Incidence and outcome of weaning from mechanical ventilation in medical wards at Thammasat University Hospital

BACKGROUND: Weaning from mechanical ventilation is classified as simple, difficult, or prolonged according to weaning process. Theoretically, simple weaning group usually has better clinical outcomes than non-simple group; however, the results of previous studies were still inconsistent. OBJECTIVES: The purpose of the study was to determine the incidence, predictors, and outcomes of ventilator weaning and causes of weaning failure. METHODS: A prospective observational study was performed between June and December 2013 in all patients (n = 164) who required mechanical ventilation with endotracheal intubation in medical wards at Thammasat University Hospital, Thailand. Duration of weaning, causes of weaning failure, extubation, reintubation, tracheostomy, number of ventilator-free days within 28 days, length of hospital stay, and hospital mortality were measured. RESULTS: 103 patients were eligible for final analysis. Mean ± SD age was 65.1±17.5 years and 55.3% were males. The incidences of simple, difficult and prolonged weaning were 46.6%, 36.9% and 16.5%, respectively. The mortality rates for simple, difficult, and prolonged weaning were 0%, 10.5% and 23.5% (p = 0.006), respectively. The 3 causes of weaning failure in non-simple weaning were bronchospasm, pneumonia, and malnutrition. CONCLUSIONS: Non-simple weaning increased mortality. Bronchospasm, pneumonia, and malnutrition were key risk factors for weaning failure. Strategies are needed to minimize their effects.