Originally published March 2020
The troubling impact of the opioid crisis in North America has been evident for almost half a decade, with Canada officially declaring a public health crisis in 2017.1 While the number of opioids prescribed in Canada decreased between 2012 and 2017,2 rates of hospitalization and death continue to increase.3 The most prevalent harms associated with this crisis are accidental overdoses, but another important sequelae is the increasing number of intravenous drug use (IDU) associated diseases, including infectious diseases. Some of these diseases, such as skin abscesses, may be relatively straightforward to diagnose when clear symptoms and clinical signs are present. Others, such as infective endocarditis and spinal abscess, can pose a much greater diagnostic challenge.
Case example: Delayed diagnosis of an epidural abscess
A 47-year-old woman4 presents to a walk-in clinic complaining of thoracic back pain after a recent fall. Her medical history includes frequent visits to the emergency department and therapeutic use of methadone. Findings on physical examination include multiple skin abscesses on her arms and a low-grade fever. The doctor diagnoses a musculo-skeletal cause to explain her back pain, prescribes an analgesic, and orders thoraco-lumbar spine X-rays.
The following day, the patient presents to the emergency department of a community hospital with back and abdominal pain. She has a temperature of 39.2°C and her white cell count is 21 x 109/l. The physician prescribes oral ciprofloxacin, documents musculo-skeletal pain, and orders repeat blood work. At shift change, care transfers to a second physician who performs an incision and drainage of a lesion on the patient’s arm, and discharges her with a diagnosis of subcutaneous abscess.
The patient returns that evening, staggering, somnolent, and complaining of numbness in both legs. The physician on duty reaches the patient’s family doctor who shares that the patient currently uses intravenous fentanyl. The physician administers naloxone, admits the patient, and orders blood cultures. Both blood cultures are positive for Staphylococcus aureus. The patient now complains of weakness in her legs and difficulty voiding. The physician orders an urgent MRI, which reveals an epidural abscess with cord compression at T3, and the patient is referred for an urgent laminectomy. The patient is left with paraplegia and launches a legal action.
In their review of the case, peer experts expressed concern about the absence of a documented neurological exam in the emergency department, and were critical of the first physician for a lack of clear differential diagnosis. Criticisms of the care in the first emergency visit focused on a lack of clear follow-up arrangements, inadequate discharge instructions, and poor documentation. The CMPA settled on behalf of the physicians.
Infective endocarditis, discitis, and epidural abscesses are well known among physicians for being difficult to diagnose, and characterized by symptoms that may mimic more common conditions. If the patient is using intravenous drugs, diagnosis can be further complicated by social stigma, variability in terms of patient consent, and adherence to treatment and follow-up plans (e.g. being unable to afford medications or poor access to transportation for appointments).
From 2017 to 2018, Canadians experienced an 11.4% increase in opioid-related deaths,2 and a 27% increase in opioid-related hospital admissions.5 A retrospective analysis of IDU associated infective endocarditis in Ontario similarly reported a rise in the average number of hospital admissions, from 13.4 per quarter in 2006 to 35.1 per quarter in 2015.6
A review of CMPA cases closed between 2002 and 2014 revealed 14 medical-legal matters related to diagnostically challenging, IDU-associated conditions: 11 involving spinal epidural abscess or infective discitis, and three involving infective endocarditis (Figure 1). All of the matters were civil legal cases except for one College complaint (Figure 2). Of the 13 civil legal cases, 8 ended in a settlement and 5 were dismissed by the court (Figure 3). Of the 8 cases ending in a settlement, 5 involved shared liability of the physician(s) with hospitals or telehealth services.
Distribution of 14 closed civil legal and College cases (2002–2014) related to diagnostically challenging, IDU associated conditions by infection type
Distribution of 14 closed civil legal and College cases (2002–2014) related to diagnostically challenging, IDU associated conditions by case type
Distribution of 13 closed civil legal cases (2002–2014) related to diagnostically challenging, IDU associated conditions by case outcome
Diagnostic difficulties resulting from lost situational awareness, complex patient social circumstances, and communication breakdowns were prominent in these cases, and have a particular relevance when treating patients who use intravenous drugs. For example, all of the primary care practitioners worked in walk-in clinics, contributing to continuity of care issues.7 The complexities of communication within emergency care teams presented additional challenges, and communication issues in this setting led to diminished team situational awareness. In three spinal abscess cases, this resulted in a failure to recognize neurological deterioration over time. Failure to appreciate the significance of repeat presentations to the emergency department was also prominent, as were cognitive biases.8 Attribution bias (i.e. assumptions about addiction influencing perceptions of patient behaviour) in particular appeared common, and could be observed in some of the language used to describe patients.
Risk management strategies
When managing patients with a history of substance abuse disorder be aware of how cognitive biases can narrow diagnostic inquiry, and be on the lookout for indicators of increasingly prevalent rare infections in patients with a history of IDU. Some additional risk management strategies of relevance to the diagnostic challenges observed during this review include:
- Consider the use of structured tools at handover to communicate management plans, including monitoring and risk of deterioration, to facilitate team situational awareness.
- Be aware of repeat presentations to the emergency department9 and the presence of worsening symptoms that can provide an indicator of a condition that has been overlooked. Biases toward this patient population can also influence diagnostic reasoning. Recognizing these can motivate the caregivers to reconsider the differential diagnosis.
- Consider seeking a collateral history from family members or other care providers when crucial information remains unavailable.
The bottom line
The opioid crisis has been associated with an increasing prevalence of serious infections related to intravenous drug use. These conditions can be diagnostically challenging, and many of the affected patients are vulnerable to stigma and bias. Factors contributing to diagnostic error in these cases include breakdowns in team communication, loss of situational awareness, and inadequate physical examination.
- Health Canada [Internet]. Ottawa(CA): Health Canada; 2017. New Federal Initiatives to Address the Opioid Crisis [cited 2020 Jan]
- Canadian Institute for Health Information [Internet]. Ottawa(CA): CIHI; 2018. Pan-Canadian Trends in the Prescribing of Opioids and Benzodiazepines, 2012-2017 [cited 2020 Jan]
- Special Advisory Committee on the Epidemic of Opioid Overdoses [Internet]. National report: Opioid-related Harms in Canada Web-based Report. Ottawa(CA): Public Health Agency of Canada; December 2019 (cited 2020 Jan)
- This case history is a composite based on actual medical negligence claims. However, certain facts have been omitted or changed to ensure the anonymity of the parties involved
- Canadian Institute for Health Information [Internet]. Ottawa(CA): CIHI; 2018. Opioid-Related Harms in Canada, December 2018 [cited 2020 Jan]
- Weir MA, Slater J, Jandoc R, et al. The risk of infective endocarditis among people who inject drugs: a retrospective, population-based time series analysis. CMAJ [Internet]. 2019 [cited 2020 Jan];191(4):E93-E9
- Canadian Medical Protective Association [Internet]. Ottawa(CA): CMPA; 2019 Sept. Walk-in clinics: Unique challenges to quality of care, medical-legal risk [cited 2020 Jan]
- Edlin BR, Kresina TF, Raymond DB, et al. Overcoming barriers to prevention, care, and treatment of hepatitis C in illicit drug users. Clin Infect Dis [Internet]. 2005 [cited 2020 Jan];40(5): Suppl:S276-S285
- Canadian Medical Protective Association [Internet]. Ottawa(CA): CMPA; Sept 2013 (revised 2018 Sept). Stop and think: Return visits offer another chance [cited 2020 Jan]