Risk factors associated with phrenic nerve damage in patients post-COVID-19

Objective: To identify risk factors for phrenic nerve injury, a condition impacting respiratory function, in post-COVID-19 patients, and to understand its role in neurological complications to inform clinical strategies.Methods: A cross-sectional study with retrospective data collection analyzed medical records and electrophysiological studies of 228 post-COVID-19 patients (114 with phrenic nerve damage confirmed by nerve conduction studies and 114 controls without it) from a public rehabilitation unit (Mexican Social Security Institute, Jan-Jul 2021).Analyzed variables included demographics, pre-existing comorbidities (e.g., obesity, asthma, and type 2 diabetes), COVID-19 clinical details, and electrophysiological parameters confirming phrenic nerve status.Results: Multivariable logistic regression identified obesity (odds ratio [OR] 10.36, p < 0.001), asthma (OR 7.93, p = 0.02), male sex (OR 2.2, p = 0.01), and advanced age (OR 1.07/year, p < 0.001) as significant independent risk factors for phrenic nerve damage.Type 2 diabetes mellitus approached statistical significance (p = 0.05) but was not an independent predictor in the final model.Descriptively, in patients with phrenic nerve damage, 49.12% received corticosteroids and 68.42% had other peripheral nerve involvement; however, these were not identified as significant independent risk factors in the adjusted analysis.Conclusions: Phrenic nerve injury is an important post-COVID-19 complication.The conditions of obesity, asthma, being of male sex, and presenting an advanced age emerged as significant independent risk factors, identified through multivariable analysis, adjusting for potential confounders.These findings highlight the need for vigilant monitoring and tailored management strategies in post-COVID-19 patients with these characteristics.