Clinical Focus


  • Pain Management

Academic Appointments


  • Clinical Associate Professor, Anesthesiology, Perioperative and Pain Medicine

Professional Education


  • Fellowship: Stanford University Pain Management Fellowship (2024) CA
  • Board Certification: American Board of Anesthesiology, Anesthesia (2013)
  • Fellowship: UCSD Regional Anesthesia and Acute Pain Management Fellowship (2013) CA
  • Residency: UCSD Anesthesiology Residency (2012) CA
  • Internship: Ascension St Joseph Hospital (2009) WI
  • Medical Education: University of Wisconsin School of Medicine and Public Health (2007) WI

All Publications


  • Development of entrustable professional activities for regional anesthesia and pain medicine fellowship training. Regional anesthesia and pain medicine Porter, S., Prendiville, E., Allen, B. F., Booth, G., Boublik, J., Burnett, G. W., Elkassabany, N., Hausman, J., Klesius, L., Le-Wendling, L., Machi, A. T., Maniker, R., Parra, M., Rosenquist, R., Spofford, C. M., Suresh, S., Tedore, T., Wilson, E. H., Zhou, J. Y., Woodworth, G. 2022

    Abstract

    INTRODUCTION: The Accreditation Council for Graduate Medical Education (ACGME) offers descriptions of competencies and milestones but does not provide standardized assessments to track trainee competency. Entrustable professional activities (EPAs) and special assessments (SAs) are emerging methods to assess the level of competency obtained by regional anesthesiology and acute pain medicine (RAAPM) fellows.METHODS: A panel of RAAPM physicians with experience in education and competency assessment and one medical student were recruited to participate in a modified Delphi method with iterative rounds to reach consensus on: a list of EPAs, SAs, and procedural skills; detailed definitions for each EPA and SA; a mapping of the EPAs and SAs to the ACGME milestones; and a target level of entrustment for graduating US RAAPM fellows for each EPA and procedural skill. A gap analysis was performed and a heat map was created to cross-check the EPAs and SAs to the ACGME milestones.RESULTS: Participants in EPA and SA development included 19 physicians and 1 medical student from 18 different programs. The Delphi rounds yielded a final list of 23 EPAs, a defined entrustment scale, mapping of the EPAs to ACGME milestones, and graduation targets. A list of 73 procedural skills and 7 SAs were similarly developed.DISCUSSION: A list of 23 RAAPM EPAs, 73 procedural skills, and 7 SAs were created using a rigorous methodology to reach consensus. This framework can be utilized to help assess RAAPM fellows in the USA for competency and allow for meaningful performance feedback.

    View details for DOI 10.1136/rapm-2022-103854

    View details for PubMedID 35878963

  • Recommendations for effective documentation in regional anesthesia: an expert panel Delphi consensus project. Regional anesthesia and pain medicine Ahmed, H. M., Atterton, B. P., Crowe, G. G., Barratta, J. L., Johnson, M., Viscusi, E., Adhikary, S., Albrecht, E., Boretsky, K., Boublik, J., Breslin, D. S., Byrne, K., Ch'ng, A., Chuan, A., Conroy, P., Daniel, C., Daszkiewicz, A., Delbos, A., Dirzu, D. S., Dmytriiev, D., Fennessy, P., Fischer, H. B., Frizelle, H., Gadsden, J., Gautier, P., Gupta, R. K., Gurkan, Y., Hardman, H. D., Harrop-Griffiths, W., Hebbard, P., Hernandez, N., Hlasny, J., Iohom, G., Ip, V. H., Jeng, C. L., Johnson, R. L., Kalagara, H., Kinirons, B., Lansdown, A. K., Leng, J. C., Lim, Y. C., Lobo, C., Ludwin, D. B., Macfarlane, A. J., Machi, A. T., Mahon, P., Mannion, S., McLeod, D. H., Merjavy, P., Miscuks, A., Mitchell, C. H., Moka, E., Moran, P., Ngui, A., Nin, O. C., O'Donnell, B. D., Pawa, A., Perlas, A., Porter, S., Pozek, J., Rebelo, H. C., Roques, V., Schroeder, K. M., Schwartz, G., Schwenk, E. S., Sermeus, L., Shorten, G., Srinivasan, K., Stevens, M. F., Theodoraki, K., Turbitt, L. R., Valdes-Vilches, L. F., Volk, T., Webster, K., Wiesmann, T., Wilson, S. H., Wolmarans, M., Woodworth, G., Worek, A. K., Moran, E. M. 2022

