Abstract / Summary
Coronavirus disease 2019 (COVID-19) is a highly contagious and potentially fatal infection. The World Health Organization recommends the use of non-invasive mechanical ventilation (NIMV) in cases of respiratory failure, together with appropriate personal protective equipment. NIMV can affect intra-abdominal pressure (IAP), although the prognostic significance of this in critical COVID-19 patients is unclear. This study examines the relationships between ventilator parameters during NIMV and IAP, and between these variables and intensive care mortality. The research was conducted in a COVID-19 intensive care unit. Following receipt of permission from the Turkish Ministry of Health, the study was approved by the Marmara University Medical Faculty clinical research ethical committee (no.09.2021.570). Fifty-two critical COVID-19 patients were enrolled in this prospective, observational, single-center study. IAP measurements were performed prior to NIMV, at 2 and 4 h during NIMV, and 2 h after the discontinuation of NIMV. Respiratory mechanics, gas exchange, renal functions, and clinical scores were evaluated concomitantly. Survival analyses were conducted using Kaplan–Meier and multivariate Cox regression models. The mean age of the patients was 66.40 ± 13.27 years, 33 (63.5%) were male, and the mean body mass index (BMI) was 30.87 ± 8.44 kg/m². Forty patients (76.9%) died during their ICU stay. IAP increased significantly at 2 and 4 h compared with baseline and decreased significantly at 6 h compared with the 2- and 4-hour measurements ( p < 0.001). The highest IAP value was observed at 4 h, with an area under the receiver operating characteristic (ROC) curve of 0.681 (95% CI: 0.532–0.830; p = 0.009) for discriminating mortality. However, given that the sensitivity of the identified cutoff value was only 50%, IAP was considered not to have sufficient discriminatory performance to support its use as an individual prognostic tool. Patients with both hypoxemia and hypercapnia had a shorter median survival time than those with hypoxemia alone (8 vs. 14 days; p = 0.014). In the multivariable Cox regression analysis, BMI was independently associated with ICU mortality (HR 1.06; 95% CI: 1.01–1.12; p = 0.017). In contrast, IAP, age, and peak inspiratory pressure were not independently associated with mortality. In critically ill patients with COVID-19 receiving NIMV, IAP was shown to increase during the early phase of NIMV and decrease after NIMV discontinuation. This finding suggests that IAP undergoes time-dependent and dynamic changes during NIMV. The ability of IAP at the 4th hour to discriminate mortality was limited and, given its low sensitivity and the exploratory nature of the mortality analyses, does not support its use as an individual prognostic tool. The coexistence of hypoxemia and hypercapnia was associated with shorter survival compared with hypoxemia alone. Although BMI was independently associated with ICU mortality, IAP and peak inspiratory pressure were not shown to be independent predictors of mortality. These findings should be interpreted in the context of the small sample size, single-center design, and exploratory nature of the mortality analyses. Larger, prospective, multicenter studies are needed. Not applicable.