Anyone who has spent a long night in an Ontario emergency department in the last few years recognizes the pattern. The waiting room is full. Stretchers line the corridors outside the treatment area. Patients who should be in monitored beds are instead in hallways, behind curtains, or on chairs in the ambulance bay. Triage nurses are overwhelmed. Physicians are running between patients with incomplete information. Vital signs are not reassessed for hours. People who arrive with chest pain, severe abdominal pain, neurological symptoms, or sepsis are sometimes sent home with a diagnosis that does not match the seriousness of what is actually happening.
This is what is known as hallway medicine, and it is no longer an exception. It has become a routine feature of how care is delivered across Ontario hospitals. From a medical-legal perspective, the question that increasingly arises is straightforward: when an overcrowded emergency department contributes to a delayed diagnosis, a missed condition, a premature discharge, or a death, who is legally responsible?
The short answer is that the legal standard of care does not change because the system is in crisis. Patients who are harmed by negligent emergency care still have rights, and physicians and hospitals can still be held accountable. The framework operates the way it has always operated: by reference to what a reasonably competent professional would have done in the same circumstances. Where the answer is that the standard of practice was not met and harm followed, the framework supports a claim.
This foundational explainer is for patients and families navigating the aftermath of a serious adverse outcome in an Ontario emergency department, and for clinicians thinking about how the framework applies to the conditions they actually practise in. The framework is calibrated to the practical reality of emergency medicine without bending to systemic pressure.
What “hallway medicine” actually means
The term refers to patients receiving care, including admitted, post-operative, and acutely ill patients, in spaces never designed for it: hallways, conference rooms, family lounges, and unmonitored alcoves. The Office of the Auditor General of Ontario has documented the scale of the problem in detail. In its 2023 value-for-money audit of Ontario emergency departments, the Auditor General found that the average wait to be assessed by a physician had grown to roughly two hours, and that patients who needed to be admitted were often waiting more than 24 hours for an inpatient bed. There were over 200 unplanned, temporary ED closures across 23 hospitals (most of them rural or northern) in a single twelve-month period, driven largely by nursing and physician shortages.
A 2025 follow-up audit found that, while progress has been made on some recommendations, hospital occupancy continues to hover above 95% and serious adverse events remain a recurring feature of return ED visits, including missed diagnoses, delayed diagnoses, and unsafe discharges.
Ontario’s “left without being seen” rate, the percentage of patients who give up and leave the emergency department before being assessed, has more than doubled in recent years. At some hospitals, more than one in ten patients walks out before seeing a physician. Each of those patients is a person whose condition was never assessed, never diagnosed, and never treated. Some are fine. Some are not.
The downstream consequences are significant. A recent analysis published in Healthy Debate cited research estimating that as many as 15,000 Canadians die each year as a result of hospital overcrowding. That is not a failure of any one nurse, physician, or hospital. But it does set the stage for a real and growing volume of preventable harm.
The CTAS framework and the practical structure of emergency triage
A brief overview of the practical structure of emergency triage is useful for the analysis.
The Canadian Triage and Acuity Scale. Most Ontario emergency departments operate under the framework of the Canadian Triage and Acuity Scale (CTAS), a five-level system that classifies arriving patients by clinical urgency:
- Level 1: Resuscitation. The patient requires immediate aggressive intervention. Examples include cardiac arrest, severe respiratory distress, major trauma, and unresponsiveness. The framework target is immediate physician assessment.
- Level 2: Emergent. The patient has a condition that could be a threat to life or limb, or could potentially cause major deterioration. Examples include chest pain consistent with acute coronary syndrome, sepsis, stroke symptoms, and severe abdominal pain. The framework target is physician assessment within 15 minutes.
- Level 3: Urgent. The patient has a condition that could progress to serious harm but is not immediately life-threatening. Examples include moderate abdominal pain, vomiting and dehydration, headache with concerning features, and significant orthopedic injuries. The framework target is physician assessment within 30 minutes.
- Level 4: Less Urgent. The patient has a condition that is acute but not progressing rapidly. The framework target is physician assessment within 60 minutes.
- Level 5: Non-Urgent. The patient has a condition that is chronic without acute change, or an acute condition that is minor. The framework target is physician assessment within 120 minutes.
The CTAS framework is the structured response to the practical reality that emergency departments must allocate finite clinical resources across patients with substantially different acuity. The framework supports clinically appropriate prioritization and provides a structured documentation framework for triage decisions.
