000005710

    View details for PubMedID 34908540

  • Prediction of Prolonged Opioid Use After Surgery in Adolescents: Insights From Machine Learning. Anesthesia and analgesia Ward, A., Jani, T., De Souza, E., Scheinker, D., Bambos, N., Anderson, T. A. 2021


    BACKGROUND: Long-term opioid use has negative health care consequences. Patients who undergo surgery are at risk for prolonged opioid use after surgery (POUS). While risk factors have been previously identified, no methods currently exist to determine higher-risk patients. We assessed the ability of a variety of machine-learning algorithms to predict adolescents at risk of POUS and to identify factors associated with this risk.METHODS: A retrospective cohort study was conducted using a national insurance claims database of adolescents aged 12-21 years who underwent 1 of 1297 surgeries, with general anesthesia, from January 1, 2011 to December 30, 2017. Logistic regression with an L2 penalty and with a logistic regression with an L1 lasso (Lasso) penalty, random forests, gradient boosting machines, and extreme gradient boosted models were trained using patient and provider characteristics to predict POUS (≥1 opioid prescription fill within 90-180 days after surgery) risk. Predictive capabilities were assessed using the area under the receiver-operating characteristic curve (AUC)/C-statistic, mean average precision (MAP); individual decision thresholds were compared using sensitivity, specificity, Youden Index, F1 score, and number needed to evaluate. The variables most strongly associated with POUS risk were identified using permutation importance.RESULTS: Of 186,493 eligible patient surgical visits, 8410 (4.51%) had POUS. The top-performing algorithm achieved an overall AUC of 0.711 (95% confidence interval [CI], 0.699-0.723) and significantly higher AUCs for certain surgeries (eg, 0.823 for spinal fusion surgery and 0.812 for dental surgery). The variables with the strongest association with POUS were the days' supply of opioids and oral morphine milligram equivalents of opioids in the year before surgery.CONCLUSIONS: Machine-learning models to predict POUS risk among adolescents show modest to strong results for different surgeries and reveal variables associated with higher risk. These results may inform health care system-specific identification of patients at higher risk for POUS and drive development of preventative measures.

    View details for DOI 10.1213/ANE.0000000000005527

    View details for PubMedID 33939656

  • Pediatric Anesthesia, an Issue of Anesthesiology Clinics, Volume 38-3. Anesthesia and analgesia Anderson, T. A. 2021; 132 (5): e68

    View details for DOI 10.1213/ANE.0000000000005470

    View details for PubMedID 33857985

  • Modeling Intraoperative Opioid Administration Variation: A Single-Center Retrospective Cohort Study of Children Safranek, C., Poole, S., De Souza, B., Hong, T., Wang, E., Scheinker, D., Anderson, T. A. LIPPINCOTT WILLIAMS & WILKINS. 2021: 795-797
  • Association between regional anesthesia and analgesic outcomes: a single-center retrospective study of 2,761 pediatric regional anesthetics Xie, J. J., De Souza, B., Perez, F. D., Suarez-Nieto, M. V., Wang, E., Anderson, T. A. LIPPINCOTT WILLIAMS & WILKINS. 2021: 934-936
  • Publication misrepresentation amongst pediatric anesthesiology fellowship applicants: A retrospective single center cohort study Mehta, A., Patel, P. V., Caruso, T., Anderson, T. A. LIPPINCOTT WILLIAMS & WILKINS. 2021: 401-402
  • Diagnostic Point-of-Care Ultrasound: Recommendations From an Expert Panel. Journal of cardiothoracic and vascular anesthesia Bronshteyn, Y. S., Anderson, T. A., Badakhsh, O., Boublik, J., Brady, M. B., Charnin, J. E., Coker, B. J., Deriy, L. B., Hardman, H. D., Haskins, S. C., Hollon, M., Hsia, H. J., Neelankavil, J. P., Panzer, O. P., Perlas, A., Ramsingh, D., Sharma, A., Shore-Lesserson, L. J., Zimmerman, J. M., American Society of Anesthesiologists Ad Hoc Committee on PoCUS 2021


    Diagnostic point-of-care ultrasound (PoCUS) has emerged as a powerful tool to help anesthesiologists guide patient care in both the perioperative setting and the subspecialty arenas. Although anesthesiologists can turn to guideline statements pertaining to other aspects of ultrasound use, to date there remains little in the way of published guidance regarding diagnostic PoCUS. To this end, in 2018, the American Society of Anesthesiologists chartered an ad hoc committee consisting of 23 American Society of Anesthesiologists members to provide recommendations on this topic. The ad hoc committee convened and developed a committee work product. This work product was updated in 2021 by an expert panel of the ad hoc committee to produce the document presented herein. The document, which represents the consensus opinion of a group of practicing anesthesiologists with established expertise in diagnostic ultrasound, addresses the following issues: (1) affirms the practice of diagnostic PoCUS by adequately trained anesthesiologists, (2) identifies the scope of practice of diagnostic PoCUS relevant to anesthesiologists, (3) suggests the minimum level of training needed to achieve competence, (4) provides recommendations for how diagnostic PoCUS can be used safely and ethically, and (5) provides broad guidance about diagnostic ultrasound billing.

    View details for DOI 10.1053/j.jvca.2021.04.016

    View details for PubMedID 34059438

  • Pediatric Anesthesia, an Issue of Anesthesiology Clinics, Volume 38-3. Anesthesia and analgesia Anderson, T. A. 2021; 132 (5): e68

    View details for DOI 10.1213/ANE.0000000000005470

    View details for PubMedID 34042083

  • Publication misrepresentation amongst pediatric anesthesiology fellowship applicants: A retrospective single center cohort study. Paediatric anaesthesia Mehta, A., Patel, P., Caruso, T. J., Anderson, T. A. 2021


    Many medical specialties have found publication misrepresentation in residency and fellowship applications, but pediatric anesthesia fellowship application data is lacking.We sought to determine the prevalence of publication misrepresentation among pediatric anesthesia fellowship applications.In this retrospective cohort study, fellowship applications to Stanford University's pediatric anesthesiology fellowship program from 2009 to 2019 were reviewed. Only peer-reviewed journal articles listed as accepted or published were included. Nine additional variables were collected: applicant age, gender, citizenship status, American vs. international medical school, public vs. private medical school, allopathic doctor versus osteopathic doctor, number of years between college and medical school, additional degrees, and application year. The primary outcome was the rate of publication misrepresentation, defined as peer-reviewed journal citations listed on the application that could not be verified or on which the applicant was not listed as an author. Secondary outcomes were the associations between publication misrepresentation and the additional collected variables.1280 peer-reviewed journal publications from 877 applicants were reviewed. 3.4% of all citations listed as peer-reviewed journal articles were misrepresented and 9.0% of all applicants with at least 1 publication had ≥ 1 misrepresented publications. 30.2% of publications labelled "misrepresented" were located in our search of databases but did not have the applicant as an author, and 69.8% could not be located using the search databases. Only one of the 9 collected variables (public vs private medical school) was significantly associated with publication misrepresentation.In this single center retrospective study, publication misrepresentation was found to occur in one out of 11 pediatric anesthesia fellowship applications with at least one publication. Since residency and fellowship applicant publications may be heavily weighted during the application process, programs may want to include additional inquiries into the accuracy of applicant publications.

