Targeted temperature control following traumatic brain injury: ESICM/NACCS best practice consensus recommendations.

AIMS AND SCOPE: The aim of this panel was to develop consensus recommendations on targeted temperature control (TTC) in patients with severe traumatic brain injury (TBI) and in patients with moderate TBI who deteriorate and require admission to the intensive care unit for intracranial pressure (ICP) management. METHODS: A group of 18 international neuro-intensive care experts in the acute management of TBI participated in a modified Delphi process. An online anonymised survey based on a systematic literature review was completed ahead of the meeting, before the group convened to explore the level of consensus on TTC following TBI. Outputs from the meeting were combined into a further anonymous online survey round to finalise recommendations. Thresholds of ≥ 16 out of 18 panel members in agreement (≥ 88%) for strong consensus and ≥ 14 out of 18 (≥ 78%) for moderate consensus were prospectively set for all statements. RESULTS: Strong consensus was reached on TTC being essential for high-quality TBI care. It was recommended that temperature should be monitored continuously, and that fever should be promptly identified and managed in patients perceived to be at risk of secondary brain injury. Controlled normothermia (36.0-37.5 °C) was strongly recommended as a therapeutic option to be considered in tier 1 and 2 of the Seattle International Severe Traumatic Brain Injury Consensus Conference ICP management protocol. Temperature control targets should be individualised based on the perceived risk of secondary brain injury and fever aetiology. CONCLUSIONS: Based on a modified Delphi expert consensus process, this report aims to inform on best practices for TTC delivery for patients following TBI, and to highlight areas of need for further research to improve clinical guidelines in this setting.

Postarrest Care Bundle Improves Quality of Care and Clinical Outcomes in the Normothermia Era.

PURPOSE: Temperature targets in patients with cardiac arrest and return of spontaneous circulation (ROSC) have changed. Changes to higher temperature targets have been associated with higher breakthrough fevers and mortality. A post-ROSC normothermia bundle was developed to improve compliance with temperature targets. METHODS: In August 2021, "ad hoc" normothermia at the discretion of the attending intensivist was initiated. In December 2021, a post-ROSC normothermia protocol was implemented, incorporating a rigorous, stepwise approach to fever prevention (temperature ≥ 37.8). We conducted a before-after cohort study of all adult patients post-ROSC who survived to intensive care unit admission between August 1, 2021, and April 1, 2022. They were divided into "ad hoc" and "protocol" groups. Clinical outcomes compared included fevers, active cooling, and paralytic use. RESULTS: Fifty-eight post-ROSC patients were admitted; 24 in the "ad hoc" and 34 in the "protocol" groups. Patient demographics were similar between groups. The "ad hoc" group had more shockable rhythms (67% vs 24%, P = .001) and cardiac catheterizations (42% vs 15%, P = .03). The "protocol" group were significantly less likely to have a fever at 40 h (6% vs 40%, P < .001) and 72 h (14% vs 65%, P ≤ .001). Patients in the normothermia "protocol" used significantly less neuromuscular blocking agents (24% vs 50%, P = .05). The normothermia "protocol" resulted in similar mortality (56% vs 58%, P = 1.0). CONCLUSION: Use of a normothermia "protocol" resulted in fewer fevers and less neuromuscular blocker administration compared to "ad hoc" management. A protocolized approach for improved quality of care should be considered in institutions adopting normothermia.

Inadvertent Hypothermia in the Perspective of Operating Room Nurses: A Phenomenological Qualitative Study.

PURPOSE: The aim of the study was to reveal the awareness and perceptions of operating room nurses concerning inadvertent hypothermia, as well as their experiences and recommendations for its prevention. DESIGN: The study employed a phenomenological qualitative approach. METHODS: This study was conducted with 17 nurses working in the operating room of a university hospital in Konya, Turkey. Data were collected face to face between 15 August and 30 September 2022 using the in-depth individual interview method. The data were subjected to inductive content analysis. Written permission was obtained from the hospital, the ethics committee, and the participants to conduct the study. FINDINGS: The mean age of the nurses was 28.4 years and the majority were female. The nurses were graduates of a four-year health vocational high school, a two-year nursing associate degree program, or a four-year nursing bachelors' degree program. Their operating room experience ranged from 1 to 22 years. All the nurses were aware of inadvertent hypothermia, and all but one encountered hypothermia and applied preventive measures. The data analysis revealed 263 codes, 12 categories, and 4 themes on the awareness and perceptions of operating room nurses about inadvertent hypothermia and their experiences and recommendations for its prevention. CONCLUSIONS: The findings showed that the majority of the participants were aware of inadvertent hypothermia and its risk factors, and frequently encountered inadvertent hypothermia despite implementing preventive measures.