The undertriage framework. Where a patient is assigned a CTAS level less urgent than their actual presentation warrants, the framework can produce significant delays in care. Undertriage is a well-recognized category of triage error and is one of the most common patterns in hallway medicine litigation. The framework for assessing undertriage operates against the standard of practice for triage nurses (typically the standard articulated in the CTAS guidelines and the professional standards for emergency nursing).
The reassessment framework. CTAS includes reassessment intervals for patients who remain in the department awaiting physician assessment or treatment. The framework targets reassessment of vital signs and clinical status at intervals calibrated to the assigned CTAS level. Where the reassessment framework is not engaged (patients in hallways effectively forgotten for hours), the framework can produce delayed recognition of deterioration.
The framework’s limits under operational pressure. CTAS operates as the framework for ideal practice. The reality in many Ontario EDs is that the target intervals are routinely missed because of operational pressure. The framework for legal liability does not treat the operational pressure as a defence; it treats the framework targets as the expected standard.
The standard of care does not bend to system pressure
In Ontario, the legal standard of care for a physician or nurse is what a reasonably competent professional would have done in the same circumstances. That standard is not waived because the department is busy, because there is a nursing shortage, or because the patient was being seen in a hallway rather than a treatment bay.
This principle was applied directly in Ibrahimova v Cavanagh, where the Ontario Superior Court of Justice found an emergency medicine physician negligent for failing to refer a pregnant patient with ruptured membranes to an obstetrician. The patient went on to develop septic shock and required multiple amputations. The decision confirms what plaintiffs’ counsel have long argued: emergency physicians are not relieved of their duty to recognize red flags, escalate appropriately, and arrange specialist input simply because the department around them is under strain.
Put bluntly, an overcrowded ED is the context for the analysis, not a defence to it. Triage decisions, reassessment intervals, the decision to admit or discharge, the decision to order or repeat a test, the decision to consult: each of these is still measured against what a competent emergency physician or nurse should have done. The framework recognizes the difficulty of the conditions but does not waive the obligations.
The framework operates this way for sound reasons. If the standard of care bent to systemic pressure, the patient would bear the loss caused by the system’s failure. The framework instead places the loss on the parties who can effect change: the physicians whose professional obligations operate regardless of the operational context, and the institutions whose obligations include providing the resources necessary for safe practice. Where the institution has not provided those resources, the framework supports liability of the institution for the systemic failure.
Where liability most often arises
In our experience litigating these claims, the patterns are remarkably consistent. The most common categories of negligence in overcrowded Ontario emergency departments include:
Triage errors. A patient is undertriaged at the front door (assigned a less urgent CTAS level than their presentation warrants) and is then left in the waiting room while their condition deteriorates. Sepsis, stroke, and acute coronary syndromes are particularly vulnerable to this failure. The framework for triage operates against the CTAS guidelines and emergency nursing standards.
Failure to reassess. A patient is triaged, vitals are taken once, and they are then effectively forgotten in a hallway for several hours. By the time someone returns, the clinical picture has changed dramatically. The framework for reassessment operates against the CTAS reassessment intervals and the professional standards for monitoring patients in the department.
Premature discharge. A patient is sent home before pending test results are reviewed, before symptoms have meaningfully resolved, or with safety-net instructions that are inadequate to the actual diagnosis on the differential. The framework treats discharge as a clinical decision that requires the same clinical reasoning as any other clinical decision and that engages the framework of consent, instructions, and follow-up arrangements.
Missed sepsis, missed stroke, missed cardiac events. These are time-sensitive diagnoses where every hour of delay materially worsens outcomes. They account for a disproportionate share of catastrophic ED claims in this province. The framework for evaluation includes specific clinical pathways (sepsis bundles; stroke protocols; ACS protocols) that have been developed precisely because of the time sensitivity.
Missed other time-sensitive diagnoses. Beyond the three most common categories, several other time-sensitive diagnoses recur in ED malpractice including:
- Bowel perforation, where delay in diagnosis can produce sepsis and death
- Ectopic pregnancy, where delay in diagnosis can produce hemorrhagic shock
- Abdominal aortic aneurysm, where rupture is rapidly fatal without intervention
- Intracranial hemorrhage, where time to neurosurgical evaluation affects outcomes
- Meningitis, where time to appropriate antibiotic therapy affects outcomes
- Testicular torsion, where time to surgical correction determines whether the testicle is salvageable
- Compartment syndrome, where time to fasciotomy determines whether the limb is salvageable
- Necrotizing fasciitis, where time to surgical debridement affects survival
Each of these conditions has a window during which intervention can substantially change the outcome. The framework treats missing the window as a category of clinical failure that requires the same standard of care analysis as any other clinical decision.
