Study objectives: To compare the diagnostic capability of recently available hand-held echocardiography (HHE) and of conventional transthoracic echocardiography (TTE) used as a gold standard in critically ill patients under mechanical ventilation.
Design: A prospective and descriptive study.
Setting: The general intensive care unit of a teaching hospital.
Patients: All mechanically ventilated patients requiring a TTE study with a full-feature echocardiographic platform (Sonos 5500; Philips Medical Systems, Andover, MA, USA) also underwent an echocardiographic examination using a small battery-operated device (33 x 23 cm2, 3.5 kg) (Optigo; Philips Medical Systems).
Interventions: Each examination was performed independently by two intensivists experienced in echocardiography and was interpreted online. For each patient, the TTE videotape was reviewed by a cardiologist experienced in echocardiography and the final interpretation was used as a reference diagnosis.
Results: During the study period, 106 TTE procedures were performed in 103 consecutive patients (age, 59 +/- 18 years; Simplified Acute Physiology Score, 46 +/- 14; body mass index, 26 +/- 9 kg/m2; positive end-expiratory pressure, 8 +/- 4 cmH2O). The number of acoustic windows was comparable using HHE and TTE (233/318 versus 238/318, P = 0.72). HHE had a lower overall diagnostic capacity than TTE (199/251 versus 223/251 clinical questions solved, P = 0.005), mainly due to its lack of spectral Doppler capability. In contrast, diagnostic capacity based on two-dimensional imaging was comparable for both approaches (129/155 versus 135/155 clinical questions solved, P = 0.4). In addition, HHE and TTE had a similar therapeutic impact in 45 and 47 patients, respectively (44% versus 46%, P = 0.9).
Conclusions: HHE appears to have a narrower diagnostic field when compared with conventional TTE, but promises to accurately identify diagnoses based on two-dimensional imaging in ventilated critically ill patients.