Effects of high-frequency jet ventilation on intracranial pressure and cerebral elastance in dogs

In order to assess the effect of high-frequency jet ventilation (HFJV) on intracranial pressure (ICP) and cerebral elastance (CE), a model of progressive intracranial hypertension was developed. Six healthy dogs were ventilated using HFJV and another six with conventional mechanical ventilation. ICP and its pulse amplitude (Amp) were measured by means of an epidural transducer, and CE was assessed by analysis of the relationship between the Amp and the mean ICP. The mean ICP, under basal conditions, did not differ between the two forms of ventilation, the Amp and the slope of the relationship Amp/ICP being lower with HFJV (p less than .001). Since the lower airway pressure created with HFJV was the only difference, it is suggested that the differences found in this study are related to these pressures.