[Lung inflation or mechanical ventilation in extracorporeal circulation?]

Area of Science:

• Cardiovascular Surgery
• Pulmonary Physiology
• Anesthesiology

Background:

• Extracorporeal circulation (ECC) can cause lung injury, known as postperfusion syndrome, due to altered pulmonary perfusion.
• Understanding the impact of ventilation strategies during ECC on postoperative lung function is crucial for patient outcomes.

Purpose of the Study:

• To investigate the effects of different ventilation methods during ECC on postoperative pulmonary function.
• To analyze the resulting changes in pulmonary blood gases.

Main Methods:

• Thirty patients undergoing aortocoronary bypass surgery were divided into three groups: static inflation, low-frequency ventilation, and medium-frequency ventilation during ECC.
• Pulmonary function was assessed by venous admixture (QVA/Qt), and pulmonary vascular resistance was determined.
• Blood gases were analyzed from pulmonary artery blood during ECC.

Main Results:

• Static pulmonary inflation during ECC led to a significant increase in postoperative venous admixture.
• Both low- and medium-frequency ventilation during ECC significantly reduced postoperative venous admixture compared to preoperative levels.
• Pulmonary vascular resistance changes were similar across all ventilation groups; blood gas analysis showed adequate oxygenation during ECC.

Conclusions:

• Pulmonary ventilation during ECC effectively prevents the postoperative increase in venous admixture.
• Low- and medium-frequency ventilation strategies during ECC demonstrate comparable efficacy in improving pulmonary function.
• Ventilation during ECC does not alter ECC-related pulmonary vascular changes.