Missed sepsis is one of the most consequential diagnostic failures in emergency medicine. Patients with early sepsis can look deceptively well: vital signs may be only modestly abnormal, the patient may be conversational, and the presenting complaint may overlap with much more common conditions. The narrow window in which intervention can change the trajectory is typically measured in hours rather than days. A patient who is sent home with a missed sepsis often returns far sicker, and sometimes does not return at all. The regulatory and medico-legal record on missed sepsis is correspondingly substantial.
College of Physicians and Surgeons of Ontario v Duic, 2025 ONPSDT 11, released by the Ontario Physicians and Surgeons Discipline Tribunal (OPSDT) on March 18, 2025, is a recent illustration. The respondent is an emergency medicine physician. The patient was a 19-year-old woman who returned to the emergency department by ambulance 23 days after a medical termination of pregnancy. On examination she had a peritonitic abdomen with diffuse guarding. She was given intravenous morphine, a partial workup was ordered, and she was discharged on oxycodone with a provisional diagnosis of “abdominal pain not yet diagnosed ? cyclic vomiting.” She subsequently died of complications of septic shock. The Tribunal imposed a three-month suspension of the respondent’s licence followed by a period of clinical supervision.
The case is doctrinally important for several reasons. It articulates the standard of practice for emergency physicians evaluating patients with peritoneal signs after a recent procedure. It illustrates the diagnostic anchoring problem: where a physician fixes on an initial impression early and fails to consider the differential, the result can be a catastrophic miss. It addresses the related questions of inadequate reassessment, inadequate documentation of differential diagnosis, and opioid prescribing in the context of an undefined acute abdominal presentation. And it adds a seventh case to the rapidly developing regulatory discipline cluster in modern Ontario malpractice law.
The clinical context — peritonitis, sepsis, and the abdominal examination
A brief clinical overview is useful for the analysis.
Peritonitis. The peritoneum is the membrane that lines the abdominal cavity and covers the abdominal organs. Peritonitis is inflammation of the peritoneum, typically caused by infection (bacterial peritonitis) or by chemical irritation (from bile, gastric content, or blood). Bacterial peritonitis is a serious clinical entity that can rapidly progress to sepsis and septic shock if not promptly recognized and treated.
The classic signs of peritonitis on examination are:
- Diffuse abdominal tenderness (the entire abdomen is tender to palpation)
- Guarding (involuntary tightening of the abdominal wall muscles when the examining hand approaches the abdomen)
- Rigidity (a board-like abdominal wall)
- Rebound tenderness (worsened pain when the examining hand is suddenly removed)
- Decreased or absent bowel sounds
The combination of diffuse tenderness, guarding, and rigidity is sometimes called a “peritonitic abdomen” or an “acute abdomen.” Modern emergency medicine treats these findings as a clinical emergency that requires structured workup to identify the underlying cause and prompt treatment to prevent progression to sepsis.
The standard workup for a peritonitic abdomen. The standard emergency department workup for a patient with peritoneal signs typically includes:
- Vital signs and ongoing monitoring
- Blood work (complete blood count, electrolytes, lactate, blood cultures where infection is suspected)
- Inflammatory markers (C-reactive protein, procalcitonin where available)
- Urine analysis
- Imaging (depending on the clinical context, but typically including computed tomography of the abdomen and pelvis with intravenous contrast for the unexplained acute abdomen)
- Surgical consultation
- Empiric antibiotics where infection is suspected and the cause may be intra-abdominal
The CT scan is particularly important in the unexplained peritonitic abdomen. Plain X-rays can identify free air (suggesting a perforated viscus) but are otherwise of limited use. Ultrasound can identify some causes (gallbladder disease, pelvic collections in women) but does not reliably identify the wide differential of an acute abdomen. CT remains the principal investigative tool.
Post-procedural sepsis. A patient who presents with peritoneal signs after a recent gynecological or gastrointestinal procedure has a recognizable risk for procedure-related complications. The complications can include:
- Direct injury to a hollow organ (uterus, bowel, bladder) with subsequent infection
- Retained products of conception (after pregnancy termination) with subsequent infection
- Endometritis (infection of the uterine lining)
- Tubo-ovarian abscess
- Pelvic abscess
- Generalized peritonitis from any of the above
The window between procedure and presentation matters. A patient who presents within hours typically has a procedure-related complication. A patient who presents at 23 days, as in Duic, has a clinical course that extends beyond the immediate procedure but remains within the range where procedure-related causes (particularly retained tissue with delayed infection) are recognized possibilities. The differential diagnosis must consider both procedure-related and unrelated causes.
