Clinical Research Directory

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.

Comparison of the Effects of Target-Controlled Infusion Method and Manual Propofol Administration on Respiratory Function, Recovery, and Electroencephalogram in Endoscopic Submucosal Dissection Cases

Endoscopic submucosal dissection (ESD) has become widely used as a minimally invasive alternative for the resection of early-stage gastrointestinal neoplasms. Due to the lengthy procedure time and intense pain caused by stretching, cutting, and dissecting the gastric wall during ESD, a deeper level of sedation is recommended compared to traditional endoscopic procedures (1). While ensuring adequate patient immobilisation during ESD, preserving respiratory function and rapid recovery are important clinical goals. Total intravenous anaesthesia (TIVA) is an alternative method to inhalation anaesthesia, achieved through the combination of agents such as propofol and remifentanil. TIVA applications can be performed using manual or target-controlled infusion (TCI) systems. TCI systems aim to achieve and maintain the targeted plasma or effect site concentration based on pharmacokinetic models. These systems have been shown to provide advantages such as more stable depth of sedation during endoscopy, less haemodynamic fluctuation, and faster recovery (2-4). Preserving spontaneous breathing is preferred during ESD procedures, which requires careful monitoring of respiration. The Capnostream® device records four variables (SpO₂, RR, non-invasive EtCO₂, heart rate) every 30 seconds via a nasal cannula and integrates them into a single, dimensionless value called the integrated pulmonary index (IPI). The IPI can range from 1 to 10, with 4 and below requiring intervention and 8 to 10 representing the normal range. Furthermore, the use of the bispectral index (BIS) enables objective monitoring of anaesthesia depth by analysing EEG waves and can increase the safety of the recovery process (5). This study aims to compare the effects of manual TIVA and TCI applications on recovery time, BIS, and respiratory parameters during ESD procedures in the stomach or colon region performed under sedation in the endoscopy unit. The findings will contribute to the safer and more effective planning of sedation applications. References; 1. Sasaki T, Tanabe S, Azuma M, Sato A, Naruke A, Ishido K, et al. Propofol sedation with bispectral index monitoring is useful for endoscopic submucosal dissection: a randomised prospective phase II clinical trial. Endoscopy. 2012 Jun;44(6):584-9. 2. Chang YT, Tsai TC, Hsu H, Chen YM, Chi KP, Peng SY. Sedation for gastrointestinal endoscopy with the application of target-controlled infusion. Turk J Gastroenterol Off J Turk Soc Gastroenterol. 2015 Sep;26(5):417-22. 3. Sarraj R, Theiler L, Vakilzadeh N, Krupka N, Wiest R. Propofol sedation in routine endoscopy: A case series comparing target controlled infusion vs manually controlled bolus concept. World J Gastrointest Endosc. 2024 Jan 16;16(1):11-7. 4. García Guzzo ME, Fernandez MS, Sanchez Novas D, Salgado SS, Terrasa SA, Domenech G, et al. Deep sedation using propofol target-controlled infusion for gastrointestinal endoscopic procedures: a retrospective cohort study. BMC Anaesthesiol. 10 August 2020;20(1):195. 5. Sandler NA, Hodges J, Sabino M. Assessment of recovery in patients undergoing intravenous conscious sedation using bispectral analysis. J Oral Maxillofac Surg Off J Am Assoc Oral Maxillofac Surg. 2001 Jun;59(6):603-11; discussion 611-612. 6. Ding Y, White PF. Simplified quality of anaesthesia scoring system. Anaesthesia. 1992 Oct;47(10):906-7.

A Comparative Study of Eleveld and Schnider Pharmacokinetic Models for Target-Controlled Infusion of Propofol in Sedation of Mechanically Ventilated ICU Patients

This prospective observational study aims to compare the clinical performance of two target-controlled infusion (TCI) models, Eleveld and Schnider, for propofol sedation in mechanically ventilated intensive care unit (ICU) patients. The study evaluates sedation depth, hemodynamic stability, and recovery profiles using the Bispectral Index (BIS) and Riker Sedation-Agitation Scale. Secondary outcomes include awakening time, total propofol dose, and incidence of delirium after sedation withdrawal. The findings may help identify the most reliable pharmacokinetic model for safe and effective ICU sedation.