Postoperative hypercapnic respiratory failure in patients with obstructive sleep apnoea: treatment with non-invasive ventilation

Abstract

Acute hypercapnic respiratory failure is a rare but life-threatening complication in grossly obese patients with severe obstructive sleep apnoea (OSA). Facial trauma or upper airway surgery, respiratory tract infections, bronchospasm, use of pain medication and concomitant obstructive or restrictive pulmonary impairment predispose to the development of respiratory failure in such patients. We present a case of a morbidly obese male patient in whom moderately severe OSA (the apnoea-hypoponea index, AHI of 37/hour) was treated with uvulapalatopharyngoplasty (UPPP) because he declined treatment with non-invasive ventilation. The early postoperative period was complicated by severe hypercapnic respiratory failure in association with worsening of OSA: arterial PO2 was 4.14 kPa, PCO2 9.7 kPa, AHI increased to 93.8/hour, minimal nocturnal arterial oxygen saturation was 46%. Therapy with non-invasive ventilation using bi-level positive airway pressure (BiPAP) was initiated immediately, and resulted in marked improvements in the patient's clinical condition, in association with the improvements in arterial blood gases. Before the discharge, nocturnal continuous positive airway pressure (CPAP) therapy to treat OSA on the long-term basis was initiated. Two months after the release, the patient's blood gases were within the normal range, and he reported marked improvements in his clinical condition including alleviation of daytime sleepiness and increased physical endurance. Our case demonstrates that in the presence of severe OSA, life-threatening hypoxaemia and hypercapnia were successfully alleviated using BiPAP in the postoperative period after UPPP.