Perioperative Temperature Management During Burn Care:

Management of operating theatre ambient temperature for major burn patients in a state-wide adult burns centre

INTRODUCTION

The aim of this study was to investigate the efficacy of limiting increases in theatre ambient temperature to 27°C to prevent intraoperative patient hypothermia.

METHODS

This single-centre, comparative cohort clinical study investigated the management of theatre ambient temperatures involving patients with ≥ 20 % TBSA burn injuries at Victorian Adult Burns Service (Melbourne, Australia). Data from the intervention group (August 2021 - February 2023, theatre ambient temperature increase limited to 27°C) was compared with a historical cohort (August 2019 - August 2021). Patient hypothermia was defined as core temperature below 36°C.

RESULTS

In total, 29 patients underwent 107 surgical procedures in the operating theatre. Patient hypothermia was recorded on 45 occasions (42.1 %) and of these, between 35.1 and 36.0°C on 28 occasions (62.2 %). There was no statistically significant difference in the incidence of hypothermia, hospital LOS, ICU LOS, total operations, or mortality between the study cohort and historical cohort. Patients who suffered hypothermia had lower BMI, lower preoperative temperature, and shorter ICU LOS.

CONCLUSION

Increasing theatre ambient temperature to 27°C is adequate in most cases. A more nuanced approach with selective increase of theatre ambient temperature beyond 27°C, only where clinically indicated, is a refinement that will benefit both patients and staff.

Survey about target temperature and thermal management in intensive care for severe thermal trauma in burn centres of Germany, Austria and Switzerland

Burn trauma induces hypermetabolism and alters thermoregulation resulting in elevated body temperature. Because patients with burns are prone to heat loss and hypothermia, maintaining physiologic body temperature is important. However, optimal target temperature is widely unknown because thermoregulation of burn trauma has mainly been studied in the previous century, when treatment concepts differed from current era. The aim of this study was to investigate current thermal management of burn treatment and to investigate the discrepancies between classical concepts of thermoregulation in burn trauma and current practice of temperature management. A paper-based survey was conducted in burn centres in Germany, Austria, and German-speaking Switzerland. Participants were asked for expected temperatures, temperature goals, and thermal management of severely burned patients. Results were evaluated for adults and children. 37 of 38 approached burn centres participated in this survey. 59 % expected that adults with burn trauma would develop hyperthermia (>37.5 °C) but only 27 % expected hyperthermia in children (>38 °C). The average target body temperature was 37.1 °C for adults and 36.9 °C for children. Adults below 35.7 °C and children below 36.0 °C were assessed to be hypothermic. Temperatures above 38.8 °C in adults and 38.7 °C in children raised suspicion for sepsis. Antipyretic treatment was assumed to be justified at temperatures above 39.1 °C in adults and 38.5 °C in children. Although the most common warming method was to increase ambient temperature, 89 % of all participants felt their wellbeing was affected by an increased ambient temperature and 68 % were concerned about temperature-related negative effects. Although 57 % of the responding centres had established a standard operating procedure for thermal management, only 41 % considered the available literature to be very relevant in daily practice and 89 % criticized the lack of guidelines. Limit and target temperatures in European burn centres are heterogeneous. Classic concepts of thermal management in burn care are not universally adopted. A majority of the centers expresses the need for specific guidelines. The basis for this should be multicentre clinical trials on temperature management in burn trauma.

An integrative literature review of factors contributing to hypothermia in adults during the emergent (ebb) phase of a severe burn injury

BACKGROUND

During the emergent (ebb) phase (first 72 h), the adult person with a severe burn experiences loss of body heat, decreased metabolism, and poor tissue perfusion putting them at risk of hypothermia, increased morbidity, and mortality. Therefore, timely and targeted care is imperative.

AIM

The aim of this integrative literature review was to develop a framework of the factors contributing to hypothermia in adults with a severe burn injury during the emergent (ebb) phase.

METHODS

An integrative review of research literature was undertaken as it provides an orderly process in the sourcing and evaluation of the literature. Only peer reviewed research articles, published in scholarly journals were selected for inclusion (n = 26). Research rigor and quality for each research article was determined using JBI Global appraisal tools relevant to the methodology of the selected study.

FINDINGS

Contributing factors were classified under three key themes: Individual, Pre-hospital, and In-hospital factors.

CONCLUSION

The structured approach enabled the development of an evidence-based framework identifying factors contributing to hypothermia in adults with a severe burn injury during the emergent (ebb) phase and adds knowledge to improve standardized care of the adult person with a severe burn injury.

Postoperative hypothermia is associated with reduced length of stay in adult acute burn survivors

BACKGROUND

The hypermetabolic response after a burn predisposes patients to hypothermia due to dysfunction of thermoregulation. Traditionally, hypothermia is avoided actively in burn care due to reported complications associated with low body temperature. The likelihood of hypothermia with acute burn surgery is compounded by general anesthesia, exposure of wound areas and prolonged operation times. However, we find limited studies exploring the effects of perioperative hypothermia on length of stay in the adult burn population.

OBJECTIVE

To determine associations between postoperative hypothermia and hospital length of stay in adult burns patients.

METHOD

This retrospective cohort study involved patients admitted to the State Adult Burn Unit in Western Australia between 1st January 2015 to 28th February 2021. All adults who underwent surgery for acute burn, and had postoperative recovery room body temperature recorded, were included in the study. In this study, we defined normothermia as >36.5C and hypothermia as < 36.0 °C with mild, moderate, and severe hypothermia being 35.0-35.9 °C, 34.0-34.9 °C and < 34.0 °C, respectively. Patients with hyperthermia were excluded. Multivariable general linear models explored if hypothermia was independently associated with length of stay.

RESULTS

Among 1486 adult patients, 1338 (90%) were normothermic postoperatively, with temperatures >36.0C. We included 148 (10%) patients with hypothermia (temperature <36.0 °C) postoperatively. Most burns in the study population were minor: 96% had burns < 15% TBSA. Data modelling demonstrated that hypothermia was associated with a shorter length of hospital stay (coefficient = -0.129, p = 0.041).

