2002 OPEN FORUM Abstracts
HIGH FREQUENCY PERCUSSIVE VENTILATION: A VENTILATORY APPROACH TO IMPROVE OXYGENATION AND REDUCE INTRACEREBRAL PRESSURE
Ali Salim, MD; Kenneth Miller,
RRT, MEd; William Dougherty, MD; Steven Pyne, RRT,BS; Larry Mann, RRT; Robert
Leshko, RRT; Joseph Groller, RRT; Susan Adam RRT.
Lehigh Valley Hospital, Allentown, PA 18105
Introduction: Approximately 20% of patients with significant intracerebral injury develop acute lung injury (ALI). Conventional lung-protective ventilatory strategies such as permissive hyper-capnia, prone positioning, and elevated mean airway pressure utilization often contribute to further intracerebral pressure elevation by reducing cerebral perfusion pressure. This can increase the likelihood of a negative outcome in this patient population.
Hypothesis: High Frequency Percussive Ventilation (HFPV) can improve outcomes in patients with intracerebral injury who develop ALI by stabilizing or reducing intracranial pressures (ICP) and by improving oxygenation.
Patients and Methods: This is a retrospective case series over a 1 year period of patients with significant head injury who developed ALI. Significant head injury was defined as a Glasgow Coma Score (GCS) <8. All patients were managed via the guidelines dictated by the Brain Trauma Foundation. The presence of ALI was defined by the American-European Consensus on ALI. HFPV was instituted as a ventilatory strategy in patients who failed conventional lung-protective ventilatory management. Failure was defined as a Pa02/FI02 ratio (P/F) <200 on positive end-expiratory pressure (PEEP) >13cm/h20 and intracranial pressure (ICP) >20mm/Hg. Only patients with ICP monitors were included in this study. Data regarding P/F ratio and ICP were compared before and after the institution of HFPV (VDR-4, Percussionaire, Sandpoint, ID) as a ventilatory strategy.
Results: HFPV was utilized for ICP and ALI management for a total of 6 patients over the 1 year period of this study. Data is expressed as + SEM.
|Pre HFPV||4hrs Post HFPV||16 hrs Post HFPV|
|P/F ratio||86.8 + 7.0||198.0 + 21.7*||320.8 + 37.3**|
|ICP(mm/hg)||31.5 + 5.4||18.7 + 3.1*||15.7 + 2.4#|
*p<0.01 vs. HPFV, **p<0.01 4hrs, #p<0.05 vs. 16hrs
Conclusion: Ventilatory management with HPFV produced a significant improvement in oxygenation with an associated reduction in ICP. Therefore HFPV may represent an important new ventilatory modality in the management of ALI in head injured patients.