Effect of Total Intravenous Anesthesia vs Inhalational Anesthesia on the Level of Inflammatory Markers

Aim of study: Several studies showed that the anesthetic technique can affect several postoperative outcomes including the level of inflammatory markers such as Interleukins (ILs), C-reactive protein (CRP), ferritin, and neutrophil-to-lymphocyte ratio (NLR). This study aims to compare the postoperative levels and trends of change of inflammatory markers, namely IL-6, CRP, ferritin, and NLR in patients undergoing inguinal hernia repair using propofol and dexmedetomidine-based total intravenous anesthesia (TIVA) vs sevoflurane-based inhalational anesthesia (IA).

Type of Study: Prospective, randomized, double-blind, comparative clinical study.

Study Setting: Ain Shams University hospitals, Cairo, Egypt. Study Period: 6-12 months. Study Population: Adult patients scheduled for elective inguinal hernia repair. Sampling Method: Random sampling Sample Size: Using the PASS 15 program from sample size calculation, reviewing results from the previous study (Yediyıldız et al., 2025) showed that postoperative IL-6 levels were significantly lower in the TIVA group than in the sevoflurane group 20,1±23,5 versus 54,8±45,4, based on these findings a sample size of at least 20 patients per group achieve 80% power to reject the null hypothesis of equal means when the population mean difference is μ1-μ2 = 54.8- 4 20.1 = 34.7 with standard deviations of 45.0 for group 1 and 23.5 for group 2, and with a significance level (alpha) of 0.050 using a two-sided two-sample unequal-variance t-test. Ethical Considerations: The study protocol received ethical approval from the Research Ethical Committee, Faculty of Medicine Ain Shams University. Written informed consent will be signed by all participants before starting study.

Randomization and blinding: Group allocation will be contained in sequentially numbered, sealed opaque envelopes, which will be opened by the primary investigator. The collector of blood samples and the data analyzer will be blinded about the study group.

Study Procedures:

All patients will be assessed preoperatively by careful history taking and airway examination. Complete blood count (CBC), coagulation profile, liver and kidney function tests for all patients and electrocardiogram (ECG) for patients older than 40 years of age will be reviewed from patients medical records. All patients will be admitted after completing fasting hours for both solid food and clear fluids. Upon arrival to the operating room (OR), IV access of the size 20 gauge (G) will be inserted. All patients will be monitored with a five-lead ECG, non-invasive blood pressure (NIBP) measurement and finger pulse oximetry. Baseline vital data (MAP, HR, and oxygen saturation (SO2)) will be recorded. HR and SO2 will be monitored continuously and BP will be measured every 5 minutes (min) till the end of the surgery.

All patients will be premedicated with 0.03 mg/kg IV midazolam. Preoxygenation will be performed using 100% oxygen at a fresh gas flow (FGF) of 10 L/min via face mask for 3 minutes, followed by induction of general anesthesia.

Detailed anesthetic technique followed with both groups (TIVA group and Sevoflurane group) will be mentioned in arms and interventions section.

After induction, intubation will be done for all patients using suitable size endotracheal tube (ETT). Both groups will be mechanically ventilated using volume control mode with tidal volume 7-10 ml/kg/min, positive end-expiratory pressure (PEEP) 5 cmH2O and oxygen-air mixture with fraction of inspired oxygen (FiO2) 50% and FGF of 3 L/min, and respiratory rate adjusted with target end-tidal carbon dioxide (ET CO2) 30-40 mmHg. 0.1 mg/kg IV atracurium will be given as needed to maintain muscle relaxation. 0.5 mcg/kg fentanyl will be given if HR or MAP increase ≥20% from their basal value. HR and MAP ≤20% of the basal value will be treated with needed doses of atropine and ephedrine, respectively. All patients will be extubated in the operating room and transferred to postanesthesia care unit (PACU).

Sample Collection and Laboratory Analysis:

Venous blood samples for IL-6, CRP, ferritin, and CBC will be collected from each patient at three time points: preoperative (baseline, sample 0), 6 hours postoperative (sample 1), and 24 hours postoperative (sample 2). All laboratory analysis will be conducted at the main laboratories of Ain Shams University Hospital.

❖ The main researcher of the study will be the principal investigator responsible for the preparation and conduct of the study under supervision of the director and co-directors. Each member of the team will ensure that the study is conducted according to the protocol approved in their meetings that will be arranged on regular basis. Results of the study and any complications that might occur during the study will be recorded and reported by the principal investigator and revised by the director and co-directors. Statistical Analysis The collected data will be revised, coded and introduced to a PC using statistical package for social science (SPSS 23).

Data will be presented as mean and standard deviation (+/-SD) for quantitative parametric data, median and range for quantitative non-parametric data and as numbers and percentage for qualitative data. Suitable analysis will be done according to the type of data obtained. P< 0.05 will be considered significant.

Inclusion criteria

• Adult patients between 18 and 50 years of age undergoing elective inguinal hernia repair.
• American Society of Anesthesiologists physical status classification (ASA) I and II.

Exclusion criteria

• Patient's refusal.
• ASA > II
• Complicated hernia.
• Previous hernia repair with mesh.
• History of allergy to any of the study drugs.
• History of any heart disease affecting cardiac function or rhythm or receiving medications that decrease the heart rate (HR).
• Baseline HR≤60 beat/min.
• Baseline mean arterial pressure (MAP)≤70 mmHg.
• Psychiatric illness.
• Patients with chronic kidney or liver disease. (Creatinine clearance<50 mL/min or serum albumin level<2g/dL.)
• Patients with immunological disorders or receiving immunosuppressive treatment or anti-inflammatory drugs.
• Patients with neoplasms, chronic inflammatory states, or active infections.
• Patients with any type of anemia or those who received iron therapy or blood transfusion within 4 weeks.