Looking at the day after COVID-19… what laryngeal sequelae should we expect?
airway management is crucial in effective treatment of COVID-19 patients with critical/severe disease. In the literature, the risk of nosocomial SARS-CoV-2 transmission ascribable to increased request for tracheostomy continues to be debated 1,2; in addition, we have to take into account that, once the acute phase passes, we may have to face other problems, such as laryngo-tracheal sequelae following prolonged endotracheal intubation and tracheostomy 3. Now that infectious spreading and contagion has been steadily decreasing in Italy, we observed an escalation in requests for ENT consultation for laryngeal complaints in COVID-19 patients who underwent endotracheal intubation or tracheostomy, independently of age, and were able to overcome the critical stage of disease at our frontline hospital in Milan, located in epicentre of the Italian COVID-19 epidemic.
Several factors could be responsible for a remarkable prevalence of laryngeal dysfunction in post-acute COVID-19 patients: more time needed for respiratory weaning resulting in prolonged endotracheal intubation/tracheostomy maintenance to continuous positive airway pressure ventilation; the use of high-pressure ventilation to treat acute respiratory distress syndrome; Adoption of surgical and anaesthesiologic protocols aimed at reducing dispersal of infected aerosols during/after endotracheal intubation and tracheostomy performance 1,2, such as: the use of non-fenestrated and cuffed tubes with adequate cuff inflation, reduction/avoidance of tracheostomy change 1,2; poor pulmonary performance and hypoxaemia with increased respiratory rate, negatively affecting the respiration/swallowing balance; a possible reduced cortical/subcortical laryngeal coordination due to peripheral and/or central SARS-CoV-2 neuroinvasive propensity through a synapse-connected route 4,5, suspected on the grounds of documented neurological complaints and smell impairment 4.
On one hand, this scenario results in perpetuation of mucosal trauma and mechanical lesions/scaring leading to reduced laryngo-tracheal patency. On the other hand, laryngeal/hypopharyngeal sensation as well as airway protection are reduced; muscle weakness and atrophy related to disuse and critical illness myopathy and neuropathy with impairment in coordination of respiration/swallowing pattern may occur and predispose to swallowing disorders 6.
In the post-COVID era, we must be prepared to deal with an increased prevalence of patients with laryngo-tracheal sequelae, and to adequately manage them, also considering that the therapeutic approach can be troublesome and outcomes are not always predictable. In addition, traditional diagnostic and rehabilitative pathways have been reconsidered and applied only to urgent cases 7-9, and optimising non-instrumental swallowing assessment tools as an alternative to fiberoptic endoscopic evaluation is difficult to carry out in a short-time period. All of this may cause further difficulties in management.
A proposed follow-up schedule to be considered by ENT specialists for post-critical assessment of COVID-19 patients with documented or suspected laryngeal sequelae after intensive care management is presented in Figure 1.