How to manage bilateral lower lobe volume loss in an intubated patient?

From the Guidelines

Optimizing ventilator settings by increasing positive end-expiratory pressure (PEEP) to 8-12 cmH2O and ensuring tidal volumes of 6-8 mL/kg ideal body weight is crucial in managing bilateral lower lobe volume loss in an intubated patient. This approach is supported by the latest evidence from the study published in Critical Care in 2017 1, which emphasizes the importance of low tidal volume ventilation and sufficient PEEP in minimizing the risks of ventilator-induced lung injury (VILI) in patients with acute respiratory distress syndrome (ARDS).

To further address the issue, the following strategies can be employed:

• Implement regular position changes every 2 hours, particularly prone positioning for 12-16 hours daily if not contraindicated, as this redistributes ventilation to dependent lung regions 1.
• Perform endotracheal suctioning as needed, but at least every 4-6 hours, using closed-circuit suction systems to maintain PEEP during the procedure.
• Administer bronchodilators such as albuterol 2.5-5 mg via nebulizer or 4-8 puffs via metered-dose inhaler with spacer every 4-6 hours to reduce bronchospasm.
• Consider chest physiotherapy with manual percussion and vibration techniques for 15-20 minutes every 4 hours to mobilize secretions.
• If secretions are thick, ensure adequate hydration and consider mucolytics like N-acetylcysteine 300-600 mg nebulized every 8 hours.
• Perform recruitment maneuvers such as sustained inflation at 30-40 cmH2O for 30-40 seconds if oxygenation remains poor, as recommended in the study published in Intensive Care Medicine in 2001 1.

These interventions work by increasing transpulmonary pressure, improving mucociliary clearance, and redistributing ventilation to collapsed areas, ultimately addressing the pathophysiology of lower lobe collapse which commonly occurs in supine, mechanically ventilated patients due to the weight of the heart and abdominal contents compressing the lower lobes. By prioritizing the most recent and highest quality study, we can ensure that our management strategy is evidence-based and focused on improving patient outcomes in terms of morbidity, mortality, and quality of life.

From the Research

Management of Bilateral Lower Lobe Volume Loss

To manage bilateral lower lobe volume loss in an intubated patient, several strategies can be employed:

• Lung Recruitment Maneuvers: Lung recruitment maneuvers, such as the use of positive end-expiratory pressure (PEEP)-induced lung recruitment maneuver, can help improve oxygenation and increase lung volume 2.
• Prone Positioning: Prone positioning can also be used to improve oxygenation and increase lung volume by reducing atelectasis and improving ventilation distribution 2, 3.
• Individualized PEEP: Individualized PEEP titration can help improve lung mechanics and blood gases 3.
• Low Tidal Volumes: Using low tidal volumes can help reduce lung injury and improve outcomes in patients with acute respiratory distress syndrome (ARDS) 4.
• Recruitment Maneuvers with Inhaled Nitric Oxide: The combination of recruitment maneuvers and inhaled nitric oxide can further improve oxygenation in patients with ARDS 5.

Considerations for Volume Loss in Lower Lobes

Volume loss in the lower lobes can be due to various factors, including:

• External Compression: The heart and abdomen can exert external compression on the lower lobes, contributing to volume loss 6.
• Atelectasis: Atelectasis can occur in the lower lobes due to gravity and external compression, leading to volume loss 6.
• Lung Injury: Lung injury, such as that seen in ARDS, can also contribute to volume loss in the lower lobes 4, 3.

Monitoring and Assessment

Monitoring and assessment of lung volume and recruitment are crucial in managing bilateral lower lobe volume loss:

• Electric Impedance Tomography (EIT): EIT can be used to monitor ventilation distribution and lung volume 2.
• Pressure/Volume Curves: Pressure/volume curves can be used to assess lung recruitability and mechanical properties of the lung 6.
• Blood Gases: Blood gases can be used to assess oxygenation and ventilation 2, 4, 5, 3.