Opioid analgesia in the undifferentiated abdomen. Modern emergency medicine practice does not absolutely prohibit opioid analgesia in patients with abdominal pain. Earlier teaching that opioids would “mask” peritoneal signs and obscure the diagnosis has been largely set aside in favour of evidence that adequate analgesia is humane and does not substantially compromise the examination. The framework is, however, more nuanced than simply “opioids are fine.” Opioids can blunt the patient’s response to repeat examination, can mask deterioration, and can lower the urgency of the clinical disposition. A patient who receives opioids and then appears more comfortable is not necessarily better; the underlying pathology may be progressing while the pain signal is suppressed.
The discharge decision with opioids requires additional caution. A patient with a peritonitic abdomen who is given opioids and discharged is at risk for:
- Continued progression of the underlying pathology without further reassessment
- Suppressed recognition of deterioration at home
- A delayed return to medical care
- A worse outcome when the patient does return
The framework for opioid prescribing at discharge has evolved substantially in the past decade in response to the opioid crisis. Discharge prescriptions for short-duration opioids may be appropriate where the diagnosis is established and the pain trajectory is understood. Discharge with opioids and an unestablished diagnosis is harder to justify.
Cognitive bias and diagnostic anchoring. Modern emergency medicine teaching addresses cognitive biases that contribute to diagnostic errors. The relevant biases include:
- Anchoring: fixing on an initial impression and failing to revise as new information emerges
- Premature closure: accepting a diagnosis before adequate workup
- Confirmation bias: weighting evidence that supports the working diagnosis while discounting evidence that does not
- Search satisficing: stopping the diagnostic search after one explanation is found, even where other significant findings remain unexplained
The clinical teaching is to actively guard against these biases by structured differential diagnosis development, periodic re-examination of the working diagnosis, and explicit consideration of “what else could this be?” before discharge.
The facts
The patient. The patient was a 19-year-old woman. She had undergone a medical termination of pregnancy 23 days before the relevant ED presentation.
The presentation. On February 21, 2022, the patient was brought to the emergency department by ambulance. The mode of arrival (by ambulance rather than self-transport) is itself a clinical signal: a patient who is sick enough to need an ambulance has typically experienced something significant. The ambulance call also creates pre-hospital records (the paramedic assessment, the vital signs in transit) that form part of the clinical picture available to the ED physician.
The examination. The respondent assessed the patient. The findings documented in the chart included:
- Diffuse abdominal tenderness
- A peritonitic abdomen
- Diffuse guarding
The combination of findings is the classic clinical picture of peritonitis. The standard of practice in emergency medicine for a patient with these findings includes structured differential diagnosis development, advanced imaging (typically CT abdomen and pelvis with contrast), monitoring, and consideration of surgical consultation depending on the working diagnosis.
The workup. The respondent ordered:
- Intravenous morphine
- Point-of-care urinalysis
- Laboratory studies
- Pelvic ultrasound
- Chest X-ray
- Abdominal X-ray
The workup is partial. The notable omission is the CT scan. A pelvic ultrasound is appropriate for evaluation of pelvic pathology in women, but it does not reliably identify the broader differential for a peritonitic abdomen (perforated viscus, intra-abdominal abscess, mesenteric ischemia, and so on). The chest and abdominal X-rays can identify some specific findings (free air under the diaphragm in a perforated viscus, certain patterns of bowel obstruction) but are inadequate for the comprehensive evaluation of an acute abdomen. The CT scan is the standard of care investigation in this presentation.
The documentation gaps. The respondent did not document:
- A reassessment of the patient after the initial workup
- A differential diagnosis
- An analysis of the working diagnosis against the differential
The documentation framework matters because the contemporaneous medical record is the principal evidence of the clinical reasoning. Absence of documentation does not necessarily mean that the reasoning did not occur, but it is unusual for sophisticated diagnostic reasoning to occur without contemporaneous documentation in the ED setting where charting is part of the workflow.
The diagnosis and discharge. The respondent’s provisional diagnosis was recorded as “abdominal pain not yet diagnosed ? cyclic vomiting.” The patient was discharged with a prescription for 16 oxycodone (Percocet) tablets.
