Laryngeal mask airway use tied to less pharyngolaryngeal complications after thyroid surgery

The study, published in Scientific Reports, found that LMA used was associated with a reduced postoperative sore throat (POST) risk at 24 h and lower intensity of POST and postoperative hoarseness risk in the patients in the LMA group versus the patients who received ETT at one, 24, and 48 h.

Postoperative sore throat is a frequent complication after anesthesia with an endotracheal tube, affecting up to 62% of patients. It could last 2–3 days, causing discomfort and dissatisfaction and delaying the resumption of patients' normal daily activities. In patients receiving thyroid surgery, the incidence of POST is specifically hog.

The laryngeal mask airway permits the maintenance of upper airway patency without needing the direct visualization of the vocal cords and could prevent potential trauma during tracheal intubation. It is an alternative to ETT that is getting popular in head and neck surgery.

Against the above background, Kuo-Chuan Hung, Department of Anesthesiology, Chi Mei Medical Center, Tainan, Taiwan, and colleagues aimed to investigate the effectiveness of laryngeal mask airway against postoperative pharyngolaryngeal complications following thyroidectomy.

For this purpose, the researchers searched the online databases from inception through February 2021 for randomized controlled trials comparing the incidence of pharyngolaryngeal complications after using LMA or endotracheal tube.

The study demonstrated the following findings:

• Pooled results from seven RCTs compriisng 600 patients demonstrated an association of LMA with a reduced postoperative sore throat risk at 24 h [risk ratio (RR) 0.75] but not at one h and 48 h following thyroidectomy.
• In the LMA group, the POST severity and hoarseness risk were lower than in the ETT group at one h, 24 h, and 48 h.
• In the LMA group, hoarseness severity was lower only at postsurgical 48 h.
• In patients using LMA, the risk of emergence cough was lower than those receiving ETT (RR = 0.14).
• There was no difference in the two groups regarding severity of dysphagia at postoperative one h, 24 h, and 48 h.

LMA use was associated with a reduced POST risk at 24 h but not at one and 48 h following thyroid surgery. Also, emergence cough risk was lower in patients who used LMA compared to those who received ETT.

"Our results supported LMA use in patients undergoing thyroid surgery in reducing postoperative POST and hoarseness without significantly increasing the severity of fluctuation in airway pressure or dysphagia," the authors wrote in their study. Further large-scale studies are warranted o verify our findings, they added.

Reference:

Hung, KC., Wu, SC., Hsu, CW. et al. Efficacy of laryngeal mask airway against postoperative pharyngolaryngeal complications following thyroid surgery: a systematic review and meta-analysis of randomized controlled studies. Sci Rep 12, 18210 (2022). https://doi.org/10.1038/s41598-022-21989-5