    View details for DOI 10.1111/pan.14251

    View details for PubMedID 34214229

  • Ex Vivo Whole Nerve Electrophysiology Setup, Action Potential Recording, and Data Analyses in a Rodent Model. Current protocols in neuroscience Sun, S., Delgado, J., Behzadian, N., Yeomans, D., Anderson, T. A. 2020; 93 (1): e99


    Ex vivo rodent whole nerves provide a model for assessing the effects of interventions on nerve impulse transmission and consequent sensory and/or motor function. Nerve impulse transmission can be measured through sciatic nerve compound action potential (CAP) recordings. However, de novo development and implementation of an ex vivo whole nerve resection protocol and an electrophysiology setup that retains nerve viability, that produces low noise CAP signals, and that allows for data analysis is challenging. Additionally, some of the existing literature lacks detail and accuracy and may be out of date. This article describes detailedprotocols for rodent ex vivo sciatic nerve dissection and handling; importance of an optimal physiologic solution; computer-aided designs for 3D printing of readily adaptable ex vivo rodent whole nerve electrophysiology chambers; construction of low-cost, effective suction electrodes; setup and use of nerve stimulators and amplifiers; acquisition of low noise, small voltage CAP data and digital conversion; use of software for data analyses of CAP components; and tips for troubleshooting. © 2020 Wiley Periodicals LLC. Basic Protocol 1: Electrophysiology wiring and hardware setup Support Protocol 1: 3D printing an electrophysiology chamber Support Protocol 2: Building suction electrodes Basic Protocol 2: Sciatic nerve dissection and compound action potential recording Basic Protocol 3: Data export and analysis Support Protocol 3: Preparation of HEPES-buffered physiologic solution.

    View details for DOI 10.1002/cpns.99

    View details for PubMedID 32663369

  • Rates of, and Risk Factors for, Chronic Pain in Children and Young Adults Before and After Surgery Thapa, I., Ward, A. T., De Souza, B., Bambos, N., Anderson, T. A. LIPPINCOTT WILLIAMS & WILKINS. 2020: 691
  • Association Of Race and Ethnicity with Postoperative Analgesic Administration and Pain Scores in Pediatric Patients: A Single-Center Study of 29,614 Surgical Cases Perez, F. D., De Souza, B., Wang, E., Rosenbloom, J. M., Anderson, T. A. LIPPINCOTT WILLIAMS & WILKINS. 2020: 680–81
  • Association between regional anesthesia and analgesic outcomes: a single-center retrospective study of 2038 pediatric regional anesthetics Xie, J. J., De Souza, B., Wang, E., Anderson, T. A. LIPPINCOTT WILLIAMS & WILKINS. 2020: 862–63
  • Development and Validation of a Machine Learning Algorithm for Prediction of Prolonged Opioid Use After Surgery in Adolescents and Young Adults Jani, T., Ward, A. T., De Souza, B., Bambos, N., Anderson, T. A. LIPPINCOTT WILLIAMS & WILKINS. 2020: 712–13
  • Rates of, and Risk Factors for, Substance Use Disorder in Children and Young Adults Before and After Surgery Thapa, I., Ward, A. T., De Souza, B., Bambos, N., Anderson, T. A. LIPPINCOTT WILLIAMS & WILKINS. 2020: 689–90
  • Non-Opioid Analgesic Usage Among Pediatric Anesthesiologists: A Survey of Society for Pediatric Anesthesia Members. Paediatric anaesthesia King, M. R., Wu, R. L., De Souza, E., Newton, M. A., Anderson, T. A. 2020


    There is growing evidence to support the perioperative use of non-opioid analgesic medications in the pediatric population,1 but the use of, and attitudes toward, these agents among pediatric anesthesiologists is unknown. In order to characterize utilization of opioid-sparing agents in pediatric anesthesia, we designed a survey to study usage patterns for several non-opioid adjuncts by members of the Society for Pediatric Anesthesia (SPA) during and in the 24 hours following procedures.

    View details for DOI 10.1111/pan.13891

    View details for PubMedID 32323361

  • Doing more and doing better: improving racial and ethnic disparities research in anaesthesiology. British journal of anaesthesia Rosenbloom, J. M., King, M. R., Anderson, T. A. 2020

    View details for DOI 10.1016/j.bja.2020.11.003

    View details for PubMedID 33256991

  • Effects of High Neuromuscular Blocking Agent Dose on Postoperative Respiratory Complications in Infants and Children. Acta anaesthesiologica Scandinavica Scheffenbichler, F. T., Rudolph, M. I., Friedrich, S., Althoff, F. C., Xu, X., Spicer, A. C., Patrocinio, M., Ng, P. Y., Deng, H., Anderson, T. A., Eikermann, M. 2019


    BACKGROUND: This study evaluated the association between neuromuscular blocking agent dose and postoperative respiratory complications in infants and children.METHODS: Data from 6507 general anaesthetics provided to children ≤10 years undergoing surgery were analysed to examine the effects of neuromuscular blocking agent dose on postoperative respiratory complications (primary endpoint) and secondary endpoints. Confounder-adjusted analyses addressed age, surgical duration, and comorbidity burden.RESULTS: In confounder-adjusted analyses, high doses of neuromuscular blocking agents were associated with higher risk of postoperative respiratory complications (OR 2.27; 95%CI 1.12-4.59; P=0.022). The effect was modified by age (P-for-interaction=0.016) towards a more substantial risk in infants ≤1 year (OR 3.84; 95%CI 1.35-10.94; P=0.012), by duration of surgery (P-for-interaction=0.006) towards a higher difference in odds for surgeries <90mins (OR 4.25; 95%CI 1.19-15.18; P=0.026), and by ASA physical status (P-for-interaction=0.015) with a greater effect among patients with higher operative risk (ASA >1: OR 3.17; 95%CI 1.43-7.04; P=0.005). Neostigmine reversal did not modify the association between neuromuscular blocking agents and postoperative respiratory complications (P-for-interaction =0.38). Instrumental variable analysis confirmed that high doses of neuromuscular blocking agents were associated with postoperative respiratory complications (probit coefficient 0.25, 95%CI 0.04-0.46; P=0.022), demonstrating robust results regarding concerns of unobserved confounding.CONCLUSIONS: High dose of neuromuscular blocking agents is associated with postoperative respiratory complications. We have identified subcohorts of paediatric patients who are particularly vulnerable to the respiratory side-effects of neuromuscular blocking agents: infants, paediatric patients undergoing surgeries of short duration, and those with a high ASA risk score.

