The standard duration of an SBT by protocol is 2 hours. The duration of SBT may be shorter at the discretion of the ICU attending physician. Additionally, the standard ventilators settings for an SBT is 10 cm of Pressure Support and 5 cm of PEEP (positive and expiratory pressure). This may vary some by the attending's preference though we encourage the use of the standard setting during the study unless there is a clear need to deviate from the protocol. This is to limit the confounding impact that differing levels of Pressure Support may have on the parameters tracked. Patients who are felt to be failing the SBt will be placed back on fill ventilator support at any point directed by the MICU team. Given the lack of objective criteria to define failure of SBT, there are no clear criteria defined and the decision that a patient is failing their SBT will be determined by the attending physician.