Early release, published at www.cmaj.ca on May 27, 2020. Subject to revision. RESEARCH Baseline characteristics and outcomes of patients with COVID-19 admitted to intensive care units in Vancouver, Canada: a case series Anish R. Mitra MD MPH, Nicholas A. Fergusson MSc, Elisa Lloyd-Smith PhD, Andrew Wormsbecker MD, Denise Foster RN, Andrei Karpov MD MHSc, Sarah Crowe NP, Greg Haljan MD, Dean R. Chittock MD MS(Epi), Hussein D. Kanji MD MPH, Mypinder S. Sekhon MD, Donald E.G. Griesdale MD MPH n Cite as: CMAJ 2020. doi: 10.1503/cmaj.200794; early-released May 27, 2020 ABSTRACT BACKGROUND: Pandemic severe agement and outcome data were col- the ICU. Tocilizumab was administered acute respiratory syndrome coronavi- lected by review of patient charts and to 4 patients and hydroxychloroquine rus 2 (SARS-CoV-2) is associated with electronic medical records. to 1 patient. As of May 5, 2020, a total high intensive care unit (ICU) mortal- of 18 (15.4%) patients had died, 12 ity. We aimed to describe the clinical RESULTS: Between Feb. 21 and Apr. 14, (10.3%) remained in the ICU, 16 characteristics and outcomes of crit- 2020, 117 patients were admitted to (13.7%) were discharged from the ICU ically ill patients with coronavirus the ICU with a confirmed diagnosis of but remained in hospital, and 71 disease 2019 (COVID-19) in a Canad- COVID-19. The median age was 69 (60.7%) were discharged home. ian setting. (interquartile range [IQR] 60–75) years, and 38 (32.5%) were female. At least INTERPRETATION: In our setting, mor- METHODS: We conducted a retrospec- 1 comorbidity was present in 86 tality in critically ill patients with tive case series of critically ill patients (73.5%) patients. Invasive mechanical COVID-19 admitted to the ICU was with laboratory-confirmed SARS-CoV-2 ventilation was required in 74 (63.2%) lower than in previously published infection consecutively admitted to 1 patients. The duration of mechanical studies. These data suggest that the of 6 ICUs in Metro Vancouver, British ventilation was 13.5 (IQR 8–22) days prognosis associated with critical ill- Columbia, Canada, between Feb. 21 overall and 11 (IQR 6–16) days for ness due to COVID-19 may not be as and Apr. 14, 2020. Demographic, man- patients successfully discharged from poor as previously reported. evere acute respiratory syndrome coronavirus 2 (SARS- Canadian data describing critically ill patients with COVID-19 are CoV-2) causes coronavirus disease 2019 (COVID-19), now lacking, and better characterization is crucial to direct critical care characterized as a pandemic by the World Health Organiza- resource allocation and to understand the disease in our local con- Stion.1 Infection rates and deaths worldwide increased exponen- text. The aim of our multicentre case series was to describe the tially. About 35 000 confirmed cases and more than 1600 deaths demographic characteristics, management patterns and outcomes were reported in Canada as of Apr. 21, 2020.2 In British Columbia, as among critically ill patients with COVID-19 in Metro Vancouver. of May 20, 2020, there were 2467 confirmed cases and 149 deaths.3 However, the number of new cases has been decreasing since the Methods beginning of April 2020. More than 85% of the cases of COVID-19 in BC have been located in the Metro Vancouver area.3 We conducted a case series of all patients with COVID-19 admitted Initial studies from China4 and Italy5 showed mortality ranging to an ICU in the Metro Vancouver area from Feb. 21 to Apr. 14, from 26% to 62% in critically ill patients with COVID-19. Studies 2020, with outcomes followed until May 5, 2020. This area serves from Seattle6 and New York7 reported overall mortality ranging about 3 million residents of BC (population 4.9 million). The hospi- from 23% to 50%. In these case series, between 13% and 71% of tals included were Vancouver General Hospital (46 ICU beds, qua- patients remained in the intensive care units (ICUs) at the time of ternary hospital), Surrey Memorial Hospital (46 ICU beds, tertiary publication, so actual mortality may be greater than reported. hospital), Lions Gate Hospital (11 ICU beds, community hospital), © 2020 Joule Inc. or its licensors CMAJ 1 St. Paul’s Hospital (15 ICU beds, tertiary hospital), Royal Colum- Ethics approval bian Hospital (30 ICU beds, tertiary hospital) and Richmond Hospi- The University of British Columbia Clinical Research Ethics Board tal (8 ICU beds, community hospital). All included ICUs are staffed and Fraser Health Research Ethics Board approved this study. by fellowship-trained intensive care physicians, operate on a Owing to the retrospective and minimal-risk nature of the study, nurse-to-patient ratio of about 1:1.2, and are affiliated with the the need for informed consent was waived. University of British Columbia. They