Successful treatment of intubation-induced severe neurogenic post-extubation dysphagia using pharyngeal electrical stimulation in a COVID-19 survivor: a case report

Following the global spread of the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, which first emerged in China in December 2019, the World Health Organization (WHO) declared the coronavirus disease 2019 (COVID-19) outbreak a pandemic on March 11, 2020. The percentages (9–32%) of severely or critically ill COVID-19 patients admitted to intensive care units (ICU) differed among the affected countries [1‐4]. Overall, 20–40% of patients in the United States required mechanical ventilation by the time of their ICU admission [5].

Prolonged ICU stay—especially a prolonged duration of mechanical ventilation coupled with sedation and bed rest—is associated with neurological disorders due to a reduction in afferent sensitivity; consequently, there is a high risk of dysfunction of the swallowing musculature, which can persist for months or years after ICU discharge [6]. COVID-19 can also manifest with neurological symptoms [7], both myopathy and myositis [8], which aggravate post-extubation dysphagia (PED). Indeed, the trauma caused by the endotracheal tube is considered one of the main causes of ICU-acquired dysphagia [9]. PED is defined as swallowing difficulty after extubation. In a systematic review including nine clinical studies analyzing 775 ICU patients after oral endotracheal intubation, 49% of patients presented with PED [9]. A large prospective observational trial (DYnAMICS) evaluating dysphagia in 1304 mechanically ventilated, unselected ICU patients reported PED incidence of 18.3%. Moreover, in that study, among the 90 patients discharged from the hospital, 58 (64.4%) showed persistent swallowing dysfunction [10]. Dysphagia complications following prolonged hospitalization are well known and are associated with a high risk of malnutrition and dehydration, decreased health-related quality of life, and increased occurrence of aspiration pneumonia.

Currently, three different therapeutic options exist for treatment of oropharyngeal dysphagia: (i) patient-specific variation in dietary texture, (ii) postural changes/compensatory maneuvers, and (iii) medical devices delivering personalized neuromuscular stimulation to improve swallowing function by treating the afferent sensory pathways involved in the pharyngeal impairment [13]. The Phagenyx^® system (a medical device CE-marked since 2012 from Phagenesis Ltd., Manchester, UK) was designed to treat the symptoms of swallowing disorders by stimulating sensory nerves in the oropharynx through directed electrical pulses. Pharyngeal electrical stimulation (PES) uses a nasogastric feeding tube-like stimulation catheter incorporating two specially designed electrodes (Fig. 1). Through communication with the patient, the healthcare worker finds an individually adjusted stimulation intensity for optimized PES. Typically, stimulation is delivered using a current intensity range between 1 and 50 mA, a stimulation frequency of 5 Hz, and a pulse width of 200 μs. Each period of PES usually lasts 10 minutes. Three treatment sessions may be given on several consecutive days to patients with neurogenic dysphagia [14, 15]. PES therapy has been used to safely and successfully treat neurogenic dysphagia in patients presenting with multiple medical conditions: in orally intubated ICU patients [15], in tracheotomized severely dysphagic stroke patients [14, 16, 17], in patients with brain injury [18], and patients suffering from multiple sclerosis [19]. Moreover, a large European registry (PHADER registry) in which over 230 patients with neurogenic dysphagia were successfully treated with Phagenyx^® was recently reported [20]. Despite its frequent occurrence in intubated patients and significant morbidity, there is a lack of awareness of the need to systematically screen patients for PED and its consequences, to allow earlier intervention and treatment [10].

We describe the case of a COVID-19 patient presenting with severe general muscle weakness and ICU-acquired swallowing dysfunction who—despite her viral infection and prolonged ICU stay—was successfully treated with PES (post-extubation). This enhanced safe swallowing allowed the patient to resume a more normal nutritional intake, avoided re-intubation or tracheostomy, and therefore permitted a stable ICU discharge.

We are presenting the first case report of a COVID-19 patient with ICU-acquired PED, showing full recovery of swallowing function following PES therapy, and importantly, in the absence of any PES-related adverse events. COVID-19-associated symptoms need to be taken into consideration in the treatment of dysphagic patients, as these patients seem to be at increased risk for healthcare-associated infections. Indeed, bacterial co-infections, as observed in this patient, seem to be a typical characteristic of severe and critical forms of SARS-CoV-2 infection [26], along with severe muscle weakness [27].