    Abstract

    BACKGROUND AND OBJECTIVES: Documentation is important for quality improvement, education, and research. There is currently a lack of recommendations regarding key aspects of documentation in regional anesthesia. The aim of this study was to establish recommendations for documentation in regional anesthesia.METHODS: Following the formation of the executive committee and a directed literature review, a long list of potential documentation components was created. A modified Delphi process was then employed to achieve consensus amongst a group of international experts in regional anesthesia. This consisted of 2 rounds of anonymous electronic voting and a final virtual round table discussion with live polling on items not yet excluded or accepted from previous rounds. Progression or exclusion of potential components through the rounds was based on the achievement of strong consensus. Strong consensus was defined as ≥75% agreement and weak consensus as 50%-74% agreement.RESULTS: Seventy-seven collaborators participated in both rounds 1 and 2, while 50 collaborators took part in round 3. In total, experts voted on 83 items and achieved a strong consensus on 51 items, weak consensus on 3 and rejected 29.CONCLUSION: By means of a modified Delphi process, we have established expert consensus on documentation in regional anesthesia.

    View details for DOI 10.1136/rapm-2021-103136

    View details for PubMedID 35193970

  • Superficial vs. deep serratus anterior plane block for analgesia in patients undergoing mastectomy: A randomized prospective trial. Journal of clinical anesthesia Edwards, J. T., Langridge, X. T., Cheng, G. S., McBroom, M. M., Minhajuddin, A., Machi, A. T. 2021; 75: 110470

    Abstract

    In the initial description of the serratus anterior plane block (SAPB), both superficial and deep SAPB provided effective blockade. The purpose of this study was to investigate the difference in opioid consumption and postoperative analgesia between superficial and deep SAPB for patients undergoing mastectomy.Randomized prospective trial.Academic hospital.64 women, >18 years of age, ASA I-III, undergoing single or bilateral mastectomy, with and without lymph node biopsy, with and without tissue expander reconstruction.Either superficial or deep SAPB by an ultrasound-guided technique in addition to multimodal analgesia.The primary outcome was opioid consumption in the first 24 h. Secondary outcomes were pain scores, satisfaction scores, incidence of PONV, length of stay and block performance time.Subjects who received a deep SAPB required 30% less oral morphine equivalents (OME) (113.5 mg vs. 147 mg, p = 0.009) and reported lower pain scores. There were no significant differences in satisfaction scores, incidence of PONV, LOS, or block performance time between the two groups.There was a significant difference in opioid consumption between the deep and superficial SAPB groups. Subjects in the deep SAPB group had lower pain scores at 12 h; however, the difference was not statistically significant at other time points. While both the superficial and the deep SAPB can be used for post-operative analgesia in patients undergoing mastectomy, our study suggests that the deep SAPB may improve analgesia to a greater degree than the superficial SAPB as shown through decreased opioid consumption of 30% over a 24-h period post-block. CLINICAL TRIAL NUMBER AND REGISTRY URL: clinicaltrials.gov: NCT03154658.