CONCLUSION

In adult acute burn patients, postoperative hypothermia was associated with reduced length of stay after surgery. The positive results of this study indicate that a review of the core temperature targets with acute burn surgery, and timing of burn patient cooling practices in general is warranted.

Development and validation of a nomogram to predict hypothermia in adult burn patients during escharectomy under general anesthesia

BACKGROUND

It is very common for burn patients to have hypothermia during escharectomy under general anesthesia, which increases the blood transfusion demand of burn patients, and may lead to blood coagulation disorder or even increase the mortality of patients. It is important to predict the occurrence of hypothermia in advance, but we lack a prognostic prediction model. Our study aimed to develop a nomogram to predict the incidence of hypothermia in adult burn patients undergoing escharectomy under general anesthesia to intervention the hazards associated with hypothermia early.

METHODS

This retrospective study included 978 adult burn patients who underwent simple escharectomy under general anesthesia during hospitalization between January 2017 and December 2022, they were further divided into a training cohort and a validation cohort. The clinical data were recorded in electronic medical record system and a self-made collection table of intraoperative hypothermia. The preliminary predictive factors for hypothermia which undergoing simple escharectomy under general anesthesia in burn patients were determined using least absolute shrinkage and selection operator (LASSO) at first, then the final predictive factors determined using binary logistic regression analyses and a nomogram to predict the occurrence of hypothermia was established. The index of concordance(C-index), calibration curves, receiver operating characteristic (ROC) curve, and decision curve analysis (DCA) were used to evaluate the performance of the model.

RESULTS

A total of 211 patients with hypothermia and 767 patients without hypothermia were selected. Least absolute shrinkage and selection operator regression analysis and binary logistic regression results concluded that burn index, urinary volume, blood transfusion volume and irrigation volume were significantly associated with hypothermia in burn patients undergoing escharectomy under general anesthesia. The nomogram based on these four variables had good predictive efficiency for hypothermia in adult burn patients during escharectomy under general anesthesia, the C-index in the training cohort was 0.903, areas under the receiver operating characteristic curves (AUROC) of for the training cohort (95 % CI 0.877-0.920) and 0.875 for the validation cohort (95 % CI 0.852-0.897) indicated satisfactory discriminative ability of the nomogram, and the calibration curves for the training cohort and the validation cohort also fit as well, indicating that the nomogram had good clinical application value.

CONCLUSIONS

Hypothermia in burn patients during escharectomy under general anesthesia is associated with burn index, urinary volume, blood transfusion volume and irrigation volume. We successfully developed a practical nomogram to accurately predict hypothermia, which is a practical method helping clinicians rapidly and conveniently diagnose and guide the treatment of hypothermia in burn patients during escharectomy under general anesthesia.

Incidence of Unintentional Intraoperative Hypothermia and Its Risk Factors in Oral and Maxillofacial Surgery: A Prospective Study

PURPOSE

Unintentional intraoperative hypothermia is a common complication in patients who undergo open surgery, increasing the risk of adverse outcomes. However, few studies have focused on intraoperative hypothermia during oral and maxillofacial surgery. Our study aimed to analyze the prevalence and risk factors of hypothermia in patients who underwent oral and maxillofacial surgery.

DESIGN

A prospective cohort study was conducted on 128 patients who underwent oral and maxillofacial surgery.

METHODS

This prospective study was conducted at West China Hospital of Stomatology between December 2020 and May 2021, and each patient was followed for at least 1-month postoperatively. Patients who underwent oral and maxillofacial surgery under general anesthesia, with at least 1-month follow-up were analyzed. The primary variable was intraoperative hypothermia, defined as core body temperature less than 36°C, measured using a tympanic thermometer during the surgery. We performed univariate and multivariate logistic regression analyses to identify the risk factors of unintentional intraoperative hypothermia.

FINDINGS

The mean age of the 128 patients was 31.0 ± 20.9 years, and there was a male predominance (53.1%), with male to female ratio of 1.13:1. Thirty-one patients (24.2%) developed hypothermia intraoperatively. Older age (OR = 1.068, 95% CI: 1.028-1.110, P = .001), lower weight (OR = 0.878, 95% CI: 0.807-0.955, P = .002), greater blood loss (OR = 1.003, 95% CI: 1.000-1.006, P = .034), and undergoing cancer surgery (OR = 0.210, 95% CI: 0.067-0.656, P = .007) were associated with intraoperative hypothermia.

CONCLUSIONS

Unintentional intraoperative hypothermia is common in patients who undergo surgery for oral cancer. Warming interventions to prevent intraoperative hypothermia for high-risk patients (older, lower weight, or more intraoperative bleeding) should be considered. Meanwhile, with careful nursing and rehabilitation instructions, intraoperative hypothermia does not lead to serious perioperative complications.

An Overview of Recent Developments in the Management of Burn Injuries

According to the World Health Organization (WHO), around 11 million people suffer from burns every year, and 180,000 die from them. A burn is a condition in which heat, chemical substances, an electrical current or other factors cause tissue damage. Burns mainly affect the skin, but can also affect deeper tissues such as bones or muscles. When burned, the skin loses its main functions, such as protection from the external environment, pathogens, evaporation and heat loss. Depending on the stage of the burn, the patient's condition and the cause of the burn, we need to choose the most appropriate treatment. Personalization and multidisciplinary collaboration are key to the successful management of burn patients. In this comprehensive review, we have collected and discussed the available treatment options, focusing on recent advances in topical treatments, wound cleansing, dressings, skin grafting, nutrition, pain and scar tissue management.

