Patient characteristics, clinical course and factors associated to ICU mortality in critically ill patients infected with SARS-CoV-2 in Spain: A prospective, cohort, multicentre study

Abstract

Background: The clinical course of COVID-19 critically ill patients, during their admission in the intensive care unit (UCI), including medical and infectious complications and support therapies, as well as their association with in-ICU mortality has not been fully reported.

Objective: This study aimed to describe clinical characteristics and clinical course of ICU COVID-19 patients, and to determine risk factors for ICU mortality of COVID-19 patients.

Methods: Prospective, multicentre, cohort study that enrolled critically ill COVID-19 patients admitted into 30 ICUs from Spain and Andorra. Consecutive patients from March 12^th to May 26^th, 2020 were enrolled if they had died or were discharged from ICU during the study period. Demographics, symptoms, vital signs, laboratory markers, supportive therapies, pharmacological treatments, medical and infectious complications were reported and compared between deceased and discharged patients.

Results: A total of 663 patients were included. Overall ICU mortality was 31% (203 patients). At ICU admission non-survivors were more hypoxemic [SpO₂ with non-rebreather mask, 90 (IQR 83 to 93) vs. 91 (IQR 87 to 94); P<.001] and with higher sequential organ failure assessment score [SOFA, 7 (IQR 5 to 9) vs. 4 (IQR 3 to 7); P<.001]. Complications were more frequent in non-survivors: acute respiratory distress syndrome (ARDS) (95% vs. 89%; P=.009), acute kidney injury (AKI) (58% vs. 24%; P<10^-16), shock (42% vs. 14%; P<10^-13), and arrhythmias (24% vs. 11%; P<10^-4). Respiratory super-infection, bloodstream infection and septic shock were higher in non-survivors (33% vs. 25%; P=.03, 33% vs. 23%; P=.01 and 15% vs. 3%, P=10^-7), respectively. The multivariable regression model showed that age was associated with mortality, with every year increasing risk-of-death by 1% (95%CI: 1 to 10, P=.014). Each 5-point increase in APACHE II independently predicted mortality [OR: 1.508 (1.081, 2.104), P=.015]. Patients with AKI [OR: 2.468 (1.628, 3.741), P<10^-4)], cardiac arrest [OR: 11.099 (3.389, 36.353), P=.0001], and septic shock [OR: 3.224 (1.486, 6.994), P=.002] had an increased risk-of-death.

Conclusions: Older COVID-19 patients with higher APACHE II scores on admission, those who developed AKI grades ii or iii and/or septic shock during ICU stay had an increased risk-of-death. ICU mortality was 31%.

Figure 1

Chronology of treatments and complications during ICU stay for discharged (upper graph) and deceased (lower graph) patients. The upper part of the graph represents discharged patients. The lower part of the graph represents deceased patients. Day 0 is the day of ICU admission. The vertical lines represent day of symptoms onset, day of hospital admission, day of ICU admission (day 0), and day of discharged (upper graph) or death (lower graph). Each horizontal bar plots the median day of start and median day of end of each treatment among patients with the treatment. Complications are represented at the median day of onset among patients with the complication. Infectious complications: 1 Septic shock; 2 Pneumonia; 3 Bacteraemia; 4 Urinary infection; 5 Respiratory co-infection; 6 Other infectious complication. Medical complications: 1 ARDS; 2 Acute renal failure; 3 Arrhythmias; 4 Shock; 5 Bleeding; 6 Nonspecific neurological complications; 7 Thromboembolism; 8 Heart failure; 9 Cardiac arrest; 10 Ischemic Stroke; 11 Elevated liver enzymes; 12 Hyperglycaemia.