The long and difficult road to better evaluation of outcomes of prolonged mechanical ventilation: not yet a highway to heaven

The study conducted by Cox and coworkers included in this issue of Critical Care demonstrates that prolonged mechanical ventilation ( MV; defined as MV for 21 days or longer) is more specific than Diagnosis Related Group 541/542 as a marker of resource utilization, hospital costs and potentially ineffective care. These patients also had greater 1-year mortality and lower functional ability than patients who had received MV for 48 to 96 hours, despite having better baseline functional status. However, predictors of mortality and long-term functional outcomes that are reliable and accurate at the level of the individual patient remain to be identified.