Over the past several decades, numerous investigators have attempted to predict successful liberation from mechanical ventilation. A variety of parameters have been examined. Some parameters are complex and require specialized equipment for measurement, while others have been more globally applicable given the ease of measurement and simplicity of assessment tools. However, as was well-outlined in a supplement to CHEST,1–
a simple, reliable, discriminating parameter continues to elude us. The focus has been directed at determining which variables indicate a reduction in ventilatory support or successful 2-h spontaneous breathing trial (SBT) with or without subsequent discontinuation of mechanical ventilation (DOMV). Pulmonary mechanics have been measured prior to reducing ventilatory support or initiating an SBT as well as trended during an SBT. The study by Martinez et al2
in the April issue of CHEST provides a fresh approach. It trends basic measurements of pulmonary mechanics over the resumption of ventilatory support after a 2-h SBT.