Intracranial pressure and cardiac output remain stable during high frequency oscillation

In 6 anesthetized and paralyzed adult cats, intracranial pressure (ICP) and cardiovascular variables were studied during high frequency oscillation (HFO). Over 2 h of HFO, cardiac output, right heart pressures, and blood gases remained stable, and were not different from control period values. Good ventilation and oxygenation were achieved. ICP was 5.7 mm Hg during the control period, and remained within +/- 1.25 mm Hg throughout HFO. Further, respiration-induced ICP waveforms were abolished during HFO. We believe that high frequency ventilation (HFV) does not alter cardiovascular and ICP dynamics for the duration tested in healthy anesthetized animals.