Comparison of the Effects of Total Intravenous Anaesthesia With Target-Controlled Infusion (TCI) and Inhalation Anaesthesia on Airway Complications During Extubation and in the Early Postoperative Period in Thyroidectomy Surgery

Thyroid surgery is one of the most complex operations in the head and neck region due to its close relationship with anatomical structures and the high risk of recurrent laryngeal nerve injury. The proximity of the surgical field to the trachea and larynx increases the likelihood of postoperative airway complications. Common complications include hypoparathyroidism (HP), recurrent laryngeal nerve (RLN) injury, injury to the external branch of the superior laryngeal nerve (EBLN), postoperative bleeding, thoracic canal injury, laryngeal oedema, tracheospasm, tracheal injury, and oesophageal injury. Serious complications such as dyspnoea, asphyxia, or thyroid crisis can lead to patient death.

Severe hypertension or coughing during awakening and extubation may cause bleeding from the surgical site, along with possible haematoma formation. In this context, safe extubation, maintenance of postoperative airway patency, and prevention of early complications are critical components of anaesthesia management in thyroid surgery.

Currently used anaesthesia techniques can directly affect the quality of the recovery process, the sensitivity of airway reflexes, and the reliability of nerve monitoring techniques. Total intravenous anaesthesia (TIVA) regimens, particularly when administered via target-controlled infusion (TCI) systems, allow for more precise control of anaesthetic depth and provide a more predictable, stable transition during the extubation period. In target-controlled intravenous anaesthesia, bolus and infusion of the anaesthetic agent are administered to achieve the desired target concentration based on the pharmacokinetic models of the drug according to the patient's age, gender, height, and weight. Various studies have indicated that the combination of propofol and remifentanil causes fewer complications such as agitation, coughing, and laryngospasm during the recovery period; in contrast, volatile agents such as sevoflurane may trigger undesirable effects such as increased secretion in the respiratory tract and laryngeal sensitivity more frequently.

Furthermore, intraoperative neuromonitoring (IONM) applications are increasingly being used to prevent recurrent laryngeal nerve injuries. However, the accuracy and signal quality of this technology are directly affected by the impact of the anaesthetic regimen on nerve-muscle transmission. The literature has shown that inhalation anaesthetics may weaken IONM responses by suppressing synaptic transmission, whereas TIVA provides more reliable and stable signal transmission. A study comparing propofol and inhalation anaesthesia in patients with papillary thyroid carcinoma showed that propofol-based total intravenous anaesthesia was associated with fewer postoperative recurrences.

In a study comparing TCI-TIVA and sevoflurane inhalation anaesthesia in laparoscopic cholecystectomy surgery, TCI was reported to be associated with less postoperative nausea and vomiting and haemodynamic instability. In a study involving 50 patients undergoing lumbar disc surgery who received general anaesthesia with sevoflurane-fentanyl and propofol-remifentanil, less coughing and haemodynamic instability during awakening were observed in the TIVA group.

The hypothesis of this study is that TIVA administered using the TCI method will result in fewer airway complications after extubation and higher intraoperative neuromonitoring signal quality compared to inhalation anaesthesia. The study will comparatively evaluate the advantages and disadvantages of two different anaesthesia techniques in terms of both postoperative airway safety and haemodynamics, as well as intraoperative nerve monitoring.