The majority of patients removed from protocol were weaned by IMV with a longer total ventilation time and weaning time. There was a significant difference in TVT between patients in the IMV and T-piece groups who were withdrawn from protocol because two patients (arbitrarily assigned to the IMV group) required longer stabilization, and the number of patients was small. In general, the patients on the medical service required longer mechanical ventilation (stabilization) because of preexisting lung disease and multiorgan system failure.
This study demonstrates that properly executed weaning by either IMV or T-piece can be carried out successfully and rapidly in a similar time frame when simple bedside criteria for ventilation are met. The strengths of this study are in the design (prospective, same ventilator, same IMV system, large number of medical and surgical patients, randomization to stabilization and weaning mode, strict criteria to start and fail wean). The study did evaluate weaning modes in patients with short-term mechanical ventilation. Unfortunately, there were not enough patients who had required long-term mechanical ventilation or difficult to wean patients, especially with COPD. The issue of which weaning mode is preferable for a specific type of acute respiratory failure and for long-term mechanical ventilation still remains unanswered. Simple bedside spontaneous ventilatory measurements have been confirmed to be excellent predictors of a successful wean for most patients. Source
The study was not designed to evaluate the prediction of weaning. However, it was observed that of five patients who did not satisfy weaning criteria and were removed from the protocol, two failed and three were weaned successfully. Patients who do not satisfy criteria can be given a short T-piece trial or IMV rate reduction with careful observation. As shown previously, some of these patients can be weaned, yet most cannot. It is exactly these patients who have to be observed constantly during a weaning trial. Patients who are clinically stable and meet weaning parameters should be able to be weaned rapidly by either T-piece or IMV The use of a weaning protocol, after satisfying specific weaning criteria, can facilitate a short wean with a minimum of personnel. Rapid weaning should be an important cost-containment measure by reducing patient stay in the ICU.