An observational study in Perfusion Index and Hypothermia; Anesthesia, sponsored by Ain Shams University. Completed at 1 site in Egypt. Open to participants aged 18 Years to 70 Years. Per ClinicalTrials.gov, last updated 2025-05-31.
Sponsored by Ain Shams University · Observational
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.
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.
502 studies on the registry are indexed under Hypothermia; 54 are open to participants now.
This study's enrollment of 50 is below the median of 97 across 128 observational studies indexed under Hypothermia.
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Patients undergoing elective surgery under general anesthesia in the months between April 2024 and June 2024 at Ain Shams University Hospitals
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Exclusion Criteria:
Adult patients undergoing elective general surgery
Diagnostic Test: 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
To measure the change of PI associated with change in core and peripheral body temperatures as measured by the oropharyngeal probe and the pattern of this change
The PI was recorded by attaching a sensor to the patient's finger (Ultralife Pulse Oximeter JPD-500D). The baseline body temperature (T1) was measured using a Granzia GT-3 Digital thermometer. Subsequently, the PI was recorded and assessed every 15 min until completion of the surgery.
Time frame: Through study completion, 3 months from April 2024 to June 2024
To detect the change of PI with the change in temperature gradient (it is defined as the difference between the skin temperature and the core temperature)
Time frame: Through study completion, 3 months from April 2024 to June 2024
To detect the incidence of a low reading of PI and the increase in serum lactate level in an arterial blood gases sample.
A baseline ABG (B1) was drawn, and serum lactate value was recorded. A follow up ABG (B2) was drawn at PI values \<0.2%, and serum lactate was recorded again.
Time frame: Through study completion, 3 months from April 2024 to June 2024
Plan to share: No
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