Cold hemagglutination pathophysiology. Evaluation and management of patients undergoing cardiac surgery with induced hypothermia.

The widespread induction of systemic hypothermia and use of iced cardioplegic solutions in cardiac surgery may promote occasional cold autoagglutination. Routine laboratory methods used to detect cold-agglutinating autoantibodies may not take into account the extremely low temperatures that the heart and body may attain during cardiopulmonary bypass. Several cold-mediated complications have now been encountered during cardiac surgery in patients with both known and unsuspected cold-reactive autoantibodies. This review will provide the clinician with a working knowledge of the cold autoimmune disorders, a rapid method for differential diagnosis in unproved cases, and an ability to select techniques for reliable myocardial and renal protection in both known and unsuspected cases.