Outcome of adult critically ill patients mechanically ventilated on general medical wards

Abstract

Objective A significant number of critically ill mechanically ventilated patients are not admitted to the Intensive Care Unit but are cared for on general wards. This study looked at the outcome of these patients. Design Case series. Setting A 1100-bed tertiary hospital in Hong Kong. Patients All adult patients admitted in a 2.5-year period who received invasive mechanical ventilation on general medical wards without admission to Intensive Care Unit or other special care areas. Interventions Invasive mechanical ventilation. Main outcome measures The observed number of deaths, the expected number of deaths as derived from the Mortality Probability Model II system admission model, and other morbidity measures. Results Among 755 patients studied, the observed number of deaths was 673, which amounts to a mortality of 89.1%. The expected number of deaths was 570. The risk-standardised mortality ratio was 1.18 (95% confidence interval, 1.09-1.28; P<0.0005). Patients with chronic obstructive pulmonary disease had the lowest mortality rate of 70.8% (P<0.005). The post-cardiac arrest subgroup had the highest mortality of 99.0%. Conclusions There was a worse-than-predicted survival in the absence of Intensive Care Unit care for the critically ill patients who received mechanical ventilation on general wards. Patients with chronic obstructive pulmonary disease warranted more Intensive Care Unit admissions. Early discontinuation of invasive support should be seriously considered in the post-cardiac arrest patients.