Prevention of Hypothermia During Caesarean Section: Continuous Core Temperature Monitoring With Zero-heat-flux

Study Overview
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Brief Summary
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Nowadays, caesarean sections account for about 7% of all surgical procedures worldwide. Over 30% of the patients undergoing a caesarean section experience a fall of the body core temperature under 36°C during the procedure. Following a retrospective cohort design, this study aims to examine the magnitude of hypothermia in the parturient and newborn population as well as the impact and efficiency of forced-air warming on preventing it. The researchers plan to conduct a retrospective analysis of the caesarean section treatment protocol at our institution over a period of 5 months including approximately 300 patients who underwent both elective and emergency caesarean sections.

Detailed Description
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This research seeks to address the necessity of standardizing the use of forced-air warming and monitoring the maternal temperature during caesarean sections. We will also examine the impact of the maternal hypothermia on the newborn temperatures at the time of partus and also 2 hours after birth. The key research question of this study is whether the use of forced-air warming will significantly lower the hypothermia rates and account for a faster temperature recovery in our parturient patients. A major contribution of our research is that it provides modern high-resolution, continuous and user-error free thermometry. This is achieved through zero-heat-flux technology and automatically recorded by data-loggers. Also, the heterogeneity of our study population, which has not been attended in previous studies, corresponds to the clinical reality of the most obstetric clinics. This research could provide new information about the necessity of standardizing the use of forced-air warming and monitoring the maternal temperature during caesarean sections, in the concept of bonding the babies to the mother's chest immediately after birth, and derive practical implications on the efficiency of intraoperative warming for the standard clinical routine of the majority of the obstetric clinics.

Official Title
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Prevention of Hypothermia During Caesarean Section: Forced-air Warming and Continuous Core Temperature Monitoring With Zero-heat-flux

Conditions
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Inadvertent Perioperative Hypothermia

Intervention / Treatment
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* Procedure: Convective Forced-Air Active Warming


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Included will be all Caesarean section deliveries under spinal anaesthesia at our facility in the period from 01.04.2019 to 31.08.2019 Exclusion Criteria: different anaesthesia procedure (e.g. intubation anaesthesia, peridural anaesthesia etc.), American Society of Anesthesiologists (ASA) Classification III or higher, BMI( Body mass index) >45 kg·m-2, patients with incomplete documentation, estimated perioperative blood loss > 500ml, other perioperative complications (ex. insufficient analgesia and change of anaesthesia procedure).

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 45 Years

Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| No Warming<br>Patients in this group were treated according to our institution's old protocol and did not receive any warming intervention during the surgical procedure. | |
| Active Warming<br>This group will include the patients treated after the implementation of the S3 Guidelines for prevention of hypothermia. For this purpose convective warming through an underbody blanket was used during the surgical procedure | Procedure: Convective Forced-Air Active Warming<br>* Underbody Blanket Model 585 of the 3M BairHugger Series<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Hypothermia rate OR | Hypothermia rate in % intraoperatively. The temperature measurements will be started prior to the induction of the anaesthesia and ended when the patient leaves the OR (operating room). | Through completion of the surgical procedure, an average of 1 hour | 
| Hypothermia rate RR | Hypothermia rate in % in the RR (recovery room). The temperature measurements will be started when the patient enters the RR and ended approximately after 2-3 hours when the patient leaves the RR | Through completion of the postoperative recovery, an average of 2 hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Delta_Temp | Temp= Temperature. Delta_Temp=The difference between Tmax -Tmin( the maximum and the minimum recorded temperatures) | Through completion of the surgical procedure, an average of 1 hour | 
| Delta_Time | The time from the induction of anesthesia to Nadir of temperature values | Through completion of the surgical procedure, an average of 1 hour | 
| Delta_recovery | The time from Tmin (minimum recorded temperature values) to the recovery of 30% of the dropped body core temperature in degrees Celsius. | Through completion of the surgical procedure and the postoperative recovery phase , an average of 3 hour | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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cesarean section, C-Section, Hypothermia, Spinal Anesthesia, caesarean section, zero heat flux technology, active warming