Living in Western Australia induces some physiological adaptations of seasonal acclimatisation in the surgical burns team

Seasonal acclimatization is known to result in adaptations that can improve heat tolerance. Staff who operate on burn injuries are exposed to thermally stressful conditions and seasonal acclimatization may improve their thermoeffector responses during surgery. Therefore, the aim of this study was to assess the physiological and perceptual responses of staff who operate on burn injuries during summer and winter, to determine whether they become acclimatized to the heated operating theater. Eight staff members had physiological and perceptual responses compared during burn surgeries conducted in thermoneutral (CON: 24.1 ± 1.2°C, 45 ± 7% relative humidity [RH]) and heated (HOT: 31.3 ± 1.6°C, 44 ± 7% RH) operating theaters, in summer and winter. Physiological parameters that were assessed included core temperature, heart rate, total sweat loss, sweat rate, and urinary specific gravity. Perceptual responses included ratings of thermal sensation and comfort. In summer, CON compared to winter CON, baseline (85 ± 15 bpm VS 94 ± 18 bpm), mean (84 ± 16 bpm VS 93 ± 18 bpm), and peak HR (94 ± 17 bpm VS 105 ± 19 bpm) were lower (p < 0.05), whereas core temperature was not different between seasons in either condition (p > 0.05). In HOT, ratings of discomfort were higher in summer (15 ± 3) than winter (13 ± 3; p > 0.05), but ratings of thermal sensation and sweat rate were similar between seasons (p > 0.05). The surgical team in burns in Western Australia can obtain some of the physiological adaptations that result from seasonal acclimatization, but not all. That is most likely due to a lower than required amount of outdoor heat exposure in summer, to induce all physiological and perceptual adaptations.

Changes in coagulation and temperature management in burn patients - A survey of burn centers in Switzerland, Austria and Germany

BACKGROUND

Severely burned patients suffer from both coagulopathy and hypothermia, with a lack of international consensus and appropriate treatment guidelines. This study examines recent developments and trends in coagulation and temperature management in European burn centers.

METHODS

A survey was sent to burn centers in Switzerland, Austria and Germany in 2016 and again in 2021. The analysis was performed using descriptive statistics, with categorical data reported in absolute numbers (n) and percentages (%) and numerical data reported as mean and standard deviation.

RESULTS

The rate of completed questionnaires was 84 % (16 of 19 questionnaires) in 2016 and 91 % (21 of 22 questionnaires) in 2021. The number of global coagulation tests performed has decreased over the observation period in favor of single factor determination and bed-side point-of-care coagulation tests. This has also led to increased administration of single factor concentrates in therapy. Although many centers had a defined treatment protocol for hypothermia in 2016, coverage increased such that in 2021 all centers surveyed had such a protocol. The body temperature was measured more consistently in 2021; thus, hypothermia was more actively sought, detected and treated.

CONCLUSION

A point-of-care guided, factor-based coagulation management and the maintenance of normothermia have gained importance in the care of burn patients in recent years.

Ambient Room Temperatures in a Burn Intensive Care Unit-A Quality Improvement Project

Introduction: Patients with major burn injuries are particularly susceptible to hypothermia. The ability to maintain and rapidly increase ambient temperatures may reduce the impact of hypothermia and the hypermetabolic response. The purpose of this study was to determine ambient patient room temperatures in a burn intensive care unit (ICU) and to evaluate our ability to adjust these temperatures. Methods: The ambient temperatures of 9 burn ICU patient rooms were recorded hourly over a 6-month period in an American Burn Association-verified burn centre. Temperatures were recorded using wall-mounted smart sensors, transmitted to a mobile smartphone application via Bluetooth, and then exported to Excel for analysis. On 2 predetermined dates, thermostats in all rooms were simultaneously set to maximum, and monitored over 3 h. This represented a sound change initiative, and replicated a medical order to increase the ambient temperature during critical stages of patient care. Results: We recorded 4394 individual hourly temperature measurements for each of the 9 rooms. The mean ambient temperature was 23.5 ± 0.3 °C (range 22.8-24). After intervention 1, ambient temperatures increased <2 °C in 7 rooms and by only 2 °C-3 °C in the other 2 rooms. The overall mean increase in temperature over 3 h across all rooms was 1.03 °C ± 1.19 °C (range -0.88 to 3.26). Following intervention 2, temperatures could be increased by ≥2 °C in only 2 rooms with an overall mean increase in temperature of only 0.76 °C ± 0.99 °C (range -0.29 to 2.43) across all rooms. Conclusions: The burn ICU rooms were relatively cool and our ability locally to adjust ambient temperatures quickly was limited. Burn centres should have regular facility assessments to assess whether ambient temperatures can be adjusted expeditiously when required.

Temperature Derangement on Admission is Associated With Mortality in Burn Patients-A Nationwide Analysis and Opportunity for Improvement

Although single-institution studies have described the relationship between hypothermia, burn severity, and complications, there are no national estimates on how temperature on admission impacts hospital mortality. This study aims to evaluate the relationship between admission temperature and complications on a national scale to expose opportunities for improved outcomes. The US National Trauma Data Bank (NTDB) was analyzed between 2007 and 2018. Mortality was modeled using multivariable logistic regression including burn severity variables (% total burn surface area (TBSA), inhalation injury, emergency department (ED) temperature), demographics, and facility variables. Temperature was parsed into three categories: hypothermia (<36.0°C), euthermia (36.0-37.9°C), and hyperthermia (≥38.0°C). A total of 116,796 burn encounters were included of which 77.9% were euthermic, 20.6% were hypothermic and 1.45% were hyperthermic on admission. For every 1.0C drop in body temperature from 36.0°C, mortality increased by 5%. Both hypothermia and hyperthermia were independently associated with increased odds of mortality when controlling for age, gender, inhalation injury, number of comorbidities, and %TBSA burned (p < .001). All temperatures below 36.0°C were significantly associated with increased odds of mortality. Patients with ED temperatures between 32.5 and 33.5°C had the highest odds of mortality (22.0, 95% CI 15.6-31.0, p < .001). ED hypothermia and hyperthermia are independently associated with mortality even when controlling for known covariates associated with inpatient death. These findings underscore the importance of early warming interventions both at the prehospital stage and upon ED arrival. ED temperature could become a quality metric in benchmarking burn centers to improve mortality.

