Clinical Assistant Professor, Anesthesiology, Perioperative and Pain Medicine
Internship: Kaiser Permanente Santa Clara Internal Medicine Residency (2012) CA
Board Certification: American Board of Anesthesiology, Anesthesia (2016)
Residency: Stanford University Hospital and Clinics (2015) CA
Medical Education: University of California, San Francisco (2011) CA
Safety and Utility of Transnasal Humidified Rapid-Insufflation Ventilatory Exchange (THRIVE) for Laser Laryngeal Surgery.
Otolaryngology--head and neck surgery : official journal of American Academy of Otolaryngology-Head and Neck Surgery
OBJECTIVE: Transnasal humidified rapid-insufflation ventilatory exchange (THRIVE) is gaining acceptance as a safe method for apneic ventilation and oxygenation during laryngeal procedures, but remains controversial during laser laryngeal surgery (LLS) due to the theoretical risk of airway fire. This study describes our experience with THRIVE during LLS.STUDY DESIGN: Retrospective cohort study.SETTING: Stanford University Hospital, October 15, 2015 to June 1, 2021.METHODS: Retrospective chart review of patients ≥18 years who underwent LLS involving the CO2 or KTP laser with THRIVE as the primary mode of oxygenation.RESULTS: A total of172 cases were identified. 20.9% were obese (BMI≥30). Most common operative indication was subglottic stenosis. The CO2 laser was used in 79.1% of cases. Median lowest intraoperative SpO2 was 96%. 44.7% cases were solely under THRIVE while 16.3% required a single intubation and 19.2% required multiple intubations. Mean apnea time for THRIVE only cases was 32.1minutes and in cases requiring at least one intubation 24.0minutes (p<.001). Mean apnea time was significantly lower for patients who were obese (p<.001) or had a diagnosis of hypertension (p=.016). Obese patients and patients with hypertension were 2.03 and 1.43 times more likely to require intraoperative intubation, respectively. There were no intraoperative complications or fires since the institution of our LLS safety protocol.CONCLUSION: By eliminating the fuel component of the fire triangle, THRIVE can be safely used for continuous delivery of high FiO2 during LLS, provided adherence to institutional THRIVE-LLS protocols.
View details for DOI 10.1002/ohn.324
View details for PubMedID 37021493
EEG response of dexmedetomidine during drug induced sleep endoscopy.
Frontiers in neuroscience
2023; 17: 1144141
Introduction: Dexmedetomidine is one of the anesthetics of choice for drug induced sleep endoscopy (DISE), with advantages including limited respiratory depression, analgesia, and decreased incidence of emergence delirium. However, challenges with determining sedation levels and prolonged recovery have limited its usage. An improved understanding of the effect of dexmedetomidine on the level of sedation and the corresponding electroencephalographic (EEG) changes could help overcome these barriers.Methods: Fifty-one patients received dexmedetomidine sedation with Richmond Agitation-Sedation Scale (RASS) score assessment and continuous EEG monitoring via SedLine for DISE. We constructed a pharmacokinetic model to determine continuous dexmedetomidine blood concentration. From the SedLine, we extracted the patient state index (PSI), and from the EEG we calculated the spectral edge frequency 95% (SEF95) and the correlation dimension (CD), a type of fractal dimension used to assess the complexity of a system. These metrics were subsequently compared against one another and with the dexmedetomidine concentration.Results: Our pharmacokinetic model yielded a two-compartment model with volumes of 51.8L and 106.2L, with clearances of 69.5 and 168.9L/h, respectively, and a time to effect of 9min, similar to prior studies. Based on this model, decreasing RASS score, SEF95, CD, and PSI were all significantly associated with increasing dexmedetomidine concentration (p<0.001, p=0.006, p<0.001 respectively). The CD, SEF95, and PSI better captured the effects of increasing dexmedetomidine concentration as compared to the RASS score. Simulating dexmedetomidine concentration based on titration to target levels derived from CD and PSI confirmed commonly used dexmedetomidine infusion dosages.Conclusion: Dexmedetomidine use for DISE confirmed previous pharmacokinetic models seen with dexmedetomidine. Complex EEG metrics such as PSI and CD, as compared to RASS score and SEF95, better captured changes in brain state from dexmedetomidine and have potential to improve the monitoring of dexmedetomidine sedation.
View details for DOI 10.3389/fnins.2023.1144141
View details for PubMedID 37521700
Evaluation of patient state index, bispectral index, and entropy during drug induced sleep endoscopy with dexmedetomidine.
