Perioperative hypothermia: Causes, consequences and treatment

The Effect of Warmed Serum on Shivering and Recovery Period of Patients Under General and Spinal Anesthesia: A Randomized Clinical Trial

PURPOSE

Postoperative hypothermia followed by shivering is a common phenomenon in patients undergoing surgery under anesthesia, and should be prevented and treated in postoperative patient care units. This study was conducted to investigate the effect of warmed serum injection on postoperative shivering and recovery period of patients operated under general and spinal anesthesia.

DESIGN

In this clinical trial, patients to be operated on under general and spinal anesthesia were randomly assigned into two groups of test and control. In the test group, patients received warmed intravenous fluids and blood products. All patients were monitored to record vital signs, incidences of hypothermia and shivering, and recovery period.

METHODS

The collected data were analyzed with repeated measures analysis of variance to detect significant differences between groups and significant changes within groups over time.

FINDINGS

The incidence of nausea, vomiting, and shivering in the intervention and control groups was (4.7%, 42%), (2.8%, 16.8%), and (6.6%, 43%), respectively. Patients in the intervention group had higher body temperature than the control group (<0.001). Also, patients under spinal anesthesia had higher body temperature than patients under general anesthesia (<0.001). Blood pressure reduction was also significantly higher in the control group than in the intervention group. The patients who received warm intravenous serum, and especially those who had received spinal anesthesia spent less time in the recovery room (<0.001).

CONCLUSIONS

The use of warmed intravenous serum increased the patients' core temperature, reduced their postoperative shivering, and shortened their recovery period. Considering the potential risks associated with hypothermia, using such methods for hypothermia prevention can be highly effective in preventing shivering and prolongation of the recovery period and other potential complications. Anesthesia specialists and technicians are therefore encouraged to use this method as a preventive measure.

The Effect of Using a Normothermia Checklist on Awakening Time From Anesthesia and Coagulation Disorder: A Randomized Controlled Trial

BACKGROUND

Inadvertent perioperative hypothermia (IPH) is a common issue in surgical patients. To avoid this issue, the patient should be monitored continuously throughout the perioperative process. Evidence-based practices in line with relevant guidelines are necessary to maintain normothermia.

PURPOSE

This study was developed to determine the effect of using a control list developed for preventing IPH on time of awakening from anesthesia and coagulation disorder in surgical patients.

METHODS

In this randomized controlled study, nursing interventions were applied to patients in accordance with the normothermia checklist (NC) developed by the researchers to prevent IPH.

RESULTS

In this study, 30 patients were respectively assigned to the experimental and control groups. Conducting nursing interventions in accordance with the control checklist was found to be effective in preventing IPH. Moreover, time of awakening from anesthesia was significantly shorter in the experimental group (3.77 ± 1.10 minutes) than the control group (11.03 ± 2.51 minutes; p < .05). Furthermore, tendency to bleed was higher in the control group than the experimental group, and a statistically significant between-group difference in coagulation disorders was found ( p < .05).

CONCLUSIONS/IMPLICATIONS FOR PRACTICE

The results of this evidence-based study indicate that implementing nursing interventions in line with the developed NC is effective in preventing IPH. Preventing IPH, which increases the risk of numerous complications in surgical patients, is an important responsibility of nurses. Nurses may employ the NC proposed in this study to better secure the safety and minimize the risk of complications in surgical patients.

Effects of Active Heating Methods on Body Temperature, Shivering, Thermal Comfort, Pain, Nausea and Vomiting During General Anesthesia: A Randomized Controlled Trial