    View details for DOI 10.1111/aas.13478

    View details for PubMedID 31529484

  • Anesthesia Workspace Cleanliness and Safety: Implementation of a Novel Syringe Bracket Using 3D Printing Techniques. Anesthesiology research and practice Long, D. R., Doney, A., Bartels, D. L., Tan, C. E., Sayal, P. K., Anderson, T. A., Agarwala, A. V. 2019; 2019: 2673781


    Wide variability persists in the preparation and storage of common anesthetic medications despite the recognition of anesthesia workspace standardization as a national quality improvement priority. Syringe contamination and medication swaps continue to pose significant hazards to patient safety.We assessed differences in practice related to the availability of commonly prepared anesthetic medications. Using baseline provider surveys (n = 87) and anesthesia workspace audits (n = 80), we designed a custom syringe organization device using 3D printing techniques to serve as a cognitive aid and organizational tool. We iteratively tested and then deployed this device in all 60 operating rooms at a single institution, and then, repeated postintervention surveys (n = 79) and workspace audits (n = 75) one year after introduction.Implementation was associated with significant improvements in provider-reported medication availability during coverage and handoff situations (43.7% versus 76.2% reporting 95% confidence preintervention versus postintervention, p < 0.001). This was substantiated by audits of the anesthesia workspace which demonstrated reduced variability in the location (p < 0.001) and availability (p < 0.001) of key medications. Provider confidence in the cleanliness of syringes was also improved (p=0.01). A high degree of acceptance and compliance with the intervention was reported, with 80.4% of syringes observed to be stored in the device one year after implementation and approximately 95% of respondents reporting positive measures of usability and convenience.Use of a simple organizational device for syringes in the anesthesia workspace has numerous safety benefits. 3D printing offers improvements in adaptability and affordability compared with prior approaches.

    View details for DOI 10.1155/2019/2673781

    View details for PubMedID 31354811

    View details for PubMedCentralID PMC6636519

  • The Opioid Wars-CON The Risks of Opioids for Pain Management Outweigh the Benefits CLINICAL JOURNAL OF PAIN Anderson, T. A. 2019; 35 (6): 463–67
  • High-Frequency Heart Rate Variability Index: A Prospective, Observational Trial Assessing Utility as a Marker for the Balance Between Analgesia and Nociception Under General Anesthesia. Anesthesia and analgesia Anderson, T. A., Segaran, J. R., Toda, C., Sabouri, A. S., De Jonckheere, J. 2019


    Maintaining a balance between nociception and analgesia perioperatively reduces morbidity and improves outcomes. Current intraoperative analgesic strategies are based on subjective and nonspecific parameters. The high-frequency heart rate (HR) variability index is purported to assess the balance between nociception and analgesia in patients under general anesthesia. This prospective observational study investigated whether intraoperative changes in the high-frequency HR variability index correlate with clinically relevant nociceptive stimulation and the addition of analgesics.Instantaneous and mean high-frequency HR variability indexes were measured continuously in 79 adult subjects undergoing general anesthesia for laparoscopic cholecystectomy. The indexes were compared just before and 2 minutes after direct laryngoscopy, orogastric tube placement, first skin incision, and abdominal insufflation and just before and 6 minutes after the administration of IV hydromorphone.Data from 65 subjects were included in the final analysis. The instantaneous index decreased after skin incision ([SEM], 58.7 [2.0] vs 47.5 [2.0]; P < .001) and abdominal insufflation (54.0 [2.0] vs 46.3 [2.0]; P = .002). There was no change in the instantaneous index after laryngoscopy (47.2 [2.2] vs 40.3 [2.3]; P = .026) and orogastric tube placement (49.8 [2.3] vs 45.4 [2.0]; P = .109). The instantaneous index increased after hydromorphone administration (58.2 [1.9] vs 64.8 [1.8]; P = .003).In adult subjects under general anesthesia for laparoscopic cholecystectomy, changes in the high-frequency HR variability index reflect alterations in the balance between nociception and analgesia. This index might be used intraoperatively to titrate analgesia for individual patients. Further testing is necessary to determine whether the intraoperative use of the index affects patient outcomes.

    View details for DOI 10.1213/ANE.0000000000004180

    View details for PubMedID 31008745

  • Association Between Race and Ethnicity in the Delivery of Regional Anesthesia for Pediatric Patients: A Single-Center Study of 3189 Regional Anesthetics in 25,664 Surgeries. Anesthesia and analgesia King, M. R., De Souza, E. n., Rosenbloom, J. M., Wang, E. n., Anderson, T. A. 2019


    Racial and ethnic disparities in health care are well documented in the United States, although evidence of disparities in pediatric anesthesia is limited. We sought to determine whether there is an association between race and ethnicity and the use of intraoperative regional anesthesia at a single academic children's hospital.We performed a retrospective review of all anesthetics at an academic tertiary children's hospital between May 4, 2014, and May 31, 2018. The primary outcome was delivery of regional anesthesia, defined as a neuraxial or peripheral nerve block. The association between patient race and ethnicity (white non-Hispanic or minority) and receipt of regional anesthesia was assessed using multivariable logistic regression. Sensitivity analyses were performed comparing white non-Hispanic to an expansion of the single minority group to individual racial and ethnic groups and on patients undergoing surgeries most likely to receive regional anesthesia (orthopedic and urology patients).Of 33,713 patient cases eligible for inclusion, 25,664 met criteria for analysis. Three-thousand one-hundred eighty-nine patients (12.4%) received regional anesthesia. One thousand eighty-six of 8884 (13.3%) white non-Hispanic patients and 2003 of 16,780 (11.9%) minority patients received regional anesthesia. After multivariable adjustment for confounding, race and ethnicity were not found to be significantly associated with receiving intraoperative regional anesthesia (adjusted odds ratios [ORs] = 0.95; 95% confidence interval [CI], 0.86-1.06; P = .36). Sensitivity analyses did not find significant differences between the white non-Hispanic group and individual races and ethnicities, nor did they find significant differences when analyzing only orthopedic and urology patients, despite observing some meaningful clinical differences.In an analysis of patients undergoing surgical anesthesia at a single academic children's hospital, race and ethnicity were not significantly associated with the adjusted ORs of receiving intraoperative regional anesthesia. This finding contrasts with much of the existing health care disparities literature and warrants further study with additional datasets to understand the mechanisms involved.

    View details for DOI 10.1213/ANE.0000000000004456

    View details for PubMedID 31569162

  • Is a Retrolaminar Approach to the Thoracic Paravertebral Space Possible? A Human Cadaveric Study REGIONAL ANESTHESIA AND PAIN MEDICINE Sabouri, A., Crawford, L., Bick, S. K., Nozari, A., Anderson, T. A. 2018; 43 (8): 864–68


    The retrolaminar block (RB) is used for truncal analgesia, but its mechanism of neural blockade remains obscure. We sought to learn the pattern of local anesthetic spread after thoracic RB using cadaveric models.In 8 fresh cadavers, an ultrasound-guided T4 RB was performed with 20 mL of methylene blue 1% and bupivacaine 0.5%. For comparison, an RB at T9 in 1 cadaver and a T4 thoracic paravertebral block in another cadaver were performed. Subsequently, posterior and anterior thoracic dissections were performed to examination where the dye spread.After T4 RB, dye was noted to spread in the ipsilateral retrolaminar plane (all 8 cadavers, median cephalad spread 3.5 cm, caudad spread 10.7 cm, lateral spread 2.5 cm), the contralateral retrolaminar plane (6 cadavers), the paravertebral space (5 cadavers, median of 3 segments, T3-T5), the intercostal space (5 cadavers, median of 3.5 cm laterally), the T4 epidural space (6 cadavers), and the intervertebral foramina (4 cadavers, median of 2 segments, T4-T5). After T9 retrolaminar injection, dye was noted in the ipsilateral retrolaminar plane (5.5 cm cephalad, 13.5 cm caudad, and 2.5 cm lateral), the contralateral retrolaminar plane, and the epidural space. Dye after T4 traditional paravertebral block spread to T1-T6 paravertebral space with 15-cm lateral spread.Injectate spread to the paravertebral space, epidural space, intercostal space, and intervertebral foramina is possible in the RB but is quite variable. In comparison to the thoracic paravertebral block, injectate spread within the paravertebral space is more limited.

