Prevention Of Inadvertent Perioperative Hypothermia Research Articles

Prewarming for Prevention of Hypothermia in Older Patients Undergoing Hand Surgery Under Brachial Plexus Block.

BackgroundOlder patients are more vulnerable to inadvertent perioperative hypothermia. Prewarming contributes to the prevention of inadvertent perioperative hypothermia in patients under general or neuraxial anesthesia. However, the effects of brachial plexus block (BPB) on thermoregulation and the efficacy of prewarming in the prevention of hypothermia in older patients undergoing surgery with BPB remain unclear. This study evaluated the effects of BPB on thermoregulation and the efficacy of prewarming during BPB in older patients.MethodsPatients aged ≥65 years were randomly allocated to receive either standard preoperative insulation (control group, n=20) or preanesthetic forced-air warming for 20 minutes before BPB (prewarming group, n=20). During the perioperative period, tympanic temperatures were measured. Thermal comfort scores and shivering grades were also obtained.ResultsThe tympanic temperatures at the end of surgery did not differ between the groups (36.9°C±0.5°C and 37.0°C±0.4°C in the control and prewarming groups, respectively; p=0.252). The maximum temperature change was significantly lower in the prewarming group compared to the control group (0.36°C±0.4°C and 0.65°C±0.3°C, respectively; p=0.013). The hypothermia incidence and severity, thermal comfort scores, and shivering grades did not differ between the groups.ConclusionRegardless of the application of prewarming, BPB did not cause a clinically significant impairment of thermoregulation. Moreover, the efficacy of prewarming appeared to be low; thus, it may not be routinely required in patients undergoing orthopedic hand surgery under BPB.

Comparison of two different uses of underbody forced-air warming blankets for the prevention of hypothermia in patients undergoing arthroscopic shoulder surgery: a prospective randomized study

BackgroundForced-air warming (FAW) is an effective method of preventing inadvertent perioperative hypothermia (IPH). However, its warming effects can be influenced by the style and position of the FAW blanket. This study aimed to compare the effects of underbody FAW blankets being placed under or over patients in preventing IPH.MethodsPatients (n=100) undergoing elective arthroscopic shoulder surgery in the lateral decubitus position were randomized into either under body (UB) group or the over body (OB) group (50 per group). The body temperature of the patients was recorded from baseline to the end of anesthesia. The incidences of postoperative hypothermia and shivering were also collected.ResultsA steady decline in the body temperature was observed in both groups up to 60 minutes after the start of FAW. After 60 minutes of warming, the OB group showed a gradual increase in the body temperature. However, the body temperature still decreased in UB group until 75 minutes, with a low of 35.7℃ ± 0.4℃. Then the body temperature increased mildly and reached 35.8℃ ± 0.4℃ at 90 minutes. After 45 minutes of warming, the body temperature between the groups was significantly different (P < 0.05). The incidence of postoperative hypothermia in the UB group was significantly higher than that in the OB group (P = 0.023).ConclusionsThe body temperature was significantly better with the use of underbody FAW blankets placed over patients than with them placed under patients. However, there was not a clinically significant difference in body temperature. The incidence of postoperative hypothermia was much lower in the OB group. Therefore, placing underbody FAW blankets over patients is recommended for the prevention of IPH in patients undergoing arthroscopic shoulder surgery.Trial registrationThis single-center, prospective, RCT has completed the registration of the Chinese Clinical Trial Center at 13/1/2021 with the registration number ChiCTR2100042071. It was conducted from 14/1/2021 to 30/10/2021 as a single, blinded trial in Sichuan Provincial Orthopedic Hospital.

The use of forced air warmer for the prevention of inadvertent perioperative hypothermia under general anaesthesia - A prospective observational study

Temperature is an important parameter which determines patient outcomes perioperatively. Iatrogenic hypothermia during surgery under general anaesthesia leads to significant side effects which can be corrected with the use of active body surface warming devices like the forced air warmer. A prospective observational study was conducted with a sample size of 362 which included patients of either sex aged 18-65years posted for any elective surgery under general anaesthesia lasting &amp;#62;60 and ≤180minutes. Baseline oral temperature was recorded preoperatively. Patients were warmed with forced air warmer intraoperatively at 44°C with half hourly monitoring of nasopharyngeal temperature until extubation. Intravenous fluids were given at room temperature. Further, oral temperature was monitored at 15 and 60 minutes in post anaesthesia care unit and patients were warmed if hypothermic or shivering. The final mean intraoperative temperature (nasopharyngeal) was 36.01⁰C (n=362) with a range from 34.7⁰C to 37.1⁰C. 139 of 362(n) (38.4%) patients were hypothermic (&amp;#60;36⁰C) at the end of surgery. 61.6% of patients were normothermic. In 9 patients (2.5%, n=362) the forced air warmer was turned off due to over heating (temperature &amp;#62;37⁰C). 33 patients (n=362, 9.1%) had shivering postoperatively. Comparing the nasopharyngeal temperature (mean) at half hourly intervals post induction revealed statistically significant results (p&amp;#60;0.001). The establishment of near constant temperature (36±0.03°C) following the initial fall in core body temperature can be attributed to the forced air warmer. However, it is imperative to continuously monitor core body temperature to detect temperature changes(hypo/hyperthermia) in order to use the device safely as chances of overheating is always present.