To investigate the effect of forced-air warming and heated intravenous (IV) and irrigation fluids alone and in combination on body temperature, shivering, thermal comfort, pain, nausea and vomiting in adult patients undergoing surgery under general anesthesia in a prospective, four-group, randomized controlled trial. After induction of anesthesia, 120 patients were divided into the following groups: patients warmed with forced-air warming (n = 30), patients receiving warmed IV and irrigation fluid (n = 30), patients receiving warmed IV and irrigation fluid with forced-air warming (n = 30), and the control group without any intervention (n = 30). Body temperature, shivering, thermal comfort, pain, nausea and vomiting were monitored in the first 24 hours after surgery. The general characteristics of the groups, mean body temperature, length of stay, ambient temperature, and duration of surgery in the preoperative waiting unit were similar (p > 0.05). Compared with the other groups, patients in the control group had a significant decrease in body temperature from the 30th minute during surgery (p < 0.001), lower body temperature in the first 2 hours and thermal comfort in the first three hours after surgery (p < 0.01), and higher shivering levels in the first hour after surgery (p < 0.01). There was no significant difference between the groups in terms of postoperative pain, nausea and vomiting (p > 0.05). The study findings showed that normothermia was maintained in all three intervention groups during the surgery and in the first 24 hours after surgery. Moreover, postoperative thermal comfort increased and shivering levels decreased compared with the control group, but pain, nausea and vomiting levels were not affected. The study was registered on ClinicalTrials.gov (NCT04907617).

Barriers and Solutions in Implementing Evidence-Based Recommendations to Prevent Intraoperative Inadvertent Hypothermia: A Qualitative Study

In this study, it was aimed to understand the barriers and solutions for operating room (OR) nurses and anesthesiologists to implement evidence-based recommendations to prevent intraoperative inadvertent hypothermia (IIH). A qualitative, inductive, and descriptive study was conducted. This qualitative interview study was conducted face-to-face with 19 participants working in OR units between February and March 2023. The interviews were analyzed using qualitative content analysis. The COREQ checklist was followed. Two main themes and five sub-themes were identified as a result of content analysis. According to the participants, barriers to IIH prevention interventions are caused by individual and organizational inefficiencies and personal opinions, and the main solution is education. Participants reported many factors that hinder IIH prevention practices. The individual characteristics of OR staff and the opinions and behavior of the institution are very important for IIH prevention.

Outpatient-Based High-Volume Liposuction: A Retrospective Review of 310 Consecutive Patients

BACKGROUND

Currently, the definition of large-volume liposuction is the removal of 5 L or more of total aspirate. Higher volumes of lipoaspirate come into consideration with higher BMIs, because more than 5 L is often required to achieve a satisfactory aesthetic result. The boundaries of what lipoaspirate volume is considered safe are based on historical opinion and are constantly in question.

OBJECTIVES

Because to date there have been no scientific data available to support a specific safe maximum volume of lipoaspirate, the authors discuss necessary conditions for safe high-volume lipoaspirate extraction.

METHODS

This retrospective study included 310 patients who had liposuction of ≥5 L over a 30-month period. All patients had 360° liposuction alone or in combination with other procedures.

RESULTS

Patient ages ranged from 20 to 66 with a mean age of 38.5 (SD = 9.3). Average operative time was 202 minutes (SD = 83.1). Mean total aspirate was 7.5 L (SD = 1.9). An average of 1.84 L (SD = 0.69) of intravenous fluids and 8.99 L (SD = 1.47) of tumescent fluid were administered. Urine output was maintained above 0.5 mL/kg/hr. There were no major cardiopulmonary complications or cases requiring blood transfusion.

CONCLUSIONS

High-volume liposuction is safe if proper preoperative, intraoperative, and postoperative protocols and techniques are employed. The authors believe that this bias should be modified and that sharing their experience with high-volume liposuction may help guide other surgeons to incorporate this practice with confidence and safety for better patient outcomes.

LEVEL OF EVIDENCE: 3

The effect of anesthesia type on the outcomes of percutaneous nephrolithotomy in elderly males