    View details for DOI 10.1016/j.jclinane.2021.110470

    View details for PubMedID 34364099

  • Anesthesia residency training in regional anesthesiology and acute pain medicine: a competency-based model curriculum. Regional anesthesia and pain medicine Woodworth, G. n., Maniker, R. B., Spofford, C. M., Ivie, R. n., Lunden, N. I., Machi, A. T., Elkassabany, N. M., Gritsenko, K. n., Kukreja, P. n., Vlassakov, K. n., Tedore, T. n., Schroeder, K. n., Missair, A. n., Herrick, M. n., Shepler, J. n., Wilson, E. H., Horn, J. L., Barrington, M. n. 2020

    Abstract

    The Accreditation Council for Graduate Medical Education has shifted to competency-based medical education. This educational framework requires the description of educational outcomes based on the knowledge, skills and behaviors expected of competent trainees. It also requires an assessment program to provide formative feedback to trainees as they progress to competency in each outcome. Critical to the success of a curriculum is its practical implementation. This article describes the development of model curricula for anesthesiology residency training in regional anesthesia and acute pain medicine (core and advanced) using a competency-based framework. We further describe how the curricula were distributed through a shared web-based platform and mobile application.

    View details for DOI 10.1136/rapm-2020-101480

    View details for PubMedID 32474420

  • Continuous peripheral nerve blocks in the ambulatory setting: an update of the published evidence. Current opinion in anaesthesiology Machi, A. T., Ilfeld, B. M. 2015; 28 (6): 648-55

    Abstract

    To review the evidence recently published involving the use of continuous peripheral nerve blocks (cPNBs) in the ambulatory setting.New evidence exists involving the risks and benefits of cPNB in ambulatory patient populations such as pediatric ambulatory and postmastectomy patients. In addition, new related equipment is now available to facilitate ambulatory cPNB.Recent advancements in equipment for cPNB facilitate the usage in the ambulatory setting. Research-supported ambulatory cPNB indications have expanded to include pediatric subpopulations and major breast surgery, while further evidence mounts for its efficacy in patient populations with previously demonstrated benefits, such as foot, ankle and shoulder surgery.

    View details for DOI 10.1097/ACO.0000000000000254

    View details for PubMedID 26356291

  • Discharge Readiness after Tricompartment Knee Arthroplasty: Adductor Canal versus Femoral Continuous Nerve Blocks-A Dual-center, Randomized Trial. Anesthesiology Machi, A. T., Sztain, J. F., Kormylo, N. J., Madison, S. J., Abramson, W. B., Monahan, A. M., Khatibi, B., Ball, S. T., Gonzales, F. B., Sessler, D. I., Mascha, E. J., You, J., Nakanote, K. A., Ilfeld, B. M. 2015; 123 (2): 444-56

    Abstract

    The authors conducted a randomized, controlled, parallel-arm, superiority study to test the hypothesis that a continuous adductor canal block decreases the time to attain four discharge criteria compared with a continuous femoral nerve block after tricompartment knee arthroplasty.Subjects undergoing tricompartment knee arthroplasty were randomized using computer-generated lists to either an adductor canal or femoral perineural catheter (3-day ropivacaine 0.2% infusion) in an unmasked manner. The primary outcome was the time to attain four criteria: (1) adequate analgesia; (2) intravenous opioids independence; (3) ability to stand, walk 3 m, return, and sit down; and (4) ambulate 30 m.Subjects with an adductor canal catheter (n = 39) reached all four criteria in a median of 55 h (interquartile, 42 to 63 h) compared with 61 h (49 to 69 h) for those with a femoral catheter (n = 41; 95% CI, -13 to 1 h; P = 0.12). The percentage of subjects who reached the two mobilization criteria on postoperative days 1 and 2 were 72 and 95% for those with an adductor canal catheter (n = 39), but only 27 and 76% in subjects with a femoral catheter (n = 41; both P < 0.001). Differences in pain scores at rest and intravenous opioid requirements were minimal, but femoral infusion improved dynamic analgesia (P = 0.01 to 0.02).Compared with a continuous femoral nerve block, a continuous adductor canal block did not appreciably decrease the time to overall discharge readiness even though it did decrease the time until adequate mobilization, primarily because both groups experienced similar analgesia and intravenous opioid requirements that--in most cases--exceeded the time to mobilization.