The strength of surgical knots involves a critical interplay between friction and elastoplasticity

Knots are the weakest link in surgical sutures, serving as mechanical ligatures between filaments. Exceeding their safe operational limits can cause fatal complications. The empirical nature of present guidelines calls for a predictive understanding of the mechanisms underlying knot strength. We identify the primary ingredients dictating the mechanics of surgical sliding knots, highlighting the previously overlooked but critical effect of plasticity and its interplay with friction. The characterization of surgeon-tied knots reveals the relevant ranges of tightness and geometric features. Using model experiments coupled with finite element simulations, we uncover a robust master curve for the target knot strength versus the tying pre-tension, number of throws, and frictional properties. These findings could find applications in the training of surgeons and robotic-assisted surgical devices.

Higher operating theatre temperature during burn surgery increases physiological heat strain, subjective workload, and fatigue of surgical staff

Raising the ambient temperature of the operating theatre is common practice during burn surgeries to maintain the patient's core body temperature; however, the effects of operating in the heat on cognitive performance, manual dexterity, and perceived workload of surgical staff have not been assessed in a real-world context. Therefore, the aim was to assess the real-time impact of heat during burn surgeries on staff's cognitive function, manual dexterity, and perceptual measures (workload, thermal sensation, thermal comfort, perceived exertion, and fatigue) and physiological parameters (core temperature, heart-rate, fluid loss, and dehydration). Ten burn surgery staff members were assessed in CON (24.0±1.1°C, 45±6% relative humidity [RH]) and HOT (30.8±1.6°C, 39±7% RH) burn surgeries (average 150 min duration). Cognitive performance, manual dexterity, and perceptual measures were recorded pre- and post-surgery, while physiological parameters were recorded throughout surgery. HOT conditions did not significantly affect manual dexterity or cognitive function (p > .05), however HOT resulted in heat strain (increased heart-rate, core temperature, and fluid loss: p < .05), and increased subjective workload, discomfort, perceived exertion, and fatigue compared to CON conditions (p < .05). Cognitive function and manual dexterity were maintained in hot conditions, suggesting that operating in approximately 31°C heat is a safe approach for patient treatment. However, job burnout, which is positively correlated with perceived workload, and the impact of cumulative fatigue on the mental health of surgery staff, must be considered in the context of supporting an effective health workforce.

Reducing Blood Loss in a Burn Care Unit: A Review of Its Key Determinants

Patients with a major burn injury differ considerably from the typical critical ill and trauma population. Very often, burn patients suffer from anemia throughout their hospital stay. This is caused both by combination of persistent blood loss with decreased erythropoiesis. Therefore, burn patients do have major transfusion requirements. However, transfusion is not devoid of risks or costs. We hereby review the best surgical techniques and medical approaches, aiming to reduce blood loss in a burn patient and optimize red cell production, so that we can reduce the need of RBC transfusion. The implementation of a combination of surgical techniques aiming to reduce blood loss and medical care approaches to prevent anemia, rather than single attitudes, should be adopted in burn care. There is an urgent need for clear guidelines that can easily be accepted, applied, and spread across different burn units to methodically implement measures to reduce blood loss and transfusion needs, and ultimately improve burn patients' outcome and the health care financial status.

Burns: Classification, Pathophysiology, and Treatment: A Review

Burns and their treatment are a significant medical problem. The loss of the physical barrier function of the skin opens the door to microbial invasion and can lead to infection. The repair process of the damage caused by the burn is impaired due to the enhanced loss of fluids and minerals through the burn wound, the onset of hypermetabolism with the concomitant disruption of nutrient supply, and derangements in the endocrine system. In addition, the initiated inflammatory and free radical processes drive the progression of oxidative stress, the inhibition of which largely depends on an adequate supply of antioxidants and minerals. Clinical experience and research provide more and more data to make the treatment of patients with thermal injury increasingly effective. The publication discusses disorders occurring in patients after thermal injury and the methods used at various stages of treatment.

Venous Thromboembolism in Severe Burns Patients with Intravascular Warming Catheter: A Retrospective Cohort Study

Background: Use of intravascular warming catheters following major burns has been shown to be effective to maintain normothermia, but their use may be associated with complications. The aim of this study was to determine what proportion of patients with an intravascular warming catheter developed a potentially catheter-related venous thromboembolism (VTE) and to identify contributing risk factors. Methods: This was a retrospective cohort study of patients admitted to the Victorian Adult Burns Service January 2013 to July 2018 with major burns (TBSA > 20%) who had an ICYTM intravascular warming catheter. Warming catheter insertion and other details were identified with a manual search of the patients' medical records by a single author while incidence of VTE was determined by the coding department from a central database. Results: Forty patients had an intravascular warming catheter inserted during the study period. The number of patients in the catheter group that sustained a VTE was eight (20%), of which four (10%) could have been catheter-related due to the anatomical location. In the cases of the four potentially catheter-related VTE, other preventable VTE risk factors including suboptimal prophylactic anticoagulation (n = 2), prolonged catheter duration (n = 1) and prolonged haemoconcentration (n = 2) were identified. Conclusions: We found 20% of major burns patients with an intravascular warming device had significant VTE; however, only half of these may have been related to the catheter. A careful assessment for each patient that balances risks and benefits should be undertaken prior to using intravascular warming devices.