PED, which has been reported by up to 62% of patients with severe COVID-19 requiring mechanical ventilation, is one of the mid- to long-term sequelae [11]. Critically ill COVID-19 dysphagic patients seem to be particularly at higher risk of aspiration and subsequent aspiration pneumonia; indeed, brain areas and peripheral nerves and muscles, which are responsible for normal deglutition, are often impaired as a consequence of COVID-19 [12, 28]. The swallowing dysfunction observed in the previously dysphagia-naïve patient reported here is most likely the result of endotracheal tube trauma, a commonly observed problem in cases of intubation in an emergency setting [10]. Our observations, as reported in a recent publication [29], also suggest that there is a direct neurological component involved in the pathology of COVID-19 patients. Further research will nevertheless be needed to understand the full extent of this novel coronavirus disease and its consequences.

Of note, a high stimulation level was required on the first day of PES, showing the lack of neuromuscular sensitivity by this patient following her prolonged (12-day) intubation; such reduced local sensitivity has been previously described in patients with ICU-acquired dysphagia [12]. From the second stimulation day, a more normal range of stimulation values were used according to patient responses, showing a recovery of sensibility after a single 10-minute PES treatment session. PES can be delivered while patients are still intubated as well; in this case, the stimulation threshold can be deduced from more autonomic cues from lightly sedated patients (Richmond Agitation-Sedation Scale [RASS]-1), such as sweating, mimics, increased blood pressure, or stress. A recent pilot study by Koestenberger et al. showed a significantly earlier improvement in swallowing after PES treatment in orally intubated ICU patients compared to those stimulated following extubation, suggesting a faster recovery of dysphagia when PES is performed sooner [15]. Moreover, patients receiving PES treatment had a lower prevalence of pneumonia and frequency of re-intubation than patients without PES stimulation. Had we started PES therapy during intubation in this patient, we may have accelerated her recovery by minimizing the consequences of dysphagia.

At the beginning of the COVID-19 outbreak, the priority for ICUs was simply to keep patients alive, and therefore no therapeutic procedures other than those associated with intensive care were performed. As time progressed, medical staff gained experience and came slowly back to normality. A balance had to be found between the limited exposure of medical staff and the rights of critically ill COVID-19 ICU patients for an optimal health-related quality of life and the full program of medical care they needed. In this sense, a recently published WHO guideline recommends continuous rehabilitation interventions for patients with severe COVID-19 [30].

For ICU patients, systematic bedside screening for PED—for which a feasible and pragmatic approach has already been published [12]—as well as rehabilitation measures of neurogenic dysphagia should be implemented into clinical protocols. To minimize the risk of viral exposure through aerosol emissions during dysphagia therapy, medical staff should wear adequate personal protective equipment (PPE) for procedures on suspected or confirmed COVID-19 cases [31, 32]. This will allow early dysphagia assessment and the subsequent implementation of personalized treatment [12]. COVID-19 survivors in the acute, subacute, and long-term phases of care have specific rehabilitation needs; PES therapy can be used to facilitate early recovery, further transfer of dysphagic patients to non-intensive case rehabilitation facilities, and contribute overall to shorten hospital length of stay.

Clinical management guidelines related to dysphagia therapy, as well as international intensive care societies such as the ÖGARI [Österreichische Gesellschaft für Anästhesiologie, Reanimation und Intensivmedizin] in Austria, recommended in their recently published position statements that aerosol-generating procedures be restricted on COVID-19-positive or suspected patients in order to avoid contamination risk for health care personal [29, 33]. Consequently, only non-instrumental bedside examinations are performed to assess dysphagia in potentially infected ICU patients [26‐28]. Although instrumental assessments in COVID-19-positive cases are currently limited, optimal rehabilitation of PED following prolonged ICU stay is feasible; the use of SLT interventions or equipment-based therapies like PES leads to effective and early management of dysphagia [34]. A holistic approach within an intensive care multidisciplinary team is needed to optimally take care of patients with acute and early post-acute neurogenic dysphagia. In the absence of any established standard treatments for dysphagic COVID-19 patients, PES may facilitate early discharge to non-intensive care units and reduce the risk of ICU readmission. As we have unfortunately learned from the ongoing COVID-19 pandemic, maintaining adequate ICU efficiency and bed capacity is a critical factor in preventing the health care system from being overwhelmed.