are all mixed units caring for both medical and surgical patients. In preparation for the pan- Results RESEARCH demic, these hospitals were designated as COVID-19 centres, and, as such, critically ill patients with COVID-19 in their catchment Between Feb. 21 and Apr. 14, 2020, we identified 117 critically ill areas were transferred to these sites. Admission into the ICUs patients with laboratory-confirmed SARS-CoV-2 infection admit- occurred at the discretion of the attending critical care physician, ted to an ICU in the region. There were no exclusions. The daily but general criteria included all patients with suspected or con- prevalence for patients admitted to hospital with COVID-19, strat- firmed SARS-CoV-2 infection who were requiring rapidly increasing ified by admission to ICU, is presented in Figure 1. On a daily oxygen supplementation, oxygen via high-flow nasal cannula, basis, a median of 40% (IQR 38%–45%) of hospital-admitted noninvasive positive pressure ventilation, mechanical ventilation patients were admitted to the ICU. or vasopressors. All consecutive patients with laboratory- Eighty-eight (75.2%) patients were admitted from home, 25 confirmed SARS-CoV-2 infection who were admitted to one of the (21.4%) patients were admitted from another hospital, and 4 participating ICUs during the study period were enrolled. (3.4%) were admitted from long-term care facilities. Baseline Laboratory confirmation for SARS-CoV-2 was defined as a posi- demographic and clinical characteristics are shown in Table 1 and tive result on real-time reverse transcription polymerase chain reac- are comparable to those in previous reports (Appendix 1, avail- tion assay of nasal, pharyngeal or lower respiratory tract samples. able at www.cmaj.ca/lookup/suppl/doi:10.1503/cmaj.200794/-/ DC1). The median age of the patients was 69 (IQR 60–75) years, Data collection with a range of 23 to 92 years. Overall, 38 (32.5%) patients were Data were obtained from patient charts and the electronic medical female, and the mean duration of symptoms before ICU admis- record from each institution using a combination of professional sion was 8 (SD 4.5) days. A total of 86 (73.5%) patients had at least clinical reviewers, 2 attending intensivists (A.R.M. and A.W.) and a 1 medical comorbidity. The most common comorbidities were clinical research assistant (N.A.F.). Demographic data, patient hist- hypertension (54 patients, 46.2%), dyslipidemia (43 patients, ories and examinations, laboratory data and clinical outcomes were 36.8%) and diabetes mellitus (36 patients, 30.8%). collected throughout each patient’s hospital admission. Severity of Laboratory results at ICU admission and for the first 3 days in the illness was characterized by the APACHE II (Acute Physiology and ICU are presented in Table 2. A baseline leukocyte count above Chronic Health Evaluation II) score using data from the first 24 hours 10.0 ×109/L was present in 35 (29.9%) patients, and 9 (7.7%) had of ICU admission.8 Additionally, Sequential Organ Failure Assess- counts below 4 ×109/L. Lymphocytopenia was common, with 79 ment (SOFA)9 on the initial day of ICU admission was used to further (67.5%) patients having a lymphocyte count less than 1.0 ×109/L. A describe illness acuity. Depending on the variable, laboratory results total of 37 (31.6%) patients had baseline serum creatinine values of were either presented at baseline value or at their peak value within 106 µmol/L or greater. Baseline serum lactate was 2.0 U/L or greater the first 3 days of ICU stay. Mechanical ventilation parameters were in 21 (17.9%) patients. A total of 67 (57.2%) had a peak d-dimer result recorded about 24 hours after the initiation of mechanical ventila- greater than 500 µg/L during the first 3 days in the ICU with an overall tion to ensure these parameters stabilized after intubation. Ther- median of 1560 (IQR 740–4000) µg/L. Overall, a total of 32 patients apies received during the ICU stay were recorded, including sup- (27.4%) had either a peak troponin I level greater than 26 ng/L or a portive measures and pharmacologic agents. All investigations and peak troponin T level greater than 0.02 ng/L during the first 3 days in therapies were performed at the discretion of the treating phys- the ICU. icians. Daily hospital admission and ICU prevalence data were The frequency of ICU interventions and therapies is shown in obtained from the Vancouver Coastal Health and Fraser Health Table 3. The most frequent interventions were mechanical ventila- authorities. Available ICU capacity data were obtained as part of the tion (74 patients, 63.2%), vasopressors (65 patients, 55.6%), neuro- COVID-19 phase 1 critical care requirements planning. muscular blockade (50 patients, 42.7%) and high-flow nasal cannula (43 patients, 36.8%).