Abstract
OBJECTIVE
To evaluate hemodynamic effects of sternal retractor removal and sternal closure after cardiopulmonary bypass and to correlate these changes with preoperative and intraoperative variables.
DESIGN
Prospective.
SETTING
University hospital.
PARTICIPANTS
Fifty adults undergoing cardiac surgery.
MEASUREMENTS AND MAIN RESULTS
Arterial, pulmonary artery, and transesophageal echocardiography measurements were obtained immediately before and 1 minute after removal of the sternal retractor and immediately before and 1 minute after sternal closure. Retractor removal caused a significant decrease in cardiac index by 5.6% (p < 0.01), stroke volume index by 4.0% (p < 0.05), and mean pulmonary artery pressure by 4.8% (p < 0.001). Sternal closure caused a significant decrease in cardiac index by 7.7%, stroke volume index by 10.2%, and left ventricular end-diastolic area by 9.2% (p < 0.001) There were significant increases in pulmonary capillary wedge pressure and systemic vascular resistance by 9.1% and 10.8% (p < 0.01). There was no significant change in the ejection fraction area. The magnitude of decrease in stroke volume index with sternal closure correlated positively with end-diastolic area immediately before the closure.
CONCLUSION
Chest closure is associated with significant hemodynamic changes and a change in the ventricular transmural pressure-volume relationship. Patients with lower preload immediately before closure are more vulnerable to a decrease in cardiac index. Based on the results of this study, volume appears to be the appropriate preventive and treatment option to limit the impact of chest closure.
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