Discussion
In this study, 90% of patients intubated as part of COVID-19 management
across the ROI who were referred to SLT presented with new onset PED
based on oral intake status. Over half (59%) required tube feeding
based on SLT assessment and over a third were unable for any nutrition
orally post-extubation. This high rate of PED compares with recent
research (3, 4). Post-extubation oral intake status was associated with
length of ICU stay and hospital stay duration in this study.
There was a threefold increase in impact on oral intake status with
proning in this study. Lower cranial nerve paralysis and oropharyngeal
oedema have previously been linked to proning, and cranial nerves IX to
XII are hypothesised to be affected by proning (7, 23). Pre-existing
respiratory disease was also identified as a predictor of PED in this
study. Adults with respiratory disease may already have altered
respiratory swallow coordination, which could be exacerbated
post-extubation. There was approximately a 6% increase in the relative
odds of oral intake status change per year of age in this study. Older
people may have a pre-existing presbyphagia, which pre-disposes them to
PED. Furthermore, frailty and sarcopaenia may also be prevalent amongst
older people, which could contribute towards PED. In contrast to
previous research (5), duration of intubation was not predictive of oral
intake status in this study. This may be due to the fact that patients
with tracheostomy were not excluded in this study, as researchers aimed
to capture all adults with COVID-19 post extubation. Additionally,
prolonged intubation duration with COVID-19 may explain contrasting
findings to previous PED research.
There was a tenfold increase in impact on voice quality for those with
intubation injury, which aligns with previous research (15). This
highlights the importance of post-extubation endoscopy to evaluate vocal
cord function in the ICU setting. Those with a history of respiratory
disease were at threefold risk of impact on voice quality. Dysphonia is
prevalent in adults with COPD which is due, in part, to altered
pulmonary function (24). This alteration may be exacerbated
post-extubation, which may negatively impact on voice. In contrast to
previous research (14), endotracheal cuff pressure was not associated
with post-extubation dysphonia in this study.
The number of adults receiving SLT rehabilitation during hospital stay
appeared low in this study and some adults did not receive dysphagia and
dysphonia intervention when indicated. Concerns regarding aerosol
generated procedures as well as lack of instrumental evaluations may
have influenced the amount and type of intervention being offered during
the first pandemic wave (16). Other influencing factors may be access to
personal protective equipment, SLT services in ICU settings across ROI,
and local dysphagia training.
The rates of persistent dysphagia and dysphonia at hospital discharge
mirrors previous COVID-19 research (3, 4). These subgroups may require
long term rehabilitation due to ICU acquired weakness, post-intensive
care syndrome (PICU) or neurological deficits. These figures are clear
evidence that speech and language therapists should be core members of
outpatient multidisciplinary COVID-19 clinics.
Limitations to this study included missing data on oral health,
delirium, grade of intubation and endotracheal tube size. Missing data
was particularly difficult to access from intensive care records due to
transmission risk. Patient reported outcomes would have been beneficial
but not feasible post-extubation given how medically unwell this cohort
were. Validated scales to measure frailty and sarcopaenia amongst adults
intubated may have been useful but again this was not feasible in the
context of this study.
FEES was not available in ICU settings during the first wave of the
pandemic due to concerns regarding transmission risk (16). FEES provides
physiological data on secretions, pharyngeal sensation and aspiration or
residue. However, it could be argued that oral intake is a more
meaningful outcome from the patient perspective. Nevertheless,
endoscopic assessment of intubation injury would be valuable to ensure
the presence and nature of laryngeal injuries are accurately identified
(25).
Post-extubation dysphonia and dysphagia research is needed from future
pandemic waves to establish the impact of evolving intensive care
management and mutating virus variants on voice and swallowing outcomes.
Post-discharge timepoints to capture longer term voice and swallowing
difficulties would guide multidisciplinary service delivery in the
community.
Conclusions
This study highlights the prevalence of post-extubation dysphagia and
dysphonia amongst adults intubated with COVID-19. Awareness of the
predictors of altered swallowing and voice quality post-extubation will
promote early in-depth evaluation and monitoring during hospital stay.
Prompt dysphagia and dysphonia evaluation and management is needed to
minimise clinical and quality of life complications.