We recently developed a nurse-driven ventilator weaning protocol for all ICUs at St. Luke's and Roosevelt hospitals. The protocol was approved by the Critical Care Committee and is implemented as of May 2007. All ICU nurses, respiratory therapists, and ICU physicians have been educated on this protocol We plan to prospectively collect data to look at length of stay on mechanical ventilation in patients weaned by nurse-driven ventilator weaning protocol. We plan to compare such data to retrospectively collected ventilator LOS data in patients weaned by physician-initiated ventilator weaning method.