About

Michael O'Connor, MD, is a Professor of Anesthesia and Critical Care and a Professor of Medicine at the University of Chicago. His clinical interests include Acute Respiratory Distress Syndrome (ARDS), Airway Disorders, Liver Transplant Anesthesia, Sedation, Transfusion Medicine, and Vascular Thoracic Anesthesia. His work involves both clinical practice and research within the Department of Anesthesia & Critical Care, contributing to advancements in anesthesia techniques and critical care management.

Selected publications

• Pause for Policy - The Cognitive Cost of Cannabis use in Adolescence

  Arrow@TU Dublin · 2026-04-15

  articleOpen access1st authorCorresponding
  PublisherDOI

• Vascularised Composite Allotransplantation: Emerging Applications in Reconstructive Surgery and Solid Organ Transplantation

  Medicina · 2026-01-23 · 1 citations

  articleOpen access

  Vascularised composite allotransplantation (VCA) has an evolving role in the reconstruction of complex functional and aesthetic deficits non-amenable to autologous or implant-based reconstructive modalities. International applications of VCA span upper extremity, face, abdominal wall, uterus, and penile transplantation, with more than 300 procedures performed worldwide. Among these, abdominal wall transplantation has uniquely contributed to the development of the sentinel skin flap (SSF) concept, in which solid organ transplant patients undergo simultaneous transplantation of a solid organ and a donor-derived vascularised skin flap, with the skin component of the SSF being trialled internationally as a means of monitoring for rejection within the solid organ allograft. Despite growing clinical success, VCA continues to face substantial barriers to wider adoption. Acute rejection remains highly prevalent, affecting up to 89% of recipients, with significant morbidity linked to intensive systemic immunosuppression. Challenges are further amplified by the unique immunological heterogeneity of composite grafts, ethical concerns surrounding identity-linked tissues, and the lack of standardised outcomes reporting across VCA subtypes. Advances in machine perfusion technologies and emerging cellular and biomaterial-based immunomodulation strategies show promise in reducing immunosuppression burden and improving graft longevity. This review outlines the current state of VCA, including clinical applications, outcomes, and mechanistic insights from pre-clinical studies, while highlighting key ethical considerations and evolving regulatory frameworks. Future progress will depend on standardised reporting systems, improved donor-recipient matching, better understanding of ischemia-reperfusion injury, and the development of next-generation immunosuppressive/immuno-modulatory therapies. Collectively, these innovations position VCA as a rapidly advancing field with significant potential to redefine reconstructive and transplant surgery.

  PublisherOA PDFDOI

• Mitigating Post-operative Right Ventricular Dysfunction After Left Ventricular Assist Device: The RV Protection Study

  Journal of Cardiac Failure · 2025-02-13 · 8 citations

  article
  PublisherDOI

• Perioperative Resuscitation and Life Support (PeRLS): An Update

  Anesthesiology · 2025-11-11 · 1 citations

  article

  Cardiovascular collapse and arrest in the periprocedural setting and intensive care unit differ from arrests in other contexts (such as out-of-hospital or hospital ward) because clinicians almost always witness the event, and the most likely precipitating cause may be known. In comparison to other settings, the response can be timelier and more focused on treating the underlying cause(s). Since many patients deteriorate over minutes to hours, clinicians can evaluate the patient expeditiously, generate a diagnosis, and initiate appropriate treatment more rapidly than in other arrest circumstances. This iteration of Perioperative Resuscitation and Life Support (PeRLS) employs Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) methodology to review the most recent evidence on preventing and managing cardiac arrest during the perioperative period. Furthermore, many of the recommendations and algorithms may also be applicable to areas outside the operating room, such as the intensive care unit and emergency room.

  PublisherDOI

• NF-κB-mediated developmental delay extends lifespan in Drosophila

  Iowa State University Digital Repository (Iowa State University) · 2025-05-08

  articleOpen access

  Developmental time (or time to maturity) strongly correlates with an animal’s maximum lifespan, with late-maturing individuals often living longer. However, the genetic mechanisms underlying this phenomenon remain largely unknown. This may be because most previously identified longevity genes regulate growth rate rather than developmental time. To address this gap, we genetically manipulated prothoracicotropic hormone (PTTH), the primary regulator of developmental timing in Drosophila, to explore the genetic link between developmental time and longevity. Loss of PTTH delays developmental timing without altering the growth rate. Intriguingly, PTTH mutants exhibit extended lifespan despite their larger body size. This lifespan extension depends on ecdysone signaling, as feeding 20-hydroxyecdysone to PTTH mutants reverses the effect. Mechanistically, loss of PTTH blunts age-dependent chronic inflammation, specifically in fly hepatocytes (oenocytes). Developmental transcriptomics reveal that NF-κB signaling activates during larva-to-adult transition, with PTTH inducing this signaling via ecdysone. Notably, time-restricted and oenocyte-specific silencing of Relish (an NF-κB homolog) at early 3rd instar larval stages significantly prolongs adult lifespan while delaying pupariation. Our study establishes an aging model that uncouples developmental time from growth rate, highlighting NF-κB signaling as a key developmental program in linking developmental time to adult lifespan.

