Inflammatory Response, Laparoscopic Cholecystectomy, Perioperative Hypothermia, Surgical Stress Response
Conditions
Keywords
Intraoperative warming, Forced-air warming, Combined warming, Hypothermia prevention, Fluid warming, Hematologic inflammatory indices, Neutrophil-to-lymphocyte ratio (NLR), Platelet-to-lymphocyte ratio (PLR), Systemic immune-inflammation index (SII), Laparoscopic surgery, Cholecystectomy
Brief summary
Perioperative hypothermia is a frequent and preventable complication that may cause adverse outcomes such as increased blood loss, impaired coagulation, and delayed recovery. Various active warming techniques are used to maintain normothermia during anesthesia; however, their comparative effects on systemic inflammatory responses remain unclear. This randomized controlled clinical trial aims to evaluate the effects of different intraoperative warming methods on hematologic inflammatory indices - including neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and systemic immune-inflammation index (SII) - in patients undergoing elective laparoscopic cholecystectomy under general anesthesia. A total of eligible adult patients will be randomly assigned into four groups according to the intraoperative warming method applied: Control Group: No active warming applied. Forced-Air Warming (FAW) Group: Warming blanket system used throughout surgery. Fluid Warming (FW) Group: Intravenous fluids warmed to maintain normothermia. Combined Warming (FAW + FW) Group: Both forced-air and fluid warming applied simultaneously. Core body temperature and perioperative data will be recorded. Venous blood samples will be obtained preoperatively and 24 hours postoperatively to calculate inflammatory indices. The primary objective is to determine whether active intraoperative warming techniques modulate postoperative inflammatory markers compared to no warming. Secondary outcomes include intraoperative temperature trends, recovery times, and the incidence of hypothermia-related complications. The results are expected to identify the most effective warming strategy to minimize inflammation and optimize postoperative recovery in laparoscopic procedures.
Detailed description
Unintended perioperative hypothermia (core temperature \<36°C) commonly occurs during laparoscopic surgeries due to anesthesia-induced thermoregulatory impairment, pneumoperitoneum, and cold ambient conditions. Even mild decreases in body temperature can impair coagulation, delay drug metabolism, and alter immune function. Maintaining normothermia is therefore critical for improving surgical outcomes. While both forced-air warming systems and fluid warming devices are routinely used, limited data exist comparing their individual and combined effects on postoperative inflammatory responses. Hematologic inflammatory indices such as NLR, PLR, and SII provide cost-effective and reproducible markers that reflect systemic inflammation and immune balance. This prospective, randomized, controlled, parallel-group study will be conducted at Atatürk University Faculty of Medicine, Department of Anesthesiology and Reanimation. Eligible participants are adult patients (aged 18-65 years, ASA I-II) scheduled for elective laparoscopic cholecystectomy under general anesthesia. Patients with infection, chronic inflammatory disease, hematologic disorder, or those converted to open surgery will be excluded. Participants will be randomly assigned to one of four groups: Group C (Control): No active warming; standard passive insulation only. Group FAW (Forced-Air Warming): Forced-air warming blanket applied from induction until the end of surgery. Group FW (Fluid Warming): Intravenous fluids administered through a warming device. Group CF (Combined Warming): Both forced-air warming and fluid warming used together. Standardized anesthesia induction and maintenance protocols will be followed for all patients. Core temperature will be continuously monitored via nasopharyngeal probe. Temperature, hemodynamic parameters, and perioperative variables will be recorded at fixed intervals. Blood samples will be obtained at two time points - preoperatively and at 24 hours postoperatively - for complete blood count analysis. The inflammatory indices (NLR, PLR, SII) will be calculated and compared among groups. Primary Outcome: Postoperative change in hematologic inflammatory indices \[(neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and systemic immune-inflammation index (SII)\]. Secondary Outcomes: Intraoperative temperature maintenance, recovery characteristics, and hypothermia-related adverse events. Statistical analyses will be performed using SPSS. Continuous variables will be expressed as mean ± SD or median (IQR) and analyzed using ANOVA or Kruskal-Wallis test, as appropriate. Categorical data will be compared using Chi-square or Fisher's exact test. A p-value \<0.05 will be considered statistically significant. This study seeks to clarify whether intraoperative thermal management strategies influence the systemic inflammatory response, potentially guiding clinicians toward the most effective warming method to enhance recovery and minimize postoperative complications.
