A131 POINT OF CARE ULTRASOUND CHANGES THE NEEDLE INSERTION LOCATION FROM AN ANATOMICALLY LANDMARKED SITE DURING BEDSIDE PARACENTESIS.

Abstract

Abstract Background Paracentesis is a bedside procedure to obtain ascitic fluid from the peritoneum. It is traditionally performed using anatomic landmarking and percussion to ascertain a safe drainage site. The serious complication rate has been reported as less than 2%. Point-of-care ultrasound (POCUS) has been adopted into education and clinical use and has been shown to improve the safety of certain procedures such as central line insertion and thoracentesis. However, the evidence supporting its use is limited. Aims We aimed to assess if POCUS would yield a user-preferred site for needle insertion compared to conventional landmarking, defined as a >5cm change in location. Methods Adult patients under the care of gastroenterology or general internal medicine at Kingston Health Sciences Centre undergoing paracentesis were consecutively enrolled between January and September of 2020. Physicians performing the procedure were enrolled based on availability. An anatomic site was selected 4cm superiorly and 2-4cm medially to the anterior superior ileac spine and confirmed with dullness to percussion. POCUS was then employed to determine if there was an alternative user-preferred site. Patient and operator demographic data and procedure-related information were collected. Results A total of 30 individual patients and 24 operators were enrolled, comprising 45 unique procedure combinations. Operators were primarily in their PGY 1 and 2 years of training (33% and 31% respectively). Per procedure, patients mean age was 61, and most of the ascites was due to cirrhosis (84%) predominantly due to EtOH (47%) and NAFLD (34%). As per indication, 29% of procedures were for diagnostic purposes alone. In total, users primarily preferred the POCUS site which resulted in a change in needle insertion site >5cm from the anatomic site in 69% of cases. The average depth of fluid was greater at the POCUS site vs. the anatomic site (5.4cm+/-2.8 vs 3.0cm+/-2.5, p<0.005). On average, POCUS deflected the needle insertion site superiorly and laterally to the anatomic site. Operators listed that per procedure the POCUS site was chosen to avoid adjacent organs (38%), optimize fluid pocket (61%) and due to abdominal wall issues (primarily issues with pannus; 11.5%). Importantly 6 cases were aborted due to a lack of an appropriate fluid pocket, despite clinical and/or prior radiographic evidence of ascites. Conclusions Overall, POCUS changes the needle insertion site from the conventional anatomic site for most procedures, due to user-perceived safety concerns. POCUS also prevented an attempt at paracentesis in 6 cases that were deemed unsafe. Therefore, POCUS plays an important role in bedside paracentesis. This research supports the use of POCUS in paracentesis and argues for continued training with POCUS throughout medical school and residency. Funding Agencies None