Ventilatory Management in Neurocritical Versus Non-Neurocritical Care Patients: A Pooled Analysis From the PRIME Database

OBJECTIVES: To describe ventilatory management in neurocritical care and non-neurocritical care patients and determine whether specific ventilator settings are associated with development of acute respiratory distress syndrome (ARDS) and mortality in neurocritical care patients. The primary endpoint was a diagnosis of ARDS after initiation of invasive ventilation; one secondary endpoint was ICU mortality. DATA SOURCES: Post hoc pooled analysis of harmonized individual patient data from three recent prospective observational studies combined into the PRIME database. STUDY SELECTION: PRIME is a harmonized pooled database comprising individual patient data from three recent prospective observational studies on ventilatory management in critically ill patients: "PRactice of VENTilation in critically ill patients without ARDS" (PRoVENT), "PRactice of VENTilation in critically ill patients in Middle-income Countries" (PRoVENT-iMiC), and "Extubation strategies in Neuro-ICU patients and associations with Outcomes" (ENIO). We excluded patients with ARDS at the start of ventilation. DATA EXTRACTION: Demographic and clinical characteristics, ventilator settings, respiratory variables, arterial blood gas values, and clinical outcomes were extracted from the harmonized PRIME database. Derived ventilation parameters included tidal volume normalized to predicted body weight, driving pressure, respiratory system compliance, mechanical power, ventilatory ratio, and Pao2/Fio2 ratio. DATA SYNTHESIS: This analysis included 3848 patients, including 1702 neurocritical care and 1920 non-neurocritical care patients. Based on recorded ventilatory variables, neurocritical care patients received lower median tidal volumes (Vts), positive end-expiratory pressure, and Fio2. They had lower median driving pressure (ΔP), mechanical power (MP) of ventilation, and ventilatory ratio, as well as higher respiratory system compliance compared with non-neurocritical care patients. These differences were consistently observed at both assessed time points. ARDS was diagnosed more frequently in neurocritical care patients than in non-neurocritical care patients (8.7% vs. 3.9%; p < 0.001), while ICU mortality was lower (14.3% vs. 22.8%; p < 0.001). Among neurocritical care patients, those who developed ARDS were ventilated with lower median Vt and higher Fio2 and had higher median ΔP and MP. Vt normalized for predicted body weight in neurocritical care patients was independently associated with the development of ARDS. CONCLUSIONS: In this cohort, ventilatory management at the initial and 48-hour assessments differed between neurocritical care and non-neurocritical care patients, particularly with respect to key ventilator settings like Vt, positive end-expiratory pressure, and Fio2. In neurocritical care patients, ARDS was more often diagnosed than in non-neurocritical care patients.