    View details for PubMedID 29923954

  • Complications in Pediatric Regional Anesthesia: An Analysis of More than 100,000 Blocks from the Pediatric Regional Anesthesia Network. Anesthesiology Walker, B. J., Long, J. B., Sathyamoorthy, M., Birstler, J., Wolf, C., Bosenberg, A. T., Flack, S. H., Krane, E. J., Sethna, N. F., Suresh, S., Taenzer, A. H., Polaner, D. M., Martin, L., Anderson, C., Sunder, R., Adams, T., Martin, L., Pankovich, M., Sawardekar, A., Birmingham, P., Marcelino, R., Ramarmurthi, R. J., Szmuk, P., Ungar, G. K., Lozano, S., Boretsky, K., Jain, R., Matuszczak, M., Petersen, T. R., Dillow, J., Power, R., Nguyen, K., Lee, B. H., Chan, L., Pineda, J., Hutchins, J., Mendoza, K., Spisak, K., Shah, A., DelPizzo, K., Dong, N., Yalamanchili, V., Venable, C., Williams, C. A., Chaudahari, R., Ohkawa, S., Usljebrka, H., Bhalla, T., Vanzillotta, P. P., Apiliogullari, S., Franklin, A. D., Ando, A., Pestieau, S. R., Wright, C., Rosenbloom, J., Anderson, T., Pediatric Regional Anesthesia Network Investigators 2018


    WHAT WE ALREADY KNOW ABOUT THIS TOPIC: WHAT THIS ARTICLE TELLS US THAT IS NEW: BACKGROUND:: Complications in pediatric regional anesthesia are rare, so a large sample size is necessary to quantify risk. The Pediatric Regional Anesthesia Network contains data on more than 100,000 blocks administered at more than 20 children's hospitals. This study analyzed the risk of major complications associated with regional anesthesia in children.METHODS: This is a prospective, observational study of routine clinical practice. Data were collected on every regional block placed by an anesthesiologist at participating institutions and were uploaded to a secure database. The data were audited at multiple points for accuracy.RESULTS: There were no permanent neurologic deficits reported (95% CI, 0 to 0.4:10,000). The risk of transient neurologic deficit was 2.4:10,000 (95% CI, 1.6 to 3.6:10,000) and was not different between peripheral and neuraxial blocks. The risk of severe local anesthetic systemic toxicity was 0.76:10,000 (95% CI, 0.3 to 1.6:10,000); the majority of cases occurred in infants. There was one epidural abscess reported (0.76:10,000, 95% CI, 0 to 4.8:10,000). The incidence of cutaneous infections was 0.5% (53:10,000, 95% CI, 43 to 64:10,000). There were no hematomas associated with neuraxial catheters (95% CI, 0 to 3.5:10,000), but one epidural hematoma occurred with a paravertebral catheter. No additional risk was observed with placing blocks under general anesthesia. The most common adverse events were benign catheter-related failures (4%).CONCLUSIONS: The data from this study demonstrate a level of safety in pediatric regional anesthesia that is comparable to adult practice and confirms the safety of placing blocks under general anesthesia in children.

    View details for PubMedID 30074928

  • Epidural Anesthesia to Facilitate Organ Blood Flow During the First Penile Transplantation in the United States: A Case Report. A&A practice Ruscic, K. J., Zamora-Berridi, G. J., McGovern, F. J., Cetrulo, C., Winograd, J. M., Eberlin, K. R., Bojovic, B., Ko, D. S., Anderson, T. A. 2018; 10 (9): 232-234


    Regional anesthesia has been used to help create local sympathectomy and improve blood flow in plastic surgery procedures involving tissue grafts and flaps. However, anesthetic techniques that reduce systemic vascular resistance must be used with caution in patients with aortic stenosis (AS). Combined neuraxial and general anesthesia with careful titration of the local anesthetic dose can be a safe approach for patients with AS undergoing microvascular procedures. We present the anesthetic management of the first North American penile transplant, on an obese patient with moderate AS.

    View details for DOI 10.1213/XAA.0000000000000672

    View details for PubMedID 29708917

  • Intraoperative Esmolol as an Adjunct for Perioperative Opioid and Postoperative Pain Reduction: A Systematic Review, Meta-analysis, and Meta-regression ANESTHESIA AND ANALGESIA Gelineau, A. M., King, M. R., Ladha, K. S., Burns, S. M., Houle, T., Anderson, T. 2018; 126 (3): 1035–49


    Esmolol is an ultrashort β-1 receptor antagonist. Recent studies suggest a role for esmolol in pain response modulation. The authors performed a meta-analysis to determine if the intraoperative use of esmolol reduces opioid consumption or pain scores.PubMed, Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, pubget, and Google Scholar were searched. Studies were included if they were randomized, placebo- or opioid-controlled trials written in English, and performed on patients 18 years of age or older. For comparison of opioid use, included studies tracked opioid consumption intraoperatively and/or in the postanesthesia care unit. Pain score comparisons were performed during the first hour after surgery.Seventy-three studies were identified, 23 were included in the systematic review, and 19 were eligible for 1 or more comparisons. In 433 patients from 7 trials, intraoperative esmolol decreased intraoperative opioid consumption (Standard Mean Difference [SMD], -1.60; 95% confidence interval [CI], -2.25 to -0.96; P ≤ .001). In 659 patients from 12 trials, intraoperative esmolol decreased postanesthesia care unit opioid consumption (SMD, -1.21; 95% CI, -1.66 to -0.77; P ≤ .001). In 688 patients from 11 trials, there was insufficient evidence of change in postoperative 1 hour pain scores (SMD, -0.60; 95% CI, -1.44 to 0.24; P = .163).This meta-analysis demonstrates that intraoperative esmolol use reduces both intraoperative and postoperative opioid consumption, with no change in postoperative pain scores.