Reduced Intraoperative Blood Loss and Hypothermia in Burn Surgery using Cardiopulmonary Bypass Pumps

Objective: Patients presenting with total body surface area (TBSA) >40% burns require significant surgical treatment. Two substantial challenges during these surgeries are limiting blood loss and maintaining core temperatures. To overcome these challenges, several techniques have been developed, ranging from the Pitkin syringe method to the pneumatic tourniquet strategy for large-volume hyperthermic insufflation. Here, we compare the pneumatic tourniquet method to a roller pump method for maintenance of intraoperative normothermia and control of bleeding. Methods: We conducted a retrospective chart review of 20 patients presenting with TBSA >40% burns, 10 of whom were treated with the rapid infusion roller pump and 10 of whom were treated with the pneumatic tourniquet technique. Patients from each group were controlled for % TBSA, presence of inhalation injury, age, and date of admission. We reviewed transfusion requirement and the intraoperative temperatures, as well as the average intraoperative drop in temperature. Results: We observed improvement in the infusion volume, operative time, intraoperative temperature drop, minimum intraoperative temperature, estimated blood loss, and amount of required transfusion. Conclusions: Our study suggests that the rapid infusion roller pump technique is capable of achieving superior intraoperative bleeding control and temperature maintenance compared to the pneumatic tourniquet technique, resulting in decreased transfusion requirement.

Case Report: Anesthesia for a Neonate With Cutis Aplasia

Cutis aplasia is a rare condition characterized by skin and subcutaneous tissue defects. Researchers have previously described both conservative and surgical management methods. We report herein the case of a neonate with extensive cutis aplasia involving 37% of the total body surface area. Due to the risk of meningitis and catastrophic hemorrhage associated with scalp defects, she underwent staged surgical procedures with skin harvesting and synthetic skin application, followed by the application of cultured epithelial autografts. This report highlights the challenges in temperature and fluid management as well as intraoperative positioning in a neonate with cutis aplasia.

Current understanding of thermo(dys)regulation in severe burn injury and the pathophysiological influence of hypermetabolism, adrenergic stress and hypothalamic regulation—a systematic review

Background

In this systematic review, we summarize the aetiology as well as the current knowledge regarding thermo(dys)regulation and hypothermia after severe burn trauma and aim to present key concepts of pathophysiology and treatment options. Severe burn injuries with >20% total body surface area (TBSA) affected commonly leave the patient requiring several surgical procedures, prolonged hospital stays and cause substantial changes to body composition and metabolism in the acute and long-term phase. Particularly in severely burned patients, the loss of intact skin and the dysregulation of peripheral and central thermoregulatory processes may lead to substantial complications.

Methods

A systematic and protocol-based search for suitable publications was conducted following the PRISMA guidelines. Articles were screened and included if deemed eligible. This encompasses animal-based in vivo studies as well as clinical studies examining the control-loops of thermoregulation and metabolic stability within burn patients

Results

Both experimental animal studies and clinical studies examining thermoregulation and metabolic functions within burn patients have produced a general understanding of core concepts which are, nonetheless, lacking in detail. We describe the wide range of pathophysiological alterations observed after severe burn trauma and highlight the association between thermoregulation and hypermetabolism as well as the interactions between nearly all organ systems. Lastly, the current clinical standards of mitigating the negative effects of thermodysregulation and hypothermia are summarized, as a comprehensive understanding and implementation of the key concepts is critical for patient survival and long-term well-being.

Conclusions

The available in vivo animal models have provided many insights into the interwoven pathophysiology of severe burn injury, especially concerning thermoregulation. We offer an outlook on concepts of altered central thermoregulation from non-burn research as potential areas of future research interest and aim to provide an overview of the clinical implications of temperature management in burn patients.

The Impact of Ambient Temperature Control Across Various Care Settings on Outcomes in Burn Patients: A Review Article

Ambient/room temperature settings in burn treatment areas vary greatly due to a lack of evidence-based guidelines to direct care. While it is generally understood that ambient/room temperature impacts patient body temperature and metabolism, the ideal settings for optimizing patient outcomes are unclear. The literature assessing this topic is scarce, with many of the articles having significant limitations. We aim to summarize the current evidence for ambient/room temperature control, to address gaps in current reviews addressing this topic, and to elucidate topics requiring further research. PubMed and Google Scholar databases were queried for studies which evaluated the effect of the ambient/room temperature on burn patient core body temperature, patient metabolism, and outcomes among those treated in trauma bays, burn ICUs, and operating rooms. Although existing literature lacks sufficient patient outcome data regarding specific ambient/room temperatures, we highlight physiological processes that are impacted by changes in room temperatures in an effort to describe strategies that can allow for improved patient core body temperature control and outcomes in burn care settings.

An Experimental Simulation of Heat Effects on Cognition and Workload of Surgical Team Members

OBJECTIVE

To isolate heat exposure as a cause of cognitive impairment and increased subjective workload in burns surgical teams.

SUMMARY OF BACKGROUND DATA

Raising ambient temperature of the operating room can improve burns patient outcomes, but risks increased cognitive impairment and workload of surgical team members. Prior research indicates ambient heat exposure depletes physiological and cognitive resources, but these findings have not been studied in the context of burns surgical teams.

METHODS

Seventeen surgical team members completed 2 surgery simulations of similar complexities in a hot and in a normothermic operating room. During each simulation, participants completed multiple cognitive tests to assess cognitive functioning and the SURG-TLX to self-assess workload. Order effects, core body temperature changes due to menstruation, and circadian rhythms were controlled for in the experimental design. Descriptive statistics, correlations, and mixed ANOVAs were performed to assess relationships between ambient heat exposure with cognitive functioning and perceived workload.

RESULTS

Heat had a main effect on executive functioning and verbal reasoning. Duration of heat exposure (heat ∗ time) increased response times and negatively impacted executive functioning, spatial planning, and mental rotation. Perceived workload was higher in the hot condition.

CONCLUSIONS

We provide causal evidence that over time, heat exposure impairs cognitive speed and accuracy, and increases subjective workload. We recommend building on this study to drive best-practices for acute burns surgery and design work to enable burns teams to maintain their cognitive stamina, lower their workload, and improve outcomes for patients and surgeons.

