Chest Physical Therapy in the Intensive Care Unit

Abstract

Critically ill patients are nursed in the supine position for extended periods of time. In the supine patient, the abdominal contents push in a cephalad direction, decreasing the functional residual capacity and causing alveolar closure in the dependent lung zones. In addition, immobility results in accumulation of mucus in the dependent lung zones. Intubated, sedated, mechanically ventilated patients are unable to mobilize their respiratory secretions. As the endotracheal tube bypasses the glottic mechanism, coughing is ineffective in intubated patients. Furthermore, the endotracheal tube interferes with normal mucociliary transport. These patients are therefore at a high risk of developing segmental or lobar atelectasis. Thoracic and abdominal surgery further predispose patients to the development of atelectasis. The most common segment to develop atelectasis is the left lower lobe, possibly due to compression by the heart in the supine position and its poor drainage. Atelectasis impairs oxygenation, increases the risk of developing pneumonia, and delays attempts at weaning. Chest physical therapy is therefore a vital component in the management of all critically ill patients to prevent retention of secretions and atelectasis.