Respiratory Assessment and Management Post Cardiac Surgery

Preoperative Respiratory Optimization

A cardiorespiratory and muscular prehabilitation program of at least 4 weeks before surgery is recommended to reduce postoperative pulmonary complications and hospital length of stay, as suggested by the American Thoracic Society 1, 2
Inspiratory muscle training using a device with an adjustable inspiratory pressure valve is most effective, requiring at least 5 days (preferably 2 weeks) of preparation with twice-daily practice, according to the American College of Chest Physicians 1, 3
Preoperative respiratory training decreases risk of postoperative pneumonia (RR 0.44-0.45) and atelectasis (RR 0.53-0.59), as reported by the American Association for Respiratory Care 1, 2
Cardiorespiratory prehabilitation improves preoperative physical condition as measured by 6-minute walking tests and reduces hospital length of stay by 1-3.2 days, based on evidence from the European Respiratory Society 1

Protective lung ventilation strategy during pre- and post-cardiopulmonary bypass (CPB) periods is recommended, especially for patients with acute respiratory failure, as suggested by the Society of Cardiovascular Anesthesiologists 4, 5
Use low tidal volumes (6-8 mL/kg ideal body weight), positive end-expiratory pressure (PEEP), and recruitment maneuvers, according to the American Society of Anesthesiologists 4, 5
Ventilation during CPB is not recommended as it does not reduce the incidence of postoperative pulmonary complications, as reported by the European Society of Anaesthesiology 4, 5

Systematic respiratory assessment should include monitoring of oxygen saturation, respiratory rate, work of breathing, and breath sounds, as recommended by the American College of Chest Physicians 6
For patients with FVC <50% of predicted (especially <30%), consider extubation directly to non-invasive positive pressure ventilation (NPPV), according to the American Thoracic Society 6
Delay extubation until respiratory secretions are well controlled and SpO2 is normal or at baseline in room air, as suggested by the Society of Critical Care Medicine 6

Use manually assisted cough and mechanical insufflation-exsufflation techniques for patients with impaired cough (peak cough flow <270 L/min or MEP <60 cm H2O), as recommended by the American Association for Respiratory Care 6
Implement early mobilization and respiratory physiotherapy to prevent atelectasis and promote lung expansion, based on evidence from the European Respiratory Society 1

For post-cardiac surgery cardiac arrest with respiratory etiology, consider potential causes such as tension pneumothorax, severe obstruction leading to air trapping, or breath stacking, as suggested by the American Heart Association 7, 8
In patients with air trapping, use lower tidal volumes, lower respiratory rates, and increased expiratory time to minimize auto-PEEP and barotrauma, according to the American College of Cardiology 7, 8
For respiratory deterioration, assess for potential surgical complications such as bleeding, tamponade, or pneumothorax, as recommended by the Society of Thoracic Surgeons 8