Effect of Preoperative Active Warming and Passive Warming Methods on Perioperative Hypothermia

70% of surgical interventions are abdominal surgeries. Open abdominal surgery is performed in patients for whom minimally invasive approaches are not suitable. In these surgeries in which general anesthesia is used, the duration of the operation is longer, complications are more frequent, and postoperative recovery occurs later. Low body temperature before surgery, preoperative fasting and fluid deprivation before anesthesia, exposure of large body surface areas, evaporative heat loss during skin preparation using volatile solutions, large open cavity or abdominal surgery longer operative time and exposure to anesthesia, during surgical intervention excessive blood loss etc. surgical intervention poses a risk for the formation of undesirable hypothermia.

Cardiovascular and respiratory system problems that may increase mortality due to hypothermia in surgical patients; may cause a decrease in heart rhythm, cardiac output, blood pressure and oxygen saturation, and an increased risk of cardiac arrest and ischemia. With the development of shivering, oxygen consumption increases and the "thermal comfort" of the patient deteriorates. The length of stay in the postoperative unit and hospital stay are prolonged, causing an increase in costs.

Among the rapid recovery protocols, it is recommended to pre-warm the patients in the preoperative period to maintain normothermia. Many complications are prevented by different methods and warming procedures performed in the perioperative period.

In our study, it was aimed to compare the effects of active and passive warming on hypothermia, vital signs and warmth comfort in the postoperative period in patients who will undergo open abdominal surgery.

Before starting the research, permission was obtained from Çukurova University Medical Faculty Balcalı Hospital General Surgery Department Academic Committee and Operating Room Committee, from Balcalı Hospital Chief Physician (Annex-11), and Çukurova Ethics Committee by the investigator . University Faculty of Medicine Non-Interventional Research Ethics Committee approval was received with the date and number of 10.04.2020/98-29 An application was made to the Scientific Research Projects Unit to support the project with all permissions. It has been approved as a Scientific Research Project.

In accordance with the results of the power analysis using the G power 3.1.9.2 program, it was planned to include 30 participants in the active warming group, 30 partici in the passive warming group and 30 participants in the control group, and a simple randomization method was used in the distribution. Sample for study groups Research data were collected in the operating room preoperative unit and postoperative unit between July 2020 and December 2020.

When the participants came to the preoperative unit before the operation, his vital signs, temperature comfort perception scale and shivering level, temperature and humidity of the room were measured by the investigator and recorded in the Personal Information Form, Vital Signs Monitoring Form, Temperature Comfort Perception Scale Form, Shivering Level Diagnostic Form. Before anesthesia was given, one group was heated with the 3M Bair Hugger Model 775 Heating Unit (Hot Air Blowing Warmer Blanket) with an active heating system and the other group with a passive heating system (wool blanket) for 20 minutes, routine application was made to the control group participants by the investigator . Vital signs, tremor levels and temperature comfort perception measurements were made at the 0th, 15th, and 30th minutes in the postoperative unit of the participants after the operation by the investigator . Statistical analyzes of the collected data were made using a package program called SPSS (IBM SPSS Statistics 24). Frequency tables and descriptive statistics were used to interpret the findings. In accordance with parametric methods, the "ANOVA" test (F-table value) was used to compare the measurement values of three or more independent groups, and the "RepeatedMeasures" test (F-Table) was used to compare the measurement values of three or more dependent groups. The "Mann-Whitney U" test (Z-table value) and the "Kruskal-Wallis H" test (χ2- table value) were used to compare the measurement values of two independent groups in accordance with non-parametric methods. ) method was used. "Wilcoxon" test (Z-table value) to compare measurement values of two dependent groups, "Friedman" test (χ2-table value) to compare measurement values of three or more dependent groups, "Pearson-χ2 To examine the relationships between two qualitative variables used "cross tables" were used.

Eligibility Criteria:
Inclusion Criteria:

1. 18 years and older,
2. Patients with ASA III and below,
3. Under elective general anesthesia, will undergo Open Abdominal Surgery,
4. BMI of 18.5- 29.9 kg/m2,
5. Without neurological, psychiatric, neuromuscular disease,
6. Not addicted to alcohol and drugs,
7. Not mentally retarded,
8. Does not use drugs that will affect thermoregulation such as vasodilators,
9. No history of thyroid disease,
10. Absence of body temperature of 36 0C and 37.5 0C on the morning of the operation,
11. No complication developed during the surgical intervention and no blood transfusion was performed.

Exclusion Criteria:

1. Refusal to participate in the research
2. Complication developed during the operation