Interventions
DEVICEStandard Active Warming Blanket
An active blanket set at 38°C is used to maintain the patient's body temperature throughout the operation. Body areas outside the surgical field are covered with passive drapes. No supplemental heating is used.
DEVICEIntravenous Warmer Group
All intravenous fluids administered during the operation are administered via a fluid warming device at 38°C. All standard practices continue in the control group.
DEVICEExternal Warmer Group
A special drape is placed over the upper extremities and thorax, and the patient is connected to an external warm air device at 38°C throughout the operation. All standard practices continue in the control group.
Sponsors
Ataturk University
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
SUPPORTIVE_CARE
Masking
NONE
Intervention model description
In this prospective, randomized, controlled trial, patients will be equally assigned to four groups: Control Group (standard blanket + passive blanket) IV Warmer Group (standard care + intravenous fluid warmer) External Warmer Group (standard care + external warmer) Combined Warmer Group (standard care + intravenous fluid warmer + external warmer)
Eligibility
Sex/Gender
ALL
Age
18 Years to 65 Years
Healthy volunteers
No
Inclusion criteria
* Patients scheduled for elective laparoscopic cholecystectomy. * ASA (American Society of Anesthesiologists) physical status I-III. * Age between 18 and 65 years. * Willingness and ability to provide written informed consent.
Exclusion criteria
* ASA IV-V patients. * Emergency surgery requirement. * Preoperative fever (\>38.0 °C) or hypothermia (\<36.0 °C). * Operation duration \<60 minutes or \>180 minutes. * Endocrine/metabolic disorders affecting body temperature (e.g., moderate-severe thyroid dysfunction, pheochromocytoma, severe dysautonomia, malnutrition). * Active infection/sepsis or systemic infection within past 2 weeks. * Chronic immunosuppressive therapy (e.g., ≥10 mg/day prednisolone equivalent ≥2 weeks or biological agents in the past month). * Hematologic disorders (e.g., leukemia, aplastic anemia, myeloproliferative disorders) or abnormal blood counts (platelet \<100 ×10⁹/L, leukocyte \<3 ×10⁹/L). * Active malignancy or ongoing chemotherapy/radiotherapy in last 3 months. * Severe organ failure (Child-Pugh C liver, eGFR \<30 mL/min/1.73 m² or dialysis, NYHA III-IV heart failure, GOLD III-IV COPD). * Coagulopathy or uncontrolled antithrombotic therapy. * Pregnancy or lactation. * Conversion from laparoscopic to open surgery. * Non-adherence to assigned warming protocol. * Inability to place esophageal temperature probe or unreliable temperature monitoring. * Intraoperative hemodynamic instability requiring prolonged vasopressor support or blood transfusion. * Missing or incomplete preoperative or postoperative CBC preventing calculation of inflammatory indices. * Withdrawal of consent or loss to follow-up.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Postoperative Core Body Temperature | Intraoperative, measured continuously and recorded at the end of surgery (1 time point) | Core body temperature will be continuously monitored via esophageal probe throughout laparoscopic cholecystectomy. The primary outcome is the mean core temperature at the end of surgery, comparing the four intraoperative warming strategies (Control, IV warming, External warming, Combined IV + External warming). |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Systemic Immune-Inflammation Index (SII) | Preoperative baseline, postoperative 1 hour, and postoperative 24 hours | SII will be calculated using neutrophil, lymphocyte, and platelet counts from complete blood counts to assess systemic inflammatory response. |
| Neutrophil-to-Lymphocyte Ratio (NLR) | Preoperative baseline, postoperative 1 hour, and postoperative 24 hours | NLR will be calculated from complete blood counts to evaluate the balance between acute inflammation and immune function. |
| Platelet-to-Lymphocyte Ratio (PLR) | Preoperative baseline, postoperative 1 hour, and postoperative 24 hours | PLR will be calculated from platelet and lymphocyte counts to assess postoperative inflammatory and thrombotic response. |
| Lymphocyte-to-Monocyte Ratio (LMR) | Preoperative baseline, postoperative 1 hour, and postoperative 24 hours | LMR will be calculated from lymphocyte and monocyte counts to evaluate immune regulation and inflammatory balance after surgery. |
Countries
Turkey (Türkiye)
Contacts
Primary ContactErkan Cem Çelik, Doctor
Backup ContactMehmet Akif Yılmaz, assistant doctor
Outcome results
None listed