A Systemic Review on the Diagnostic Accuracy of Point-of-Care Ultrasound in Patients With Undifferentiated Shock in the Emergency Department

Abstract

Early identification of the shock type and correct diagnosis is associated with better outcomes. Previous studies have suggested that point-of-care ultrasound (POCUS) increases the diagnostic accuracy of patients in undifferentiated shock. However, a complete overview of the diagnostic accuracy of POCUS and the related treatment changes when compared to standard care is still limited. Our objective was to compare POCUS against standard practice regarding the diagnostic accuracy and specific therapeutic management changes (fluid volume administration and vasopressor use) in patients with undifferentiated shock in the emergency department (ED). We conducted a systematic review in concordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. A systematic search was performed using Embase, PubMed, Cochrane Central Register for Controlled Trials, and clinicaltrials.gov. Two physicians independently selected the articles and assessed the quality of the studies independently with the Quadas-2 tool. All included studies used POCUS in adult patients in undifferentiated shock and described diagnostic accuracy or specific therapeutic management changes (fluid volume administration or vasopressor use) and compared this to standard care. The primary outcome was diagnostic accuracy. Secondary outcomes were the amount of fluid administered and vasopressor use in the ED. Only articles published after 1996 were included. There were 10,805 articles found of which 6 articles were included. Four out of six studies reported diagnostic accuracy, three reported on fluid administration and vasopressors. We found that the diagnostic accuracy improved through the use of POCUS when compared to the standard care group, increasing overall diagnostic accuracy from 45-60% to 80-89% when combined with clinical information. There was no significant difference in fluid administration or vasopressor use between the groups. In our systematic review, we found that the use of POCUS in patients that presented with undifferentiated shock in the ED improved the diagnostic accuracy of the shock type and final diagnosis. POCUS resulted in no changes in fluid administration or vasopressor use when compared to standard care. However, the results should be interpreted within the limitations of some of the studies that were included in the review.

Keywords: hypotension; pocus; resuscitation; shock; ultrasound.

Figure 1. Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) flow diagram.

PICO: Population, Intervention, Comparison, Outcomes of study as mentioned in methods section [23].

Figure 2. Diagnostic Accuracy No POCUS vs POCUS.

Studies in figure from left to right: Jones [25], Javali [29], Sasmaz [27], Shookohi [26]. Three studies marked the difference in diagnostic accuracy between the two groups as significant (*) [25-27]. Javali [29] did not report significance but found a Cohen's kappa coefficient (#) of 0.89, correlating with an almost perfect agreement with the final diagnosis. The diagnostic accuracy was defined as the percentage of occurrence of the correct diagnosis with or without POCUS.