Journal of clinical monitoring and computing
Multiple electroencephalographic (EEG) monitors and their associated EEG markers have been developed to aid in assessing the level of sedation in the operating room. While many studies have assessed the response of these markers to propofol sedation and anesthetic gases, few studies have compared these markers when using dexmedetomidine, an alpha-2 agonist. Fifty-one patients underwent drug induced sleep endoscopy with dexmedetomidine sedation. Continuous EEG was captured using SedLine (Masimo, Inc), and a playback system was used to extract the bispectral index (BIS) (Medtronic Inc), the patient state index (PSI) (Masimo, Inc), the state and response Entropy (GE Healthcare), and calculate the spectral edge frequency 95% (SEF95). Richmond Agitation-Sedation Scale (RASS) scores were assessed continually throughout the procedure and in recovery. We assessed the correlation between EEG markers and constructed ordinal logistic regression models to predict the RASS score and compare EEG markers. All three commercial EEG metrics were significantly associated with the RASS score (p<0.001 for all metrics) whereas SEF95 alone was insufficient at characterizing dexmedetomidine sedation. PSI and Entropy achieved higher accuracy at predicing deeper levels of sedation as compared to BIS (PSI: 58.3%, Entropy: 58.3%, BIS: 44.4%). Lightening secondary to RASS score assessment is significantly captured by all three commercial EEG metrics (p<0.001). Commercial EEG monitors can capture changes in the brain state associated with the RASS score during dexmedetomidine sedation. PSI and Entropy were highly correlated and may be better suited for assessing deeper levels of sedation.
View details for DOI 10.1007/s10877-022-00952-9
View details for PubMedID 36550344
Expert Consensus Statement on the Perioperative Management of Adult Patients Undergoing Head and Neck Surgery and Free Tissue Reconstruction From the Society for Head and Neck Anesthesia.
Anesthesia and analgesia
2021; 133 (1): 274-283
The perioperative care of adult patients undergoing free tissue transfer during head and neck surgical (microvascular) reconstruction is inconsistent across practitioners and institutions. The executive board of the Society for Head and Neck Anesthesia (SHANA) nominated specialized anesthesiologists and head and neck surgeons to an expert group, to develop expert consensus statements. The group conducted an extensive review of the literature to identify evidence and gaps and to prioritize quality improvement opportunities. This report of expert consensus statements aims to improve and standardize perioperative care in this setting. The Modified Delphi method was used to evaluate the degree of agreement with draft consensus statements. Additional discussion and collaboration was performed via video conference and electronic communication to refine expert opinions and to achieve consensus on key statements. Thirty-one statements were initially formulated, 14 statements met criteria for consensus, 9 were near consensus, and 8 did not reach criteria for consensus. The expert statements reaching consensus described considerations for preoperative assessment and optimization, airway management, perioperative monitoring, fluid management, blood management, tracheal extubation, and postoperative care. This group also examined the role for vasopressors, communication, and other quality improvement efforts. This report provides the priorities and perspectives of a group of clinical experts to help guide perioperative care and provides actionable guidance for and opportunities for improvement in the care of patients undergoing free tissue transfer for head and neck reconstruction. The lack of consensus for some areas likely reflects differing clinical experiences and a limited available evidence base.
View details for DOI 10.1213/ANE.0000000000005564
View details for PubMedID 34127591
- Anesthetic considerations for functional endoscopic sinus surgery: a narrative review Journal of Head & Neck Anesthesia 2020; 4 (2)
The Safety and Efficacy of Transnasal Humidified Rapid-Insufflation Ventilatory Exchange for Laryngologic Surgery.
Transnasal humidified rapid-insufflation ventilatory exchange (THRIVE) is an intraoperative ventilatory technique that allows avoidance of tracheal intubation (TI) or jet ventilation (JV) in selected laryngologic surgical cases. Unimpeded access to all parts of the glottis may improve surgical precision, decrease operative time, and potentially improve patient outcomes. The objective of this prospective, randomized, patient-blinded, 2-arm parallel pilot trial was to investigate the safety and efficacy of THRIVE use for adult patients undergoing nonlaser laryngologic surgery of short-to-intermediate duration.Twenty adult, American society of anesthesiology class 1-3 patients with body mass index (BMI) < 35 kg/m2 were randomly assigned to either an experimental THRIVE group or active comparator conventional ventilation group (TI or supraglottic high-frequency JV [SHFJV]). Primary outcomes included intraoperative oxygenation, anesthesia awakening/extubation time, time to laryngoscopic suspension, number of intraoperative suspension adjustments, and operative time. Secondary patient outcomes including postanesthesia and functional patient recovery were investigated.Compared to TI/SHFJV, THRIVE use was associated with significantly lower intraoperative oxygenation (SpO2 93.0 ± 5.6% vs. 98.7 ± 1.6%), shorter time to suspension (1.8 ± 1.1 minutes vs. 4.3 ± 2.1 minutes), fewer suspension adjustments (0.4 ± 0.5 vs. 1.7 ± 0.9), and lower postoperative pain scores on recovery room admission (1.3 ± 1.9 vs. 3.7 ± 2.9) and discharge (0.9 ± 1.3 vs. 2.7 ± 1.8). The study was underpowered to detect other possible outcome differences.We confirm the safe intraoperative oxygenation profile of THRIVE for selected patients undergoing nonlaser laryngologic surgery of short-to-intermediate duration. THRIVE facilitated surgical exposure and improved early patient recovery, suggesting a potential economic benefit for outpatient laryngologic procedures. The results of this exploratory study provide a framework for designing future adequately powered THRIVE trials.ClinicalTrials.gov (NCT03091179).II Laryngoscope, 2020.