Objective: To compare the anaesthesia methods in percutaneous nephrolithotomy in terms of safety and effectiveness in elderly men.Methods: Elderly male patients who had undergone percutaneous nephrolithotomy were screened retrospectively and divided into 2 groups: percutaneous nephrolithotomy under combined spino-epidural anaesthesia (Group CSEA, n = 70) and percutaneous nephrolithotomy under general anaesthesia (Group GA, n = 114). Preoperative, perioperative and postoperative outcome measures were examined.Results: Between the two groups, there was no statistically significant difference in terms of stone burden, stone location, presence of the previous operation in the same kidney, presence of staghorn stones, mean American Society of Anesthesiologists scores and presence of abnormal kidney (p > 0.05). The mean duration time in the operation room and post-anaesthesia care unit (PACU) was statistically shorter in the Group CSEA (p < 0.01). There was no significant difference between the two groups in terms of Clavien Grade 1 and above complications (p > 0.05). Stone-free rates and success rates were similar in both groups (p = 0.133 and p = 0.273, respectively).Conclusion: The type of anaesthesia does not affect the success rate and complication rate of percutaneous nephrolithotomy in elderly male patients. Patients who underwent percutaneous nephrolithotomy under CSEA needed less analgesic injection during the postoperative period. CSEA can shorten the time a patient spends in the operating room and PACU, which provides more effective use of operation room working hours.

Prospective analysis of intraoperative critical incidents relevant to anaesthesia in a tertiary care teaching hospital in India

Background and Aims

Critical incidents associated with anesthesia can affect the patient's outcome, may cause transient damage, and contribute to mortality. We aimed at recording anesthesia-related critical incidents in patients undergoing general surgical, ear, nose, and throat (ENT) and orthopedic surgical procedures in our institution. The critical incidents data were analyzed regarding the cause to establish protocols to prevent recurrences.

Material and Methods

We conducted a prospective analysis of voluntarily reported perioperative critical incidents occurring in patients subjected to anesthesia over 1 year. Critical incidents were noted in terms of time (while inducing/intraoperative/while extubating), location (operating theater/recovery room) of the incident, anesthesia-related or surgery-related complications. Data collected were expressed as numbers and proportions to calculate incidence.

Results

Anesthesia was administered to 5,645 patients of which 131 (2.32%) patients had critical incidents. Of these 131, 46 (35.11%) patients had more than one critical incident. A total of 216 (3.82%) critical incidents were noted. A majority of the patients were in the age range of 51-60 years. The maximum incidents occurred during the intraoperative period (35.11%) and in the operating theater (86.25%). Of the 216 incidents, 154 (71.30%) were anesthesia-related, 18 (8.33%) were surgery-related, 1 (0.46%) was patient-related and 43 (19.91%) were recovery-related. Of the 216 incidents, cardiovascular-related incidents accounted for the maximum incidents (18.05%, n = 39). Most of the events were preventable.

Conclusion

The critical incident reporting system should be encouraged and protocols established to reduce the frequency and severity of these occurrences.

Nurses' Awareness and Practices of Unintentional Perioperative Hypothermia Prevention: A Cross-Sectional Study

Unintentional perioperative hypothermia can cause potentially life-threatening complications. The aim of this study was to determine the awareness and practices of nurses regarding unintentional perioperative hypothermia prevention. The study was conducted at a teaching hospital in Gambia with descriptive cross-sectional design. A total of 53 nurses voluntarily participated in this study. The questionnaire used in this study was developed based on the American periOperative Registered Nurses (AORN) and National Institute for Health and Care Excellence perioperative hypothermia guidelines. Descriptive statistics, Pearson correlation, Student t-test, and one-way ANOVA were used in the analysis of data. The result of the study showed that nurses had high level of awareness of unintentional perioperative hypothermia prevention; however, practice levels were found to be low. Based on the results of the study, development of policies, implementation of the unintentional perioperative hypothermia prevention guidelines, and continuous education to improve nurses' knowledge and practices were recommended.

Infectious complications of intercostal nerve cryoablation mediated by perioperative hypothermia during pediatric Nuss procedure

BACKGROUND

Intercostal nerve cryoablation (cryoanalgesia) is increasingly used for pain control in minimally invasive repair of pectus excavatum (MIRPE) by Nuss procedure. Cryoanalgesia may lower core body temperature and increase the risk of postoperative infectious complications. We investigated cryoanalgesia effects on infectious complications following MIRPE.

METHOD

We performed a retrospective review of patients undergoing MIRPE at our institution. Patients treated via multimodal analgesia with cryoanalgesia (Cryo) were compared to patients treated via multimodal analgesia +/- elastomeric pain pumps (Non-cryo). Core body and intraoperative minimum/maximum temperatures were recorded. Primary outcomes were wound infection and pneumonia; secondary outcome was length of stay (LOS). Fisher's Exact and Mann-Whitney U tests compared proportions and medians respectively, p-value ≤ 0.05 being significant.