Plastic surgical trainees' perspectives toward burn surgery in Australia and New Zealand: Changes in the last 17 years?

INTRODUCTION

An emerging amount of literature emphasises the ever-growing shortage of burn surgeons worldwide. Despite burn surgery being a fundamental competency in the Australia and New Zealand plastic and reconstructive surgery training curriculum, a perceived lack of interest amongst trainees exists. The aim of this study was to investigate Australasian plastic surgery trainees' interest in burn surgery as a career and compare with the Brown and Mills survey in 2004.

METHODS

An electronic survey was distributed to all Australian and New Zealand plastic and reconstructive surgery trainees during the March 2021 registrar trainee conference. This anonymous survey was adapted from the original survey conducted by Brown and Mills in 2004, with additional questions to determine the perceived importance of burns surgery as a subspecialty of plastic and reconstructive surgery, and to elicit possible solutions to the issue of workforce shortage. A reminder email was sent one month following the conference to improve the response rate. The survey was hosted by Survey Monkey (San Mateo, California, USA).

RESULTS

The survey was distributed to all 121 trainees and 71 (58.7%) responded. An increase in interest amongst trainees in pursuing a career in burn surgery was found, with 34 trainees (48.6% of respondents) interested, mostly on a half time or sessional basis. The three most common barriers to practising burn surgery remain unchanged, and were nature of burn operations, nature of burn care and on-call commitments; inadequacy of exposure or training ranked fourth. We found a strong overall response that burn surgery and burn care remained an important component of plastic and reconstructive surgery.

DISCUSSION

Inadequate exposure or training has evolved to present a bigger barrier in this study compared to a similar study conducted 17 years ago. Burn units and training bodies may offer additional job placements to address these feelings of insufficient exposure. Facilitating employment of burn surgeons on a half-time or sessional capacity is a sustainable model, and will arguably improve clinical service provision. Strong and early mentorship and allocation of commensurate resources and funding will help to address the high workload.

CONCLUSIONS

Interest in burn surgery has improved over the last 17 years and the most common deterrents persist, namely nature of burn operations, nature of burn care and on-call commitments. However, many of these issues are modifiable or amenable to change. The opportunity exists for relevant stakeholders to address some of these concerns raised, and thereby addressing the issue of burn surgeon shortage.

The Impact of Thermal Stress on Cognition and the Use of Cooling Wear for Alleviation - an Explorative Study

Increased ambient temperatures during the care of severely burned patients are essential for mitigating hypothermia and minimizing the impact of the consecutive hypermetabolism. For involved medical staff, those conditions may lead to impaired concentration, possibly negatively affecting an optimal patient care. Yet, alleviation strategies are lacking. As a novel coping strategy, cooling wear may be an effective means. This explorative study aimed to investigate the effect of high ambient temperatures on the concentration capacity and cooling wear to alleviate thermal stress. The effects of high ambient temperatures and the additional use of cooling wear on the concentration capacity of medical staff were investigated in six subjects during two simulated burn surgeries. Each individual served as his/her own control undergoing one simulation with and one without cooling wear. Concentration capacity was measured before and after each simulation with a standardized test. The results suggested that high ambient temperatures, as used in burn medicine, negatively affect human concentration capacity. The initial assessment of concentration capacity yielded homogenous values. After heat exposure, subjects wearing cooling wear showed a higher concentration capacity and a lower error rate compared to subjects without cooling wear. Summing up, temperature-related decrements in vigilance and performance among medical personnel may impair the patients' outcome. As an opportunity to withstand thermal stress and improve medical care and safety, cooling wear showed promising results and may be used as heat alleviator. Burn medicine may particularly benefit from further development and rigorous investigation of cooling strategies.

Factors contributing to the restoration of normothermia after hypothermia in people with a major burn injury in the first 24 h of hospital admission

BACKGROUND

People with burn injury experiencing hypothermia are at risk of serious complications such as shock, multisystem organ failure, and death. There is limited information available for health professionals with regard to factors that contribute to restoration of normothermia after hypothermia in people with a major burn injury.

OBJECTIVE

The aim of the study was to identify factors that contribute to normothermia restoration after hypothermia in people with 10% or more total body surface area (TBSA) burn in the first 24 h of admission to a burn care hospital.

METHODS

The study was guided by the Gearing Framework for retrospective chart audit. The sample comprised medical charts of all adult people (n = 113) with a burn injury more than 10% of their TBSA admitted to a single-site burn care hospital intensive care unit in Victoria, Australia, between May 31, 2013, and June 1, 2015. Descriptive statistics were used to describe the sample, and logistic regression was conducted to predict variables contributing to return to normothermia in people with burn injury. Charts with incomplete data were excluded.

FINDINGS

The sample (n = 50) recorded a median initial temperature on admission to the emergency department (ED) of 35.4°C (range = 31.9-37.2°C) and took on an average of 6.2 (standard deviation [SD] = 4.96) hours to return to normothermia (36.5°C). Women took around 6 h longer than men to return to normothermia (mean = 11.14 h, SD = 5.58; mean = 5.38 h, SD = 4.41). Positive correlations were noted between TBSA%, the length of time between admission to the ED and the intensive care unit, and the hours taken to reach normothermia. Regression analysis suggests the initial recorded temperature on admission to the ED was the main predictor of the time body temperature takes to return to normothermia (β = .513, p < .001).

CONCLUSION

This study provides information for practice changes by highlighting the need for guidelines and education programs for health professionals to ensure the delivery of optimum care to people with burn injury.

