Alarming hypoxemia during one-lung ventilation in a patient with respiratory bronchiolitis-associated interstitial lung disease

PURPOSE: To report a patient with respiratory bronchiolitis-associated interstitial lung disease (RB-ILD) who developed severe hypoxemia during one-lung ventilation (OLV). CLINICAL FEATURES: A 27-yr-old female, ex-smoker presented with productive cough and dyspnea of 18-month duration. The chest x-ray revealed diffuse abnormalities involving both lungs consisting of interstitial emphysema with irregular shadowing. Preoperative PaO(2) was 88 mmHg and pulmonary function tests showed moderate obstructive disease. The patient underwent right open lung biopsy. After induction of anesthesia, a left double lumen tube was inserted and its position verified with auscultation and fibreoptic bronchoscopy. Upon initiation of OLV, the patient developed severe hypoxemia and the PaO(2) dropped from 500 mmHg during two-lung ventilation (TLV) to 50 mmHg. Hypoxemia was readily corrected by resuming TLV. CONCLUSION: The severe hypoxemia during OLV in this patient with RB-ILD may be attributed to impaired hypoxic pulmonary vasoconstriction. Other causes were not excluded. Caution is warranted when initiating OLV in these patients.