Abstract
Dear Editor,
I read with interest the recent article “Aloe vera Lotion Used as a Potential Alternative Couplant for Sonography, in a Low-Resource Health Care Facility” by Paulinus et al.
1
The authors describe the use of a homemade aloe vera–based lotion that they found to be suitable for use as an acoustic coupling agent for sonographic imaging. The authors concluded that Aloe vera lotion has suitable acoustic transmission compared with commercial coupling gel. In areas where resources are scarce and supply chain issues may exist, Aloe vera lotion may be an alternative coupling medium to provide sonographic imaging. The use of Aloe vera lotion, as an alternative, has a potential to provide and encourage public and private investments.
Although the authors indicate that a limitation of their study was “. . . the suitability of the Aloe vera lotion, in terms of safety, consistency, and shelf life . . .” they do not specifically consider or discuss the potential damage that their aloe vera–based lotion could have on ultrasound transducers. The faces of ultrasound transducers are delicate and susceptible to damage if exposed to some chemicals. ECRI has investigated such incidents including problems that can result from the use of hand sanitizer as a coupling agent. Problems can be exacerbated if a substance is not thoroughly cleaned off the transducer or is used for extended periods of time. I am concerned that your article could encourage others in resource-limited settings to create and use an aloe vera lotion, which could damage their transducers.
A brief review of several ultrasound scanner Instructions for Use (IFU; also referred to as User Manuals) indicates that manufacturers typically indicate “approved” coupling agents for use with their transducers, and none of the manufacturers’ IFUs that I reviewed list aloe vera as an approved coupling agent. In fact, several manufacturers, including GE HealthCare and Healcerion, specifically state in their IFUs that aloe vera products should not be used as coupling agents with their transducers.
The use of coupling agents, whether homemade as in this case, or commercially available, that are not approved by the transducer manufacturer can void the probe’s warranty and have the potential to damage the transducer. Although the authors indicate that their recommendation for an aloe vera lotion has benefits in resource-limited settings, if their homemade lotion damages the ultrasound transducer, it could lead to the transducer becoming inoperable, thus posing a patient safety issue when imaging is indicated but not available and increasing the cost if the probe must be repaired.
Thank you for considering this concern. Please let me know if you have any questions.
Regards,