Targeted temperature management in patients with intracerebral haemorrhage, subarachnoid haemorrhage, or acute ischaemic stroke: updated consensus guideline recommendations by the Neuroprotective Therapy Consensus Review (NTCR) group.

BACKGROUND: There is a lack of consistent, evidence-based guidelines for the management of patients with fever after brain injury. The aim was to update previously published consensus recommendations on targeted temperature management after intracerebral haemorrhage, aneurysmal subarachnoid haemorrhage, and acute ischaemic stroke in patients who require admission to critical care. METHODS: A modified Delphi consensus, the Neuroprotective Therapy Consensus Review (NTCR), included 19 international neuro-intensive care experts with a subspecialty interest in the acute management of intracerebral haemorrhage, aneurysmal subarachnoid haemorrhage, and acute ischaemic stroke. An online, anonymised survey was completed ahead of the meeting before the group came together to consolidate consensus and finalise recommendations on targeted temperature management. A threshold of ≥80% for consensus was set for all statements. RESULTS: Recommendations were formulated based on existing evidence, literature review, and consensus. After intracerebral haemorrhage, aneurysmal subarachnoid haemorrhage, and acute ischaemic stroke in patients who require critical care admission, core temperature should ideally be monitored continuously and maintained between 36.0°C and 37.5°C using automated feedback-controlled devices, where possible. Targeted temperature management should be commenced within 1 h of first fever identification with appropriate diagnosis and treatment of infection, maintained for as long as the brain remains at risk of secondary injury, and rewarming should be controlled. Shivering should be monitored and managed to limit risk of secondary injury. Following a single protocol for targeted temperature management across intracerebral haemorrhage, aneurysmal subarachnoid haemorrhage, and acute ischaemic stroke is desirable. CONCLUSIONS: Based on a modified Delphi expert consensus process, these guidelines aim to improve the quality of targeted temperature management for patients after intracerebral haemorrhage, aneurysmal subarachnoid haemorrhage, and acute ischaemic stroke in critical care, highlighting the need for further research to improve clinical guidelines in this setting.

Targeted temperature management at 36°C is a risk factor for ventilator-associated pneumonia.

BACKGROUND: In contrast to the adult population, limited information is currently available on risk factors for ventilator-associated pneumonia (VAP) in children. Therapeutic hypothermia has been identified as a risk factor for the early onset of VAP in adults; however, the relationship between VAP and normothermia remains unclear. The present study investigated risk factors for VAP in children, with a focus on the deleterious effects of therapeutic normothermia on VAP. METHODS: We retrospectively investigated the clinical characteristics of children treated with mechanical ventilation for more than 48 h and analyzed risk factors for VAP. The endpoint was the onset of VAP by the seventh day after the initiation of mechanical ventilation. RESULTS: Among the 288 patients enrolled, seven (2.4%) developed VAP. No significant differences were observed in clinical backgrounds between the VAP and non-VAP groups. A univariate analysis identified target temperature management (TTM) at 36°C (p < 0.0001) and methylprednisolone (mPSL) pulse therapy (p = 0.02) as risk factors for VAP. An analysis of the time to the onset of VAP by the Kaplan-Meier plot and log-rank test revealed a significantly higher incidence of VAP in the TTM group (p < 0.0001) and mPSL pulse group (p = 0.001). CONCLUSION: TTM at 36°C and mPSL pulse therapy may be risk factors for VAP in the pediatric population.

Cavoatrial hypernephroma resection on cardiopulmonary bypass: Mild/normo-versus moderate hypothermia.

