Intracranial Pressure During Pressure Control and Pressure-Regulated Volume Control Ventilation in Patients with Traumatic Brain Injury: A Randomized Crossover trial.

Abstract

Mechanical ventilation with control of partial arterial CO2 pressures (PaCO2) is used to treat or stabilize intracranial pressure (ICP) in patients with traumatic brain injury (TBI). Pressure-regulated volume control (PRVC) is a ventilator mode where inspiratory pressures are automatically adjusted to deliver the patient a pre-set stable tidal volume (TV). This may result in a more stable PaCO2 and thus a more stable ICP compared with conventional pressure control (PC) ventilation. The aim of this study was to compare PC and PRVC ventilation in TBI patients with respect to ICP and PaCO2. This is a randomized crossover trial including eleven patients with a moderate or severe TBI who were mechanically ventilated and had ICP monitoring. Each patient was administered alternating 2-h periods of PC and PRVC ventilation. The outcome variables were ICP and PaCO2. Fifty-two (26 PC, 26 PRVC) study periods were included. Mean ICP was 10.8mmHg with PC and 10.3mmHg with PRVC ventilation (p=0.38). Mean PaCO2 was 36.5mmHg (4.87kPa) with PC and 36.1mmHg (4.81kPa) with PRVC (p=0.38). There were less fluctuations in ICP (p=0.02) and PaCO2 (p=0.05) with PRVC ventilation. Mean ICP and PaCO2 were similar for PC and PRVC ventilation in TBI patients, but PRVC ventilation resulted in less fluctuation in both ICP and PaCO2. We cannot exclude that the two ventilatory modes would have impact on ICP in patients with higher ICP values; however, the similar PaCO2 observations argue against this.