Characterization of dysphagia and laryngeal findings in COVID-19 patients treated in the ICU-An observational clinical study

Abstract

Background: Dysphagia appears to be common in patients with severe COVID-19. Information about the characteristics of dysphagia and laryngeal findings in COVID-19 patients treated in the intensive care unit (ICU) is still limited.

Objectives: The aim of this study was to evaluate oropharyngeal swallowing function and laryngeal appearance and function in patients with severe COVID-19.

Method: A series of 25 ICU patients with COVID-19 and signs of dysphagia were examined with fiberendoscopic evaluation of swallowing (FEES) during the latter stage of ICU care or after discharge from the ICU. Swallowing function and laryngeal findings were assessed with standard rating scales from video recordings.

Results: Pooling of secretions was found in 92% of patients. Eleven patients (44%) showed signs of silent aspiration to the trachea on at least one occasion. All patients showed residue after swallowing to some degree both in the vallecula and hypopharynx. Seventy-six percent of patients had impaired vocal cord movement. Erythema of the vocal folds was found in 60% of patients and edema in the arytenoid region in 60%.

Conclusion: Impairment of oropharyngeal swallowing function and abnormal laryngeal findings were common in this series of patients with severe COVID-19 treated in the ICU. To avoid complications related to dysphagia in this patient group, it seems to be of great importance to evaluate the swallowing function as a standard procedure, preferably at an early stage, before initiation of oral intake. Fiberendoscopic evaluation of swallowing is preferred due to the high incidence of pooling of secretion in the hypopharynx, silent aspiration, and residuals. Further studies of the impact on swallowing function in short- and long-term in patients with COVID-19 are warranted.

Fig 1. Penetration, aspiration, and residue during swallowing in COVID-19 patients treated in the ICU at the time of the first FEES examination.

Proportions of different degrees of impairment for boluses of different consistencies (carb = carbonated water, thick = mildly thick liquid, and thin = thin liquid). PAS denotes Penetration-Aspiration Scale (1 = no penetration or aspiration, 7–8 = aspiration to trachea; see Table 1). Residue after swallow is evaluated with the Yale Pharyngeal Residue Severity Scale (grade 1 = no residue, grade 5 = filled to the epiglottic rim or to the aryepiglottic folds, respectively; see Table 1). Dotted red filling represents patients in whom the boluses were considered unsafe and not given due to high risk for aspiration. Grey filling indicates the proportion of patients who did not receive the particular bolus for other reasons. NA denotes that the rating was not possible to perform due to insufficient visibility on the video.

Fig 2. Proportions of pooling of secretions and recommendations of oral intake in COVID-19 patients treated in the ICU at the time of the first FEES examination.

Ratings of secretion were made according to the Murray Secretion Scale (“normal” refers to grade 1, no secretion, “mild” to grade 2, deeply pooled secretions, “moderate” to grade 3, transient pooling in the larynx, and “severe” to grade 4, secretions in the laryngeal vestibule). Ratings of recommendations of oral intake were made according to the Functional Oral Intake Scale (FOIS) (“normal” refers to grade 7, total oral intake without restriction, “mild” to grade 5–6, total oral intake with restrictions, “moderate” to grad 3–4, total oral intake with a single consistency or consistent oral intake with tube supplements, and “severe” to grade 1–2, tube dependent with no/minimal/inconsistent oral intake).

Fig 3. Examples of findings during the FEES.

A) Secretions in vallecula and hypopharynx before first bolus. B) Penetration to the level of the vocal folds. C) Aspiration of thin liquid. D) Residue in hypopharynx and larynx after swallow. E) Edema in the arytenoid region on the left side. F) Bilateral vocal fold erythema.

Fig 4. Box plots of FEES variables with a significance of p <0.05 on post-hoc analysis.

(A,B) Pooling of secretions; (C) Residue in the vallecula and (D) Arytenoid edema versus total time in hospital (A, C), number of days in ICU (B), and days with tracheostomy (D). Variables with a significance of p <0.05 on post-hoc analysis using the Kruskal-Wallis test are included. Median, 25th and 75th percentiles are shown.