What is barotrauma in mechanical ventilation?
Barotrauma is a condition in which the alveoli (air sacs of the lungs) rupture with a subsequent entry of air into the surrounding extra alveolar space.
Barotrauma is typically caused by lung air sacs rupturing or a direct injury.
Barotrauma can complicate mechanical ventilation, as it is associated with life-threatening conditions or even death. Hence, diagnosing and preventing barotrauma during mechanical ventilation is crucial.
What are the causes of barotrauma in mechanical ventilation?
Barotrauma mainly occurs either due to the rupture of the air sacs (alveolus) of lungs or a direct injury.
Alveolar rupture can be either ventilator-related or disease-related.
Ventilator-related causes include:
- Positive pressure ventilation: Normal respiratory cycle is dependent on negative pressure. However, mechanical ventilation delivers positive pressure. Positive pressure ventilation results in increased pressure in the adjacent areas of the alveolus, causing it to rupture.
- Elevated pressure: Elevated pressure can result in the injury of the alveolus.
Disease-related causes include:
- Asthma
- Chronic obstructive pulmonary disease (COPD)
- Chronic interstitial lung disease
- Acute respiratory distress syndrome
Direct injury to the alveolus may result in an escape of the air to the surrounding tissue and cause conditions similar to barotrauma.
What are the signs and symptoms of barotrauma in mechanical ventilation?
The common manifestations of barotrauma include:
- Pneumothorax: It occurs when air escapes into the space between the lung and chest wall. The symptoms of pneumothorax include:
- Chest pain
- Shortness of breath
- Increased heart rate
- Abnormally rapid breathing
- Increased blood pressure
- Low level of oxygen in the blood
- Pneumomediastinum: It occurs when air is trapped in the middle part of the chest. The symptoms of pneumothorax include:
- Chest pain
- Shortness of breath
- Neck pain
- Pneumoperitoneum: It occurs due to the presence of air in the abdominal cavity. The symptoms of pneumoperitoneum include:
- Abdominal pain
- Stomach tenderness
- Bloating and swelling in the abdomen
- Tympany (hollow drum-like sound produced when air is trapped in the cavity)
- Subcutaneous emphysema: It occurs when air is trapped into tissues under the skin. Sudden painless tissue swelling is the typical manifestation of subcutaneous emphysema.
How is barotrauma in mechanical ventilation managed?
Adjustment of ventilator settings and ventilator management is the main focus of the treatment.
Additional management technique involves:
- Insertion of a chest tube for draining the air in the lungs for managing pneumothorax
- Surgical means to remove the pressure (surgical decompression)
- Reduction in ventilator pressure
- The patient should be taken off of the mechanical ventilator as a last resort
- Treating the underlying medical conditions
Once barotrauma is treated, the patient’s vital signs and ventilator settings are closely monitored. Chest radiography may be performed every eight to 12 hours to check for evidence of barotrauma.