Thermal imaging ‘may help improve hand hygiene technique’

Portable thermal imaging cameras could help monitor and assess the quality of hand hygiene technology used by health professionals, according to US researchers.

Findings, published in the American Journal of Infection Control, suggest that portable thermal imagers may offer a new approach to improving hand hygiene practices.

“Our study shows that thermal imaging holds promise as an approach that warrants additional research”

John Boyce

The World Health Organization and the U.S. Centers for Disease Control and Prevention both recommend the use of alcohol-based hand sanitizer (ABHS) in their hand hygiene guidelines.

However, the application technique of ABHS, including the amount of liquid used and the duration of hand rubbing, can have a significant impact on antimicrobial effectiveness.

Several studies have found that health professionals often don’t apply ABHS to their thumb and fingertips, researchers said.

Research author Dr. John Boyce, an epidemiologist who leads an infection control consultancy, said: “Effective hand hygiene is recognized as the single most important act of preventing the transmission of potentially pathogenic microbes in healthcare.

“But there is no widely accepted method to assess the effectiveness of healthcare professionals’ hand hygiene technique.”

Mr Boyce and his fellow author Dr. Richard Martinello, Yale School of Medicine, based their pilot on a previous study, which showed temporary reductions in skin temperature after topical application of ABHS.

They wanted to see if thermal imaging with a portable infrared thermal camera could show whether ABHS had been properly applied by health professionals, including on their fingertips and thumbs.

Using an infrared camera attached to an iPhone, they collected thermal images of the dominant hands of 12 health professionals.

They recorded baseline measurements of the center of the palm, the tips of the third finger and thumb in front of it, and then at different times after the participants performed hand hygiene with the ABHS. The times that immediately followed felt dry and one and two minutes later.

In 11 of the 12 volunteers, thermal images showed a significant drop in the temperature of the palm, finger and thumb after the participants practiced hand hygiene, confirming that the infrared camera could detect color changes that reflect a drop in temperature.

The researchers also found that when participants performed hand hygiene with ABHS without including their thumbs, a lack of colorimetric change in the thumbs was visible in the thermal images.

In addition, a participant with large hands had no reduced temperature in the palm, finger or thumb after ABHS application, suggesting that thermal imaging could also help measure the amount of ABHS needed based on the health professional’s individual hand surface area.

Mr Boyce said: “Our study shows that thermal imaging shows promise as an approach that warrants additional research to determine whether it can be used for routine monitoring of hand hygiene techniques to improve patient care.”

The study concluded that additional studies involving a larger number of people in wearing conditions would be needed to establish whether thermal imaging could be a practical modality for teaching or monitoring hand hygiene.

Linda Dickey, a registered nurse and president of the American Association for Professionals in Infection Control and Epidemiology, described the pilot study’s findings as “exciting.”

“They are the first to evaluate a new tool that can help infection prevention professionals assess the quality of hand hygiene technique during educational sessions, periodic competency assessments and routine patient care,” she said.

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