Risk Factors of Post-operative Sore Throat and Hoarseness.

OBJECTIVE: To identify the risk factors of post-operative sore throat (POST) with and without hoarseness (PH) after general anesthesia.

MATERIAL AND METHOD: A retrospective cohort case-controlled study was done at Siriraj Hospital, Mahidol University, Bangkok, Thailand. Two thousand six hundred anesthetic records from between July 2013 and January 2014 were retrieved. Inclusion criteria were complete records of patients older than 18 years and elective surgery under general anesthesia longer than 30 minutes using endotracheal intubation (ETT) or Laryngeal mask airway (LMA). All patients went through complete post-operative evaluation.

RESULTS: Two thousand five hundred three cases were analyzed. Incidences of POST and PH were 41 and 19.7% respectively, mostly graded as mild symptoms. When severity of POST was increased, the incidence of PH also increased significantly (p<0.001). Both POST and PH were strictly related to insertion of ETT. The use of LMA instead of ETI reduced the incidences of POST and PH effectively. In female patients, reduction of ETT from size 7.5 to 7 reduced incidences of POST significantly.

CONCLUSION: The use of LMA reduced the incidences of both POST and PH. This conclusion is limited to selected cases and not applicable to all. Further studies should focus on possible factors to decrease the incidence of POST and PH after endotracheal intubation, which could increase patient satisfaction.