Shake No Bake: A Homemade Ultrasound Gel Recipe for Low-Resource Settings.

Commercially produced ultrasound coupling gel is often a scarce resource in rural regions of low-income countries that use sonography as their main imaging modality and, when available, may be cost prohibitive. Various homemade gels were created and tested to assure image quality was not compromised. Glucomannan-based gel and guar gum-based gel had superior physical properties in initial testing and showed no substantial difference compared with commercially available ultrasound gel on subject and phantom imaging and analysis (P > .05 using a 1-tailed sign test). Neither gel required heating, attracted insects, damaged ultrasound transducers, stained samples of clothing, or had harmful effects to subjects.

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.

A randomised experiment comparing low-cost ultrasound gel alternative with commercial gel.

OBJECTIVE: Point-of-care ultrasound is a portable, relatively low-cost imaging modality with great potential utility in low-resource settings. However, commercially produced ultrasound gel is often cost-prohibitive and unavailable. We investigated whether images obtained using an alternative cornstarch-based gel would be of comparable quality with those using commercial gel. METHODS: This was a blinded, randomised, cross-over study comparing commercially produced ultrasound gel with home-made cornstarch-based gel. Ultrasound-trained faculty obtained three video clips with each gel type from patients at one urban ED. The clips were evaluated by a radiologist and an ultrasound-trained emergency physician. Images were assessed in terms of overall adequacy (dichotomous) and quality, resolution and detail using a rating scale (0-10). All sonographers and physicians reviewing the images were blinded to the type of gel used. RESULTS: Thirty-four patients were enrolled in the study, producing 204 separate images (102 with each gel). The cornstarch gel clips were deemed accurate in 70.6% (95% CI 63.9% to 76.5%) of the scans, as compared with 65.2% (95% CI 58.4% to 71.4%) of those using commercial gel. There was no difference between the two groups with respect to image detail, resolution or quality. CONCLUSIONS: Images produced using the cornstarch-based alternative ultrasound gel were of similar quality to those using commercial gel. The low cost and easy preparation of the cornstarch-based gel make it an attractive coupling medium for use in low-resource settings.

In vitro assessment of water vapour transmission of synthetic wound dressings.

The water vapour transmission rate (WVTR) of 14 commercially available wound dressings (11 hydrocolloids, 2 hydrogels and 1 polyurethane film) was evaluated over 24 and 48 h periods using a modified ASTM standard method (ASTM E96-90). For the 48 h studies a novel microcomputer-controlled apparatus was employed. The dressings exhibited a wide range of WVTRs (76-9360 g m-2 d-1 at 24 h under forced air convection of 0.4 m s-1). The influence of air velocity of 0.4 m s-1 was not significant if the WVTR of the dressing was less than 880 g m-2 d-1 when measured under static air conditions. The influence of outer barrier layers and additional bandages on WVTR was also examined.