INTRODUCION: Renal cell carcinoma (RCC) is one of the most prevalent malignant tumors. It extends up into the systemic veins and right atrium. Surgical extraction of such extensions is usually carried out using cardiopulmonary bypass (CPB) with moderate hypothermic (MH) being frequently applied in order to obtain a clear surgical field. However, due to obvious disadvantages of hypothermia, approaches with mild/normothermia (NT) during CPB have also been established. The current study aims to compare the outcomes of patients undergoing RCC tumor and extensions resection using MH versus NT. MATERIAL AND METHODS: This is a retrospective, non-randomized study. All patients who underwent RCC tumor and extensions resection for stage III or IV (Staehler) RCC in a single center between 2006 and 2020 were included. During surgery, MH or NT were applied. CPB was realized using aortic and bicaval cannulation. We compared the procedural times, transfusion requirements and postoperative outcomes, respectively between the MH and NT groups. RESULTS: A total of 24 consecutive patients (n(NT) = 12, n(MH) = 12) were included in the study (median age NT 68.5 and MH 66.5). The study only showed a significant difference in heart-lung machine times (median CPB time NT 45.5 min and MH 110.0 min, p = 0.004). All other results, loss of drainage, administration of blood products, as well as the postoperative course and mortality were comparable in both groups. CONCLUSION: The results showed a high perioperative and long-term mortality. The perioperative course was similar after surgery with NT or MH. Therefore, NT which minimizes potential complications of MH should be preferred.

Reducing Hypothermia After Cardiac Ablation Using the ASPAN Normothermia Guidelines.

PURPOSE: The purpose of this quality improvement project was to determine if the integration of the ASPAN 2010 Normothermia Guidelines would reduce postprocedural hypothermia and recovery time in patients undergoing cardiac ablation under general anesthesia. DESIGN: A retrospective cohort design over a continuous 12-week period was used. METHODS: Fifty-five patients were divided into 2 groups. The preintervention group (n = 26) consisted of patients who received care over a 6-week period before the implementation of the ASPAN 2010 Normothermia Guidelines. The postintervention group (n = 29) included patients who received care for 6 weeks with guidelines in place. An electronic health record review of cardiac ablation patients was conducted to compare the difference in PACU discharge times, the occurrence of hypothermia, and how well body temperature was maintained between the groups. FINDINGS: Hypothermia was detected in 3.85% of the preintervention group, while there was none in the postintervention group. Compared with the preintervention group (M = 53.6 minutes, SD = 18), patients meeting inclusion criteria in the postintervention group (M = 44.73 minutes, SD = 9.78) spent less time recovering from anesthesia in PACU; t(42) = 2.03, P = .048. Body temperatures in the preintervention group (M = -0.068°C, SD = 0.456) fell throughout the perioperative period while the postintervention group's temperature (M = 0.154°C, SD = 0.275) was higher following cardiac ablation; t (41) = -2.13, P= .04. CONCLUSIONS: The ASPAN 2010 Normothermia Guidelines reduced recovery time and mitigated changes in patient temperatures throughout the periprocedure period in patients undergoing cardiac ablation under general anesthesia.

Using a Normothermia Bundle With Perioperative Prewarming to Reduce Patient Hypothermia.

PURPOSE: To determine if implementing a normothermia bundle, which includes preoperative forced-air warming blankets, reduces incidence of inadvertent perioperative hypothermia (IPH). DESIGN: Intervention study using retrospective chart review. METHODS: Patients received a preoperative forced-air warming blanket and temperature management with the normothermia bundle. Temperature status data was collected from patient charts to evaluate the incidences of IPH and findings from this data analysis was used to measure improvement in perioperative temperature management. FINDINGS: Of 200 patients, 63 (31.5%) remained normothermic, 37 (18.5%) had at least one documented hypothermic temperature, and 100 (50%) had no documented temperature during the intraoperative phase of care. Although compliance with intraoperative temperature monitoring decreased by 13% postintervention, the incidence of documented IPH in reviewed records was decreased by 3.6-fold. CONCLUSION: Implementing a normothermia bundle that includes a preoperative forced-air warming blanket may lower the incidences of IPH, especially in surgical cases lasting over 120 minutes.

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 (ß = .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.

Targeted Temperature Management in Unconscious Survivors of Postcardiac Arrest: A Systematic Review and Meta-analysis of Randomized Controlled Trials.

