Contrast microbubbles improve diagnostic yield in ICU patients with poor echocardiographic windows

Objective: To determine the value of contrast echocardiographic studies in patients admitted to ICUs who have poor echocardiographic windows secondary to COPD, ventilator use, or inability to obtain optimal positioning for th e echocardiogram. Design: A prospective comparison study of technically difficult patients in the ICU. Outcome measure: The total scores for the left ventricle (LV) in the two-ch amber and four-chamber views were calculated at baseline and following inje ction of 1 to 2 mL of a contrast agent. The mean numbers of segments visual ized in all patients at baseline and after injection of contrast agent were compared to assess the effect on improved visualization. Results: Forty consecutive patients underwent echocardiography in the ICU f or evaluation of LV function. Of these, 25 patients (63%) had poor visualiz ation of the endocardium and required IV contrast agent. In these 25 patien ts, the average baseline segmental score was 4.5, compared to 11.6 in patie nts who received an IV contrast agent. Nineteen patients had an average bas eline segmental score of 3.9 and were deemed to have a nondiagnostic study. After administration of IV contrast, all patients converted to a diagnosti c study, with an average score of 11.6 segments visualized. Conclusions: Use of echocardiographic contrast agents in selected patients with poor baseline echocardiographic windows in the ICU setting significant ly enhances segmental LV visualization and yielded 100% conversion from non diagnostic to diagnostic studies.