Purpose: To determine the relative impact of each category-based TEE indication according to the ASA guidelines.
Methods: In 851 patients undergoing cardiac surgery, TEE clinical indications were classified as category I or II according to the ASA guidelines. Category I indications are patients in which TEE is considered useful and category II are those where TEE is potentially useful but indications are less clear. All TEE examinations were reviewed by two anesthesiologists with advanced training in TEE. For each patient, the clinical impact of TEE in the clinical management was assessed using five criteria: 1) change of medical therapy; 2) change in the surgical procedure; 3) confirmation of a suspected diagnosis; 4) positioning of an intravascular device, and 5) substitute to a pulmonary artery catheter (PAC).
Results: TEE had greater utility in category I than in category II indications (15/53 (28%) vs. 110/798 (14%) respectively) (P<0.01). The nature of the clinical impact was as follows: modification of medical therapy in 67/125 (53%), modification of planned surgical intervention in 38/125 (30%), confirmation of a diagnosis in 34/125 (27%). The impact on therapy was higher in complex surgical procedures (39%) than in valvular replacement (19%) (P<0.01) and coronary artery bypass surgery (10%) (P<0.001).
Conclusions: Our findings validate the usefulness of the ASA practice guidelines demonstrating a greater impact of TEE on clinical management for category I indications than for category II. TEE also had a greater clinical impact in complex surgical procedures and in valvular replacement.