Background: Targeted temperature management (TTM) is a vital element of postresuscitation management after cardiac arrest. Though international guidelines recommend TTM, the supporting evidence is of low certainty. Aims and objectives: To estimate the effect of TTM strategy on mortality and neurological outcomes in postcardiac arrest survivors. Materials and methods: Randomized controlled trials (RCTs) published in English evaluating the use of TTM in adult comatose survivors of cardiac arrest were included. Studies were categorized into two groups, based on hypothermia vs normothermia. The main outcome was death due to any origin. The secondary outcome measures evaluated neurological outcome and complications associated with TTM. Outcomes were analyzed by calculating Odds Ratio (OR) of a worse outcome. ORs with 95% CIs in a forest plot were used to show the results of random-effects meta-analyses. Results: On pooled analysis of 11 RCTs, no difference was observed in death due to any origin rates in the hypothermia compared to the normothermia group (OR; 0.88, 95% CI: 0.39-1.16). Overall, no difference in poor neurological outcome was observed between the two groups (OR; 0.86, 95% CI: 0.66-1.12). Trial sequencing analysis for mortality and poor neurological outcome showed that number to achieve power to predict futility has been achieved in both the parameters. Conclusions: This meta-analysis showed that hypothermia compared to normothermia TTM strategies does not improve survival or neurologic outcomes. How to cite this article: Mishra SB, Patnaik R, Rath A, Samal S, Dash A, Nayak B. Targeted Temperature Management in Unconscious Survivors of Postcardiac Arrest: A Systematic Review and Meta-analysis of Randomized Controlled Trials. Indian J Crit Care Med 2022;26(4):506-513.

Induced normothermia ameliorates the procoagulant host response in human endotoxaemia.

BACKGROUND: Dysregulation of coagulation occurs commonly in sepsis, ranging from mild coagulopathy with decreased platelets to disseminated intravascular coagulation (DIC). We investigated the effect of induced normothermia on coagulation during lipopolysaccharide (LPS)-induced endotoxaemia in healthy volunteers. METHODS: Twelve volunteers received an infusion of bacterial lipopolysaccharide (Escherichia coli; 2 ng kg-1) and were assigned to either induced normothermia or control. Induced normothermia to maintain core temperature at 37°C consisted of external surface cooling, cold i.v. fluids, and medication to reduce shivering (buspirone, clonidine, and magnesium sulphate). The primary outcome was the DIC score (International Society on Thrombosis and Haemostasis guideline). Prothrombin time (PT), activated partial thromboplastin time (aPTT), D-dimer, plasma von Willebrand factor (vWf), and rotational thromboelastometry (ROTEM) were measured before and 1, 3, 6, and 8 h after LPS infusion. Differences between groups were tested with a mixed effects model. RESULTS: In control subjects, lipopolysaccharide caused a fever, transiently decreased platelet levels and lowered activated partial thromboplastin time, while prolonging prothrombin time and increasing D-Dimer and vWf levels. Normothermia prevented the DIC-score exceeding 4, which occurred in 50% of control subjects. Normothermia also reduced the fall in platelet count by 67x109 L-1([95%CI:27-107]; p=0.002), aPTT (mean difference:3s [95%CI:1-5]; p=0.005) and lowered vWf levels by 89% ([95%CI:6-172]; p=0.03), compared to the fever group. ROTEM measurements were unaffected by lipopolysaccharide. CONCLUSION: In human endotoxaemia, induced normothermia decreases markers of endothelial activation and DIC. Maintaining normothermia may reduce coagulopathy in hyperinflammatory states.

A multimodal quality improvement approach to promote normothermia in very preterm infants.

AIM: To achieve the National Neonatal Audit Programme (NNAP) standard of 90% normothermia among preterm infants born under 30 weeks of gestation. METHODS: Project SHIP (Stopping Hypothermia In Premmies) was a quality improvement programme to improve admission normothermia. Phase 1 of the project implemented low-fidelity simulations during 2011-2016. In Phase 2 (2017), a multimodal approach to quality improvement was used, including in situ simulations, videos of simulated scenarios, an allocated team member for thermal care, a clear protocol for thermal care, a coordinating 'lollipop man' role and monthly performance feedback. Additionally, continuous temperature monitoring using servo-control during stabilisation was introduced during Phase 2. Phase 3 (2018-2019) focused on embedding practice and maintaining performance. RESULTS: Phase 1 initiatives resulted in improvement of normothermia rates from 58% to 75%. However, the results plateaued. During Phase 2, the hypothermia rate fell from 16% to 3%. During Phase 3, this improvement in the hypothermia rate was sustained, achieving the standard of 90% normothermia in 2018 and falling just short in 2019 due to an increased hyperthermia rate. CONCLUSION: A multimodal quality improvement approach achieved sustained improvement in normothermia. Continuous temperature monitoring during stabilisation allows resuscitating teams to plan interventions to treat hypothermia and hyperthermia.