[Target Temperature Control in Patients with Burns]

Severe burns lead to a persistent hypermetabolic response of the organism with significantly increased resting energy turnover, multi-organ dysfunction, muscle breakdown and increased risk of infection. Elevated core and skin temperatures are characteristic. A further increase in the metabolic rate can be triggered by heat losses, for which these patients are particularly predisposed due to high heat dissipation via evaporation of moisture and impairment of the thermoregulatory and insulating properties of the burnt skin. This is especially true in all treatment situations with exposure to large, uncovered skin surfaces, such as primary care, dressing changes in the intensive care unit and surgery with extensive sterile operating field. It has been shown that hypothermia is associated with numerous risks for the burn patient. Consistent heat management with measurement of the core body temperature and application of external and internal heat protection measures is recommended. Traditionally, an increase in room temperature is used here. However, this effective measure is limited by the resilience of the intensive care practitioners and the surgeons. To avoid perioperative hypothermia, strict surgical planning with limitation of the duration of surgery and close intraoperative communication about the risk of hypothermia are of particular importance.The differentiation between accepted temperature increase and infectious fever is often only possible by the inclusion of further examination findings. The criterion for sepsis is a temperature above 39 °C or below 36.5 °C.

Early protein C activation is reflective of burn injury severity and plays a critical role in inflammatory burden and patient outcomes

BACKGROUND

Navigating the complexities of a severe burn injury is a challenging endeavour where the natural course of some patients can be difficult to predict. Straddling both the coagulation and inflammatory cascades that feature strongly in the burns systemic pathophysiology, we propose the pleiotropic protein C (PC) system may produce a viable biomarker to assist traditional evaluation methods for diagnostic and prognostic purposes.

METHODS

We enrolled 86 patients in a prospective observational cohort study. Over three weeks, serial blood samples were taken and measured for PC, activated (A)PC, their receptor endothelial protein C receptor (EPCR), and a panel of inflammatory cytokines including C-reactive protein (CRP), tumour necrosis factor-α, interleukin (IL)-1β, IL-6, IL-8, and IL-17. Their temporal trends were analysed alongside clinical factors including burn size, burn depth, presence of inhalational injury, and a composite outcome of requiring increased support.

RESULTS

(i) APC increased from a nadir on Day 3 (2.3±2.1ng/mL vs 4.1±2.5ng/mL by Day 18, p<0.0005), only becoming appropriately correlated to PC from Day 6 onwards (r=0.412-0.721, p<0.05 for all Days 6-21). (ii) This early disturbance in the PC system was amplified in the more severe burns (≥30% total body surface area, predominantly full thickness, or with inhalational injury), which were characterised by a marked fall in PC activation (approximated by APC/PC ratio) and APC levels during Days 0-3 with low unchanged PC levels. Critically low levels of this cytoprotective agent was associated with greater inflammatory burden, as reflected by significantly elevated CRP, IL-6, and IL-8 levels in the more severe compared to less severe burns, and by negative correlations between both PC and APC with most inflammatory cytokines. (iii) Alongside clinical markers of severity at admission (burn size, burn depth, and presence of inhalational injury), only Day 0 APC/PC ratio (OR 1.048 (1.014-1.083), p=0.006), APC (OR 1.364 (1.032-1.803), p=0.029), PC (OR 0.899 (0.849-0.953), p<0.0005), and not any inflammatory cytokines were predictive markers of requiring increased support. Uniquely, decreased Day 0 PC was further individually associated with each increased total length of stay, ICU length of stay, intravenous fluid resuscitation, and total surgeries, as well as possibly mortality.

CONCLUSION

An early functional depletion of the cytoprotective PC system provides a physiological link between severe burns and the cytokine storm, likely contributing to worse outcomes. Our findings on the changes in APC, PC and PC activation during this pathological state support APC and PC as early diagnostic and prognostic biomarkers, and provides a basis for their therapeutic potential in severe burn injuries.

Challenges in anaesthesia and pain management for burn injuries

Burn-injured patients provide unique challenges to those providing anaesthesia and pain management. This review aims to update both the regular burn anaesthetist and the anaesthetist only occasionally involved with burn patients in emergency settings. It addresses some aspects of care that are perhaps contentious in terms of airway management, fluid resuscitation, transfusion practices and pharmacology. Recognition of pain management failures and the lack of mechanism-specific analgesics are discussed along with the opioid crisis as it relates to burns and nonpharmacological methods in the management of distressed patients.

Impact of Prehospital Hypothermia on the Outcomes of Severely Burned Patients

When treating burn injuries, to date, there still remains significant disagreement whether presence of hypothermia (HT) on burn centers' intensive care unit (BICU) admission improves or worsens outcomes. The presented single burn center experiences set out to further evaluate the incidence, cause, and potential effects of HT on outcomes in severely burned patients. Between January 2015 and February 2017, 142 severely burned patients were admitted to a BICU. Temperature at BICU admission of <36.0°C was defined as HT and ≥36.0°C as normothermia (NT). The cases were divided into two groups: HT vs NT. Fifty-four patients met inclusion criteria and were analyzed retrospectively regarding encountered complications, time of hospitalization, and overall survival. The overall incidence of HT on arrival was 62.9%. Mean duration from burn accident to BICU admission did not differ significantly, but the groups showed significant differences regarding total body surface area (TBSA; P < .05). Both groups showed a similar distribution, regarding number of surgeries, duration until first burn excision, length of ventilation, and mortality rate of patients (P > .05). However, time until death was significantly shorter in the HT group. HT at admission remains a common problem following burn injury. Main risk factors include inappropriate temperature management after injury and during transport, extent of TBSA burn, and quantity of resuscitation. Given the high incidence, the involved health care and, especially, also prehospital providers should be further educated about existing recommendations and guidelines to prevent HT.

Effects of a hot ambient operating theatre on manual dexterity, psychological and physiological parameters in staff during a simulated burn surgery

OBJECTIVES

Hot environmental conditions can result in a high core-temperature and dehydration which can impair physical and cognitive performance. This study aimed to assess the effects of a hot operating theatre on various performance, physiological and psychological parameters in staff during a simulated burn surgery.