The provisional diagnosis is problematic on multiple levels:
- “Abdominal pain not yet diagnosed” acknowledges that the diagnostic question has not been answered
- “? cyclic vomiting” introduces a hypothesis (cyclic vomiting syndrome is a chronic episodic vomiting disorder) that does not fit the clinical picture of a peritonitic abdomen with guarding
- The discharge decision is at odds with the documented examination findings
- The opioid prescription compounds the problem by both treating the pain and potentially masking the deterioration
The outcome. The patient subsequently died of complications of septic shock post medical termination of pregnancy.
The expert evidence
The CPSO retained two experts in emergency medicine to review the care. Their opinions converged on several points.
The standard of practice. The respondent failed to maintain the standard of practice of the profession. The standard requires structured differential diagnosis development, appropriate investigations including CT scan for an unexplained peritonitic abdomen, reassessment after initial management, and a discharge decision supported by the diagnostic conclusion.
Knowledge, skill, and judgment. The respondent demonstrated a lack of knowledge, skill, and judgment in his care and treatment of the patient. The clinical picture (a young woman with a peritonitic abdomen 23 days after a pregnancy termination) presented a recognizable differential that the respondent did not adequately address.
Risk of harm and injury. The pattern of care exposed the patient to risk of harm and injury. The risk was actualized: the patient died of complications of septic shock that, on the available record, would have been amenable to identification and treatment had the workup been completed.
The systemic dimension. One of the experts noted that the pattern of deficits (in history-taking, differential diagnosis development, and clinical reasoning) was not just specific to this case. If applied to populations of patients, the pattern would likely cause harm to a substantial proportion. The framework is doctrinally important: regulatory discipline addresses not only the individual case but also the systemic implications of how the physician practices generally.
The legal framework — the DDU statutory standard
The disgraceful, dishonourable, or unprofessional (DDU) standard appears in O Reg 856/93, s 1(1)33 under the Medicine Act, 1991, SO 1991, c 30. The standard captures conduct that falls short of the basic expectations of the profession. The framework is applied through tribunal decisions across a range of misconduct categories.
In Duic, the DDU framework was applied to a pattern of clinical conduct that the Tribunal accepted (the misconduct was uncontested) as falling below the standard. The framework supports a finding of professional misconduct even in the absence of any intentional wrongdoing. The clinical conduct itself, evaluated against the standard of practice, is what was at stake.
The application of DDU to clinical conduct (as distinct from intentional misconduct such as fraud or sexual misconduct) is doctrinally consistent with the framework articulated in Kilian v College of Physicians and Surgeons of Ontario, 2024 ONCA 226, which confirmed that DDU operates as a professional standards standard rather than a strict-liability rule. A clinical pattern that falls sufficiently below the standard can be DDU.
The sanction
The OPSDT imposed:
- A three-month suspension of the respondent’s medical licence
- A subsequent period of clinical supervision
The sanction is at the lower end of the spectrum of recent CPSO discipline outcomes. By way of comparison with other recent decisions:
- CPSO v Trozzi, 2024 ONPSDT 13: licence revocation (misleading public statements about COVID-19)
- CPSO v Luchkiw, 2023 ONPSDT 8: licence revocation (refusal to cooperate with investigation)
- CPSO v Thirlwell, 2026 ONPSDT 5: licence revocation (1,400 COVID-19 exemption letters)
- CPSO v Nahvi, 2024 ONPSDT 31: permanent licence undertaking (drugging incident)
- CPSO v Li, 2024 ONPSDT 6: 12-month suspension (parking permit billing)
- CPSO v Sharma, 2025 ONPSDT 5: 10-month suspension plus supervision (anesthesia inattention plus record falsification plus OHIP billing)
- CPSO v Duic, 2025 ONPSDT 11: 3-month suspension plus supervision (clinical SOC failure in ED)
The relatively modest sanction despite the patient death likely reflects several factors visible from the public record:
- The misconduct was uncontested. Where the respondent admits the misconduct and cooperates with the disciplinary process, the framework supports more moderate sanctions.
- The conduct was clinical rather than intentional. The respondent did not engage in record falsification, fraud, or dishonesty. The misconduct was a diagnostic and clinical failure.
- The clinical supervision component provides ongoing oversight and supports safe return to practice.
