Interpreting EVERDAC: Deferring arterial cannulation in critically ill patients with shock.

Patients admitted to the intensive care unit with shock do not automatically need to have an arterial catheter inserted immediately. This is the main take-away point from the Early Versus Deferred Arterial Catheterization in Critically Ill Patients With Acute Circulatory Failure (EVERDAC) trial, which found that slightly fewer patients died in a group randomly assigned to not have an arterial catheter inserted unless it was truly needed, compared with putting one in immediately. This result easily met the trial's predefined criterion for noninferiority of deferring arterial catheterization, and it challenges our standard practice.