METHODS

Due to varying activity levels, surgery staff were allocated to either an Active (n = 9) or Less-Active (n = 8) subgroup, with both subgroups performing two simulated burn surgery trials (CONTROL: ambient conditions; 23±0.2°C, 35.8±1.2% RH and HOT: 34±0°C, 28.3±1.9% RH; 150 min duration for each trial), using a crossover design with four weeks between trials. Manual dexterity, core-temperature, heart-rate, sweat-loss, thermal sensation and alertness were assessed at various time points during surgery.

RESULTS

Pre-trials, 13/17 participants were mildly-significantly dehydrated (HOT) while 12/17 participants were mildly-significantly dehydrated (CONTROL). There were no significant differences in manual dexterity scores between trials, however there was a tendency for scores to be lower/impaired during HOT (both subgroups) compared to CONTROL, at various time-points (Cohen's d = -0.74 to -0.50). Furthermore, alertness scores tended to be higher/better in HOT (Active subgroup only) for most time-points (p = 0.06) compared to CONTROL, while core-temperature and heart-rate were higher in HOT either overall (Active; p<0.05) or at numerous time points (Less-Active; p<0.05). Finally, sweat-loss and thermal sensation were greater/higher in HOT for both subgroups (p<0.05).

CONCLUSIONS

A hot operating theatre resulted in significantly higher core-temperature, heart-rate, thermal sensation and sweat-loss in staff. There was also a tendency for slight impairment in manual dexterity, while alertness improved. A longer, real-life surgery is likely to further increase physiological variables assessed here and in turn affect optimal performance/outcomes.

Plasma protein C levels are directly associated with better outcomes in patients with severe burns

Protein C circulates in human plasma to regulate inflammation and coagulation. It has shown a crucial role in wound healing in animals, and low plasma levels predict the presence of a wound in diabetic patients. However, no detailed study has measured protein C levels in patients with severe burns over the course of a hospital admission. A severe burn is associated with dysfunction of inflammation and coagulation as well as a significant risk of morbidity and mortality. The current methods of burn assessment have shortcomings in reliability and have limited prognostic value. The discovery of a biomarker that estimates burn severity and predicts clinical events with greater accuracy than current methods may improve management, resource allocation and patient counseling. This is the first study to assess the potential role of protein C as a biomarker of burn severity. We measured the plasma protein C levels of 86 patients immediately following a severe burn, then every three days over the first three weeks of a hospital admission. We also analysed the relationships between burn characteristics, blood test results including plasma protein C levels and clinical events. We used a primary composite outcome of increased support utilisation defined as: a mean intravenous fluid administration volume of five litres or more per day over the first 72 h of admission, a length of stay in the intensive care unit of more than four days, or greater than four surgical procedures during admission. The hypothesis was that low protein C levels would be negatively associated with increased support utilisation. At presentation to hospital after a severe burn, the mean plasma protein C level was 76 ± 20% with a range of 34-130% compared to the normal range of 70-180%. The initial low can be plausibly explained by impaired synthesis, increased degradation and excessive consumption of protein C following a burn. Levels increased gradually over six days then remained at a steady-state until the end of the inpatient study period, day 21. A multivariable regression model (Nagelkerke's R² = 0.83) showed that the plasma protein C level on admission contributed the most to the ability of the model to predict increased support utilisation (OR = 0.825 (95% CI = 0.698-0.977), P = 0.025), followed by burn size (OR = 1.252 (95% CI = 1.025-1.530), P = 0.027), burn depth (partial thickness was used as the reference, full thickness OR = 80.499 (1.569-4129.248), P = 0.029), and neutrophil count on admission (OR = 1.532 (95% CI = 0.950-2.473), P = 0.08). Together, these four variables predicted increased support utilisation with 93.2% accuracy, 83.3% sensitivity and 97.6% specificity. However if protein C values were disregarded, only 49.5% of the variance was explained, with 82% accuracy, 63% sensitivity and 91.5% specificity. Thus, protein C may be a useful biomarker of burn severity and study replication will enable validation of these novel findings.

Effect of primary admission to burn centers on the outcomes of severely burned patients

OBJECTIVE

Burns represent a special form of severe trauma. Due to long hospitalization, rehabilitation, and extensive scar treatment, severe burn injuries rank among the most expensive traumatic injuries regarding associated health care costs. The presented single-burn-center experiences evaluated the effects of primary versus secondary burn intensive care unit (BICU) admissions on outcomes in severely burned patients.

METHODS

Within 30 months, 186 patients were admitted to the BICU. The cases were divided into two groups depending on their admission type: "primary" vs. "secondary". All patients were analyzed retrospectively regarding the need for surgery, encountered complications, time of hospitalization and overall survival.

RESULTS

The incidence of primary BICU-admissions was 65.1%. Both patient groups were comparable regarding demographics, comorbidities, % TBSA burn, associated inhalation injuries, ABSI scores and intubation rates (p>0.05). Both groups received similar numbers of operations and had overall comparable mortality rates (p>0.05). However, duration until first burn excision, length of ventilation, as well as BICU- and overall hospital length of stay were significantly shorter in the "primary"- compared to the "secondary" group (p<0.05).

CONCLUSION

Several burn societies have published precise criteria of when a patient needs to be referred to a burn center. In the presented series, patients that were primarily treated at a BICU showed significantly better outcomes regarding several parameters. In order to further optimize treatment of burn patients it therefore appears that precise initial assessment and if appropriate respective primary transport to dedicated burn centers needs to be re-emphasized, especially among first- and emergency care providers.

Nitroglycerin: An unusual solution to intraoperative hypothermia in a 4-year-old burn patient

We describe the case of a 4-year-old child undergoing extensive burn surgery with refractory intraoperative hypothermia. A low-dose nitroglycerin infusion was initiated to reverse vasoconstriction and improve heat absorption, after which the child's temperature steadily improved. In hypothermic burn patients, topical vasoconstrictors may hinder surface warming efforts. A vasodilator infusion may aid in warming the pediatric patient undergoing extensive excision and grafting.