    View details for DOI 10.1097/ALN.0000000000000741

    View details for PubMedID 26079800

  • Continuous Adductor Canal Versus Continuous Femoral Nerve Blocks: Relative Effects on Discharge Readiness Following Unicompartment Knee Arthroplasty. Regional anesthesia and pain medicine Sztain, J. F., Machi, A. T., Kormylo, N. J., Abramson, W. B., Madison, S. J., Monahan, A. M., Khatibi, B., Ball, S. T., Gonzales, F. B., Sessler, D. I., Mascha, E. J., You, J., Nakanote, K. A., Ilfeld, B. M. 2015; 40 (5): 559-67

    Abstract

    We tested the hypothesis that, following unicompartment knee arthroplasty, a continuous adductor canal block decreases the time to reach 4 discharge criteria compared with a continuous femoral nerve block.Subjects were randomized to either an adductor canal or femoral perineural catheter (2-day ropivacaine 0.2% infusion) in an unmasked fashion. The primary outcome was the time to attain 4 discharge criteria: (1) adequate analgesia; (2) intravenous opioid independence; (3) ability to independently stand, walk 3 m, return, and sit down; and (4) ambulate 30 m.Subjects with an adductor canal catheter (n = 15) reached all 4 criteria in a median of 35 hours (interquartile range, 24-43 hours), compared with 40 hours (interquartile range, 27-69 hours) for those with a femoral catheter (n = 15; Wilcoxon rank sum test: P = 0.46; log-rank test: P = 0.16). However, the percentages of subjects (adductor canal: femoral) who reached the 2 mobilization criteria were 27%:0% on postoperative day (POD) 0, 93%:53% on POD 1, and 100%:73% on POD 2. Of adductor canal subjects, 100% were discharge ready by POD 2, compared with only 73% of femoral subjects (P < 0.001).Compared with a continuous femoral nerve block, a continuous adductor canal block did not appreciably decrease the median number of hours to overall discharge readiness, yet did decrease the number of discrete days until discharge readiness. These results are applicable to only unicompartment knee arthroplasty and must be considered preliminary because of the limited sample size of this pilot study.

    View details for DOI 10.1097/AAP.0000000000000279

    View details for PubMedID 26115189

  • A-P positioning of medialization thyroplasty in an excised larynx model. The Laryngoscope Czerwonka, L., Ford, C. N., Machi, A. T., Leverson, G. E., Jiang, J. J. 2009; 119 (3): 591-6

    Abstract

    Posterior positioning of medialization thyroplasty provides the best acoustic and aerodynamic outcomes.Ex vivo excised canine larynx.Unilateral thyroplasty windows were cut in the thyroid cartilages of 10 excised canine larynges. Each larynx was mounted on an artificial lung and the vocal fold opposite the thyroid window was adducted by medializing its arytenoid cartilage. Then, medialization thyroplasty was simulated with a probe placed anterior, central, and posterior in the thyroid window. The glottal area, airway reduction, medialization force, phonation threshold pressure and flow, aerodynamic power, intensity, efficiency, jitter, shimmer, and signal-to-noise ratio (SNR) were measured at each medialization position.Posterior medialization probe placement minimized the glottal area, provided the best voice as determined by perturbation measures and SNR, reduced the work of phonation, and increased efficiency. Anterior and middle probe placement minimized the work of phonation but provided only modest gains in sound quality and decreased sound intensity. Medializing the vocal fold with posterior probe placement required twice as much force as central and anterior probe placement.The results suggest that posterior medialization provides the greatest improvement in acoustic parameters and efficiency in patients who can tolerate the airway reduction. Middle and anterior medialization can decrease work of phonation, but in this experiment objective improvement in sound quality was limited. Subtle changes in displacement shim contour, especially in middle and anterior locations, have a substantial impact on voice outcome, affirming the value of intraoperative voice assessment.

    View details for DOI 10.1002/lary.20122

    View details for PubMedID 19235760

    View details for PubMedCentralID PMC3313598