Aim 1: To derive and validate a prediction model for difficult airway (three or more attempts at laryngoscopy to place an endotracheal tube and/or the need for another operator among the critically ill) \[37\].
Aim 2: To derive and validate a prediction model for hemodynamic compromise, i.e., post-intubation hypotension \[defined as a decrease at any point in mean arterial pressure less than 65 mmHg; systolic blood pressure less than 80 mm Hg and/or a reduction in systolic blood pressure of 40% from baseline; or the initiation of, or increase in infusion dosage of, any vasopressor medication (bolus or infusion) during the 30 minute period following intubation\] \[38-39\].
Aim3: To derive and validate a predication model for hypoxemia (decrease in pulse oximetry to oxygen saturation less than 88% during the procedure).
