The accuracy of PoCUS using pocket-sized echo apparatus at home medical care and in the outpatient clinic

Abstract

Introduction I clarify the accuracy of Point of care ultrasound (PoCUS) using pocket-sized echo apparatus at home medical care and in the outpatient clinic and show its problems and measures. Method The study subjects were 418 people out of 1,984 patients examined at home and in the general internal medicine outpatient clinic during the year from my PoCUS starting date, August 7th, 2017 to August 6th, 2018, for whom a further examination was considered to be necessary by clinical interview, inspection, palpation, percussion and auscultation. PoCUS was administered to all the 418 people prior to the further examination. The device used was Vscan with Dual Probe from GE. I classified as true positive the cases decided to have disease by both PoCUS and the further examination, and as false positive the cases decided to have disease by PoCUS but no disease by the further examination. As for the cases decided to have no disease by PoCUS, I classified as true negative when no disease was found by the further examination, and as false negative when disease was found by the further examination. Then I calculated the accuracy of PoCUS, that is, sensitivity and specificity. Results The accuracy of PoCUS using pocket-sized echo apparatus at home medical care and in the outpatient clinic was 72% sensitivity and 85% specificity. The accuracy of the 119 pulmonary region cases was 75% sensitivity and 65% specificity. The low specificity of pulmonary PoCUS was due to the existence of false positive cases showing multiple B-lines. The accuracy of the 67 heart region cases was 89% sensitivity and 98% specificity, which was quite satisfactory. Unnecessary further examinations can be reduced in cases decided to have no disease by cardiac PoCUS. The accuracy of the 196 abdominal region cases was 69% sensitivity and 90% specificity. The low sensitivity was due to the existence of false negative cases in intestinal disease. For cases in which a bowel disease is suspected, it is necessary to use a linear probe instead of a sector probe with an abdominal region preset, or to conduct the further examination with a convex probe in high-spec apparatus.