Postintubation laryngeal and tracheal injuries may be yet another part of recovery from severe COVID-19 infection for some patients.
Evidence has been accumulating on the link between prolonged intubation and lingering breathing and speaking difficulties, a concern that has become more germane in the wake of the COVID-19 pandemic. Now, researchers in Italy led by Giacomo Fiacchini, MD, and Luca Bruschini, MD, of the University of Pisa have published new research suggesting tracheal complications were particularly common in COVID-19 patients intubated for prolonged periods during the pandemic.
The study may be revealing effects of the pandemic itself, as resources and staff were at times overwhelmed by critical care patients. Of the 98 patients admitted from March 1 to May 31, 47% intubated for longer than 14 days developed full-thickness tracheal lesions, compared with 2.2% of a control group treated during the same time frame in 2019. The difference is eye-popping, but may not be generalizable. “I have not observed an increased rate of tracheal injury, but we haven’t carefully studied that outcome as far as I know,” said Daniel Ouellette, MD, FCCP, who is a senior staff physician and director of the pulmonary inpatient unit at Henry Ford Health System, and an associate professor at Wayne State University, Detroit.
He expressed concern about the retrospective nature of the study, and wondered if the different outcomes might be because of disruptions caused by the pandemic. “It’s not hard to imagine that these patients were seen [during] a great rush of patients, whereas the control group was looked at during a period where that kind of volume didn’t exist. There might have been a tendency for more inexperienced practitioners to be intubating patients because they were in the middle of the epidemic. There might have been less supervision of trainees. Individuals, physicians, teams may have been more rushed. Protocols may not have been followed as closely. It may all be an effect of the epidemic itself,” said Dr. Ouellette.
The investigators suggested that implementation of pronation maneuvers may have increased cuff pressure on the tracheal walls leading to some injuries. In addition, the prothrombotic and antifibrinolytic state of patients with COVID-19 may have contributed, along with the impact of systemic steroids that may have altered normal healing of tracheal wall microwounds caused by intubation, cuff pressure, or tracheostomy.
Other research has suggested increased complications from intubation among COVID-19 patients, including a case series that found heightened frequency of pneumomediastinum. The authors of that study suggested that aggressive disease pathophysiology and accompanying risk of alveolar damage and tracheobronchial injury may be to blame, along with larger-bore tracheal tubes and higher ventilation pressures. That study may also be reflecting the conditions of intubation during the pandemic.
Not all institutions saw an uptick in tracheal injury or pneumomediastinum. Mary Jo S. Farmer, MD, PhD, FCCP, of the department of medicine at University of Massachusetts, Springfield, asked one of the institute’s statisticians to examine pneumothorax frequency from March 15, 2020, to March 1, 2021, comparing the rates between patients who tested positive for SARS-CoV-2 within 14 days of admission, and those who tested negative. The rate was 0.5% in patients who tested positive versus 0.4% in those who tested negative. “My division chief’s gut sense is it’s just the same. The prevalence [of pneumomediastinum] is what we were seeing before,” said Dr. Farmer.
Shortly before the COVID-19 pandemic, researchers at Vanderbilt University Medical Center found that more than half of patients undergoing prolonged intubation experience breathing and speaking difficulties at 10 weeks post intubation. The group has followed up that study with another study looking at treatment timing and outcomes.
The researchers reviewed the experiences of 29 patients with laryngeal injury from endotracheal intubation between May 1, 2014,- and June 1, 2018. Ten patients with posterior glottis injury received early treatment, at a median of 34.7 days to presentation (interquartile range, 1.5-44.8 days). Nineteen patients with posterior glottis stenosis received treatment at a median of 341.9 days (absolute difference, 307.2 days; 95% confidence interval, 124.4-523.3 days). Demographic characteristics and comorbidities were similar between the two groups. At last follow-up, 90% of the early-treatment group were decannulated, compared with 58% of the late group (absolute difference, 32%; 95% CI, –3% to 68%). The early group required a mean of 2.2 interventions, compared with 11.5 in the late group (absolute difference, 9.3; 95% CI, 6.4-12.1). No patients in the early group required an open procedure, compared with 90% of the late-treatment group.
Although early treatment seems promising, the timing of laryngeal injury repair would be a key consideration. “You would worry about patient stability, [making] sure they’re clinically stable and didn’t have any acute ill effects from the injury itself or the underlying illness that led to intubation,” said Dr. Ouellette. For COVID-19 patients, that would mean recovery from pneumonia or any other lung problems, he added.
Together, the studies raise concerns and questions over tracheal and laryngeal injury in the context of COVID-19, but fall short of providing clinical guidance. “It raises the awareness in the mind of the critical care physician about these potential injuries to the larynx surrounding intubation,” said Dr. Farmer.
The studies received no funding. Dr. Ouellette and Dr. Farmer reported no relevant financial disclosures.