Safety and Feasibility of a Novel Transnasal Cooling Device to Induce Normothermia in Febrile Cerebrovascular Patients.

BACKGROUND: Inducing normothermia with surface cooling temperature modulating devices (TMDs) is cumbersome and often associated with significant shivering. We tested the safety and feasibility of a novel transnasal evaporative cooling device to induce and maintain normothermia in febrile patients following ischemic and hemorrhagic stroke. METHODS: A single-center study utilizing the CoolStat® transnasal cooling device was used to achieve core temperature reduction in mechanically ventilated stroke patients with fever (T ≥ 38.3 C) refractory to acetaminophen by inducing an evaporative cooling energy exchange in the nasal turbinates thru a high flow of dehumidified air into the nasal cavity and out through the mouth. Continuous temperature measurements were obtained from tympanic and core (esophageal or bladder) temperature monitors. Safety assessments included continuous monitoring for hypertension, tachycardia, and raised intracranial pressure (when monitored). Otolaryngology (ENT) evaluations were monitored for any device-related nasal mucosal injury with a pre- and post-visual examination. Shivering was assessed every 30 min using the Bedside Shivering Assessment Scale (BSAS). Duration of device use was limited to 8 h, at which time patients were transitioned to routine care for temperature management. RESULTS: Ten subjects (median age: 54 years, BMI: 32.5 kg/m2, 60% men) were enrolled with normothermia achieved in 90% of subjects. One subject did not achieve normothermia and was later refractory to other TMDs. Median baseline temperature was 38.5 ± 0.1 C, with a reduction noted by 4 h (38.5 ± 0.1 vs 37.3 ± 0.8, P < 0.001) and sustained at 8 h (38.5 ± 0.1 vs 37.1 ± 0.7, P = 0.001). Time to normothermia was 2.6 ± 1.9 h. The median BSAS was 0 (range 0-1) with only 4 episodes necessitating meperidine across 76 h of study monitoring. No treatment was discontinued due to safety concerns. ENT evaluations noted no device-related adverse findings. CONCLUSIONS: Inducing normothermia with a novel transnasal TMD appears to be safe, feasible and not associated with significant shivering. A multicenter trial testing the ability of the CoolStat to maintain normothermia for 24 h is currently underway.

Impact of Fever Prevention in Brain-Injured Patients (INTREPID): Study Protocol for a Randomized Controlled Trial.

BACKGROUND: Multiple studies demonstrate that fever/elevated temperature is associated with poor outcomes in patients with vascular brain injury; however, there are no conclusive studies that demonstrate that fever prevention/controlled normothermia is associated with better outcomes. The primary objective of the INTREPID (Impact of Fever Prevention in Brain-Injured Patients) trial is to test the hypothesis that fever prevention is superior to standard temperature management in patients with acute vascular brain injury. METHODS: INTREPID is a prospective randomized open blinded endpoint study of fever prevention versus usual care in patients with ischemic or hemorrhagic stroke. The fever prevention intervention utilizes the Arctic Sun System and will be compared to standard care patients in whom fever may spontaneously develop. Ischemic stroke, intracerebral hemorrhage or subarachnoid hemorrhage patients will be included within disease-specific time-windows. Both awake and sedated patients will be included, and treatment is initiated immediately upon enrollment. Eligible patients are expected to require intensive care for at least 72 h post-injury, will not be deemed unlikely to survive without severe disability, and will be treated for up to 14 days, or until deemed ready for discharge from the ICU, whichever comes first. Fifty sites in the USA and worldwide will participate, with a target enrollment of 1176 patients (1000 evaluable). The target temperature is 37.0 °C. The primary efficacy outcome is the total fever burden by °C-h, defined as the area under the temperature curve above 37.9 °C. The primary secondary outcome, on which the sample size is based, is the modified Rankin Scale Score at 3 months. All efficacy analyses including the primary and key secondary endpoints will be primarily based on an intention-to-treat population. Analysis of the as-treated and per protocol populations will also be performed on the primary and key secondary endpoints as sensitivity analyses. DISCUSSION: The INTREPID trial will provide the first results of the impact of a pivotal fever prevention intervention in patients with acute stroke ( www.clinicaltrials.gov ; NCT02996266; registered prospectively 05DEC2016).