RESULTS

80 patients were included, 35(43.7%) Cryo and 45(56.3%) Non-cryo. There were no significant differences in median [IQR] for age(15[13.3,16.0];p =0.86), number of bars inserted (2[1,2];p = 0.57), or operative time(123.5[98.3, 148.8]; p = 0.11) between the two groups. We found no significant differences in median [IQR] minimum temperature (35.4°C [35.0,35.8];p = 0.76), median change in intraoperative temperature (-0.13°C [-0.44,0.00];p = 0.94) or median recovery temperature (-1.10°C [-1.56,-0.65]; p = 0.59) between Cryo and Non-cryo. PACU temperature was significantly lower in the Cryo group, 36.4°C [36.2,36.6] p = 0.04. There were no postoperative wound infections in either group and no significant difference in incidence of postoperative pneumonia (8.57% versus 2.22%,p =  0.31) or median[IQR] for LOS (4[3,4];p = 0.57), between Cryo and Non-cryo patients.

CONCLUSION

Although cryoanalgesia for MIRPE resulted in lower core body temperature, there appears to be no significant difference between Cryo and Non-Cryo patients for LOS or infectious complications.

Are Non-Contact Thermometers an Option in Anaesthesia? A Narrative Review on Thermometry for Perioperative Medicine

Measurement of core body temperature—clinical thermometry—provides critical information to anaesthetists during perioperative care. The value of this information is determined by the accuracy of the measurement device used. This accuracy must be maintained despite external influences such as the operating room temperature and the patient’s thermoregulatory defence. Presently, perioperative thermometers utilise invasive measurement sites. The public health challenge of the COVID-19 pandemic, however, has highlighted the use of non-invasive, non-contact infrared thermometers. The aim of this article is to review common existing thermometers used in perioperative care, their mechanisms of action, accuracy, and practicality in comparison to infrared non-contact thermometry used for population screening during a pandemic. Evidence currently shows that contact thermometry varies in accuracy and practicality depending on the site of measurements and the method of sterilisation or disposal between uses. Despite the benefits of being a non-invasive and non-contact device, infrared thermometry used for population temperature screening lacks the accuracy required in perioperative medicine. Inaccuracy may be a consequence of uncontrolled external temperatures, the patient’s actions prior to measurement, distance between the patient and the thermometer, and the different sites of measurement. A re-evaluation of non-contact thermometry is recommended, requiring new studies in more controlled environments.

Comparison of Perioperative Active or Routine Temperature Management on Postoperative Quality of Recovery in PACU in Patients Undergoing Thoracoscopic Lobectomy: A Randomized Controlled Study

BACKGROUND

Whether intraoperative temperature management can help patients recover quickly in the postanesthesia care unit (PACU) still remains to be investigated. This study aimed to investigate the effect of intraoperative temperature management on the quality of postoperative recovery of patients who underwent pulmonary lobectomy in the PACU.

METHODS

Totally, 98 patients aged 45-60 years with a body mass index of 20-25 kg/m² who underwent elective thoracoscopic lobectomy were enrolled. Patients were categorized into two groups using a random number table: the conventional group received routine intervention to maintain normothermia (Group C, n = 49) and the aggressive group received integrated interventions (Group A, n = 49). In Group C, normothermic fluid was infused intravenously, the heating blanket was turned on when the intraoperative temperature was <35.0 °C, and the warming was stopped when the temperature reached 36.5 °C. In Group A, the fluid heated to 37 °C was infused intravenously, and the heating blanket was used intraoperatively. When the body temperature was >37 °C, the heating blanket was turned off, and when the body temperature was <36.5 °C, the heating blanket was turned on to continue heating.

RESULTS

Steward awakening scores at 1 min and 5 min after extubation and PaO₂ levels at 15 min after extubation were higher in Group A than in Group C (P < 0.05); incidence of chills, nausea, and vomiting in the PACU was lower in Group A than in Group C (P < 0.05); and length of stay in the PACU was shorter in Group A than in Group C (P < 0.05).

