The Impact of Intraoperative Change in the Body Temperature on the Perfusion Index

NCT ID: NCT06998849

Last Updated: 2025-05-31

Basic Information

• Recruitment Status: COMPLETED
• Total Enrollment: 50 participants
• Study Classification: OBSERVATIONAL
• Study Start Date: 2024-04-01
• Study Completion Date: 2024-08-05

Brief Summary

The goal of this observational study is to learn about the impact of intraoperative change in temperature in adult patients undergoing surgeries under general anaesthesia. The main question it aims to answer is:

Is the change in core body temperature reflected by changes in the prfusion index? Patients' core temperature, peripheral temperature and perfusion indices will be recorded throughout the span of the procedure.

Detailed Description

Perioperative hypothermia increases the risk of postoperative morbidity and mortality. Almost 50-90% of the patients experience perioperative hypothermia. This involves a decrease in core temperature to ≤ 36°C, which results in an increased rate of surgical site infection, haemorrhagic tendency, and ischemic heart disease, making it a serious perioperative complication.

Early hypothermia during general anaesthesia is mainly caused by the redistribution of body heat from the central to peripheral compartments, due to vasodilation following use of the anaesthetics. The degree of redistribution of body heat may be affected by the peripheral perfusion state, which differs across patients and results in a difference in gradient between temperature of the central and peripheral compartments. Low peripheral perfusion state can lead to low peripheral body temperature, thus lowering the overall core body temperature.

It was previously reported that the risk factors for intraoperative hypothermia are age, BMI, preoperative systolic blood pressure, heart rate, baseline core temperature, ASA-PS score, the type of anaesthesia and surgery, the duration of preparation and surgery, and ambient temperature.

Previous studies did not include the PI as a risk factor for intraoperative hypothermia. Therefore, further studies are needed to assess the relationship between PI and hypothermia to generate a more accurate predictive score of perioperative hypothermia.

Conditions

Perfusion Index; Hypothermia; Anesthesia

Study Design

• Observational Model Type: COHORT
• Study Time Perspective: CROSS_SECTIONAL

Study Groups

Adult patients undergoing general surgery

Adult patients undergoing elective general surgery

Perfusion index

Intervention Type: DIAGNOSTIC_TEST

The perfusion index (PI) is defined as the ratio of pulsatile light absorption to continuous light absorption, denoted as AC/DC. Initially used as a quality signal indicator in pulse oximetry, PI has increasingly been recognized for its potential in non-invasive hemodynamic monitoring. Since PI changes with peripheral blood flow, it may reflect peripheral temperature gradients and, consequently, thermoregulatory responses like peripheral vasoconstriction. Studies have reported that the core-to-peripheral temperature difference correlates with peripheral PI. The findings suggest that both peripheral and core temperatures contribute to the threshold for shivering and that PI reflects the vasoconstriction induced by thermoregulatory responses that precede shivering

Interventions

Perfusion index

The perfusion index (PI) is defined as the ratio of pulsatile light absorption to continuous light absorption, denoted as AC/DC. Initially used as a quality signal indicator in pulse oximetry, PI has increasingly been recognized for its potential in non-invasive hemodynamic monitoring. Since PI changes with peripheral blood flow, it may reflect peripheral temperature gradients and, consequently, thermoregulatory responses like peripheral vasoconstriction. Studies have reported that the core-to-peripheral temperature difference correlates with peripheral PI. The findings suggest that both peripheral and core temperatures contribute to the threshold for shivering and that PI reflects the vasoconstriction induced by thermoregulatory responses that precede shivering

Intervention Type: DIAGNOSTIC_TEST

Eligibility Criteria

Inclusion Criteria

• Patients undergoing elective surgery under general anaesthesia
• Patients aged between 20 and 70 years old.

Exclusion Criteria

• Patients who decline to give a written informed consent.
• Patients with psychiatric disorders that lead to inability to cooperate, speak, or read.
• BMI between <20 kg/m2 or >35 kg/m2.
• Patients undergoing emergency surgeries.
• Patients with peripheral vascular disease or rheumatoid disease.

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 70 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Ain Shams University

OTHER

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Locations

Ain Shams University

Cairo, Abbassia, Egypt

Countries

Egypt

Other Identifiers

MS143/2024

Identifier Type: -

Identifier Source: org_study_id