Swallowing Function in COVID-19 Patients After Invasive Mechanical Ventilation

Abstract

Objective: To explore swallowing function and risk factors associated with delayed recovery of swallowing in patients with COVID-19 post-invasive mechanical ventilation using the Functional Oral Intake Scale (FOIS).

Design: Longitudinal cohort study.

Setting: Three secondary-level hospitals.

Participants: Invasively ventilated patients (N=28) who were hospitalized with severe COVID-19 and referred to the hospitals' speech and language pathology (SLP) departments after mechanical ventilation between March 5 and July 5, 2020 for an evaluation of swallowing function before commencing oral diet.

Interventions: SLP assessment, advice, and therapy for dysphagia.

Main outcome measures: Oral intake levels at baseline and hospital discharge according to the FOIS. Patients were stratified according to FOIS (1-5, dysphagia; 6-7, functional oral intake). Data regarding comorbidities, frailty, intubation and tracheostomy, proning, and SLP evaluation were collected.

Results: Dysphagia was found in 71% of the patients at baseline (79% men; age, 61±12y; body mass index, 30±8 kg/m²). The median FOIS score at baseline was 2 (interquartile range [IQR], 1) vs 5 (IQR, 2.5) at hospital discharge. Patients with dysphagia were older (64±8.5y vs 53±16y; P=.019), had a higher incidence of hypertension (70% vs 12%; P=.006), and were ventilated invasively longer (16±7d vs 10±2d; P=.017) or had a tracheostomy (9±9d vs 1±2d; P=.03) longer. A negative association was found between swallowing dysfunction at bedside and days hospitalized (r=-0.471, P=.01), and number of days in the intensive care unit (ICU) (r=-0.48, P=.01).

Conclusion: Dysphagia is prevalent in COVID-19 patients after invasive mechanical ventilation and is associated with number of days in hospital and number of days in the ICU. Swallowing function and tolerance of oral diet improved at discharge (P<.001).

Keywords: BMI, body mass index; BSE, bedside swallowing evaluation; CFS, Clinical Frailty Score; COVID-19; Critical care; Deglutition disorders; FOIS, Functional Oral Intake Scale; Frailty; ICU, intensive care unit; IQR, interquartile range; Rehabilitation; Respiration, artificial; SLP, speech and language pathology.

Fig 1

Number of patients with each FOIS score at BSE and hospital discharge.

Fig 2

Scatterplot with regression line depicting the relationship between FOIS level and (A) number of days in the hospital and (B) number of days in the ICU.