    View details for DOI 10.1213/ANE.0000000000002469

    View details for Web of Science ID 000425343900041

    View details for PubMedID 29028742

  • Cardiac Output Measurements Based on the Pulse Wave Transit Time and Thoracic Impedance Exhibit Limited Agreement With Thermodilution Method During Orthotopic Liver Transplantation. Anesthesia and analgesia Magliocca, A. n., Rezoagli, E. n., Anderson, T. A., Burns, S. M., Ichinose, F. n., Chitilian, H. V. 2018; 126 (1): 85–92


    Orthotopic liver transplantation (OLT) is characterized by significant intraoperative hemodynamic variability. Accurate and real-time cardiac output (CO) monitoring aids clinical decision making during OLT. The purpose of this study is to compare accuracy, precision, and trending ability of CO estimation obtained noninvasively using pulse wave transit time (estimated continuous cardiac output [esCCO; Nihon Kohden, Tokyo, Japan]) or thoracic bioimpedance (ICON; Osypka Medical GmbH, Berlin, Germany) to thermodilution cardiac output (TDCO) measured with a pulmonary artery catheter.Nineteen patients undergoing OLT were enrolled. CO measurements were collected with esCCO, ICON, and thermodilution at 5 time points: (T1) pulmonary artery catheter insertion; (T2) surgical incision; (T3) portal reperfusion; (T4) hepatic arterial reperfusion; and (T5) abdominal closure. The results were analyzed with Bland-Altman plot, percentage error (the percentage of the difference between the CO estimated with the noninvasive monitoring device and CO measured with the thermodilution technique), 4-quadrant plot with concordance rate (the percentage of the total number of points in the I and III quadrant of the 4-quadrant plot), and concordance correlation coefficient (a measure of how well the pairs of observations deviate from the 45-degree line of perfect agreement).Although TDCO increased at T3-T5, both esCCO and ICON failed to track the changes of CO with sufficient accuracy and precision. The mean bias of esCCO and ICON compared to TDCO were -2.0 L/min (SD, ±2.7 L/min) and -3.3 L/min (SD, ±2.8 L/min), respectively. The percentage error was 69% for esCCO and 77% for ICON. The concordance correlation coefficient was 0.653 (95% confidence interval [CI], 0.283-0.853) for esCCO and 0.310 (95% CI, -0.167 to 0.669) for ICON. Nonetheless, esCCO and ICON exhibited reasonable trending ability of TDCO (concordance rate: 95% [95% CI, 88-100] and 100% [95% CI, 93-100]), respectively. The mean bias was correlated with systemic vascular resistance (SVR) and arterial elastance (Ea) for esCCO (SVR, r = 0.610, 95% CI, 0.216-0.833, P < .0001; Ea, r = 0.692, 95% CI, 0.347-0.872; P < .0001) and ICON (SVR, r = 0.573, 95% CI, 0.161-0.815, P < .0001; Ea, r = 0.612, 95% CI, 0.219-0.834, P < .0001).The noninvasive CO estimation with esCCO and ICON exhibited limited accuracy and precision, despite with reasonable trending ability, when compared to TDCO, during OLT. The inaccuracy of esCCO and ICON is especially large when SVR and Ea were decreased during the neohepatic phase. Further refinement of the technology is desirable before noninvasive techniques can replace TDCO during OLT.

    View details for DOI 10.1213/ANE.0000000000002171

    View details for PubMedID 28598912

  • Opioid-free anesthesia using continuous dexmedetomidine and lidocaine infusions in spine surgery. Korean journal of anesthesiology Kim, D. J., Bengali, R., Anderson, T. A. 2017; 70 (6): 652-653

    View details for DOI 10.4097/kjae.2017.70.6.652

    View details for PubMedID 29225750

    View details for PubMedCentralID PMC5716825

  • Heart rate variability: implications for perioperative anesthesia care CURRENT OPINION IN ANESTHESIOLOGY Anderson, T. 2017; 30 (6): 691–97


    Heart rate variability (HRV) is a measure of the balance between both the parasympathetic and sympathetic nervous system and may provide useful information for anesthesia care providers. HRV may offer predictive information about critically ill and operative patients. Further, HRV collection provides real-time information of patient autonomic nervous system status and may allow tailoring of the analgesia for patients in the ICU and operating room.Reduced and abnormal resting HRV predict sudden and nonsudden cardiac death. Recent evidence shows that decreased HRV correlates with worsened outcomes in both trauma patients and patients with sepsis, as well as the risk of developing hypotension after induction of general anesthesia and placement of intrathecal local anesthesia. In addition, HRV appears to provide an accurate assessment of the nociception-analgesia balance in deeply sedated ICU patients and those under general anesthesia.No study has assessed the prognostic value of preoperative HRV in patients presenting for surgery. Use of HRV for patient risk stratification and intraoperative analgesia management may allow tailored perioperative care and improved outcomes. If intraoperative HRV data leads to decreased perioperative opioid use, opioid-related adverse events, a serious perioperative issue, may be decreased.Not applicable.

    View details for PubMedID 28957877

  • Evidence for the Efficacy of Systemic Opioid-Sparing Analgesics in Pediatric Surgical Populations: A Systematic Review. Anesthesia and analgesia Zhu, A., Benzon, H. A., Anderson, T. A. 2017; 125 (5): 1569-1587


    While a large number of studies has examined the efficacy of opioid-sparing analgesics in adult surgical populations, fewer studies are available to guide postoperative pain treatment in pediatric patients. We systematically reviewed available publications on the use of systemic nonopioid agents for postoperative analgesia in pediatric surgical populations. A comprehensive literature search identified meta-analyses and randomized controlled trials (RCTs) assessing the effects of systemic, nonopioid agents on postoperative narcotic requirements or pain scores in pediatric surgical populations. If a meta-analysis was located, we summarized its results and any RCTs published after it. We located and reviewed 11 acetaminophen RCTs, 1 nonsteroidal anti-inflammatory drug (NSAID) meta-analysis, 2 NSAID RCTs, 1 dexamethasone meta-analysis, 3 dexamethasone RCTs, 2 ketamine meta-analyses, 5 ketamine RCTs, 2 gabapentin RCTs, 1 clonidine meta-analysis, 3 magnesium RCTs, 2 dexmedetomidine meta-analyses, and 1 dextromethorphan RCT. No meta-analyses or RCTs were found assessing the perioperative efficacy of intravenous lidocaine, amantadine, pregabalin, esmolol, or caffeine in pediatric surgical patients. The available evidence is limited, but suggests that perioperative acetaminophen, NSAIDs, dexamethasone, ketamine, clonidine, and dexmedetomidine may decrease postoperative pain and opioid consumption in some pediatric surgical populations. Not enough, or no, data exist from which to draw conclusions on the perioperative use of gabapentin, magnesium, dextromethorphan, lidocaine, amantadine, pregabalin, esmolol, and caffeine in pediatric surgical patients. Further pharmacokinetic and pharmacodynamics studies to establish both the clinical benefit and efficacy of nonopioid analgesia in pediatric populations are needed.

