From the Guidelines
The best ventilator mode for pneumothorax is typically pressure-controlled ventilation (PCV) with low tidal volumes and moderate positive end-expiratory pressure (PEEP). Recommended settings:
- Mode: Pressure-controlled ventilation (PCV)
- Tidal volume: 6-8 mL/kg of predicted body weight, as recommended by the international expert panel-based consensus recommendations 1
- PEEP: 5 cm H2O, which can be individualized to the patient to avoid increases in driving pressure while maintaining a low tidal volume 1
- FiO2: Start at 0.4 and titrate down to the lowest possible fraction of inspired oxygen to achieve SpO2 94% 1
- Respiratory rate: Adjust to maintain normal pH and PaCO2
These settings help minimize further lung injury and air leakage while maintaining adequate oxygenation and ventilation. The pressure-controlled mode limits peak airway pressures, reducing the risk of barotrauma. Low tidal volumes prevent overdistension of the affected lung. Moderate PEEP helps keep alveoli open and improves oxygenation without excessively increasing intrathoracic pressure. It's crucial to closely monitor for any signs of tension pneumothorax, such as sudden hypotension or increased peak airway pressures. If a chest tube is in place, ensure it's functioning properly. Adjust ventilator settings as needed based on arterial blood gases and patient response. Some airway clearance therapies, specifically positive expiratory pressure and intrapulmonary percussive ventilation, should not be used in patients with pneumothorax, as recommended by the cystic fibrosis pulmonary guidelines 1. This approach aims to support gas exchange while allowing the pneumothorax to resolve, either spontaneously or with intervention like chest tube placement.
From the Research
Ventilator Modes for Pneumothorax
The best ventilator mode for pneumothorax is not explicitly stated in the provided studies, but several lung-protective ventilation strategies are discussed:
- Low tidal volumes and moderate levels of PEEP have been recommended as strategies to prevent tidal alveolar collapse and overdistension in patients with ALI/ARDS 2, 3, 4, 5, 6
- Pressure-controlled ventilation allows regulation over injurious peak inspiratory pressures, but no study has identified the superiority of pressure-controlled ventilation over low tidal volume strategies using volume-control 2
- Other lung protective ventilation strategies include moderate to high positive-end expiratory pressure, recruitment manoeuvres, high frequency oscillatory ventilation, and airway pressure release ventilation 2, 5, 6
- A multifaceted protocolized ventilation strategy designed to recruit and open the lung resulted in no significant difference in all-cause hospital mortality or barotrauma compared with an established low-tidal-volume protocolized ventilation strategy, but did appear to improve secondary end points related to hypoxemia and use of rescue therapies 5
Key Considerations
- Tidal volumes should be kept low (less than 6 mL/kg of predicted body weight) to prevent lung injury 3, 5
- Plateau airway pressures should not exceed 30 cm H2O to prevent barotrauma 3, 5
- Positive end-expiratory pressure (PEEP) should be used to prevent alveolar collapse and promote lung recruitment 2, 5, 6
- Recruitment maneuvers and high frequency oscillatory ventilation may be beneficial in certain patients, but more research is needed to confirm their effectiveness 2, 5, 6