The clinical characteristics and hospital and post‐hospital survival of patients with the obesity hypoventilation syndrome: analysis of a large cohort

Abstract

SummaryObjectiveThe worldwide prevalence of obesity has reached epidemic proportions. Obesity hypoventilation syndrome (OHS) is a common yet largely undiagnosed and mistreated condition that likely carries a high mortality. The aim of this study was to determine the clinical characteristics, hospital outcome, outcome following hospital discharge and predictors of death in a large cohort of patients hospitalized with OHS. OHS is an important condition as many patients with this syndrome are misdiagnosed and receive inappropriate treatment.MethodsWe reviewed the electronic medical records of patients with unequivocal OHS admitted to a 525‐bed tertiary‐care teaching hospital over a 5‐year period. Demographic and clinical data as well as hospital disposition were recorded. In order to determine the patients' post‐discharge status, we linked our database to the database of death certificates of the State Registrar of Vital Records.ResultsWe identified 600 patients who met the inclusion criteria for this study. The patients' mean age was 58 ± 15 years with a mean body mass index of 48.2 ± 8.3 kg m−2; 64% were women. Thirty‐seven percent had a history of diabetes and 43% had been misdiagnosed as having chronic obstructive pulmonary disease, while none had been previously diagnosed with OHS. The most common admission diagnoses were respiratory failure, heart failure and sepsis. Ninety (15%) patients died during the index hospitalization. The patients' age, S‐creatinine, respiratory failure, sepsis and admission to the ICU were independent predictors of hospital mortality. The hospital survivors were followed for a mean of 1,174 ± 501 d (3.2 ± 1.3 years) from the index hospitalization. On follow‐up, 98 of the 510 (19%) hospital survivors died, with an overall cumulative mortality of 31.3%. The patients' age, S‐creatinine and admission to the ICU were independent predictors of post‐hospital mortality.ConclusionObesity hypoventilation syndrome is a common disease that is frequently misdiagnosed and mistreated and carries a 3‐year morality, which is significantly worse than that for most cancers combined. Considering the high mortality of this disease, all patients with a body mass index > 35 kg m−2 should be screened for OHS; those patients with both early and established OHS should be referred to a pulmonary and/or sleep specialist for evaluation for non‐invasive positive pressure ventilation, to a dietician for dietary counseling and lifestyle modification and to a bariatric surgeon for evaluation for bariatric surgery.

The Association Between Adherence to Positive Airway Pressure Therapy and Long-Term Outcomes in Patients With Obesity Hypoventilation Syndrome: A Prospective Observational Study

“…7 Moreover, previous studies showed that patients with OHS may experience higher morbidity and mortality than patients who have OSA without OHS. [38][39][40] Our study showed an even lower mortality rate among patients with OHS (5%) compared to previous studies, 10,[41][42][43] probably because of less severe cases of OHS and higher overall PAP adherence. PAP adherence < 6 h/night independently predicted mortality, irrespective of PAP mode, which seems intuitive because good adherence to PAP can improve prognosis, as reported by others.…”

Evaluation and Management of Obesity Hypoventilation Syndrome. An Official American Thoracic Society Clinical Practice Guideline

“…During this delay, patients with OHS use more healthcare resources than eucapnic patients of comparable obesity (15). Unfortunately, OHS is misdiagnosed even in patients with severe obesity who are hospitalized with hypercapnic respiratory failure (16). Early recognition and effective treatment are important in improving morbidity and mortality.…”

Contemporary Concise Review 2019: Sleep and ventilation

“…However, a number of points deserve emphasis. First, several studies have shown that a major proportion of OHS patients present decompensated in the intensive care unit, making the recent Lancet findings not applicable to such patients . A recent American Thoracic Society (ATS) clinical practice guideline on the evaluation and management of OHS recommended acute NIV therapy for these patients with hospital to home transition until they can undergo outpatient diagnostic testing .…”