The reality of patients requiring prolonged mechanical ventilation: a multicenter study

The number of patients who require prolonged mechanical ventilation increased during the last decade, which generated a large population of chronically ill patients. This study established the incidence of prolonged mechanical ventilation in four intensive care units and reported different characteristics, hospital outcomes, and the impact of costs and services of prolonged mechanical ventilation patients (mechanical ventilation dependency ≥ 21 days) compared with non-prolonged mechanical ventilation patients (mechanical ventilation dependency < 21 days).

This study was a multicenter cohort study of all patients who were admitted to four intensive care units. The main outcome measures were length of stay in the intensive care unit, hospital, complications during intensive care unit stay, and intensive care unit and hospital mortality.

There were 5,287 admissions to the intensive care units during study period. Some of these patients (41.5%) needed ventilatory support (n = 2,197), and 218 of the patients met criteria for prolonged mechanical ventilation (9.9%). Some complications developed during intensive care unit stay, such as muscle weakness, pressure ulcers, bacterial nosocomial sepsis, candidemia, pulmonary embolism, and hyperactive delirium, were associated with a significantly higher risk of prolonged mechanical ventilation. Prolonged mechanical ventilation patients had a significant increase in intensive care unit mortality (absolute difference = 14.2%, p < 0.001) and hospital mortality (absolute difference = 19.1%, p < 0.001). The prolonged mechanical ventilation group spent more days in the hospital after intensive care unit discharge (26.9 ± 29.3 versus 10.3 ± 20.4 days, p < 0.001) with higher costs.

The classification of chronically critically ill patients according to the definition of prolonged mechanical ventilation adopted by our study (mechanical ventilation dependency ≥ 21 days) identified patients with a high risk for complications during intensive care unit stay, longer intensive care unit and hospital stays, high death rates, and higher costs.