Adverse laryngeal effects following short-term general anesthesia: a systematic review.

OBJECTIVE: To conduct a systematic review to determine the occurrence and type of vocal cord injury, as well as the occurrence of hoarseness, in adults using an endotracheal tube or laryngeal mask during routine anesthetic care.

DATA SOURCES: Two reviewers independently performed a literature search using PubMed, EMBASE, and Cochrane Central Register of Controlled Trials. The search was limited to articles published in English, German, French, or Dutch. In addition, reference lists of the included articles were searched manually.

DATA EXTRACTION: Studies describing vocal cord injury and/or hoarseness following short-term general anesthesia (<5 hours) using an endotracheal tube or any type of laryngeal mask were included. To obtain a reliable outcome regarding the occurrence of anesthesia-related laryngeal morbidity, only studies reporting both preoperative and postoperative measurements of vocal cord function were included.

DATA SYNTHESIS: A total of 4119 articles were identified; of these, 13 studies met the inclusion criteria. The studies were found to be heterogeneous and hardly comparable. Hoarseness and vocal cord injuries were common findings in most investigations.

CONCLUSIONS: Hoarseness and vocal cord injuries are clinically relevant complications related to short-term general anesthesia using an endotracheal tube or laryngeal mask. However, more well-designed prospective studies are necessary to generate reliable data as well as to investigate techniques to reduce adverse laryngeal effects. For future research, a proposal to categorize the vocal cord lesions due to general anesthesia is presented. Furthermore, use of a preoperative and postoperative standardized measurement protocol using acoustic analysis and the Voice Handicap Index is advised.