The sanction nonetheless represents a meaningful interruption of practice and a public finding of professional misconduct that will appear on the respondent’s public record indefinitely.
The doctrinal anchors
Several doctrinal anchors emerge from the case.
The “peritonitic abdomen requires structured workup” framework. A patient who presents to the ED with a peritonitic abdomen requires a structured diagnostic approach. The standard of practice includes differential diagnosis development, advanced imaging (typically CT abdomen and pelvis), reassessment, and consideration of surgical consultation. Duic makes the framework explicit in the regulatory discipline context.
The “CT scan in unexplained peritonitis” framework. The CT scan is the principal investigative tool for an unexplained peritonitic abdomen. Ultrasound, plain X-rays, and laboratory investigations are useful but do not displace the CT scan in this clinical context. The failure to order CT in the unexplained peritonitic abdomen is the specific clinical failure identified in Duic.
The “diagnostic anchoring” framework. Where a physician fixes on an initial impression and fails to revise it in light of new information or unresolved findings, the diagnostic process is compromised. Duic illustrates the framework in action: the respondent’s working diagnosis of “abdominal pain not yet diagnosed ? cyclic vomiting” did not fit the documented findings (peritonitis with guarding) but was not revised before discharge. The framework is generalizable to any clinical context where the initial impression is reached prematurely.
The “failure to reassess before discharge” framework. Modern emergency medicine practice requires reassessment before discharge in any patient who presents with significant findings. The reassessment is not just a vital signs check; it is a re-evaluation of the working diagnosis against the available clinical and investigational evidence. Duic establishes the framework as part of the SOC for patients with peritoneal signs.
The “discharge with opioids in unestablished diagnosis” framework. Discharge prescriptions for opioids can be appropriate where the diagnosis is established and the pain trajectory is understood. Where the diagnosis is unestablished and the patient has significant findings (such as peritoneal signs), the opioid prescription creates additional risk: the patient may not recognize deterioration, may delay return to medical care, and may have a worse outcome when they do return. The framework is generalizable across emergency medicine practice.
The post-procedural sepsis recognition framework. A patient who presents with peritoneal signs in the period following a procedure (gynecological, gastrointestinal, urological, or otherwise) has a recognizable risk for procedure-related complications including infection. The standard of care includes specific consideration of this category of diagnoses. Duic applies the framework to the post-medical-termination context but generalizes to any post-procedural presentation.
The “ambulance arrival as clinical signal” framework. A patient who is brought to the ED by ambulance has typically experienced something significant. The mode of arrival is itself a clinical signal that informs the index of suspicion. The framework is part of the broader ED triage analysis.
The “documentation as evidence of reasoning” framework. The contemporaneous medical record is the principal evidence of clinical reasoning. Where the documentation is sparse or absent (no differential diagnosis recorded, no reassessment recorded), the trier of fact can draw inferences about whether the reasoning actually occurred. Duic illustrates the framework in action: the absence of documented differential diagnosis was treated as evidence that the differential analysis did not adequately occur.
The “populations of patients” expert framework. Expert evidence in regulatory discipline can address both the specific case and the broader implications for how the physician practices generally. Where the pattern of care, if applied to populations of patients, would likely cause harm to a substantial proportion, the regulatory implications go beyond the individual incident. The framework supports broader regulatory intervention than would be supported by a single isolated lapse.
The “uncontested misconduct” sanction pattern. Where the respondent admits the misconduct and cooperates with the disciplinary process, the sanction framework typically supports more moderate outcomes. Duic and Sharma both involved uncontested misconduct with corresponding mid-range suspensions; the cases with contested or aggravated misconduct (Trozzi, Luchkiw, Thirlwell, Nahvi) attracted revocation or permanent undertakings.
Why this case matters
For patients and families. The case is a public articulation of what emergency physicians are expected to do when patients present with peritoneal signs. For patients and families dealing with the aftermath of similar presentations, the framework helps clarify what should have happened.
Some practical observations:
Peritoneal signs are emergencies. A patient who is found to have a peritonitic abdomen with guarding has, by clinical convention, an emergency that requires structured workup. The standard of practice does not permit discharge with opioids and an unestablished diagnosis. Where a family member has experienced this presentation pattern and a poor outcome, the underlying care is worth examining.
The medical record is the principal evidence of reasoning. Where a physician’s differential diagnosis is not documented and where no reassessment is recorded before discharge, those documentation gaps are themselves evidence. The framework can support regulatory and civil claims even where the physician later attempts to reconstruct the clinical reasoning after the fact.
