Fever in the ICU: A Predictor of Mortality in Mechanically Ventilated COVID-19 Patients

Abstract

Purpose: While fever may be a presenting symptom of COVID-19, fever at hospital admission has not been identified as a predictor of mortality. However, hyperthermia during critical illness among ventilated COVID-19 patients in the ICU has not yet been studied. We sought to determine mortality predictors among ventilated COVID-19 ICU patients and we hypothesized that fever in the ICU is predictive of mortality. Materials and Methods: We conducted a retrospective cohort study of 103 ventilated COVID-19 patients admitted to the ICU between March 14 and May 27, 2020. Final follow-up was June 5, 2020. Patients discharged from the ICU or who died were included. Patients still admitted to the ICU at final follow-up were excluded. Results: 103 patients were included, 40 survived and 63(61.1%) died. Deceased patients were older {66 years[IQR18] vs 62.5[IQR10], ( p = 0.0237)}, more often male {48(68%) vs 22(55%), ( p = 0.0247)}, had lower initial oxygen saturation {86.0%[IQR18] vs 91.5%[IQR11.5], ( p = 0.0060)}, and had lower pH nadir than survivors {7.10[IQR0.2] vs 7.30[IQR0.2] ( p < 0.0001)}. Patients had higher peak temperatures during ICU stay as compared to hospital presentation {103.3°F[IQR1.7] vs 100.0°F[IQR3.5], ( p < 0.0001)}. Deceased patients had higher peak ICU temperatures than survivors {103.6°F[IQR2.0] vs 102.9°F[IQR1.4], ( p = 0.0008)}. Increasing peak temperatures were linearly associated with mortality. Febrile patients who underwent targeted temperature management to achieve normothermia did not have different outcomes than those not actively cooled. Multivariable analysis revealed 60% and 75% higher risk of mortality with peak temperature greater than 103°F and 104°F respectively; it also confirmed hyperthermia, age, male sex, and acidosis to be predictors of mortality. Conclusions: This is one of the first studies to identify ICU hyperthermia as predictive of mortality in ventilated COVID-19 patients. Additional predictors included male sex, age, and acidosis. With COVID-19 cases increasing, identification of ICU mortality predictors is crucial to improve risk stratification, resource management, and patient outcomes.

Lower Blood pH as a High Predisposing Factor for a Fatal Outcome in Critically Ill COVID-19 Patients at Intensive Care Unit: a Multivariable Analysis

“…Some results were in line with published data, and some results were unexpected. For example, in contrast to data published by Choron et al, fever was no predictor of higher mortality in our study (9). A possible reason for this seeming discrepancy may be different de nitions of fever.…”

“…Lactate, chloride, and paCO 2 , however, did not signi cantly differ in a relevant matter between the two groups. Choron et al found acidosis to be a predictor of mortality in mechanically ventilated COVID-19 patients (9).…”

“…However, no consistent overall picture has yet been drawn. Choron et al found the course of fever to be an important predictor (9). Pan et al included lymphocyte percentage, prothrombin time, lactate dehydrogenase, total bilirubin, eosinophil percentage, creatinine, neutrophil percentage, and the albumin level in their model (10).…”

Gut Microbiota Dysbiosis Correlates with Abnormal Immune Response in Moderate COVID-19 Patients with Fever

“…Previous studies have shown that fever is a predictor of poor prognosis in COVID-19 patients. 6,7,41 In our study, the patients included are all moderate patients, and there was no significant difference in the survival rate and hospital length of stay of patients with fever and without fever, which may be due to the limitation of sample size and the composition of different regions and populations. However, we subsequently followed up 55 of the above 187 patients at three months after discharge, and found that COVID-19 patients with fever in the acute phase had a higher proportion of persistent symptoms at three months after discharge, especially myalgia, which was significant difference in the two groups (54.5% vs 9.1%, p=0.018) (unpublished data).…”

Respiratory physiology of COVID-19 and Influenza associated Acute Respiratory Distress Syndrome

“…Almost all COVID-19 patients had high fevers, some as high as 40°C, which might have contributed to CO 2 accumulation. A recent retrospective analysis has connected fever of COVID-19 patients on admission to worse outcome 22 . Aggressive medical treatment of hyperthermia could limit respiratory drive and improve CO 2 clearance in both awake and intubated patients.…”