A machine commonly used for pain relief improved breathing in patients with obstructive sleep apnea, a clinical trial has found.

Results of the TESLA trial, published eClinical Medicine by researchers from King’s College London and Guy’s & St Thomas’ NHS Foundation Trust, shows the potential of a new therapeutic option for patients using a transcutaneous electrical stimulation (TENS) machine.

Many people with sleep apnea may use a continuous positive airway pressure (CPAP) machine, which pumps air into a mask worn over the mouth or nose while sleeping. However, about 75% of patients adhere to CPAP after three months, and after five years of treatment this is down to about 25%, according to a release from King’s College London. Evidence-based alternatives for CPAP are limited but include mandibular advancement devices and, in some cases, surgical options.

The TENS machine used in the TESLA trial is a small, battery-operated device that has leads connected to electrodes. It is commonly used to reduce pain from conditions such as arthritis and during labor but has not been used for people with obstructive sleep apnea before.

The TESLA trial shows this can be a cheap and non-invasive treatment method in responders. Patients with obstructive sleep apnea were randomized and set to receive a TENS machine or CPAP. The light and continuous electric stimulation of the machine is enough to keep the airway open while asleep, allowing easy breathing to continue.

Patients treated with TENS showed improvements in nocturnal breathing and a significant reduction in daytime exhaustion. The trial also shows that this treatment could be considered for patients who do not respond well to CPAP, providing a second-line treatment that is cheaper and less time-consuming to roll out. 

“Not all patients with obstructive sleep apnea are able to use CPAP therapy, often because the mask can be uncomfortable and in severe cases can lead to sleep deprivation. Alternatives for CPAP include mandibular advancement devices, and sometimes surgical options like hypoglossal nerve stimulation which requires a pre-assessment, surgical implantation, activation, and follow-up appointments,” says Joerg Steier, a professor of respiratory and sleep medicine at King’s College London and a consultant from Guy’s & St Thomas’ NHS Foundation Trust, in a release. “In contrast, a TENS machine is non-invasive, has little side effects, and is cheap. The TESLA trial shows us the potential of a new therapeutic option, transcutaneous electrical stimulation, and it will be interesting to see how the method can be used in clinical practice.”

A multi-center trial is now being planned to prove efficacy in different healthcare systems.