Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content + Download Section PDF Listen ++ For further information, see CMDT Part 9-41: Obesity-Hypoventilation Syndrome (Pickwickian Syndrome) + Key Features Download Section PDF Listen +++ ++ Hypoventilation resulting from blunted ventilatory drive and increased mechanical load imposed on the chest Obstructive sleep apnea in most Patients with obesity-hypoventilation syndrome have a higher risk of complications in the perioperative period, including respiratory failure, intubation, and heart failure + Clinical Findings Download Section PDF Listen +++ ++ Obesity Lethargy, headache, hypersomnolence Loud snoring if accompanied by obstructive sleep apnea Dyspnea often absent Signs of cyanosis and cor pulmonale may be found Many patients have erythrocytosis + Diagnosis Download Section PDF Listen +++ ++ Diagnostic criteria BMI > 30 Arterial partial pressure of carbon dioxide > 45 mm Hg Exclusion of other causes of alveolar hypoventilation Arterial blood gas measurements confirm daytime hypoxemia and hypercapnia, which improve with voluntary hyperventilation Nocturnal sleep study helpful to evaluate for obstructive sleep apnea + Treatment Download Section PDF Listen +++ ++ Weight loss is key Noninvasive positive pressure ventilation is helpful in many patients Sedative hypnotics, opioids, and alcohol should be avoided If present, obstructive sleep apnea must be treated aggressively (eg, nasal CPAP) Treatment of comorbid conditions