Purpose: To study the causes of difficulty or impossible weaning of cardiac surgical patients undergoing mechanical ventilation in the postoperative period and their outcome.
Methods: Three hundred and forty three consecutive adult patients submitted to open heart surgery were retrospectively studied and classified in three groups: I--patients in mechanical ventilation more than 24 hours; II--patients in mechanical ventilation less than 24 hours and reintubated some time after this period; III--patients successfully extubated in the first 24 hours of ventilation.
Results: The authors were able to identify the following preoperative factors associated with prolonged postoperative ventilation: cardiac failure, pulmonary hypertension, smoking, chronic obstructive pulmonary disease and previous open heart surgery. Significant factors in the immediate postoperative period (1st 24 hours) were: atelectasis, low output syndrome, perioperative myocardial infarction, reoperation for excessive bleeding, pleural effusion and cardiac arrest. This group of patients had a significant increase in nosocomial pneumonia, multiple organ failure (MOF) and surgical mortality.
Conclusion: Pre and postoperative factors were identified associated with prolonged mechanical ventilation in the postoperative period and responsible by significant morbidity as such pulmonary infection, MOF and increase in mortality.