Risk Factors and Outcomes of Patients with Prolonged Mechanical Ventilation after Successful Weaning

Prolonged mechanical ventilation (PMV) places a large burden on patients, families, and healthcare resources. Some of these patients are successfully weaned and discharged, but some experience recurrent respiratory failure and undergo reinstitution of mechanical ventilation (MV). The purpose of this paper is to identify the risk factors that lead to reinstitution of MV in patients who have undergone successful weaning, and to evaluate their outcome. From January 2006 to December 2007, 314 patients were successfully weaned in the respiratory care center (RCC) of Chang Gang Memorial Hospital. Patients with reinstitution of MV were compared to patients without reinstitution of MV to identify the risk factors that lead to reinstitution. The observation period was from the day of RCC admission to the day of discharge from the hospital. Of the 314 patients, 133 (42.4%) underwent reinstitution of MV due to recurrent respiratory failure, and 181 (57.6%) were discharged without reinstitution. Patients without tracheostomy (p＜0.005) had an increased incidence of reinstitution. Seventeen percent of PMV patients expired during RCC admission and 78 (58.7%) of the 133 patients that received reinstitution of MV expired during hospitalization. The incidence of MV reinstitution after successful weaning is increased in patients without tracheostomy and in those with congestive heart failure as the cause of acute respiratory failure. The prognosis of patients with MV reinstitution is poor.