Risk of Readmission and Mortality Following Hospitalization with Hypercapnic Respiratory Failure

PURPOSE: Hypercapnic respiratory failure (HRF) is a frequent cause of hospitalization and a common comorbidity in hospitalized patients. There are few studies addressing what factors might predict poor outcomes in this patient population. The purpose of the current study was to investigate characteristics and outcomes of patients hospitalized with HRF. METHODS: A study of patients ≥ 18 years admitted with HRF in a 1-year period. Patients with limited life expectancy related to other conditions, and those with a non-respiratory cause of HRF, were excluded. RESULTS: 202 subjects met eligibility criteria: 24% had a diagnosis of obstructive sleep apnea, 6% obesity hypoventilation, 46% chronic obstructive pulmonary disease, and 10% asthma. Fifteen (7%) died during the index admission. Forty-one patients (23%) were readmitted within 30 days: peripheral vascular disease [adjusted odds ratio (aOR) 4.78, CI 1.45–15.74] and tachycardia (aOR 2.97, CI 1.22–7.26) were associated with an increased risk of readmission. Sixty-six patients (36%) died after discharge. Risk of death was increased in older patients (aOR 1.32, CI 1.13–1.54 per 5 years), those with peripheral vascular disease (aOR 12.56, CI 2.35–67.21), higher Charlson co-morbidity index (aOR 1.39, CI 1.09–1.76), use of home oxygen (aOR 4.03, CI 1.89–8.57), and those who had been readmitted (aOR 3.07, CI 1.46–6.43). CONCLUSIONS: Hospitalization for HRF is associated with a high morbidity and mortality. Our observation that home oxygen use was associated with increased mortality suggests that oxygen use could be a risk factor for death in patients with HRF.