    View details for DOI 10.1213/ANE.0000000000002434

    View details for PubMedID 29049110

  • To Stop or Not, That Is the Question: Acute Pain Management for the Patient on Chronic Buprenorphine. Anesthesiology Anderson, T. A., Quaye, A. N., Ward, E. N., Wilens, T. E., Hilliard, P. E., Brummett, C. M. 2017; 126 (6): 1180-1186

    View details for DOI 10.1097/ALN.0000000000001633

    View details for PubMedID 28511196

  • Raman Spectroscopy Differentiates Each Tissue from the Skin to the Spinal Cord: A Novel Method for Epidural Needle Placement? Anesthesiology Anderson, T. A., Kang, J. W., Gubin, T., Dasari, R. R., So, P. T. 2016; 125 (4): 793-804


    Neuraxial anesthesia and epidural steroid injection techniques require precise anatomical targeting to ensure successful and safe analgesia. Previous studies suggest that only some of the tissues encountered during these procedures can be identified by spectroscopic methods, and no previous study has investigated the use of Raman, diffuse reflectance, and fluorescence spectroscopies. The authors hypothesized that real-time needle-tip spectroscopy may aid epidural needle placement and tested the ability of spectroscopy to distinguish each of the tissues in the path of neuraxial needles.For comparison of detection methods, the spectra of individual, dissected ex vivo paravertebral and neuraxial porcine tissues were collected using Raman spectroscopy (RS), diffuse reflectance spectroscopy, and fluorescence spectroscopy. Real-time spectral guidance was tested using a 2-mm inner-diameter fiber-optic probe-in-needle device. Raman spectra were collected during the needle's passage through intact paravertebral and neuraxial porcine tissue and analyzed afterward. The RS tissue signatures were verified as mapping to individual tissue layers using histochemical staining and widefield microscopy.RS revealed a unique spectrum for all ex vivo paravertebral and neuraxial tissue layers; diffuse reflectance spectroscopy and fluorescence spectroscopy were not distinct for all tissues. Moreover, when accounting for the expected order of tissues, real-time Raman spectra recorded during needle insertion also permitted identification of each paravertebral and neuraxial porcine tissue.This study demonstrates that RS can distinguish the tissues encountered during epidural needle insertion. This technology may prove useful during needle placement by providing evidence of its anatomical localization.

    View details for DOI 10.1097/ALN.0000000000001249

    View details for PubMedID 27466032

    View details for PubMedCentralID PMC5030194

  • Age-related incidence of desaturation events and the cardiac responses on stroke index, cardiac index, and heart rate measured by continuous bioimpedance noninvasive cardiac output monitoring in infants and children undergoing general anesthesia. Journal of clinical anesthesia King, M. R., Anderson, T. A., Sui, J., He, G., Poon, K. Y., Coté, C. J. 2016; 32: 181-8


    To assess the effects of desaturation on stroke index (SI), cardiac index (CI), and heart rate (HR) using the ICON continuous noninvasive cardiac output monitor in children undergoing general anesthesia.Retrospective analysis of a prospectively collected data set.Pediatric operating rooms in a tertiary academic medical center.Children younger than 20 years who experienced desaturation while undergoing general anesthesia.All records were retrospectively searched for desaturation events defined as a recorded Spo2 ≤ 90%. We compared the data from the prior 4 minutes (baseline) with mild, moderate, and severe levels of desaturation.The relationship between Spo2 and percent change in SI, CI, and HR from baseline was assessed using a generalized linear model with repeated measures and the least-squares method.Data from 446 patients were reviewed; 38 events were eligible for analysis after exclusions. There were significant decreases in SI at all saturation ranges below 95%: -6.5% (P < .001) for 85%-95%, -8.9% (P = .002) for 71%-84%, and -11% (P < .001) for ≤70%. Based on the result from the regression, Spo2 was associated with change in SI with borderline significance (P = .053) but not that of HR and CI. There was a strong relationship to desaturation events with young age (P < .001), particularly infants younger than 6 months.Events associated with desaturation in children under general anesthesia were significantly associated with decreased SI with a greater effect with lower saturation nadirs. It is unclear if other concurrent events could have also contributed to adverse hemodynamic responses during desaturation. In most children, a compensatory increase in HR generally offsets concurrent decreases in CI. It would appear that bradycardia is a late manifestation of hypoxemia.

    View details for DOI 10.1016/j.jclinane.2016.02.026

    View details for PubMedID 27290971

  • Perioperative Dextromethorphan as an Adjunct for Postoperative Pain: A Meta-analysis of Randomized Controlled Trials. Anesthesiology King, M. R., Ladha, K. S., Gelineau, A. M., Anderson, T. A. 2016; 124 (3): 696-705


    N-methyl-D-aspartate receptor antagonists have been shown to reduce perioperative pain and opioid use. The authors performed a meta-analysis to determine whether the use of perioperative dextromethorphan lowers opioid consumption or pain scores.PubMed, Web of Science, Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, Pubget, and EMBASE were searched. Studies were included if they were randomized, double-blinded, placebo-controlled trials written in English, and performed on patients 12 yr or older. For comparison of opioid use, included studies tracked total consumption of IV or intramuscular opioids over 24 to 48 h. Pain score comparisons were performed at 1, 4 to 6, and 24 h postoperatively. Difference in means (MD) was used for effect size.Forty studies were identified and 21 were eligible for one or more comparisons. In 848 patients from 14 trials, opioid consumption favored dextromethorphan (MD, -10.51 mg IV morphine equivalents; 95% CI, -16.48 to -4.53 mg; P = 0.0006). In 884 patients from 13 trials, pain at 1 h favored dextromethorphan (MD, -1.60; 95% CI, -1.89 to -1.31; P < 0.00001). In 950 patients from 13 trials, pain at 4 to 6 h favored dextromethorphan (MD, -0.89; 95% CI, -1.11 to -0.66; P < 0.00001). In 797 patients from 12 trials, pain at 24 h favored dextromethorphan (MD, -0.92; 95% CI, -1.24 to -0.60; P < 0.00001).This meta-analysis suggests that dextromethorphan use perioperatively reduces the postoperative opioid consumption at 24 to 48 h and pain scores at 1, 4 to 6, and 24 h.

    View details for DOI 10.1097/ALN.0000000000000950

    View details for PubMedID 26587683

    View details for PubMedCentralID PMC4755866

  • The effectiveness of nasal mask vs face mask ventilation in anesthetized, apneic pediatric subjects over 2 years of age: a randomized controlled trial. Paediatric anaesthesia Itagaki, T. n., Gubin, T. A., Sayal, P. n., Jiang, Y. n., Kacmarek, R. M., Anderson, T. A. 2016; 26 (2): 173–81


    We hypothesized that anesthetized, apneic children could be ventilated equivalently or more efficiently by nasal mask ventilation (NMV) than face mask ventilation (FMV). The aim of this randomized controlled study was to test this hypothesis by comparing the expiratory tidal volume (Vte) between NMV and FMV.After the induction of anesthesia, 41 subjects, 3-17 years of age without anticipated difficult mask ventilation, were randomly assigned to receive either NMV or FMV with neck extension. Both groups were ventilated with pressure control ventilation (PCV) at 20 cmH2 O of peak inspiratory pressure (PIP) with positive end-expiratory pressure (PEEP) levels of 0, 5, and 10 cmH2 O. An additional mouth closing maneuver (MCM) was applied for the NMV group.The Vte was higher in the FMV group compared with the NMV group (median difference [95% CI]: 8.4 [5.5-11.6] ml·kg(-1) ; P < 0.001) when MCM was not applied. NMV achieved less PEEP than FMV (median difference [95% CI]: 5.0 [4.3-5.3] cmH2 O at 10 cmH2 O; P < 0.001) though both groups achieved the set PIP level. In the NMV group, MCM markedly increased Vte (median increase [95% CI]: 5.9 [2.5-9.0] ml·kg(-1) ; P < 0.005) and PEEP (median increase [95% CI]: 5.0 [0.6-8.6] cmH2 O at 10 cmH2 O; P < 0.005); however, PEEP was highly variable and lower than that of FMV (median difference [95% CI]: 2.5 [0.8-8.5] cmH2 O at 10 cmH2 O; P < 0.05).In anesthetized, apneic children greater than 2 years of age ventilated with an anesthesia ventilator and neck extension, FMV established a greater Vte than NMV regardless of mouth status. NMV could not maintain the set PEEP level due to an air leak from the mouth. The MCM increased the Vte and PEEP.

