Reversible ventilation and perfusion abnormalities in unilateral obstructed lung.

Area of Science:

• Pulmonary Medicine
• Medical Imaging

Background:

• Intraluminal carcinoid tumors can cause significant airway obstruction.
• Airway obstruction leads to ventilation/perfusion (V/Q) mismatch and hypoxemia.

Observation:

• A patient presented with hypoxemia due to a left mainstem bronchial carcinoid tumor.
• Regional lung function studies using 133-xenon (133Xe) revealed severely reduced perfusion (22%) and ventilation (6%) in the affected lung.
• Negligible 133Xe washout indicated air trapping, consistent with obstruction.

Findings:

• Following left mainstem bronchial sleeve resection, significant improvements in perfusion, ventilation, and xenon washout were observed within four days.
• Lung function measurements approached normal levels by four months post-surgery.
• Complete restoration of perfusion relative to ventilation was delayed, suggesting a prolonged recovery period.

Implications:

• Regional lung function assessment using multiprobe systems provides valuable insights into V/Q interrelationships in large airway obstruction.
• This case demonstrates that while surgical intervention can rapidly improve lung function, complete perfusion recovery may take an extended period.
• The findings underscore the importance of long-term monitoring for patients with airway obstruction treated surgically.