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.

Logistical and Medical Aspects of SARS-CoV-2 Pandemic Influencing Swiss Pediatric Intensive Care Units (preprint)

The impact of the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) pandemic on pediatric intensive care units (PICUs) is difficult to quantify. We conducted a retrospective cohort study in all eight Swiss PICUs between 02-24-2020 and 06-15-2020 to characterize the logistical and medical aspects of the pandemic and their impact on Swiss PICUs. Out of the 1113 patients under the age of 20, who were tested positive for SARS-CoV-2 in Switzerland during the study period, 6% (63/1113) had to be hospitalized. All nine patients requiring intensive care had pediatric inflammatory multisystem syndrome temporally associated with SARS-CoV-2 (PIMS-TS) and constituted 14% (9/63) of all hospitalized patients. The patients presented with multiple organ dysfunction, needed longer stays in PICUs (p < 0.0001) and longer positive pressure ventilation (p = 0.025) than the regular PICU patients. They caused a higher workload (total Nine Equivalents of nursing Manpower use Score (NEMS) points, p = 0.0008) and were classified to higher workload categories (p < 0.0001) than regular PICU patients (n = 4881) in 2019. PICU burden was also influenced by different logistical factors such as cancellation of planned surgeries and staff recruitment to adult wards.Conclusions The different logistical and medical factors associated with the pandemic influenced the workload of the individual PICUs differently, depending on the presence of the single factors and their temporal relationship. The experiences of the study period help further to organize Swiss PICUs during the current pandemic to reduce the workload and optimize occupancy. 

Bacterial pulmonary superinfections are associated with unfavourable outcomes in critically ill COVID-19 patients (preprint)

Objectives While superinfections are associated with unfavourable disease course, their impact on clinical outcomes in critically ill COVID-19 patients remains largely unknown. We aimed to investigate the burden of superinfections in COVID-19 patients. Methods In this prospective single centre cohort study in an intensive care setting patients aged [≥] 18 years with COVID-19 acute respiratory distress syndrome were assessed for concomitant microbial infections by longitudinal analysis of tracheobronchial secretions, bronchoalveolar lavages and blood. Our primary outcome was ventilator-free survival on day 28 in patients with and without clinically relevant superinfection. Further outcomes included the association of superinfection with ICU length of stay, incidence of bacteremia, viral reactivations, and fungal colonization. Results In 45 critically ill COVID-19 patients, we identified 19 patients with superinfections (42.2%) by longitudinal analysis of 433 TBS, 35 BAL and 455 blood samples, respectively. On average, superinfections were detected on day 10 after ICU admission. The most frequently isolated clinically relevant bacteria were Enterobacteriaceae, Streptococcus pneumoniae, and Pseudomonas aeruginosa. Ventilator-free survival was substantially lower in patients with superinfection (subhazard ratio 0.37, 95%-CI 0.15-0.90, p=0.028). Patients with pulmonary superinfections more often had bacteraemia, virus reactivations, yeast colonization, and needed ICU treatment for a significantly longer time. Conclusions The detection of superinfections was frequent and associated with reduced ventilator-free survival. Despite empirical antibiotic therapy, superinfections lead to an extended ICU stay in COVID 19 patients. Longitudinal microbiological sampling in COVID-19 patients could allow targeted antimicrobial therapy, and therefore minimize the use of broad-spectrum and reserve antibiotics.