Comparison of a Continuous Noninvasive Temperature to Monitor Core Temperature Measures During Targeted Temperature Management.

BACKGROUND: Temperature modulating devices (TMD) currently utilize core temperature measurements during targeted temperature management (TTM) that are currently limited to esophageal (Et), bladder (Bt), or rectal (Rt) temperatures. We assessed the ability of a continuous noninvasive temperature monitor to accurately approximate core temperature during TTM. METHODS: All patients undergoing TTM using a gel pad surface TMD and an existing core temperature monitoring device were eligible for this study. Core and continuous noninvasive temperature monitoring values were simultaneously recorded for up to 72 h of TTM. The two sets of temperature data were downloaded from a clinical data acquisition storage system at 1-min intervals. The Bland-Altman method assessed agreement between the core and continuous noninvasive temperature monitor values, by measuring the mean difference (± 2 SD) between these values. RESULTS: There were 20 subjects that underwent study between January 2018 and March 2018 (55% women, age: 57 ± 14 years old, BMI: 28.9 + 9.8 kg/m2, 100% mechanically ventilated). The comparison patient temperature source was predominantly esophageal (n = 10) followed by bladder (n = 5) or rectal (n = 5). There were a total of 999 h of paired patient temperature data from esophageal (50%), bladder (25%), and rectal (25%) temperatures. Bland-Altman analysis demonstrated good agreement with the superficial temperature monitor and core temperature measures in all patients overall, with a difference mean of 0.06 ± 0.39 C (P = 0.99) and no proportional bias noted (ß =0.002, P = 0.917). CONCLUSIONS: Continuous noninvasive temperature monitoring is a suitable alternative method for assessing core temperature during TTM. Future studies should focus on developing connectivity with a continuous noninvasive temperature monitor to approximate core temperature during TTM.

A simplified delivery frozen elephant trunk technique to reduce circulatory arrest time in hybrid aortic arch surgery.

A simplified delivery technique for the frozen elephant trunk procedure allows the distal suture to be performed on a perfused and loaded aorta in moderate hypothermia-or even normothermia-reducing circulatory arrest time to just a few minutes. Two surgical sealing tourniquets are placed around the aortic arch, usually between the brachiocephalic trunk (BCT) and the left common carotid artery and the aorta is cross-clamped and cardioplegia started. Once in mild hypothermia, the BCT is disconnected and circulatory arrest is initiated while cerebral perfusion is maintained. This modified technique can be used in all pathologies, including dissections.

Association Between Normothermia at the End of Surgery and Postoperative Complications Following Orthopedic Surgery.

BACKGROUND: Maintaining perioperative normothermia is recommended by recent guidelines for the prevention of surgical site infections (SSIs). However, the majority of supporting data originates outside the field of orthopaedic surgery. METHODS: The effect of normothermia was explored using the prospectively collected data of consecutive patients who underwent single-site surgery in 7 tertiary referral hospitals between November 2013 and July 2016. SSIs, urinary tract infections (UTIs), respiratory tract infections (RTIs), cardiac and cerebral events (CCE), and all-cause mortality rates within 30 days after surgery were compared between patients with normothermia (body temperature ≥36°C) and those with hypothermia (<36°C) at the end of surgery, after closure. Multivariable adjusted and inverse-probability weighted regression analyses were performed. RESULTS: The final cohort included 8841 patients. Of these, 11.4% (n = 1008) were hypothermic. More than 96% were evaluated in person by the physicians. After adjusting for multiple covariates, normothermia was not significantly associated with SSIs (adjusted odds ratio [aOR] 1.18, 95% confidence interval [CI] 0.59-2.33), UTIs (aOR 1.14, 95% CI 0.66-1.95), RTIs (aOR 0.60, 95% CI 0.31-1.19), or CCE (aOR 0.53, 95% CI 0.26-1.09). In contrast, normothermia was associated with a lower risk of 30-day mortality (aOR 0.26, 95% CI 0.11-0.64; P < .01; weighted hazard ratio 0.21, 95% CI 0.07-0.68; P = .002). In a subgroup analysis, normothermia was associated with reduced mortality in all types of surgical procedures. CONCLUSIONS: Whereas our findings suggest no clear association with SSI risks following orthopedic surgery, our study supports maintaining perioperative normothermia, as it is associated with reduced 30-day mortality.

