On examination she is obviously short of breath at rest, talking in short sentences.
PR 130 regular, NSR on ECG
Sats 92% on room air
A CXR is performed:
A left sided chest drain was inserted which resulted in clinical improvement:
HR now 100/min and oxygen saturations up to 96% on room air with a RR of 24.
Repeat CXR showed incomplete re-expansion of the left sided pneumothorax and persistent mediastinal shift to the right.
A CT chest revealed the opacity to be completely fluid with no evidence of mass or malignancy.
A small gauge chest drain was inserted into the right chest. Slightly blood stained fluid was aspirated and sent for microscopy, biochemistry and cytology. However, after approx 20ml, the fluid became very difficult to aspirate with evidence of significant negative intrathoracic pressure. The tubed was clamped and the patient was admitted under cardiothoracics for further management.
The patient underwent thoracotomy and decortication of a pleural rind. She was diagnosed with "trapped lung" likely on the basis of ?endometriosis.The negative pressure on the right side of her chest was sufficient to cause a left sided pnuemothorax.
Trapped lung occurs when the visceral pleura becomes encased with a fibrotic rind that renders the lung unexpandable.
Causes of pleural inflammation that eventually lead to trapped lung include pneumonia with parapneumonic effusion (bacterial and mycobacterial), hemothorax, spontaneous pneumothorax, thoracic operations including coronary artery bypass surgery, uremia, and rheumatoid pleuritis.
On chest radiography of trapped lung, the hemithorax with the effusion is reduced in size, indicating that the pleural pressure on the side with the effusion is more negative than that on the contralateral side. Computed tomography (CT) often reveals loculation and pleural thickening, although sometimes pleural thickening is only apparent on an air contrast CT.
Direct measurement of pleural pressure at the time of thoracentesis usually reveals a negative initial pressure. With fluid removal, a rapid decrease in pleural pressure occurs.
The presence of characteristic pleural pressure changes is strongly suggestive of trapped lung and may be sufficient diagnostically in patients with minimal or absent symptoms. However, confirmation that visceral pleural thickening (a pleural rind) is present requires air contrast computed tomography (CT) or direct visualization via video-assisted thoracoscopy.
Treatment may be conservative or with decortication of the pleural rind on the visceral pleura.