ABSTRACT
Introduction
Point-of-care ultrasound (POCUS) is a tool undergoing expanding use in military medicine, including routine inpatient, outpatient, and operational environments. Specific musculoskeletal POCUS examinations require additional equipment in the form of a standoff assist device to maximize image acquisition. These devices may not be readily available to POCUS users in more austere or resource-constrained environments. We devised a study to determine if intravenous fluid bags of various volumes could be substituted for standard standoff devices in musculoskeletal POCUS.
Materials and Methods
Sequential images of a soft tissue foreign body model, an interphalangeal joint, and a chest wall were taken using a gel standoff pad or water bath and compared to images acquired using three different sizes of intravenous fluid bags after removing excess air from the bags. Images were de-identified and scored for quality using a visual analog scale. We used a two-factor analysis of variance without replication to analyze the differences in image quality between standoff devices, with a P-value less than.05 considered statistically significant.
Results
We performed 13 POCUS studies and had a group of eight POCUS-trained physicians and physician assistants score these studies, resulting in 104 total quality scores. There was no significant difference in image quality between standoff devices for chest (P-value.280) and hand (P-value 0.947) images. We found a significant difference in image quality between standoff devices for the soft tissue foreign body model (P-value 0.039), favoring larger intravenous fluid bag standoff over standard devices.
Conclusions
In the absence of a standard commercial gel standoff device or water bath, intravenous fluid bags of 50, 100, and 250 mL can facilitate quality image acquisition for musculoskeletal POCUS.
Radiolucent Foreign Body Seen on Point-of-Care Ultrasound but not on X-ray