    View details for DOI 10.1111/pan.12822

    View details for PubMedID 26725988

  • Phantom Limb Pain: A Review. International anesthesiology clinics Luo, Y. n., Anderson, T. A. 2016; 54 (2): 121–39

    View details for DOI 10.1097/AIA.0000000000000095

    View details for PubMedID 26967805

  • Anesthetic considerations in organ procurement surgery: a narrative review. Canadian journal of anaesthesia = Journal canadien d'anesthesie Anderson, T. A., Bekker, P., Vagefi, P. A. 2015; 62 (5): 529-39


    While a few publications specify the anesthetic implications of either brain or cardiac death, they lack detail on how to provide anesthesia during organ donation surgery. We provide a thorough description of important anesthetic considerations during organ donation surgery in patients with either brain or cardiac death.A thorough literature review was undertaken to locate all relevant articles that describe systemic effects of brain and cardiac death and their anesthetic implications. We searched PubMed, Pubget, and EMBASE™ for relevant articles using the following search terms: anesthesia, management, donation cardiac death, donation brain death. In addition, we reviewed the relevant protocols at our own institution.Highly specific intraoperative management by an anesthesiologist is required during organ procurement after brain death. To manage the heart-beating brain-dead donor, the anesthesiologist must incorporate knowledge of the effects of brain death on each organ system as well as the effects of the preoperative measures that the donor required in the intensive care unit. It is also important to know which organs are going to be procured in order to establish specific goals and implement strategies (e.g., lung-protective ventilation or intraoperative glycemic control) to optimize donor outcome. During organ procurement after cardiac death, an anesthesiologist's direct involvement is particularly important for lung donors.Anesthesiologist-guided physiological optimization of the brain-dead donor may be a factor in determining the outcome of the organ recipient. Additionally, anesthesiologists have an important role in helping to ensure that the highest quality and most appropriate care are rendered to non-heart-beating donors. This is achieved through establishing protocols in their hospitals for donation after cardiac death that maximize the number of available organs with the best chance for long-term graft viability.

    View details for DOI 10.1007/s12630-015-0345-8

    View details for PubMedID 25715847

  • Continuous noninvasive cardiac output in children: is this the next generation of operating room monitors? Initial experience in 402 pediatric patients. Paediatric anaesthesia Coté, C. J., Sui, J. n., Anderson, T. A., Bhattacharya, S. T., Shank, E. S., Tuason, P. M., August, D. A., Zibaitis, A. n., Firth, P. G., Fuzaylov, G. n., Leeman, M. R., Mai, C. L., Roberts, J. D. 2015; 25 (2): 150–59


    Electrical Cardiometry(™) (EC) estimates cardiac parameters by measuring changes in thoracic electrical bioimpedance during the cardiac cycle. The ICON(®), using four electrocardiogram electrodes (EKG), estimates the maximum rate of change of impedance to peak aortic blood acceleration (based on the premise that red blood cells change from random orientation during diastole (high impedance) to an aligned state during systole (low impedance)).To determine whether continuous cardiac output (CO) data provide additional information to current anesthesia monitors that is useful to practitioners.After IRB approval and verbal consent, 402 children were enrolled. Data were uploaded to our anesthesia record at one-minute intervals. Ten-second measurements (averaged over the previous 20 heart beats) were downloaded to separate files for later comparison with routine OR monitors.Data from 374 were in the final cohort (loss of signal or improper lead placement); 292,012 measurements during 58,049 min of anesthesia were made in these children (1 day to 19 years and 1 to 107 kg). Four events had a ≥25% reduction in cardiac index at least 1 min before a clinically important change in other monitored parameters; 18 events in 14 children confirmed manifestations of other hemodynamic measures; eight events may have represented artifacts because the observed measurements did not seem to fit the clinical parameters of the other monitors; three other events documented decreased stroke index with extreme tachycardia.Electrical cardiometry provides real-time cardiovascular information regarding developing hemodynamic events and successfully tracked the rapid response to interventions in children of all sizes. Intervention decisions must be based on the combined data from all monitors and the clinical situation. Our experience suggests that this type of monitor may be an important addition to real-time hemodynamic monitoring.

    View details for DOI 10.1111/pan.12441

    View details for PubMedID 24916144

  • Volatile anesthetics for status asthmaticus in pediatric patients: a comprehensive review and case series. Paediatric anaesthesia Carrié, S. n., Anderson, T. A. 2015; 25 (5): 460–67


    Status asthmaticus is an acute, intractable asthma attack refractory to standard interventions that can lead to progressive respiratory failure. Successful management requires a fundamental understanding of the disease process, its clinical presentation, and proper evaluation. Treatment must be instituted early and is aimed at reversing the airway inflammation, bronchoconstriction, and hyper-reactivity that often lead to lower airway obstruction, impaired ventilation, and oxygenation. Most patients are effectively treated with standard therapy including beta2-adrenergic agonists and corticosteroids. Others necessitate adjunctive therapies and escalation to noninvasive ventilation or intubation. We will review the pathophysiology, evaluation, and treatment options for pediatric patients presenting with status asthmaticus with a particular focus on refractory status asthmaticus treated with volatile anesthetics. In addition, we include a proven approach to the management of these patients in the critical care setting, which requires close coordination between critical care and anesthesia providers. We present a case series of three patients, two of which have the longest reported cases of continuous isoflurane use in status asthmaticus. This series was obtained from a retrospective chart review and highlights the efficacy of the volatile anesthetic, isoflurane, in three pediatric patients with refractory life-threatening status asthmaticus.

    View details for DOI 10.1111/pan.12577

    View details for PubMedID 25580870

  • Ultrasound-guided peripheral nerve blocks for ventricular shunt revision in children. A & A case reports King, M. R., Anderson, T. A. 2014; 3 (12): 157-9


    We describe using ultrasound-guided peripheral nerve blocks for postoperative pain control in 2 children undergoing ventricular shunt surgery. In the first patient undergoing ventriculo-peritoneal shunt revision, a combination of ultrasound-guided greater occipital nerve, superficial cervical plexus, and transversus abdominis plane blocks was used. In the second patient undergoing ventriculo-pleural shunt revision, a combination of ultrasound-guided greater occipital nerve, superficial cervical plexus, and intercostal blocks was used. Both patients, who underwent multiple revisions during their hospitalizations, showed decreased analgesic requirements after regional anesthesia. Our experience suggests this combined block technique may provide beneficial postoperative analgesia for patients undergoing shunt revision.

    View details for DOI 10.1213/XAA.0000000000000109

    View details for PubMedID 25612197

  • Perioperative anesthesia management of the burn patient. The Surgical clinics of North America Anderson, T. A., Fuzaylov, G. 2014; 94 (4): 851-61


    Burn patients provide numerous challenges to the anesthesiologist. It is important to understand the multiple physiologic disruptions that follow a burn injury as well as the alterations in pharmacokinetics and pharmacodynamics of commonly used anesthetics. Thought must be given to surgery during initial fluid resuscitation and the airway challenges many of these patients present. Finally, the central role of pain management through all phases of care is a constant concern.