Effects of 10-min of pre-warming on inadvertent perioperative hypothermia in intraoperative warming patients: a randomized controlled trial.

BackgroundThis study aimed to evaluate the efficacy of 10-min pre-warming in preventing inadvertent perioperative hypothermia, which is defined as a reduction in body temperature to less than 36.0℃ during the perioperative period in intraoperative warming patients.MethodsIn this prospective randomized study, 60 patients scheduled for elective surgery under general anesthesia lasting less than 120 min were divided into two groups: the 10-min pre-warming group (n = 30) and the control group (n = 30). Patients in the 10-min pre-warming group were pre-warmed for 10 min in the pre-anesthetic area using a forced-air warmer set at 47ºC. Intraoperatively, we warmed all patients with a forced-air warmer. Body temperature was measured using a tympanic membrane thermometer pre- or postoperatively and a nasopharyngeal temperature probe intraoperatively. Patients were evaluated on the shivering and thermal comfort scale in the pre-anesthetic area and post-anesthesia care unit.ResultsThe incidences of intraoperative hypothermia and postoperative hypothermia were similar in both groups (10.7% vs. 28.6%, P = 0.177; 10.7% vs. 10.7%, P = 1.000 respectively). Body temperature was higher in the 10-min pre-warming group (P = 0.003). Thermal comfort during the pre-warming period was higher in the 10-min pre-warming group (P < 0.001). However, postoperative thermal comfort and shivering grades of both groups were similar.ConclusionsTen minutes of pre-warming has no additional effect on the prevention of inadvertent perioperative hypothermia in intraoperative warming patients.

Prevalence of hypothermia on admission to recovery room remains high despite a large use of forced-air warming devices: Findings of a non-randomized observational multicenter and pragmatic study on perioperative hypothermia prevalence in France.

BackgroundDespite the availability of effective warming systems, the prevalence of hypothermia remains high in patients undergoing surgery. Occurrence of perioperative hypothermia may influence the rate of postoperative complications. Recommendations for the prevention of inadvertent perioperative hypothermia have been developed and are effective to reduce the frequency of perioperative hypothermia when professionals comply with. French Society of Anesthesiology (SFAR) decided to promote guidelines for the prevention of inadvertent hypothermia, and to conduct beforehand a pragmatic assessment of the prevalence of hypothermia in France. The hypothesis was that the rate of hypothermic patients (Tc<36°C) admitted to the RR remains high (around 50%), and that was the consequence of a warming device underutilization and/or was related to the type of health facilities.MethodsAn observational, prospective and multi-centric study was conducted in France between October 2014 and May 2016 among patients over 45 years undergoing non-cardiac, non-outpatient surgery with anesthesia lasting >30 minutes in 52 centers. Patients undergoing pulmonary or proctologic surgery and those having non-invasive procedures performed under general anesthesia (for example, digestive endoscopy) were excluded from our study. Patients being operated under plexus anesthesia alone, surgeries involving hemorrhaging or infection, and patients presenting at least one organ failure were also excluded. The primary endpoint was the percentage of patients with a core temperature (Tc) <36°C on admission to the recovery room (RR).ResultsAmong 893 subjects (median age 66.9 years), prevalence of hypothermia on admission to the RR was 53.5%. At least one warming system was used for 90.4% of the patients. Identified risk factors for Tc<36°C included age≥70 years (OR = 1.41 [CI95%: 1.02–1.94]), duration of anesthesia from 1 to 2 hours (OR = 1.94 [CI95%: 1.04–3.64]) and a decrease in Tc of >0.5°C between anesthesia induction and surgical incision (OR = 1.82 [CI95%: 1.15–2.89]). Only a combination of pre-warming and intraoperative warming prevented a Tc<36°C (OR = 0.48 [CI95%: 0.24–0.96]).ConclusionsThe prevalence of hypothermia among patients admitted to the RR remains high. Our results suggest that only the combination of pre-warming and intraoperative warming significantly decreases it.

