Sevoflurane vs Propofol Anesthesia in Obese Patients Undergoing Lumbar Surgery

Comparison of the Immunomodulatory Effects of Sevoflurane and Propofol Anesthesia on Pentraxin-3 and Serum Amyloid A Levels in Obese Patients Undergoing Lumbar Instrumentation Surgery

This randomized, single-center, single-masked clinical trial aims to compare the immunomodulatory effects of sevoflurane-based inhalational anesthesia and propofol-based total intravenous anesthesia in obese patients undergoing elective lumbar instrumentation surgery. Seventy patients will be randomized into two groups: a propofol group and a sevoflurane group. Blood samples will be collected preoperatively, at postoperative 6 hours, and at postoperative 24 hours. Pentraxin-3 and serum amyloid A levels will be evaluated as primary inflammatory biomarkers together with IL-6, TNF-α, CRP, glucose, and complete blood count parameters.

Obesity is associated with chronic low-grade inflammation and altered immune responses, which may influence perioperative outcomes. Different anesthetic techniques may modulate inflammatory and immunological pathways during the perioperative period. However, the comparative immunomodulatory effects of inhalational and intravenous anesthetic techniques in obese patients undergoing lumbar instrumentation surgery remain insufficiently investigated.

This prospective, randomized, single-center, single-masked clinical trial is designed to evaluate the effects of sevoflurane-based inhalational anesthesia and propofol-based total intravenous anesthesia on perioperative inflammatory biomarkers in obese patients undergoing elective lumbar instrumentation surgery.

A total of 70 patients aged 18-65 years with a body mass index between 30 and 34.9 kg/m² will be enrolled and randomized in a 1:1 ratio into two study groups. In both groups, anesthesia induction will be standardized using propofol, remifentanil, and rocuronium. Maintenance anesthesia will be performed with either sevoflurane inhalation or propofol infusion in combination with remifentanil infusion under BIS monitoring.

Blood samples will be collected at three different time points: preoperatively, postoperative 6th hour, and postoperative 24th hour. Pentraxin-3 and serum amyloid A levels will be evaluated as the primary inflammatory biomarkers. Secondary laboratory parameters will include IL-6, TNF-α, CRP, glucose, and complete blood count values.

The findings of this study may contribute to understanding the immunomodulatory effects of commonly used anesthetic techniques and may help optimize perioperative anesthetic management in obese patients undergoing spinal surgery.

Inclusion Criteria:

• Patients aged between 18 and 65 years
• Patients scheduled for elective lumbar instrumentation surgery
• Body mass index between 30 and 34.9 kg/m²
• Patients who provided written informed consent

Exclusion Criteria:

• Known allergy to inhalational or intravenous anesthetic agents
• Acute or chronic infectious disease
• Autoimmune disease or immunodeficiency
• Surgery within the last 3 months
• Chronic anti-inflammatory or immunomodulatory drug use
• Morbid obesity, defined as BMI >35 kg/m²
• History of malignancy or active cancer treatment
• Renal failure, defined as GFR <60 mL/min
• Liver failure, defined as AST or ALT greater than 2 times the upper limit of normal
• Diabetes mellitus, metabolic syndrome, or insulin resistance
• Pregnancy or lactation
• Neurological disease, including epilepsy, multiple sclerosis, or Parkinson's disease
• Alcohol or substance abuse
• Inability to comply with the study protocol or provide informed consent
• Known allergy to study drugs (propofol, sevoflurane, remifentanil)
• Emergency surgery