A recent study indicates that a respiratory pacemaker intended to assist breathing in people with amyotrophic lateral sclerosis (ALS) may actually reduce survival in those with the neurodegenerative disorder. The study, titled “Safety and efficacy of diaphragm pacing in patients with respiratory insufficiency due to amyotrophic lateral sclerosis (DiPALS): a multicentre, open-label, randomised controlled trial,” appeared in the prestigious journal Lancet Neurology.
In ALS (also known as Lou Gehrig’s Disease), nerve cells that control movement progressively die in the brain and spinal cord. This causes muscle weakness, paralysis, and eventually loss of breathing and death.
In people with respiratory failure due to ALS, respirators have become part of the standard treatment. A respiration device called the NeuRx RA/4 Diaphragm Pacing System received Humanitarian Device Exemption approval from the US Food and Drug Administration in 2011. The device is manufactured by Synapse Biomedical Inc., and consists of an electrode that stimulates breathing. According to the company website “The stimulator provides the timing and control of stimulus levels to activate sufficient movement of the diaphragm muscle to affect respiration.” It requires a surgical procedure, unlike a conventional (non-invasive) respirator.
In this study, researchers led by Chief Investigator Christopher J McDermott of the University of Sheffield UK, wanted to test whether the respiratory pacemaker was safe and effective when compared to a standard respirator.
The scientists conducted their study at seven specialist ALS and respiratory centers in the United Kingdom. Participants were people diagnosed with ALS and respiratory insufficiency. The team measured survival in 74 individuals between December 5, 2011 and December 18th 2013, half of whom received ventilation via a respirator and half of which received ventilation with the pacemaker device.
A total of 28 participants (76%) died in the pacemaker group compared to 19 (51%) in the ventilation alone group. In their report, the researchers note “Addition of diaphragm pacing to standard care with non-invasive ventilation was associated with decreased survival in patients with ALS. Our results suggest that diaphragmatic pacing should not be used as a routine treatment for patients with ALS in respiratory failure.”
The study appears to indicate that the use of a pacemaker respiratory system decreases survival in people with ALS when compared to a conventional respirator. In their report, the researchers note that limitations of the study included the need for surgery in the group receiving the pacemaker, therefore it was not possible to mask the treatments in the two groups. They further suggest that it is possible that some specific individuals may benefit from the pacemaker, but that overall, pacemakers should not be recommended or become a standard use in people with ALS and respiratory problems.