Changes in Therapeutic Intensity Level Following Airway Pressure Release Ventilation in Severe Traumatic Brain Injury.

ABSTRACT

PURPOSE: Airway pressure release ventilation (APRV) utilizes high levels of airway pressure coupled with brief expiratory release to facilitate open lung ventilation. The aim of our study was to evaluate the effects of APRV-induced elevated airway pressure mean in patients with severe traumatic brain injury. MATERIALS AND METHODS: This was a retrospective cohort study at a 424-bed Level I trauma center. Linear mixed effects models were developed to assess the difference in therapeutic intensity level (TIL), intracranial pressure (ICP), and cerebral perfusion pressure (CPP) over time following the application of APRV. RESULTS: The study included 21 epochs of APRV in 21 patients. In the 6-hour epoch following the application of APRV, the TIL was significantly increased ( P = .002) and the ICP significantly decreased ( P = .041) compared to that before 6 hours. There was no significant change in CPP ( P = .42) over time. The baseline static compliance and time interaction was not significant for TIL (χ2 = 0.2 [ df 1], P = .655), CPP (χ2 = 0 [ df 1], P = 1), or ICP (χ2 = 0.1 [ df 1], P = .752). CONCLUSIONS: Application of APRV in patients with severe traumatic brain injury was associated with significantly, but not clinically meaningful, increased TIL and decreased ICP. No significant change in CPP was observed. No difference was observed based on the baseline pulmonary static compliance.