Effects of volumetric diffusive respiration with normal or inverse I:E ratio on intracranial pressure

Joseph L. Nates, Janice Cravens, Cindy Hudgens, Marie Francoise Doursout

Research output: Contribution to journalArticle

4 Scopus citations


Introduction: Volumetric diffusive respiration (VDR) with intrapulmonary percussive ventilation (IPV) has been shown to significantly facilitate CO 2 wash out1. This study was designed to investigate the effects of VDR/IPV on intracranial pressure (ICP) in the first four hours after transition from controlled mechanical ventilation (CMV) to VDR/IPV. Methods: After approval by The Committee for the Protection of Human Subjects of our institution, ICU neurosurgical patients with ICP monitor who developed acute respiratory failure requiring VDR/IPV were included in the study. Patients were divided in 2 groups. Group A: inverse I:E ratio, and group B: normal I:E ratio. Age, sex, diagnosis, fractional inspired oxygen concentration (FiO2), peak inspiratory pressure (PIP), mean airway pressure, positive end expiratory pressure, respiratory rate, blood gases, end-tidal CO2, PaO 2/FiO2 ratio (P/F ratio) and complications were recorded prior to and up to 4 hours after the ventilation mode transition. Data were analyzed using a paired t-test, p≤0.05 was considered significant. Results: Eighteen patients (10 males) were included in the study. All with intracranial pathology, APACHE II score 21±17 and age 39±11. Eleven patients developed ARD'S, 6 pneumonia and 1 pulmonary edema. ICP was not affected in group A (CMV 19±3/VDR 18±3). However, VDR/IPV reduced PaCO 2 (CMV 35±2/VDR 31±2mmHg) and increased PaO2 (CMV 84±8/VDR 130±12mmHg) significantly. In group B, a significant ICP (CMV 17±6/VDR 12±2 mmHg) and PaCO2 (CMV 30±3/VDR 27±7) reduction was achieved. Mean airway pressure was elevated significantly in group A (CMV 18±2/VDR 24±2cmH 2O) and group B (CMV 11±1/VDR 15±1 mmHg). No complications were associated with the ventilation mode. Fourteen patients died from their intracranial pathology while in ICU. Conclusion: VDR/IPV reduces ICP in patients with intracranial hypertension. When used with inverse I:E ratio, VDR/IPV does not increase ICP. In addition, VDR/IPV seems to be an effective method to reduce CO2 and improve oxygenation when needed in this population.

Original languageEnglish (US)
Pages (from-to)A73
JournalCritical care medicine
Issue number12 SUPPL.
StatePublished - Jan 1 1999

ASJC Scopus subject areas

  • Critical Care and Intensive Care Medicine

Fingerprint Dive into the research topics of 'Effects of volumetric diffusive respiration with normal or inverse I:E ratio on intracranial pressure'. Together they form a unique fingerprint.

  • Cite this