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

Abstract

P Pu ur rp po os se e: : To report a patient with respiratory bronchiolitis-associated interstitial lung disease (RB-ILD) who developed severe hypoxemia during one-lung ventilation (OLV).C Cl li in ni ic ca al l f fe ea at tu ur re es s: : A 27-yr-old female, ex-smoker presented with productive cough and dyspnea of 18-month duration. The chest xray 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 twolung ventilation (TLV) to 50 mmHg. Hypoxemia was readily corrected by resuming TLV.C Co on nc cl lu us si io on n: : 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.

An anesthesiologist's guide to hypoxic pulmonary vasoconstriction: implications for managing single-lung anesthesia and atelectasis

“…In addition, patients with cirrhosis often have impaired HPV [21]. Anesthesia in such HPVdepressed patients may result in profound hypoxia, particularly upon initiation of single-lung anesthesia [20].…”

“…calcium channel blockers) or even by the ventilatory regimen (alkalosis). Weak HPV can be anticipated in certain groups (hypoxemic chronic obstructive pulmonary disease (COPD) patients [20] and cirrhotic patients [21]) allowing them to be prospectively identified and perhaps managed with different anesthetic regimens (e.g. using spinal and intravenous anesthetics).…”

Hypoxic Pulmonary Vasoconstriction

“…4,5 Although HPV can be sustained, it remains reversible on restoration of normal airway oxygen levels, unless pulmonary hypertension (PH) and adverse vascular remodeling has occurred. The reversibility of sustained lobar HPV is illustrated by a patient whose endobronchial adenoma caused longstanding left lung atelectasis and a matching V : =Q : abnormality, both of which reversed after resection of the adenoma.…”

Respiratory Bronchiolitis-Associated Interstitial Lung Disease

“…RBILD is widely regarded as an essentially benign disorder. This is not invariably the case, as illustrated by the development of severe hypoxemia during single-lung ventilation in a patient with RBILD, 39 and there are anecdotal reports, including a case known to the authors, of extensive underlying fine fibrosis at bi-opsy, not evident on HRCT. However, judging from the current limited documentation of longitudinal behavior, RBILD has a much better outcome than other forms of idiopathic interstitial pneumonia, 13 with a much better survival than seen in UIP or fibrotic nonspecific interstitial pneumonia (NSIP).…”