PURPOSE: Patients discharged from respiratory care units specialized in the care of the difficult-to-wean patient tend to have poor long-term outcomes. We sought to assess the prevalence and determinants of long-term mortality in patients discharged from one such unit.
METHODS: The study was conducted in the specialized pulmonary care unit at Harper University Hospital (Detroit, MI) from June 2001 to August 2003. Eighty of the 113 (71%) patients admitted to the PCU survived to discharge. Mortality outcomes after discharge and dates of death were determined by a review of the records, and survey in April 2005 of the Death Master File from the United States Social Security Administration. Potential determinants of mortality after discharge were prospectively collected on admission to the PCU, and analyzed using time-to-event statistics including log-rank tests, as well as Cox-proportional hazards analysis.
RESULTS: Twenty eight of the 80 patients (35%) were discharged on a ventilator. By April 2005, 60% of the patients had died, with 55% of patients dying within the first year after discharge from hospital. In a Cox-proportional hazard analysis, age, renal function and wean status on discharge were significant and independent determinants of mortality: Age > vs. < 65 years hazard ratio (HR) 2.2 (95%CI 1.2-4.0, p = 0.01), abnormal (Cr < 0.6 or > 1.4) vs. normal (Cr 0.6-1.4) renal function HR 2.0 (95% CI 1.0-3.6, p = 0.04), not weaned vs. weaned HR 1.9 (95% CI 1.0-3.5, p < 0.05).
CONCLUSION: Mortality after discharge from a specialized respiratory care unit is high, with most of the patients dying within 1 year after discharge. Our study identifies advanced age, renal impairment, and dependence on a ventilator as significant and independent predictors of mortality after discharge.
CLINICAL IMPLICATIONS: The study confirms data from other series indicating disappointing survival rates after discharge from specialized respiratory care units. We expand on those findings and identify independent predictors of mortality. Whether interventions that facilitate weaning and reduce renal dysfunction favorably affect long-term survival remains to be determined.
DISCLOSURE: Loutfi Aboussouan, None.