Prevention of inadvertent perioperative hypothermia - Guideline compliance in German hospitals.

Patients undergoing elective surgery are at risk for inadvertent postoperative hypothermia, defined as a core body temperature below 36°C. This study was conducted to investigate the acceptance of the recommendations of the German S3 Guideline, in particular with respect to the concept of pre-warming and sublingual temperature measurement. The main focus was to gather data concerning the postoperative core temperature and the frequency of perioperative hypothermia in patients receiving a pre-warming regime and those without. The study team investigated the local concept and measures employed to avoid inadvertent perioperative hypothermia with respect to defined outcome parameters following a specific protocol. In summary, the study hospitals vary greatly in their perioperative processes to prevent postoperative hypothermia. However, each hospital has a strategy to prevent hypothermia and was more or less successful in keeping its patients normothermic during the perioperative process. Our data could not demonstrate major differences between hospitals in the implementation strategy to prevent perioperative hypothermia in regard to the hospital size. The results of our study suggest a wide-spread acceptance, as no postoperative hypothermia was detected in a cohort of 431 patients.

Reducing Implant Infection in Orthopaedics (RIIiO): a pilot study for a randomised controlled trial comparing the influence of forced air versus resistive fabric warming technologies on postoperative infection rates following orthopaedic implant surgery in adults

BackgroundApproximately 70,000 to 75,000 proximal femoral fracture repairs take place in the UK each year. Hemiarthroplasty is the preferred treatment for adults aged over 60 years. Postoperative infection affects up to 3% of patients and is the single most common reason for early return to theatre. Ultraclean ventilation was introduced to help mitigate the risk of infection, but it may also contribute to inadvertent perioperative hypothermia, which itself is a risk for postoperative infection. To counter this, active intraoperative warming is used for all procedures that take 30 min or more. Forced air warming (FAW) and resistive fabric warming (RFW) are the two principal techniques used for this purpose; they are equally effective in prevention of inadvertent perioperative hypothermia, but it is not known which is associated with the lowest infection rates. Deep surgical site infection doubles operative costs, triples investigation costs and quadruples ward costs. The Reducing Implant Infection in Orthopaedics (RIIiO) study seeks to compare infection rates with FAW versus RFW after hemiarthroplasty for hip fracture. A cost-neutral intervention capable of reducing postoperative infection rates would likely lead to a change in practice, yield significant savings for the health economy, reduce overall exposure to antibiotics and improve outcomes following hip fracture in the elderly. The findings may be transferable to other orthopaedic implant procedures and to non-orthopaedic surgical specialties.MethodsRIIiO is a parallel group, open label study randomising hip fracture patients over 60 years of age who are undergoing hemiarthroplasty to RFW or FAW. Participants are followed up for 3 months. Definitive deep surgical site infection within 90 days of surgery, the primary endpoint, is determined by a blinded endpoint committee.DiscussionHemiarthroplasty carries a risk of deep surgical site infection of approximately 3%. In order to provide 90% power to demonstrate an absolute risk reduction of 1%, using a 5% significance level, a full trial would need to recruit approximately 8630 participants. A pilot study is being conducted in the first instance to demonstrate that recruitment and data management strategies are appropriate and robust before embarking on a large multi-centre trial.Trial registrationISRCTN, ISRCTN74612906. Registered on 27 February 2017.

The effect of 10 minutes of prewarming for prevention of inadvertent perioperative hypothermia: comparison with 30 minutes of prewarming

The effect of 10 minutes of prewarming for prevention of inadvertent perioperative hypothermia: comparison with 30 minutes of prewarming

Prevention and management of inadvertent perioparatve hypothermia

Центральная температура тела человека служит важнейшим показателем, мониторируемым в клинической практике анестезиологии и интенсивной терапии. Современные анестетики влияют на процессы регуляции центральной температуры и приводят к её снижению в периоперационном периоде. Непреднамеренная интраоперационная гипотермия сопровождает многие операции, проводимые под общей и регионарной анестезией. Она значительно увеличивает риск кардиальных и инфекционных послеоперационных осложнений, на её фоне возрастают послеоперационная кровопотеря и потребность в гемотрансфузии. Пациенты в условиях гипотермии медленнее просыпаются, их пробуждение чаще сопровождается мышечной дрожью. Периоперационная гипотермия приводит к увеличению сроков госпитализации и внутрибольничной летальности. В связи с этим предотвращение непреднамеренной периоперационной гипотермии - важная часть анестезиологического обеспечения больного во всех областях хирургии. Поддержание нормотермии во время операции служит важной составляющей всех программ ранней послеоперационной активизации больных.