View details for DOI 10.1002/lary.28562
View details for PubMedID 32078170
Prevention of postdural puncture headache after accidental dural puncture: a quantitative systematic review
BRITISH JOURNAL OF ANAESTHESIA
2010; 105 (3): 255-263
No clear consensus exists on how to best prevent severe headache from occurring after accidental dural puncture. We conducted a quantitative systematic review to identify all available evidence for the prevention of postdural puncture headache (PDPH) and included 17 studies with 1264 patients investigating prophylactic epidural blood patch (PEBP), epidural morphine, intrathecal catheters, and epidural or intrathecal saline. The relative risk (RR) for headache after PEBP was 0.48 [95% confidence interval (CI): 0.23-0.99] in five non-randomized controlled trials (non-RCTs) and 0.32 (0.10-1.03) in four randomized controlled trials (RCTs). The RR for epidural morphine (based on a single RCT) was 0.25 (0.08-0.78). All other interventions were based on non-RCTs and failed statistical significance, including long-term intrathecal catheters with an RR of 0.21 (0.02-2.65). There are a number of promising options to prevent PDPH, yet heterogeneity between the studies and publication bias towards small non-RCTs with positive results limits the available evidence. Thus, a large multicentre RCT is needed to determine the best preventative practices.
View details for DOI 10.1093/bja/aeq191
View details for Web of Science ID 000282074300003
View details for PubMedID 20682567
Analgesic requirements and postoperative recovery after scheduled compared to unplanned cesarean delivery: a retrospective chart review
INTERNATIONAL JOURNAL OF OBSTETRIC ANESTHESIA
2010; 19 (1): 10-15
Studies examining the effects of various analgesics and anesthetics on postoperative pain following cesarean delivery conventionally use the scheduled cesarean population. This study compares postoperative analgesic requirements and recovery profiles in women undergoing scheduled cesarean compared to unplanned cesarean delivery following labor. We postulated that unplanned cesarean deliveries may increase postoperative analgesic requirements.We conducted a retrospective chart review of 200 cesarean deliveries at Lucile Packard Children's Hospital, California. We examined the records of 100 patients who underwent scheduled cesarean delivery under spinal anesthesia (hyperbaric bupivacaine 12 mg with intrathecal fentanyl 10 microg and morphine 200 microg) and 100 patients that following a trail of labor required unplanned cesarean under epidural anesthesia (10-25 mL 2% lidocaine top-up with epidural morphine 4 mg after clamping of the umbilical cord). We recorded pain scores, analgesic consumption, time to first analgesic request, side effects, and length of hospital stay.We found no differences in postoperative pain scores and analgesic consumption between scheduled and unplanned cesarean deliveries for up to five days postoperatively. There were no differences in treatment of side effects such as nausea, vomiting, or pruritus (P>0.05).The results indicate that women experience similar pain and analgesic requirements after scheduled compared to unplanned cesarean delivery. This suggests that the non-scheduled cesarean population may be a suitable pain model to study pain management strategies; and that alterations in pain management are not necessary for the unplanned cesarean delivery population.
View details for DOI 10.1016/j.ijoa.2009.02.012
View details for Web of Science ID 000273845400004
View details for PubMedID 19954964
Vaginal twin delivery: a survey and review of location, anesthesia coverage and interventions
38th Annual Meeting of the Society-for-Obstetric-Anesthesia-and-Perinatology
CHURCHILL LIVINGSTONE. 2008: 212–16
Twin pregnancies are associated with increased perinatal morbidity and mortality. No consensus exists whether vaginal twin delivery should take place in the labor room or operating room, or whether anesthesiologists should be present. We surveyed members of the California Society of Anesthesiologists (CSA) to review management of vaginal twin delivery, and examined anesthetic intervention retrospectively at our institution.230 CSA members were asked to complete an online survey on location of vaginal twin delivery in their institution and whether they were required to be present throughout. We then retrospectively reviewed charts of vaginal twin deliveries at our institution over a 36-month period to analyze frequency and type of anesthetic intervention.The online survey response rate was 58%; 64% of responders reported that vaginal twin deliveries were performed in the operating room and 55% that an anesthesiologist was present. There was a strong association between anesthesiologist's presence and delivery in the operating room (OR 7; 95% CI 3-20). We reviewed 81 charts of women who underwent vaginal twin delivery. The median (range) time that the anesthesiologist was present for each delivery was 60 (20-380) min. Of women undergoing vaginal twin delivery, 27% required anesthetic intervention during the second stage of labor with 6% having emergency cesarean delivery.There is a lack of consensus regarding the appropriate location for vaginal twin delivery and the role of anesthesiologists. A significant percentage of women undergoing vaginal twin delivery in our institution received anesthetic intervention in the immediate delivery period.
View details for DOI 10.1016/j.ijoa.2007.04.004
View details for Web of Science ID 000257844200003
View details for PubMedID 17881218
Wolff-Parkinson-White syndrome in athletes.
Current sports medicine reports
2006; 5 (5): 254-257
View details for PubMedID 16934207