Pharyngeal Electrical Stimulation Increases Proportion of Patients Prepared for Decannulation

September 21, 2018

While PES has been debated as a successful therapy for post-stroke dysphagia, recent data has suggested it may be efficacious.

Rainer Dziewas, MD

In patients who experience a stroke and have a subsequent tracheotomy, pharyngeal electrical stimulation (PES) increased the proportion of patients who were ready for decannulation, many which received the stimulation within a month of stroke onset.

Ultimately, almost half of the patients receiving PES were ready for decannulation compared to less than 10% of those that did not, with similar rates of adverse events (AEs) occurring between the groups.1

"The main finding of PHAST-TRAC is that pharyngeal electrical stimulation substantially accelerates rehabilitation of dysphagia and thereby enables safe and rapid removal of the tracheal cannula in close to 50% of patients," Rainer Dziewas, MD, told NeurologyLive. "The main caveat at this moment is that the subgroup analysis has clearly shown that treatment was less effective in patients with longer preceding ventilation times and longer times from stroke onset to stimulation treatment. Therefore it is probably essential to start treatment as early as possible."

Dysphagia post-stroke is a common occurrence, especially so in those receiving tracheotomies. In a pilot trial, PES improved the swallowing function in those patients, prompting this new study evaluation. Led by Dziewas, from the Department of Neurology at the University Hospital Münster, in Germany, the prospective, single-blind, randomized controlled trial assessed PES at 9 sites with 69 patients. They were randomized 1:1 to either receive PES (n = 35) or sham (n = 34), with a median onset to randomization of 28 days (interquartile range, 19 to 41).

"Although only 1% to 2% of stroke patients need to be tracheotomized, on the ICU this happens much more frequently," Dzwiewas explained. "Thus, in the cohort of stroke patients needing treatment there, 25% are tracheotomized. Getting rid of the tracheal cannula later on has proven to be very difficult. Thus in a recent cohort study, only 26% of tracheostomized stroke patients were decannulated within 3 months post-stroke. The main reason why the cannula cannot be removed in these patients is persistent and severe dysphagia with impaired airway safety."

Ultimately, 49% of patients (n = 17) in the PES group were ready for decannulation compared to only 9% of patients (n = 3) in the sham group (odds ratio, 7.0; 95% CI, 2.41 to 19.88; P = .0008).

AEs were comparable between groups, with 69% (n = 24) of those in PES group reporting an AE compared to 71% (n = 24) in the sham group. In total, 29% (n = 10) of those in the PES group reported a serious AE, compared to 23% (n = 8) of those in the sham group (odds ratio, 1.30; 95% CI, 0.44 to 3.83; P = .7851).

Deaths occurred in 20% (n = 7) of the patients in the PES group and 9% (n = 3) of those in the sham group (odds ratio, 2.58; 95% CI, 0.61 to 10.97; P = .3059). Although, none of the 10 deaths were deemed related to the PES.

Martin Dennis, MD, MBBS, the Chair of Stroke Medicine at the University of Edinburgh, noted in an editorial2 that, to date, no treatments have been shown to reduce the duration or severity of dysphagia after stroke, prompting the proposal of using PES, as well as a modified feeding tube that delivers PES.

“Despite encouraging preliminary studies, the multicenter Swallowing Treatment Using Pharyngeal Electrical Stimulation (STEPS) randomized trial (n= 162), which tested whether the device reduced dysphagia defined either on videofluoroscopy or clinically, produced neutral results,” Dennis wrote. “Explanations offered by the investigators included inadequate dosing, poor adherence, and high rates of spontaneous recovery because the patients had relatively mild stroke, and they proposed that the device might have a greater effect in patients with more severe stroke.”

Although, Domenico A. Restivo, MD, and Shaheen Hamdy, MBChB, PhD, noted in an independent examination3 that there are no pharmacological treatments that have displayed efficacy in improving swallowing performances. Additionally, while multiple rehabilitative treatments have been developed in recently, the most effective protocol has yet to be confirmed.

“Although in a recent large trial of dysphagic stroke patients, PES was unable to demonstrate superiority on radiological aspiration or on clinical dysphagia, several factors including undertreatment of patients receiving PES may have contributed to these results,” they wrote.

Restivo and Hamby did write that that stimulus delivery is difficult to standardize and is subsequently applied in a variable style that may dilute any beneficial effects. But the duo also noted that In comparison with other techniques, PES has been demonstrated to be a promising treatment option for dysphagia in stroke and multiple sclerosis, calling it “repeatable and quite easy to perform at the bedside.”

Dziewas and colleagues acknowledged that future trials would need to confirm whether or not PES is beneficial in tracheotomized patients who receive stimulation similarly early after stroke, as well as to explore its effects in other cohorts.

"The most impressive finding is the high response rate of patients treated with PES and the large difference between the treatment and sham group. This detail suggests that the treatment is indeed efficacious," Dziewas said. "The second most important finding was that there were no device-related serious AEs. Therefore, treatment seems to be safe. Since, as stated above, there are no firmly established treatment options in the given clinical scenario, PES may indeed be an option to treat dysphagia in the most severely affected stroke patients. Furthermore, it is worth mentioning that although in very few patients there were problems with catheter placement, in the majority of them, treatment was applied without any difficulties. Therefore, one could conclude that treatment may indeed be efficacious, safe and sufficiently easy to apply."

REFERENCES

1. Dziewas R, Stellato R, van der Tweel I, et al. Pharyngeal electrical stimulation for early decannulation in tracheotomized patients with neurogenic dysphagia after stroke (PHAST-TRAC): a prospective, single-blinded, randomized trial. Lancet Neurol. 2018;17(10):849-859. doi: 10.1016/S1474-4422(18)30255-2.

2. Dennis M. Pharyngeal stimulation after stroke: more evidence is needed. Lancet Neurol. 2018;17(10):830-831. doi: 10.1016/S1474-4422(18)30312-0.

3. Restivo DA, Hamdy S. Pharyngeal electrical stimulation device for the treatment of neurogenic dysphagia: technology update. Med Devices (Auckl). 2018;11:21-26. doi: 10.2147/MDER.S122287.