Critical care staffing ratio and outcome of COVID-19 patients requiring intensive care unit admission during the first pandemic wave: a retrospective analysis across Switzerland from the RISC-19-ICU observational cohort (preprint)

Background: The modifications to the standard intensive care unit (ICU) organization that had to be urgently implemented worldwide to overcome the surge of ICU admissions due to patients with a severe coronavirus disease 2019 (COVID-19) have resulted in increased workload and patients-to-nurse ratio. The aim of this study was to investigate whether level of critical care staffing could be associated with an increased risk of ICU mortality (primary endpoint), length of stay, mechanical ventilation and the evolution of disease (secondary study endpoints) in critically ill patients with COVID-19. Methods Retrospective multicenter analysis of the international Risk Stratification in COVID-19 patients in the Intensive Care Unit (RISC-19-ICU) registry that prospectively enrolls patients developing critical illness due to COVID-19 in several countries worldwide. The analysis was limited to the period between March 1st, 2020 and May 31st, 2020, to ICUs in Switzerland that have collected additional data on nurse and physician staffing. Hierarchical regression models were used to investigate crude and adjusted effects of critical care staffing ratio on study endpoints. We adjusted for diseases severity and weekly caseload. Results Among the 38 Swiss participating ICUs, 17 recorded critical care staffing information. The study population included 437 patients and 2342 daily assessments of patient-to-nurse/physician ratio. Median of daily patient-to-nurse ratio started at 1.0 ([IQR] 0.5–1.5; calendar week 9) and peaked at 2.4 (IQR 0.4-2.0; calendar week 16), while the median of daily patient-to-physician ratio started at 4.0 (IQR 2.1-5.0; calendar week 9) and peaked at 6.8 (IQR 6.3–7.3; calendar week 19). Neither the patient-to-nurse ratio [adjusted Odds Ratio (OR) 1.28, 95% confidence interval (CI) 0.85–1.94; doubling of ratio] nor the patient-to-physician ratio [adjusted OR 1.08, 95% CI 0.87–1.32; doubling of ratio] was associated with ICU mortality. We found no association of critical care staffing on the investigated secondary study endpoints in adjusted models. COnclusion The Swiss health care system successfully overcame the first wave of the COVID-19 pandemic with regards to the unprecedented demand for ICU treatments. The reduced availability of critical care staffing resources per critically ill patient in Swiss ICUs did not translate in an overall increased risk of mortality.

Importance of critical care staffing and standard intensive care therapy in the COVID-19 era: a descriptive study of the first epidemic wave at a Swiss tertiary intensive care unit.

AIM: Mortality rates of COVID-19 patients hospitalised in intensive care units (ICUs) are generally high. Availability of ICU resources might influence clinical outcomes. The aim of this study was to examine the clinical course of the 42 patients treated during the first epidemic wave between 2 March and 20 May 2020 at the tertiary ICU of the Bern University Hospital, where staffing, equipment and drugs were not limited. METHODS: For this descriptive study, retrospective data of the first COVID-19 wave in an interdisciplinary adult ICU of a Swiss University hospital was used. The study included data regarding healthcare staffing and COVID-19 patients. The primary outcome was the ICU mortality in COVID-19 patients. RESULTS: Patients’ median age was 61 years (range 32–86), simplified acute physiology score (SAPS-II) was 46 (13–90), 81% of the patients were males, 79% were mechanically ventilated (3 of them on extracorporeal membrane oxygenation), 31% were under renal replacement therapy and 21% received steroids. All patients were fully anticoagulated from the time of admission. No off-label experimental antiviral or anti-inflammatory drugs were used with the exception of one patient, and antibiotic prescription was restrictive. Nurse-to-patient ratio was 1:1 during all shifts, and the physician-to-patient ratio was 1:4 (day shift) and 1:10 (night shift). Infectious disease specialists and physiotherapists were present every day. The median ICU length of stay was 10 days (1–38) days, and ICU and hospital mortality rates were 7% and 12%, respectively. CONCLUSION: Careful intensive care treatment, without off-label drug use but including steroids in selected cases, combined with an interdisciplinary approach and provision of sufficient human resources, were associated with low ICU and hospital mortality rates despite high disease severity. Availability of qualified human resources may have an important impact on the outcome of COVID-19.