Pulmonary abnormalities after coronary arterial bypass grafting operation: cardiopulmonary bypass versus mechanical stabilization.
BACKGROUND
Cardiopulmonary bypass has been implicated in causing poor pulmonary gas exchange postoperatively in patients undergoing coronary artery bypass grafting procedures. This randomized prospective study was conducted to determine whether patients undergoing coronary artery bypass grafting operations using cardiac stabilization and thereby avoiding cardiopulmonary bypass will have improved pulmonary function postoperatively.


METHODS
Fifty-eight patients were randomized to one of two groups: coronary artery bypass grafting operation with stabilization or coronary artery bypass grafting operation with cardiopulmonary bypass. Preoperative and postoperative pulmonary gas exchange measurements were performed on intubated patients, including the arterial partial pressure of oxygen on 100% inspired oxygen, the alveolar-arterial oxygen gradient, and pulmonary shunt. Static and dynamic lung compliance measurements were performed postoperatively. Hemodynamic variables (including creatine kinase-MB and troponin levels), intubation time, postoperative bleeding, and blood transfusions were compared.


RESULTS
Both study groups had a large decrease in arterial partial pressure of oxygen on 100% inspired oxygen (p < 0.0001) and a significant postoperative increase in the alveolar-arterial oxygen gradient (p < 0.0001). There was no statistical difference in the postoperative gas exchange between the two groups; however, the postoperative pulmonary shunt was significantly better in the stabilization group (24% versus 31%, p = 0.03). The patients were extubated in the intensive care unit earlier in the stabilization group (8.2 hours versus 9.2 hours, not significant). The mean static and dynamic lung compliance postoperatively was lower in the stabilization group, although not statistically significant (p = 0.06).


CONCLUSIONS
Coronary artery bypass grafting operation using cardiac stabilization technique is safe and avoids the risk of cardiopulmonary bypass. The pulmonary gas exchange postoperatively is comparable to standard cardiopulmonary bypass procedures, but a reduced postoperative pulmonary shunt was seen in the stabilization group.
Kochamba
G S
GS
Regional Department of Cardiac Surgery, Kaiser Permanente Medical Center, Los Angeles, California 90027, USA. gary.s.kochamba@scalkpg.org
Yun
K L
KL
Pfeffer
T A
TA
Sintek
C F
CF
Khonsari
S
S
D001803:Blood Transfusion; D002315:Cardiopulmonary Bypass / Q000009:adverse effects*; D001026:Coronary Artery Bypass / Q000379:methods*; D003331:Coronary Vessels / Q000601:surgery*; D005260:Female; D006470:Hemorrhage / Q000209:etiology; D006801:Humans; D008168:Lung / Q000502:physiology*; D008170:Lung Compliance; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000032:analysis / Q000097:blood; D010313:Partial Pressure; D011183:Postoperative Complications; D011446:Prospective Studies; D011652:Pulmonary Circulation; D011659:Pulmonary Gas Exchange
D010100:Oxygen