Evidence Utilisation Project: Management of Inadvertent Perioperative Hypothermia. The challenges of implementing best practice recommendations in the perioperative environment

The prevention of inadvertent perioperative hypothermia (IPH) remains an important issue in perioperative healthcare. The aims of this project were to: (i) assess current clinical practice in the management of IPH and (ii) promote best practice in the management of IPH in adult operating theatres. This project from August 2010 to March 2012 utilised a system of audit and feedback to implement best practice recommendations. Data were collected via chart audits against criteria developed from best practice recommendations for managing IPH. Evidence-based best practices, such as consistent temperature monitoring and patient warming, were implemented using multifaceted interventions. Perioperative records for 73 patients (baseline) and 72 patients (post-implementation) were audited. Post-implementation audit showed an increase in patients with temperatures >36°C admitted to the post-anaesthetic care unit (PACU) (8%) and discharged from PACU (28%). The percentage of patients receiving preoperative temperature monitoring increased (38%); however, low levels of intraoperative monitoring remained (31% of patients with surgery of 30 min or longer duration). Small increases were found in patient warming of 5% intraoperatively and 8% postoperatively. Preoperative warming was not successfully implemented during this phase of the project. Temperature monitoring, warming and rates of normothermia improved; however, barriers to best practice of IPH management were experienced, which negatively impacted on the project. Further stages of implementation and audit were added to further address IPH management in this department.

Correlation, accuracy, precision and practicability of perioperative measurement of sublingual temperature in comparison with tympanic membrane temperature in awake and anaesthetised patients

The prevention of inadvertent perioperative hypothermia requires precise, reliable and practical methods of temperature measurement in both awake and anaesthetised patients. Different methods and sites of monitoring have been evaluated, but many are imprecise, unusable in awake patients, difficult to apply or too invasive, especially for minor surgery. The aim of this study was to evaluate the performance of perioperative sublingual and tympanic temperature measurement in awake and anaesthetised patients. We enrolled 171 patients, aged 18-75 years, scheduled for surgery with duration less than 1 h under general anaesthesia. Spearman's rank correlation and Bland-Altman analysis for assessment of correlation, accuracy and precision of both methods were determined analysing 171 independent paired values at three different measurement times. Sublingual temperatures were significantly higher than tympanic temperatures by 0.1-0.2°C. The coefficient of determination (r) of both methods was between 0.50 and 0.59, and Bland-Altman analysis revealed a bias (SD) of between -0.09 (0.21) and -0.15 (0.24)°C. The accuracy and precision of sublingual temperature measurement were adequate for clinical use, and there was a high correlation with tympanic temperature monitoring. Sublingual temperature measurement has been demonstrated as a good and practical modality for perioperative temperature monitoring in both awake and anaesthetised patients.

Prevention of inadvertent perioperative hypothermia

All patients undergoing surgery are at risk of developing hypothermia; up to 70% develop hypothermia perioperatively. Inadvertent hypothermia is associated with complications such as impaired wound healing, increased blood loss, cardiac arrest and increased risk of wound infection. Anaesthesia increases the risk as the normal protective shivering reflex is absent. Ambient temperature also has a major effect on the patient's body temperature. Prevention of hypothermia not only reduces the incidence of complications, but patients also experience a greater level of comfort, and avoid postoperative shivering and the unpleasant sensation of feeling cold. Nurses should be aware of the risks of hypothermia so that preventative interventions can be employed to minimize the risk of hypothermia. Preoperative assessment is essential to enable identification of at-risk patients. Simple precautionary measures initiated by nurses can considerably reduce the amount of heat lost, minimize the risk of associated complications and ultimately improve patients' short- and long-term recovery. Minimizing skin exposure, providing adequate bed linen for the transfer to theatre and educating patients about the importance of keeping warm perioperatively are all extremely important. It is also worth considering using forced-air warmers preoperatively as research suggests that initiating active warming preoperatively may be successful in preventing hypothermia during the perioperative period.

Nurses' Knowledge of Inadvertent Hypothermia

Inadvertent hypothermia can have significant consequences in the perioperative setting. Knowing how to recognize and manage inadvertent hypothermia is an important aspect of perioperative nursing. A quantitative, descriptive study was conducted at an annual perioperative nursing conference to evaluate nurses' knowledge regarding the prevention of inadvertent perioperative hypothermia. Significant variations in responses regarding definitions of hypothermia and normothermia were noted. In addition, nurses identified a plethora of factors that prevent them from maintaining normothermia in their patients. These factors mandate a need for educational interventions and the adoption of practice guidelines in the clinical area.