Learning to apply the pocket ultrasound device on the critically ill: comparing six 'quick-look' signs for quality and prognostic values during initial use by novices

Biais and colleagues [1] have shown that echocardiographers can adequately perform a three-view cardiac examination in the emergency setting using a pocket ultrasound device (PUD). We have similarly noted that an evidencebased 'quick-look', cardiac limited ultrasound examination has diagnostic and prognostic value [2], can affect medical decision-making [3], and can be successfully taught to internal medicine residents [4]. As few data describe the learning curve of ultrasound imaging with PUDs, we observed the initial quality and prognostic value of six 'quicklook' signs obtained by residents learning to use the PUD. Internal medicine residents in an ultrasound training program [4] recorded a brief, previously described [2] cardiac limited ultrasound examination designed to detect six 'quick-look' signs of left ventricular systolic dysfunction, left atrial enlargement, ultrasound lung comet (ULC) tail artifact representing interstitial lung edema, elevated central venous pressure, pleural effusion, and right ventricular enlargement on a convenience-sample of intensive care unit (ICU) patients with respiratory failure, shock, or severe cardiac disease, using a PUD (Vscan, GE Healthcare, Wauwatosa, WI, USA). An expert echocardiographer reviewed the resident-acquired images and assigned a quality score: 0 (no image), 1 (only motion detected; off-axis), 2 ('suboptimal', poor delineation of structures), 3 ('adequate' for diagnosis of particular sign), or 4 ('optimal', good delineation of all structures).