Postoperative Pulmonary Dysfunction and Mechanical Ventilation in Cardiac Surgery

Table 1

Pathogenetic mechanisms of postoperative pulmonary dysfunction (PPD).

Specific to cardiac surgery:
(i) Median sternotomy incision
(ii) Use of cardiopulmonary bypass (CPB)
(iii) Transfusion of blood product
(iv) Topical cooling for myocardial protection
(v) Dissection of the internal mammary artery
(vi) Effects of general anesthesia
Anomalies in gas exchange:
(i) Widening of the alveolar-arterial oxygen gradient
(ii) Increased microvascular permeability in the lung
(iii) Increased pulmonary vascular resistance
(iv) Increased pulmonary shunt fraction
(v) Intrapulmonary aggregation of leukocytes and platelets
Alterations in lung mechanics:
(i) Reductions in vital capacity (VC)
(ii) Reduction of functional residual capacity (FRC)
(iii) Reduction of static and dynamic lung compliance