Determinants of long-term mortality after prolonged mechanical ventilation

Study Objectives The poor long-term survival of patients requiring prolonged mechanical ventilation may be due to potentially modifiable factors. We therefore sought to assess the early determinants of long-term survival after discharge from a specialized respiratory unit. Methods Eighty of 113 patients (71%) admitted to a respiratory care unit from June 2001 to August 2003 survived to discharge. Mortality outcomes and dates of death were determined by review of the records and survey in April 2005 of a national Death Master File. Potential determinants of survival after discharge were collected during the admission to the unit. Results Fifty-five percent of patients died within the first year after discharge. Age of 65 years or older, sacral ulcers, a serum creatinine > 124 mu mol/L, and failure to wean were each individually associated with shorter survival. Age, skin integrity, and wean status on discharge remained independent determinants of survival in a multivariable analysis. In a post-hoc analysis, chronic irreversible neurologic diseases were also independently associated with poor long-term survival. Conclusions Mortality after discharge from a respiratory care unit is high. Interventions that may favorably impact long-term survival in these patients could target the modifiable factors identified, including measures that facilitate weaning and prevent or treat renal dysfunction and skin breakdown.