PEEP-AKI-COVID ICU: Effect of Positive End-Expiratory Pressure on Acute Kidney Injury Development in Patients with COVID-19-Associated Acute Respiratory Distress Syndrome: An Ancillary Analysis of the COVID-ICU Study

Background Acute Kidney Injury (AKI) is common in patients admitted to intensive care unit (ICU) for severe SARS-CoV-2 pneumonia and is associated with a worse prognosis. Mechanical ventilation has been identified as a risk factor for renal damage in COVID-19. However, few studies have examined the specific ventilatory settings involved. We hypothesized that positive end-expiratory pressure (PEEP) may contribute to the onset of AKI. Our objective was to assess the association between higher PEEP levels and the occurrence of AKI. Methods We conducted an ancillary analysis of the international, prospective, multicenter COVID-ICU study, which included 4244 COVID-19 ICU patients across 149 intensive care units. For our study, only patients who underwent mechanical ventilation for at least 48 hours and had normal renal function before intubation were included. AKI was defined according to Kidney Disease Improving Global Outcome (KDIGO) criteria. A multivariate logistic regression model was used to evaluate the association between PEEP levels and the development of AKI. Results A total of 1,066 patients were included in the analysis. Among them, 510 (48%) developed AKI within five days of intubation. Mortality at 28 days was higher in patients with AKI (28% vs. 18%, p < 0.001) compared to those without. After adjusting for confounding factors, higher PEEP levels during the first three days of mechanical ventilation were independently associated with AKI (odds ratio [OR] 1.09; 95% confidence interval [95% CI 1.04–1.15]). A PEEP level exceeding 15 cmH₂O was strongly linked to an increased risk of AKI (OR 2.77; 95% CI [1.31–6.24]). Additionally, vasopressor use and elevated lactate levels were associated with renal impairment. AKI was significantly related to 28-day mortality, whereas PEEP levels were not. Conclusion Within five days of intubation in COVID-19 ARDS patients, higher PEEP levels were independently associated with an increased risk of AKI. While AKI was linked to higher mortality, PEEP level was not.