Recent procedure history matters. Where a patient presents with abdominal symptoms or peritoneal signs in the period following a procedure (gynecological, gastrointestinal, or otherwise), the procedure itself is a critical part of the history. Procedure-related complications including infection should be specifically considered in the differential.
Concerns can be raised with the CPSO and through civil action. Where a patient or family member has concerns about the conduct that led to a poor outcome, the CPSO complaints process and a civil malpractice action are independent paths. The two can proceed in parallel. For more on the framework, see A Patient’s Guide to Making Complaints About Health Care in Ontario and Suing for Medical Malpractice in Ontario: What You Need to Know.
For physicians and clinical teams. A few practical observations:
Document the differential diagnosis. The framework for the standard of practice in emergency medicine includes structured documentation of the differential diagnosis. The framework is not just defensive practice; it is the contemporaneous record of the clinical reasoning. Where the diagnosis is unestablished at the time of disposition, the differential should be explicit, the workup status should be documented, and the rationale for the disposition should be clear.
Reassess before discharge. Modern emergency medicine practice requires reassessment before discharge in any patient who has presented with significant findings. The reassessment should be a substantive re-evaluation of the working diagnosis against the available evidence, not just a vital signs check.
Be cautious about opioid discharge prescriptions in undifferentiated pain. The framework for discharge opioid prescribing supports moderate prescriptions where the diagnosis is established. Where the diagnosis is unestablished and the patient has significant findings, the opioid prescription compounds the risk of a missed diagnosis at home. The careful approach is to defer the opioid prescription until the diagnosis is established, with non-opioid analgesia and a planned return for re-evaluation.
Recognize the post-procedural patient. A patient who presents in the period following a procedure has a recognizable differential that includes procedure-related complications. The history of the recent procedure should be elicited and integrated into the working diagnosis development. Procedure-related sepsis (after gynecological procedures, after gastrointestinal procedures, after urological procedures) is a recognized clinical entity.
Guard against diagnostic anchoring. The structured discipline of considering “what else could this be?” before disposition is a recognized check against premature closure. The framework is part of the broader emergency medicine teaching on cognitive bias.
Cluster integration
This is a regulatory discipline decision, joining the broader CPSO discipline cluster. For other recent CPSO discipline cases, see the related case comments on CPSO v Trozzi, CPSO v Luchkiw, CPSO v Li, CPSO v Thirlwell, CPSO v Nahvi, and CPSO v Sharma.
Decision Date: March 18, 2025
Jurisdiction: Ontario Physicians and Surgeons Discipline Tribunal
Citation: College of Physicians and Surgeons of Ontario v Duic, 2025 ONPSDT 11 (CanLII)
Outcome: Three-month suspension of medical licence followed by a period of clinical supervision. The Tribunal found that the respondent had committed professional misconduct in his assessment, treatment, and discharge of a 19-year-old patient who presented to the emergency department by ambulance with a peritonitic abdomen and diffuse guarding 23 days after a medical termination of pregnancy. The findings of misconduct were uncontested. The respondent had ordered intravenous morphine, point-of-care urinalysis, laboratory studies, a pelvic ultrasound, and chest and abdominal X-rays, but had not ordered the CT scan that the standard of practice required for the unexplained peritonitic abdomen. He had not documented a reassessment or a differential diagnosis. The provisional diagnosis recorded (“abdominal pain not yet diagnosed ? cyclic vomiting”) did not fit the documented examination findings. The patient was discharged with a prescription for 16 oxycodone tablets. She subsequently died of complications of septic shock. Two expert emergency medicine reviewers concluded that the respondent had failed to maintain the standard of practice of the profession, had demonstrated a lack of knowledge, skill, and judgment, and had exposed the patient to risk of harm and injury. One expert noted that the pattern of deficits, if applied to populations of patients, would likely cause harm to a substantial proportion.
Key authorities: Medicine Act, 1991, SO 1991, c 30 and O Reg 856/93, s 1(1)33 (the DDU statutory standard); Regulated Health Professions Act, 1991, SO 1991, c 18 and the Health Professions Procedural Code (the broader regulatory framework); Kilian v College of Physicians and Surgeons of Ontario, 2024 ONCA 226 (the DDU framework as a professional standards standard).
