Hand Sanitizer as an Alternative to Ultrasound Transmission Gel

3M™ Defib-Pads as a Reusable Alternative to Commercial Ultrasound Gel in Resource-Limited Settings

INTRODUCTION

With point-of-care ultrasound (POCUS) use in austere environments comes the challenge of having an ever-available coupling medium for image generation. Commercial gel has numerous drawbacks that can limit its utility in these settings, and no studies have evaluated the potential for a reusable coupling medium. This study aimed to determine whether 3M™ Defib-Pads could be utilized as a reusable alternative to commercial gel for image generation in resource-limited settings.

METHODS

A descriptive, cross-sectional survey of Canadian physicians with POCUS interest was conducted to evaluate the interpretability of various POCUS images in a blinded fashion. Three anatomic regions (cardiac, abdominal, and nerve) were utilized, and image generation from the commercial gel and 7 Defib-Pad conditions were evaluated. These included pads that were 1) newly opened, 2) dirtied then rinsed, 3) air dried, 4) rinsed after being air dried, 5) frozen then thawed, 6) used in double thickness, and 7) used with a probe cover.

RESULTS

Compared to commercial gel, 3M™ Defib-Pads performed similarly, with adequate image interpretability of up to 100% in some conditions. The exception was pads that had prolonged air exposure, which produced images that were never interpretable. However, subsequent rinsing of these pads with water resulted in restored image generation.

CONCLUSION

3M™ Defib-Pads were found to produce interpretable POCUS images under multiple environmental stressors and with different modalities of use, suggesting that 3M™ Defib-Pads can perform as a reusable gel alternative in resource-limited settings.

Evaluation of Glucomannan Powder as an Ultrasound Transmission Gel Alternative for Resource-Constrained Environments: A Prospective, Comparative Study

INTRODUCTION

Resource and logistical constraints may limit the availability of commercial ultrasound (US) transmission gel (USTG) in austere environments. Glucomannan powder, a dietary fiber supplement, can be mixed with tap water to form a gel that may be a field-expedient substitute for USTG. We compared glucomannan gel with a commercial USTG for US image adequacy and quality.

METHODS

A single clinician obtained 193 US video clips from 14 different examinations on live-tissue and simulation training models using both commercial and glucomannan USTGs. Four US fellowship-trained providers, blinded to type of gel used, independently reviewed the randomized US video clips. The primary outcome of US image adequacy was scored as "yes" or "no" and analyzed using Pearson χ² analysis. The secondary outcome of image quality was rated on a 0 to 5 Likert scale and analyzed with the independent t test.

RESULTS

For US image adequacy, commercial USTG was superior to glucomannan gel (P=0.042, 95% CI: 96.5-96.6%), with commercial USTG adequate in 96.6% of images (375 of 388 "yes"), whereas glucomannan USTG was adequate in 93.5% (359 of 384 "yes") of images. For US image quality there was no statistically significant difference between the 2 USTGs (P=0.176, 95% CI: 93.4-93.5%), with commercial USTG rated at 3.4±1.0 and glucomannan gel at 3.3±1.1.

CONCLUSION

Despite a high image adequacy rate, glucomannan gel proved inferior to commercial USTG for US image adequacy but produced equivalent image quality. Glucomannan USTG may be a reasonable substitute when commercial USTG is unavailable.