CONCLUSION

Aggressive intraoperative temperature management of patients undergoing thoracoscopic lobectomy can improve the quality of postoperative recovery in the PACU through a safe and smooth transition compared with routine insulation measures.

Anesthesia Management of a Patient With Familial Cold Autoinflammatory Syndrome: A Case Report

Familial cold autoinflammatory syndrome (FCAS) is a rare phenotype of cryopyrin-associated periodic syndrome (CAPS) and is characterized by repetitive systemic inflammation triggered by cold stimulation. Recently, we treated a 13-year-old female with FCAS/CAPS scheduled to undergo removal of an impacted tooth. To minimize perioperative heat loss, a forced-air warming system was utilized to prewarm the patient for 10 minutes before induction of general anesthesia. The patient's core and peripheral temperatures were monitored with axillary, superficial temporal artery, and rectal thermometers. The difference in temperatures at these 3 locations decreased to 0.4° C within 60 minutes as a result of the forced-air warming system before induction. Perioperative use of the warming system successfully prevented the occurrence any significant redistribution hypothermia and any symptoms of FCAS/CAPS.

Effect of nurse-initiated forced-air warming blanket on the reduction of hypothermia complications following coronary artery bypass grafting: a randomized clinical trial

AIMS

To evaluate the effect of postoperative forced-air warming (FAW) on the incidence of excessive bleeding (ExB), arrhythmia, acute myocardial infarction (AMI), and blood product transfusion in hypothermic patients following on-pump CABG and compare temperatures associated with the use of FAW and warming with a sheet and wool blanket.

METHODS AND RESULTS

A randomized clinical trial conducted with 200 patients undergoing isolated on-pump CABG from January to November 2018. Patients were randomly assigned into an Intervention Group (IG, FAW, n = 100) and Control Group (CG, sheet and blanket, n = 100). The tympanic temperature of all patients was measured over a 24-h period. ExB was the primary outcome, while arrhythmia, AMI, and blood product transfusion were secondary outcomes. The effect of the interventions on the outcomes was investigated through using bivariate logistic regression, with a level of significance of 5%. The IG was 79% less likely to experience bleeding than the CG [odds ratio (OR) = 0.21, confidence interval (CI) 95% 0.12-0.39, P < 0.001]; the occurrence of AMI in the IG was 94% lower than that experienced by the CG (OR = 0.06, CI 95% 0.01-0.48, P < 0.001); and the IG was also 77% less likely to experience arrhythmia than the CG (OR = 0.23, CI 95% 0.12-0.47, P < 0.001); no difference was found between groups in terms of blood product transfusion (P < 0.279).

CONCLUSIONS

These findings show that FAW can be used following CABG until patients reach normothermia to avoid undesirable clinical outcomes.

TRIAL REGISTRATION

REBeC RBR-5t582g.

The incidence of inadvertent perioperative hypothermia in patients undergoing general anesthesia and an examination of risk factors

BACKGROUND

Unintended perioperative hypothermia, defined as core body temperature less than 36°C, is closely related to many complications such as cardiovascular diseases, peroperative hemorrhagic diathesis and impairment of drug metabolism. Determination of the incidence of perioperative hypothermia and examination of risk factors may help to prevent hypothermia and its complications.

METHODS

We conducted a prospective, observational study of 2015 patients who underwent various operations under general anesthesia, and the risk factors of developing hypothermia were analysed.

RESULTS

The incidence of perioperative hypothermia was 78.6%. The incidence of hypothermia within 2 hours was 56.6%, and after 2 hours, it was 100%. Mean age was 49.36 ± 16.10, and 17.8% were over 65 years old. The mean body mass index (BMI) was 27.96 ± 3.94 kg/m² ; 60.8% of the patients had American Society of Anesthesiologists (ASA) I score, 33.4% had ASA II and 5.8% had ASA III; 35.8% of the patients had co-morbidities. Intravenous and irrigation fluids were unwarmed; 99.9% of the patients were warmed passively, and only 0.1% of patients received active heating intraoperatively. The incidence of hypothermia was higher in overweight (BMI ≥ 25 kg/m² ), elderly (>65 years) patients and those with co-morbidities. High American Society of Anesthesiologists (ASA) scores, grade 3-4 surgery, endoscopic surgery, duration of anesthesia >2 hours, infusion or irrigation >1000 mL significantly increased the incidence of hypothermia.

