The effects of warmed intravenous fluids, combined warming (warmed intravenous fluids with humid-warm oxygen), and pethidine on the severity of shivering in general anesthesia patients in the recovery room

Comparison of the Effect of Forced-air Warming and Warmed Intravenous Fluid on the Comfort and Prevention of Shivering After Spinal Anesthesia in Patients Undergoing Orthopedic Surgery

PURPOSE

This study aimed to compare the effect of forced-air warming and warmed intravenous fluid on the comfort and prevention of shivering after spinal anesthesia in patients undergoing orthopaedic surgery.

DESIGN

Randomized controlled clinical trial.

METHODS

A total of 120 patients were randomly divided into three groups: forced-air warming (38°C), warmed intravenous fluid (37°C), and the control group. Patients' comfort and severity of shivering were measured and recorded five times (immediately and 15 minutes after spinal anesthesia, end of the surgery, time of entrance to the recovery room, and 15 minutes after entering the recovery room), and compared with each other.

FINDINGS

There was a significant difference between the three groups in terms of comfort at all points of evaluation times (P < .001). The comfort score in the control group was significantly higher than the two intervention groups (P < .001). Moreover, the comfort score in the warmed intravenous fluid group was significantly higher than the forced-air warming group (P < .001). In addition, there was a significant difference in shivering severity between the three groups at the end of the surgery, entrance to the recovery room, and 15 minutes after surgery (P < .001). The majority of patients in the forced-air warming group (90%) had no shivering at all three times, while the warmed IV fluid and control groups was 65% and 30% respectively.

CONCLUSIONS

Non-pharmacological methods such as forced-air warming and warmed intravenous fluid can provide comfort and prevent shivering in orthopaedic patients undergoing spinal anesthesia. However, the use of forced-air warming is more effective than warmed intravenous fluid in providing comfort and preventing shivering in these patients. It is recommended that these methods be used in the operating room to provide comfort and prevent shivering in these patients.

Intravenous magnesium sulfate <em>versus</em> intravenous meperidine to prevent shivering during spinal anesthesia

BACKGROUND Shivering is a frequent event during neuraxial anesthesia due to impaired central and peripheral thermoregulation control. Meperidine and MgSO4 are effective in lowering the shivering threshold. Hence, this study aimed to compare the efficacy of MgSO4 and meperidine to prevent shivering in patients undergoing spinal anesthesia. METHODS This was a double-blind randomized clinical trial of 100 patients divided into 2 groups. One group had MgSO4 30 mg/kg, and the other group had meperidine 0.5 mg/kg intravenously in 100 ml of 0.9% NaCl before undergoing spinal anesthesia. Participants were non-pregnant patients aged 18–65 years and had physical status I or II (based on the American Society of Anesthesiologist). Shivering was considered significant if it occurred in grade 3 or 4. Patient characteristics, shivering degree, tympanic membrane temperature, and side effects were recorded. RESULTS Shivering occurred 10% in the MgSO4 group and 19% in the meperidine group, with p = 0.23. Both groups had similar side effects of nausea, vomiting, and hypotension. CONCLUSIONS MgSO4 30 mg/kg was not superior to meperidine 0.5 mg/kg intravenously in preventing shivering in patients undergoing spinal anesthesia.

Multimodal temperature management during donor hepatectomy under combined general anaesthesia and neuraxial analgesia: Retrospective analysis

Background and Aims:

Unintended hypothermia (UIH) during surgery under general anaesthesia has adverse implications. A retrospective analysis of the perioperative temperature records of healthy voluntary liver donors was done to evaluate the efficacy of a multimodal protocol for temperature management.

Methods:

Records of 50 American Society of Anesthesiologists physical status Class 1 patients operated for Donor Hepatectomy lasting >2 h under combined general and epidural anaesthesia were analysed. Ambient temperature was maintained 24°C–27°C before induction of GA and during insertion of epidural catheter. Active warming was done using warming mattress set to temperature 38°C, hot air blanket with temperature set to 38°C and fluid warming device (Hotline™) with preset temperature of 41°C. Nasopharyngeal temperature was continuously monitored. After induction of GA and draping of the patient, ambient temperature was decreased and maintained at 21°C–24°C and was again increased to 24°C–27°C at the conclusion of surgery. During surgery, for every 0.1°C above 37°C, one heating device was switched off such that at 37.3°C all the 3 devices were switched off. Irrigation fluid was pre-warmed to 39°C.

Results:

Baseline temperature was 35.9°C ± 0.4°C. Minimum temperature recorded was 35.7°C ± 0.4°C. Mean decrease in temperature below the baseline temperature was 0.2°C ± 0.2°C. Temperature at the end of surgery was 37.4°C ± 0.5°C.

Conclusion:

Protocol-based temperature management with simultaneous use of resistive heating mattress, forced-air warming blanket, and fluid warmer along with ambient temperature management is an effective method to prevent unintended perioperative variation in body temperature.