Failure to escalate or refer. A patient with red-flag symptoms is managed entirely by the emergency physician without consultation to the appropriate specialist (obstetrics, neurology, general surgery, cardiology, vascular surgery, urology) when the standard of care required that consultation. The framework for specialist referral operates against the professional standards for emergency medicine practice and the specific clinical guidelines for the underlying condition.
Communication breakdowns. Critical results come back hours after the patient has been moved or discharged, and the loop is never closed. Abnormal imaging and abnormal labs that require urgent action sit in the chart unread. The framework for results communication operates against the institutional standards for critical results notification and the professional standards for the responsible clinician’s follow-through.
The “loop closure” framework. A specific subset of communication failures involves the closure of the diagnostic loop. A test is ordered to address a specific clinical question. The result arrives. The result must be reviewed, communicated to the responsible clinician, and acted upon. Where the loop is not closed (because the patient has moved, been discharged, or the responsible clinician has changed), the framework can produce catastrophic delays in recognition of significant findings. The framework supports liability where the loop closure obligation has not been met.
For a more detailed discussion of the specific diagnoses that are most often missed in this setting, see our earlier post on the top five most dangerous misdiagnoses in the emergency room.
Hospital liability versus physician liability
When a person is harmed in an overcrowded emergency department, the legal analysis usually involves more than one defendant. The framework distinguishes between several categories of liability that can apply individually or in combination.
Individual physician liability. Emergency physicians, consulting specialists, and any residents involved owe a personal duty of care to their patients and may be sued directly. The duty is owed by the physician personally, regardless of the physician’s employment or contractor status with the institution. Most physicians in Canada are defended by the Canadian Medical Protective Association, which is well resourced and aggressive in defending claims. The framework operates the same way for emergency physicians as for any other physician: standard of care is measured against what a reasonable specialist in emergency medicine would have done in the circumstances.
Vicarious hospital liability. Hospitals are vicariously liable for the negligence of their employees, most importantly nurses, but also residents (in many contexts), technologists, and clerical staff who play a role in patient flow. The framework for vicarious liability operates on the employer-employee relationship and the scope of employment doctrine. Where the negligence is committed by an employee acting in the scope of employment, the framework supports liability of the employer institution.
The framework is doctrinally important because hospital nurses make many of the consequential decisions in the patient’s care pathway: the triage assessment, the reassessment intervals, the recognition of deterioration, the communication of concerns to physicians, and the framework for monitoring patients awaiting beds. Where the nursing care falls below the standard, the framework supports hospital liability through the nursing employment relationship.
Direct hospital liability. Beyond vicarious liability, hospitals can be directly liable for systemic or institutional failures. The framework includes:
- Inadequate staffing in proportion to the volume and acuity of patients
- The absence of policies for reassessment of waiting patients
- Failure to implement reasonable triage protocols
- Failure to ensure that critical results are communicated to the responsible clinician
- Failure to provide an adequate physical environment for safe care
- Failure to provide adequate equipment for monitoring
- Failure to maintain a safe nurse-to-patient ratio
The direct liability framework operates on the institution’s own duty to its patients, independent of the conduct of any individual employee. The framework recognizes that the institution makes the resource allocation decisions, policy decisions, and operational decisions that shape the conditions of care.
The interplay between these theories matters. In a hallway-medicine case, the question is rarely whether something went wrong: it is whose failure caused the harm, and whether more than one defendant should answer for it. A careful pleading typically names both the individual clinicians and the hospital, and the defence positions of those parties often diverge as the case progresses. Where the hospital is a defendant, the analysis can include both the vicarious dimension (the conduct of specific employees) and the direct dimension (the systemic decisions that produced the conditions).
The fragmented care framework. Where the patient’s care has spanned multiple settings (community physician; emergency department; inpatient ward; long-term care; home care), the framework for identifying responsible parties can include multiple institutions and multiple providers. The framework supports claims against each party whose conduct fell below the standard and contributed to the outcome. The framework also supports the use of misnomer / John Doe pleadings where the specific providers cannot be identified within the limitation period, as recently illustrated in the procedural framework articulated by the Ontario Superior Court of Justice in cases addressing fragmented care for vulnerable patients in long-term care.
