Preliminary study: Low to moderate PEEP effects on ICP in acute neurological injury patients under mechanical ventilation.

Abstract

BackgroundAcute respiratory distress syndrome (ARDS) significantly impacts mortality and prognosis in acute neurological injury patients. Positive end-expiratory pressure (PEEP) is essential in mechanical ventilation to enhance oxygenation, yet its application may elevate intracranial pressure (ICP). Studies show conflicting findings regarding PEEP's effect on ICP, particularly at low to moderate levels (5-10cmH2O), warranting further investigation in acute neurological injury cases.ObjectiveTo assess the impact of low to moderate PEEP on ICP in patients with acute neurological injury who require mechanical ventilation.MethodsA retrospective analysis of 62 patients with acute neurological injury requiring mechanical ventilation at our hospital between January 2021 and September 2023 was conducted. Patients were divided into high PEEP (> 10cmH2O) and low to moderate PEEP (5-10cmH2O) groups. Parameters including PaO2, PaCO2, PaO2/FiO2, driving pressure, compliance (Cst), airway resistance, such as heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), central venous pressure (CVP), cardiac index (CI), ICP, and cerebral perfusion pressure (CPP) were recorded pre- and post-ventilation initiation, with correlation analysis performed between ICP and other parameters.ResultsPre-treatment comparisons between the high PEEP and low to moderate PEEP groups revealed no significant differences in PaO2, PaCO2, PaO2/FiO2, driving pressure, Cs, and airway resistance. However, post-treatment analysis showed significant disparities, with the high PEEP group exhibiting higher PaO2 and PaO2/FiO2 levels and lower PaCO2, driving pressure, and airway resistance levels compared to the low to moderate PEEP group. Additionally, hemodynamic parameters such as HR, SBP, DBP, CI, MAP, CVP, ICP, and CPP remained more stable in the low to moderate PEEP group post-treatment, with ICP demonstrating significant correlations with various physiological parameters.ConclusionHigh PEEP improves oxygenation and respiratory mechanics in acute neurological injury patients on mechanical ventilation but may affect hemodynamic parameters, ICP, and CPP. Conversely, low to moderate PEEP has minimal impact on these factors. Hence, personalized adjustment of PEEP levels is essential in clinical management.