The impact of anesthesia instruments and drugs on the occurrence of vocal cord injury, systematic review and meta-analysis

Objective: This study extensively examined common complications related to anesthesia drugs and equipment on vocal cords. It also delved into factors such as smoking, anesthesia duration and anesthesia induction methods. Overall, the research aimed to pinpoint influential factors for creating a general anesthesia protocol with minimal post-operative complications.

Materials and methods: We searched PubMed, Scopus, Web of Science, and Google Scholar for studies concerning the impact of anesthesia drugs and equipment on the vocal cord, until May 2023. after screening and reviewing of full text, the characteristics of the study including sample size, age, dosage or size of anesthesia drugs and equipment, Duration of intervention, Adverse effects, and Maintenance of adverse effects, were extracted. The quality assessment was done using the Newcastle-Ottawa scale and the Jadad Scale.

Results: Our review included 39 studies from 1983 to 2023. The most frequent VCAEs were cough‎ (39.17%; CI = 9.84-68.51)‎, hoarseness (‎35.32%; CI = 25.04-45.60)‎, and erythema (35.09%; CI=-4.84-75.02). VC paralysis was relatively less frequent (‎4.16%; CI = 2.90-5.43)‎. Meta-regression showed no difference in the frequency of VCAEs with or without single-lung ventilation and smoking. However, the duration of procedure was shown to be affecting three outcomes; the duration shorter than 120 min is associated with lower rates of granuloma (2.74% vs. 44.30%; p < 0.05) and higher rates of cough (48.89% vs. 15.91%; p < 0.05) and VC paralysis (42.86% vs. 0.12%; p < 0.05). The overall outcomes were not affected.

Conclusions: The most common anesthesia-related VCAEs are cough, erythema, and dysphagia, while serious complications like vocal cord hematoma and paralysis are rare. Also surgery duration significantly influences VCAE occurrence.