What patients and families should document
If you or a loved one have a serious adverse outcome after an emergency department visit, the contemporaneous record is often the most important piece of evidence. The hospital’s chart will eventually be obtained through formal disclosure, but families are often in a better position to capture details that the chart will not contain. Where possible, write down:
- The date and time of arrival, and the time triage was completed
- The triage level assigned and what the nurse said about expected wait
- Each time a clinician (nurse or physician) actually assessed the patient, and what they said
- Each set of vital signs taken, and the times
- What was said at the time of any discharge, and what written instructions were provided
- The names of treating clinicians, where known
- Any complaints made by the patient or family during the visit, and to whom
- Any communications about test results, including timing of results and how they were communicated
- Any conversations about plans for admission, transfer, or specialist consultation
- The condition of the department generally (waiting room status; corridor crowding; visible staffing) at the time of the visit
These details are routinely missing or thin in hospital charts and can become decisive in establishing what actually happened during a hallway-medicine encounter. Where the hospital chart shows reassessment intervals that did not match the lived experience of the patient and family, the contemporaneous family record can provide the basis for cross-examination of the documentation.
The framework for hospital records. Hospital records are typically obtained through formal disclosure once a claim is started. The framework for records production operates under the Rules of Civil Procedure and includes the nursing notes, the physician’s notes, the orders, the laboratory and imaging results, the medication administration record, the discharge summary, and various administrative records. The framework supports comprehensive disclosure of the records that document the care.
The framework for institutional records. Beyond the patient-specific records, the framework can support disclosure of institutional records that bear on the systemic dimension of the claim. The framework includes staffing records, triage policies, reassessment protocols, critical results notification policies, and similar institutional documentation. The framework for institutional disclosure operates somewhat differently from patient records and can be more contested.
When to speak with a medical malpractice lawyer
Not every bad outcome in an Ontario emergency department is the result of negligence. Emergency medicine is genuinely difficult, and even excellent clinicians make decisions in conditions of irreducible uncertainty. We have written separately about why many medical malpractice cases are declined in Ontario, and the analysis there applies fully to ED cases. The framework for case evaluation includes the standard of care analysis, the causation analysis, the damages analysis, and the framework for expert evidence. Where any of these dimensions is not satisfied, the framework typically does not support the case.
That said, a serious harm following an emergency department visit (a stroke that was missed, a sepsis that was sent home, a perforated viscus that was not investigated, a baby who was harmed because a transfer or consult never happened) deserves a careful legal review. There is a two-year limitation period in Ontario for most claims under the Limitations Act, 2002, with a strict two-year period under the Trustee Act for estate claims arising from death. Important evidence can be lost quickly. The earlier the case is reviewed, the better the framework for case evaluation can operate.
For more on the broader civil framework for medical malpractice claims, see Suing for Medical Malpractice in Ontario: What You Need to Know. For the framework for regulatory complaints (which operates separately from civil litigation), see A Patient’s Guide to Making Complaints About Health Care in Ontario.
If you or a family member have suffered serious injury or lost a loved one following an emergency department visit in Ontario, please contact our office for a free consultation. We will tell you honestly whether your case is one we can help with.
A final thought
The Auditor General’s reports document a system under serious strain. The framework of care that emergency physicians, nurses, and institutions are operating in is not the framework of textbook emergency medicine. It is operationally pressured, resource-constrained, and structurally difficult.
The framework of legal liability does not change because of these realities. The framework continues to ask the same questions: what did the physician or nurse know or reasonably ought to have known; what would a reasonable specialist have done in the circumstances; was the framework of care provided consistent with the standard; did the substandard care cause the harm. Where the answers support a claim, the framework supports the patient’s right to compensation regardless of the systemic context.
This calibration is sometimes uncomfortable. Physicians and nurses who are working extraordinary shifts under pressure can feel that the framework does not adequately recognize the circumstances they operate in. The framework’s response is that the standard exists precisely to protect patients, and that systemic problems cannot be allowed to become a defence to substandard care. Where the system has failed, the framework places the loss on the parties who are positioned to effect change, not on the patient who has already lost the most.
If the systemic problems are to be addressed, the framework needs to remain firm. Where the standard of care has been breached and harm has followed, the framework supports the claim.