A surgical technique for ascending aorta, aortic arch and descending aorta replacement without cross-clamp, circulatory arrest or hypothermia.

Treatment of the aneurysms comprising the aortic arch is challenging. Surgical reconstruction usually requires aortic cross-clamping, cardiac arrest, and even deep hypothermia for a bloodless field. In this report, we present our surgical technique providing normothermic ascending aorta, aortic arch, and proximal descending aorta replacement with selective cannulation and perfusion of the whole body.

The metabolic cost of subcutaneous and abdominal rewarming in king penguins after long-term immersion in cold water.

Marine endotherms in the polar regions face a formidable thermal challenge when swimming in cold water. Hence, they use morphological (fat, blubber) adjustment and peripheral vasoconstriction to reduce demands for heat production in water. The animals then regain normothermia when resting ashore. In the king penguin (Aptenodytes patagonicus) metabolic rate is lower in fed than in fasted individuals during subsequent rewarming on land. This has been suggested to be a consequence of diversion of blood flow to the splanchnic region in fed birds, which reduces peripheral temperatures. However, peripheral temperatures during recovery have never been investigated in birds with different nutritional status. The aim of this study was, therefore, to measure subcutaneous and abdominal temperatures during the rewarming phase on land in fasted and fed king penguins, and investigate to which extent any different rewarming were reflected in recovery metabolic rate (MRR) after long term immersion in cold water. We hypothesized that fed individuals would have a slower increase of subcutaneous temperatures compared to fasted penguins, and a correspondingly lower MRR. Subcutaneous tissues reached normothermia after 24.15 (back) and 21.36 min (flank), which was twice as fast as in the abdomen (46.82 min). However, recovery time was not affected by nutritional condition. MRR during global rewarming (4.56 ± 0.42 W kg-1) was twice as high as resting metabolic rate (RMR; 2.16 ± 0.59 W kg-1). However, MRR was not dependent on feeding status and was significantly elevated above RMR only until subcutaneous temperature had recovered. Contrary to our prediction, fed individuals did not reduce the subcutaneous circulation compared to fasted penguins and did not show any changes in MRR during subsequent recovery. It seems likely that lower metabolic rate in fed king penguins on land reported in other studies might not have been caused primarily by increased circulation to the visceral organs.

Changes in normothermia during surgery.

INTRODUCTION: The aim of the study was to monitor changes in normothermia in patients undergoing surgery under general anaesthesia. METHODS: Prospective, observational survey, where standardized, intentional observations, medical record statements and semi-structured interviews with patients and healthcare professionals were used for data collection. The group consisted of 95 patients, 18 years and older, undergoing surgery lasting 30 minutes and longer under general anaesthesia. The collection of data took place from October 2018 to March 2019 in operating theatres of the otorhinolaryngological department (40 patients), central operating theatres (55 patients), and in recovery rooms and intensive care units. RESULTS: Perioperative hypothermia (body temperature below 36°C) was demonstrated in 11 (11.6%) patients. A temperature lower than comfortable body temperature (36.0-36.5°C) occurred in 47, i.e. almost half of the patients (49.5%), and no relationship was demonstrated between hypothermia and the value of the Body Mass Index. The duration of surgery and its effect on the decrease in body temperature was confirmed in patients operated on in the otorhinolaryngology theatres. A relationship was confirmed between hypothermia and the length of the surgery (correlation coefficient -0.452; p=0.003). CONCLUSION: The incidence of perioperative hypothermia was demonstrated in 11.6% patients. No relationship was demonstrated between BMI and the development of hypothermia in our patients. A record sheet proposal for monitoring perioperative body temperature was published.