CT for Personalized Mechanical Ventilation

Exclusion Criteria

• •Age \< 18 years;
• •Hemodynamic instability, defined as: systolic blood pressure (SBP) \< 90 mmHg that is not adequately stabilized by vasopressors or inotropic agents. For these purposes, SBP will not be considered "adequately stabilized" if the dose of the vasopressor/inotrope has not been stable for at least one hour;
• •Hypoxemia, defined as: PaO2 \< 70 mmHg on an inspired oxygen fraction (FiO2) greater than or equal to 0.9;
• •Hemodynamic and/or respiratory instability (as defined, in items 2 and 3) that develop when the patient is mobilized during routine nursing care such as repositioning/washing the patient or changing their bed linens;
• •Hemodynamic and/or respiratory instability (as defined, in items 2 and 3) that develop when a 20 second respiratory pause is required to implement the study protocol. This will be tested by inducing such a pause prior to transporting the patient;
• •Any acute or chronic condition which, in the opinion of the investigators, might confound the imaging measurements (such as, but not limited to, severe bronchospasm, pulmonary infection, and lung tumor);
• •Any acute or chronic condition which, in the opinion of the investigators or managing critical care team, could prevent safe transport to the CT suite.
• •"Air leaks" requiring tube thoracotomy (e.g., pneumothorax, bronchopleural fistula);
• •Body mass index \> 40 kg/m2;
• •Pregnancy (since this is a study that would expose a fetus to radiation risk);
• •Patients who have taken part in other research studies involving radiation exposure, or those patients for whom this research radiation history is unavailable at the time of consent.