  Publisher

• New Approaches to Clinical Hemodynamics

  Anesthesia & Analgesia · 2025-05-16

  articleSenior author
  PublisherDOI

• Role of homeopathic materia medica in managing common day-to-day ailments: A narrative overview

  Journal of Homeopathy Studies · 2025-07-01

  articleOpen accessSenior author

  Homeopathy is widely used across many countries as a complementary system of medicine for managing common, self-limiting health problems encountered in daily life. The homeopathic Materia medica constitutes the core reference that links patient symptoms with individualized remedies through detailed drug proving and clinical observations. This narrative overview explores the role of homeopathic Materia medica in addressing frequently encountered day-to-day ailments such as headache, coryza, dyspepsia, minor skin complaints, musculoskeletal discomfort, and functional sleep disturbances. Emphasis is placed on how remedy pictures described in classical Materia medica texts guide symptom-based selection rather than disease-label-based prescribing. The paper synthesizes information from standard homeopathic literature and peer-reviewed sources published before 2023 to illustrate practical applications relevant to primary care settings. The overview highlights key remedies commonly referenced for acute and subacute conditions and discusses the relevance of characteristic symptoms, modalities, and concomitants in remedy differentiation. Attention is also given to safety considerations, scope of use, and the importance of professional judgment in managing self-care conditions. By presenting a structured yet accessible narrative, this article aims to clarify how Materia medica knowledge supports rational, individualized decision-making in everyday clinical scenarios. The overview does not attempt to evaluate efficacy outcomes but focuses on conceptual and educational aspects that inform routine practice. Overall, the article underscores the continuing relevance of classical homeopathic Materia medica as a practical tool for managing common ailments and for strengthening clinical reasoning within homeopathic practice. In addition, it situates the discussion within contemporary patterns of self-care, patient preference, and integrative health use, emphasizing how familiarity with remedy profiles enables practitioners to respond confidently to minor complaints, provide individualized guidance, and promote responsible use of homeopathy in everyday contexts without substituting for emergency or specialized medical care. Such perspectives reinforce the educational value of Materia medica for routine clinical decision making.

  PublisherOA PDFDOI

• One Strike and You’re Out!

  Anesthesiology · 2025-10-14

  articleSenior authorCorresponding
  PublisherDOI

• A Technical Policy Blueprint for Trustworthy Decentralized AI

  arXiv (Cornell University) · 2025-12-07

  preprintOpen access

  Decentralized AI systems, such as federated learning, can play a critical role in further unlocking AI asset marketplaces (e.g., healthcare data marketplaces) thanks to increased asset privacy protection. Unlocking this big potential necessitates governance mechanisms that are transparent, scalable, and verifiable. However current governance approaches rely on bespoke, infrastructure-specific policies that hinder asset interoperability and trust among systems. We are proposing a Technical Policy Blueprint that encodes governance requirements as policy-as-code objects and separates asset policy verification from asset policy enforcement. In this architecture the Policy Engine verifies evidence (e.g., identities, signatures, payments, trusted-hardware attestations) and issues capability packages. Asset Guardians (e.g. data guardians, model guardians, computation guardians, etc.) enforce access or execution solely based on these capability packages. This core concept of decoupling policy processing from capabilities enables governance to evolve without reconfiguring AI infrastructure, thus creating an approach that is transparent, auditable, and resilient to change.

  PublisherOA PDFDOI

• The vial can help: Standardizing vial design to reduce the risk of medication errors

  International Anesthesiology Clinics · 2024-01-22 · 2 citations

  article

  aDepartment of Health Policy and Management, Ben-Gurion University of the Negev, Beer-Sheva, Israel bDepartment of Anesthesia and Critical Care, The University of Chicago, Chicago, Illinois cDepartments of Anesthesiology, Perioperative Care and Pain Medicine, Neurology, Surgery and Medicine, NYU Langone Health, New York, New York Address Correspondence to: Yuval Bitan, PhD, 1 Ben-Gurion Ave., Be'er Sheva, Israel 8443944. E-mail: [email protected]

  PublisherDOI