Appropriate Use of Transthoracic Echocardiography in the General Intensive Care Unit: Experience at Te Toka Tumai Auckland

Abstract

Transthoracic echocardiography (TTE) is a key non-invasive imaging modality for the diagnosis of acute and chronic cardiac conditions. However, availability is increasingly becoming limited by chronic shortages of trained cardiac sonographers, so appropriate use of TTE is critical. Requests in the Department of Critical Care Medicine (DCCM), where scans are usually performed within 12 hours, were evaluated to assess current practice with the aim of effectively utilising TTE. A retrospective observational study of TTEs performed in DCCM over 12 months was performed. Data including demographics, clinical indications, and scan results were recorded by review of individual patient records. Appropriateness of the request and requirement for follow-up imaging were reviewed by an independent cardiologist. Requests for organ donation were excluded. A total of 141 scans were performed; 80 (57%) were males and mean age was 53±17 years. Indications included trauma (2.1%), increasing inotrope/vasopressor requirement (19.9%), and presumed acute cardiac event (78.0%). Scans were abnormal in 61 patients (43.3%), with at least one significant abnormal finding. Thirty-seven patients (26.2%) died during admission; 55% had new echo abnormalities. Overall, 113 (80.1%) requests were considered clinically appropriate, and abnormalities were present in 46.9%. Twenty-eight (19.9%) TTEs were not indicated based on clinical details provided; 20 (71.4%) were normal or had no interval change. Cardiology follow-up was considered indicated for 56 (39.7%), completed in 23 (41%), and not performed in 14 (25%). Transthoracic echocardiography was appropriately used for the stated clinical indication, but abnormalities were evident in <50%, suggesting a need for better pre-test risk stratification. Mechanisms to improve follow-up of abnormal findings are warranted.