Effects of Intraoperative Warming Methods on Hematologic Inflammatory Indices in Laparoscopic Cholecystectomy (WARM-CHOL)

November 17, 2025 updated by: Erkan Cem ÇELİK, Ataturk University

Evaluation of the Effects of Different Intraoperative Warming Techniques on Core Body Temperature and Hematologic Inflammatory Indices (SII, NLR, PLR, LMR) in Patients Undergoing Laparoscopic Cholecystectomy: A Prospective Randomized Controlled Study

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.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

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.

Study Type

Interventional

Enrollment (Estimated)

128

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Study Locations

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

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.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Supportive Care
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Other: Control Group
Patients receive standard intraoperative warming with 38 °C set active warming blanket. Surgical field outside the blanket is covered with passive drapes. No additional warming interventions are applied. (standart care)
Device: Standard 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.
Other Names:
  • MEDWARM W-300/A 150-MS/A 96116-K4656
Active Comparator: Intravenous Warmer Group
All standard procedures performed in the control group are followed. Additionally, all intravenous fluids administered during the operation are warmed to 38°C with a fluid warmer.
Device: Standard 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.
Other Names:
  • MEDWARM W-300/A 150-MS/A 96116-K4656
Device: Intravenous 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.
Other Names:
  • IV Fluid Warmer
  • Portable Flotherm QW3 Fluid And Blood Warmer
Active Comparator: External Warmer Group
All standard approaches used in the control group are performed. Additionally, a special drape is placed over the upper extremities and thorax, which is connected to a 3M Bair Hugger 700 Series device and warmed to 38°C.
Device: Standard 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.
Other Names:
  • MEDWARM W-300/A 150-MS/A 96116-K4656
Device: External 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.
Other Names:
  • External Forced-Air Warming Device
  • 3M Bair Hugger 700 Series
Active Comparator: Combined Warming Group (Intravenous + External)
All standard approaches used in the control group are performed. Additionally, intravenous fluids are warmed and an external heating device is applied to the upper extremity/thorax.
Device: Standard 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.
Other Names:
  • MEDWARM W-300/A 150-MS/A 96116-K4656
Device: Intravenous 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.
Other Names:
  • IV Fluid Warmer
  • Portable Flotherm QW3 Fluid And Blood Warmer
Device: External 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.
Other Names:
  • External Forced-Air Warming Device
  • 3M Bair Hugger 700 Series

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Postoperative Core Body Temperature
Time Frame: 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).
Intraoperative, measured continuously and recorded at the end of surgery (1 time point)

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Systemic Immune-Inflammation Index (SII)
Time Frame: 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.
Preoperative baseline, postoperative 1 hour, and postoperative 24 hours
Neutrophil-to-Lymphocyte Ratio (NLR)
Time Frame: 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.
Preoperative baseline, postoperative 1 hour, and postoperative 24 hours
Platelet-to-Lymphocyte Ratio (PLR)
Time Frame: 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.
Preoperative baseline, postoperative 1 hour, and postoperative 24 hours
Lymphocyte-to-Monocyte Ratio (LMR)
Time Frame: 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.
Preoperative baseline, postoperative 1 hour, and postoperative 24 hours

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Ataturk University

Investigators

  • Principal Investigator: Erkan Cem Çelik, doctor, Ataturk University Department of Anesthesiology and Reanimation

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

December 1, 2025

Primary Completion (Estimated)

April 1, 2026

Study Completion (Estimated)

April 2, 2026

Study Registration Dates

First Submitted

November 14, 2025

First Submitted That Met QC Criteria

November 14, 2025

First Posted (Estimated)

November 18, 2025

Study Record Updates

Last Update Posted (Actual)

November 19, 2025

Last Update Submitted That Met QC Criteria

November 17, 2025

Last Verified

November 1, 2025

More Information

Terms related to this study

Keywords

Other Study ID Numbers

  • B.30.2.ATA.0.01.00/657
  • 2025/2 (Other Identifier: Atatürk University Clinical Research Ethics Committee)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

De-identified participant data (demographics, perioperative temperature, hematologic inflammatory indices) will be made available upon reasonable request to qualified researchers after publication of the primary study results.

IPD Sharing Time Frame

Data and supporting documents will be available starting 6 months after publication of the primary study results, for a period of 5 years.

IPD Sharing Access Criteria

Qualified researchers affiliated with recognized academic or clinical institutions may request access to the de-identified dataset and supporting documents via email to the corresponding author. Requests will be reviewed for scientific validity and compliance with ethical standards, and data will be shared under a data use agreement.

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • SAP
  • ICF
  • ANALYTIC_CODE
  • CSR

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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