The impact of laryngoscopy and tracheal intubation on thyroid gland

Abstract

Stress, fear, and emotions can induce variations in thyroid and growth factor hormone levels. For many patients, surgery is a significant source of stress, and because thyroid hormone release is influenced by stress, general anaesthesia and endotracheal intubation can raise Thyroid Hormone-blood concentrations. Therefore, this study was carried up to know the impact of laryngoscopy and intubation on TSH and free T4 blood levels in ASA 1 patients. : Following approval from the Ethics Committee and informed agreement from the participants, an observational descriptive cross-sectional study was undertaken at the department of anaesthesiology on 30 patients scheduled for elective surgery under general anesthesia. Blood samples were taken in EDTA tubes and tested for Free T4 and TSH levels within 3 hours of collection. A preformatted datasheet was used to document a thorough history, examination results, and laboratory investigations.Among the study participants out of 30, majority 22(73.3%) were males and remaining 8 (26.7%) were females and the mean age ranged from 17 years to 63 years. Various surgeries included laparoscopic and laparotomy, orthopaedic and urological surgeries. TSH mean levels did not differ among the three sampling sessions. The principal finding in our study was the increase in free T4 level immediately after intubation. Out of the 30 patients, 20 patients showed an increase in free T4 levels immediately after intubation and 8 patients continued to show an increase 20 minutes following intubation. Results showed increase in free T4 level immediately after intubation with no change in TSH levels. More research is required to conclude the cause for rise in thyroid hormones after anesthesia. These hormonal alterations could shed light on the molecular and cellular effects of anesthetics.