    View details for DOI 10.1016/j.suc.2014.05.008

    View details for PubMedID 25085092

  • Anesthetic considerations in Sheldon-Hall syndrome. Paediatric anaesthesia Anderson, T. A., Kasser, J. R., Holzman, R. S. 2014; 24 (5): 538-40


    Arthrogryposis is characterized by multiple, nonprogressive joint contractures which may be caused by maternal disorders such as oligohydramnios as well as fetal akinesia resulting from primary disorders of muscle, connective tissue, or neurologic tissue. Its prevalence is about 1 : 3000. Distal arthrogryposis (DA) is a heterogenous group of genetic disorders with a characteristic flexion of the joints of the hands and feet divided into different types with additional features. Sheldon-Hall Syndrome (SHS), also known as distal arthrogryposis type 2A (DA2A), has some nonorthopedic features of specific importance to anesthetic care.

    View details for DOI 10.1111/pan.12303

    View details for PubMedID 24829975

  • Allocation of resources for organ transplantation. Anesthesiology clinics Kandula, P., Anderson, T. A., Vagefi, P. A. 2013; 31 (4): 667-74


    Over the last 6 decades, organ transplantation has achieved great success to become standard therapy for the treatment of patients with end-stage organ failure. With this success has emerged candidate wait lists that greatly outnumber the current supply of deceased donor organs. The increasing number of candidates and transplants performed has resulted in an organ allocation process that occurs at a local, regional, and sometimes national level. A brief description of the history is presented as well as the methodologies involved in allocation of a donor organ to a single recipient.

    View details for DOI 10.1016/j.anclin.2013.08.002

    View details for PubMedID 24287345

  • Sequence determinants of a conformational switch in a protein structure. Proceedings of the National Academy of Sciences of the United States of America Anderson, T. A., Cordes, M. H., Sauer, R. T. 2005; 102 (51): 18344-9


    The Arc repressor of bacteriophage P22 is a dimeric member of the ribbon-helix-helix family of transcription factors. Residues 9-14 of each wild-type Arc subunit pair to form two antiparallel beta-strands and have the alternating pattern of polar and nonpolar residues expected for a beta-ribbon with one solvent-exposed face and one face that forms part of the hydrophobic core. Simultaneously switching Asn-11 to Leu and Leu-12 to Asn changes the local binary sequence pattern to that of an amphipathic helix. Previous studies have shown that this double mutation results in replacement of the wild-type beta-ribbon by two right-handed 3(10)-helices. Moreover, an Arc variant bearing just the Asn-11 --> Leu mutation has an ambiguous binary pattern and can form either the ribbon or the helical structures, which interchange rapidly. Here, we study Arc mutants in which position 11 is occupied by Gly, Ala, Val, Ile, Leu, Met, Phe, or Tyr. These mutants adopt the wild-type beta-ribbon structure in a sequence context that stabilizes this fold, but they assume the alternative helical structure in a sequence background in which the wild-type fold is precluded by negative design. In an otherwise wild-type sequence background, the detailed chemical properties of the position 11 side chain dictate which of the two competing conformational folds is preferred.

    View details for DOI 10.1073/pnas.0509349102

    View details for PubMedID 16344489

    View details for PubMedCentralID PMC1317976

  • Role of an N(cap) residue in determining the stability and operator-binding affinity of Arc repressor. Biophysical chemistry Anderson, T. A., Sauer, R. T. 2003; 100 (1-3): 341-50


    The Arc repressor of bacteriophage P22 is a member of the ribbon-helix-helix family of transcription factors. Ser32 is a solvent-exposed position that serves a structural role as the N(cap) residue of alpha-helix B of Arc, but also serves a functional role because its side chain is packed close to the sugar-phosphate DNA backbone in the repressor-operator complex. The tolerance of this N(cap) position to amino-acid substitutions was probed by determining the repressor activity in vivo, the thermal stability and the operator-binding activity in vitro of a set of 13 mutant proteins. The stability of position-32 Arc variants, except for Cys32, correlated well with the frequencies observed for the corresponding residues at N(cap) positions in alpha-helices of other proteins. Cysteine was quite stabilizing at the helix-B N(cap) position in Arc, but surprisingly was the least frequent N(cap) residue in the protein database. This latter finding may reflect a hyper-reactivity of N(cap) cysteines, which makes them prone to chemical modification. In general, only Arc variants with small, uncharged residues at position 32 were active in vivo or showed strong operator binding in vitro. Based upon the results presented here, revised sequence alignments of the MetJ and NikR subfamilies with Arc and other ribbon-helix-helix proteins are proposed.

    View details for DOI 10.1016/s0301-4622(02)00291-0

    View details for PubMedID 12646376

  • The Use of Epinephrine in Caudal Anesthesia Increases Stroke Volume and Cardiac Output in Children. Regional anesthesia and pain medicine Liu, C. A., Sui, J. n., Coté, C. J., Anderson, T. A. ; 41 (6): 780–86


    Caudal anesthesia is a common and effective regional anesthesia technique in pediatric patients. The addition of epinephrine to local anesthetics in caudal anesthesia is a frequent practice; however, changes in hemodynamic and cardiac parameters produced by epinephrine in caudal anesthesia are not well studied. Using data collected with the ICON noninvasive cardiac output monitor, we examined the hemodynamic changes associated with the administration of epinephrine containing local anesthetics during caudal anesthesia in children.We performed a retrospective analysis of 40 patients who received caudal anesthesia among 402 patients from whom we prospectively collected continuous noninvasive cardiac output data using the ICON monitor, which estimates cardiac output by measuring changes in thoracic bioimpedance during the cardiac cycle. Twenty-three children received epinephrine with local anesthetic (ELA), and 17 children received only local anesthetic (OLA) in their caudal blocks. We compared heart rate (HR), stroke volume (SV), cardiac output (CO), and cardiac index (CI) changes from baseline before caudal injection to 1-minute intervals over 15 minutes after caudal injection for both ELA and OLA groups (Table, Supplemental Digital Content 1, We also performed subgroup analysis of the same parameters comparing both ELA and OLA groups in infants younger than 6 months and in children 6 months or older.Stroke volume, CO, and CI are significantly increased after caudal injection in the ELA group compared with baseline values at caudal injection time. Conversely, there were no statistically significant changes in SV, CO, and CI in the OLA group. There were no significant HR or blood pressure changes observed in either the ELA or OLA group within 15 minutes compared with baseline caudal injection time. In infants younger than 6 months, no significant differences were found in HR, SV, and CI in children in the ELA group compared with the OLA group. In children 6 months or older, SV and CI increased significantly in the ELA group compared with the OLA group.Epinephrine added to local anesthetic injected for caudal anesthesia produces significant increases in SV, CO, and CI in children. Stroke volume and CI changes from epinephrine added to local anesthetic for caudal anesthesia seem to take place only in children 6 months or older.

    View details for DOI 10.1097/AAP.0000000000000498

    View details for PubMedID 27755489