The effect of high-frequency ventilation of the lungs on postbypass oxygenation: A comparison with other ventilation methods applied during cardiopulmonary bypass.
OBJECTIVE
To compare the effect of high-frequency ventilation versus other ventilation methods applied during cardiopulmonary bypass on postbypass oxygenation.


METHODS
Prospective, randomized study.


METHODS
University hospital.


METHODS
Seventy-five patients undergoing coronary artery bypass graft surgery.


METHODS
Patients were allocated to 5 equal groups of different ventilation methods during bypass. Groups 1 and 2 received high-frequency, low-volume ventilation with 100% and 21% oxygen, respectively. Groups 3 and 4 received 5 cm H(2)O of continuous positive airway pressure (CPAP) with either 100% or 21% oxygen. Patients from group 5 were disconnected from the ventilator during the bypass period.


RESULTS
Spirometry data, blood gas analysis, oxygen saturation as measured by pulse oximetry, and end-tidal carbon dioxide were recorded 5 minutes before chest opening, 5 minutes before bypass, 5 minutes after bypass, 5 minutes after chest closure and 6, 12, 18, and 24 hours after surgery. There were no differences in compliance and mean airway pressures. Alveolar-to-arterial oxygen gradients increased, and PaO(2) decreased significantly (p < 0.05) in all groups 5 minutes after bypass and this trend continued in the postoperative period. Patients from group 3 had higher PaO(2) and lower alveolar-to-arterial oxygen gradients, 5 minutes after weaning from bypass (p < 0.05). Extubation times were similar in all groups.


CONCLUSIONS
The alveolar-arterial oxygen gradient was lower, and the PaO(2) was higher 5 minutes after bypass in patients receiving CPAP (100% O(2)) as compared with those ventilated with high-frequency ventilation.
Zabeeda
Deeb
D
Department of Anesthesia, Wolfson Medical Center, Holon, Affiliated with Sackler School of Medicine, Tel Aviv, Israel.
Gefen
Revaz
R
Medalion
Beniamin
B
Khazin
Vadim
V
Shachner
Arie
A
Ezri
Tiberiu
T
D000368:Aged; D001784:Blood Gas Analysis / Q000706:statistics & numerical data; D002315:Cardiopulmonary Bypass / Q000706:statistics & numerical data*; D001026:Coronary Artery Bypass / Q000706:statistics & numerical data*; D006439:Hemodynamics / Q000502:physiology; D006612:High-Frequency Ventilation / Q000706:statistics & numerical data*; D006801:Humans; D008170:Lung Compliance / Q000502:physiology; D016343:Monitoring, Intraoperative / Q000706:statistics & numerical data; D010100:Oxygen / Q000008:administration & dosage* / Q000097:blood; D011175:Positive-Pressure Respiration / Q000706:statistics & numerical data; D011446:Prospective Studies; D013997:Time Factors
D010100:Oxygen