CONCLUSION

The incidence of perioperative hypothermia found was high. Important risk factors were found as prolonged duration of anesthesia and surgery, advanced age, overweight, high ASA scores, major surgeries, endoscopic operations and unwarmed fluid administration. High incidence may be reduced by raising awareness, considering fossible risk factors and following the recommendations of the guidelines on prevention of perioperative hypothermia.

Optimal Application of Forced Air Warming to Prevent Peri-Operative Hypothermia during Abdominal Surgery: A Systematic Review and Meta-Analysis

Patients who undergo abdominal surgery under general anesthesia develop hypothermia in 80–90% of the cases within an hour after induction of anesthesia. Side effects include shivering, bleeding, and infection at the surgical site. However, the surgical team applies forced air warming to prevent peri-operative hypothermia, but these methods are insufficient. This study aimed to confirm the optimal application method of forced air warming (FAW) intervention for the prevention of peri-operative hypothermia during abdominal surgery. A systematic review and meta-analysis were conducted to provide a synthesized and critical appraisal of the studies included. We used PubMed, EMBASE, CINAHL, and Cochrane Library CENTRAL to systematically search for randomized controlled trials published through March 2020. Twelve studies were systematically reviewed for FAW intervention. FAW intervention effectively prevented peri-operative hypothermia among patients undergoing both open abdominal and laparoscopic surgery. Statistically significant effect size could not be confirmed in cases of only pre- or peri-operative application. The upper body was the primary application area, rather than the lower or full body. These findings could contribute detailed standards and criteria that can be effectively applied in the clinical field performing abdominal surgery.

Intra-operative anaesthetic management of older patients undergoing liver surgery

Older patients represent a growing proportion of the general surgical caseload. This includes those undergoing liver resection, with figures rising faster than the rate of population ageing. The physiology of ageing leads to changes in all body systems which may render the provision of safe anaesthesia more challenging than in younger patients. Anaesthesia for liver surgery has specific principles, largely aimed at reducing venous bleeding from the liver, and those related to complex major surgery. This review explores the principles of anaesthesia for liver resection and describes how they may require modification in the older patient. The traditional approach of low central venous pressure anaesthesia in order to reduce bleeding may need to be altered in the presence of a cardiovascular system less able to tolerate hypotension and hypoperfusion. These changes in physiology should also lower the threshold for invasive monitoring. The provision of effective analgesia perioperatively should be tailored to minimise the surgical stress response and opiate use. Careful consideration of general principles of intra-operative care for older patients, such as positioning, drug dosing, avoidance of excessively deep anaesthesia, and maintenance of normothermia are also important given the prolonged, complex nature of liver surgery. This individualised approach, with careful attention to changes in physiology allows liver resections to be undertaken in older patients without increases in mortality.

A qualitative study of the operating room experience of patients who underwent surgery under spinal anesthesia: "It was like an adventure"

This study aimed to explore the experiences of the people who underwent orthopedic surgery under spinal anesthesia and to report their feelings and thoughts. The study was carried out using a qualitative approach. Twenty-one patients were interviewed who underwent orthopedic surgery on the first or second postoperative day. Content analysis was performed after the collection of raw data. NVIVO 12 Pro software was used for data analysis. The frequency count (f) and participant codes (P) were used for the presentation of the findings. The themes and frequency counts obtained by analyzing the interviews with the patients were as follows: "Time passed like watching a movie" (f = 213), "Like an adventure" (f = 587), and "See, feel, look" (f = 405). Five of 21 participants (23.8%) stated that they would not recommend spinal anesthesia. The findings generally indicated the anxiety caused by the unknown, fear in the preanesthetic period, operation experienced like an adventure, and a process generally completed with satisfaction.