The combination treatment of hypothermia and intranasal insulin ameliorates the structural and functional changes in a rat model of traumatic brain injury

The present study aimed to investigate the combination effects of hypothermia (HT) and intranasal insulin (INS) on structural changes of the hippocampus and cognitive impairments in the traumatic brain injury (TBI) rat model. The rats were divided randomly into the following five groups (n = 10): Sham, TBI, TBI with HT treatment for 3 h (TBI + HT), TBI with INS (ten microliters of insulin) treatment daily for 7 days (TBI + INS), and TBI with combining HT and INS (TBI + HT + INS). At the end of the 7th day, the open field and the Morris water maze tests were done for evaluation of anxiety-like behavior and memory performance. Then, after sacrificing, the brain was removed for stereological study. TBI led to an increase in the total volume of hippocampal subfields CA1 and DG and a decrease in the total number of neurons and non-neuronal cells in both sub-regions, which was associated with anxiety-like behavior and memory impairment. Although, the combination of HT and INS prevented the increased hippocampal volume and cell loss and improved behavioral performances in the TBI group. Our study suggests that the combined treatment of HT and INS could prevent increased hippocampal volume and cell loss in CA1 and DG sub-regions and consequently improve anxiety-like behaviors and memory impairment following TBI.

Observation of the effect of hypothermia therapy combined with optimized nursing on brain protection after cardiopulmonary resuscitation: A retrospective case-control study

This study aimed to investigate the impact of optimized emergency nursing in conjunction with mild hypothermia nursing on neurological prognosis, hemodynamics, and complications in patients with cardiac arrest. A retrospective analysis was conducted on the medical records of 124 patients who received successful cardiopulmonary resuscitation (CPR) at Fujian Provincial Hospital South Branch. The patients were divided into control and observation groups, each consisting of 62 cases. The brain function of both groups was assessed using the Glasgow Coma Scale and the National Institutes of Health Stroke Scale. Additionally, serum neuron-specific enolase level was measured in both groups. The vital signs and hemodynamics of both groups were analyzed, and the complications and satisfaction experienced by the 2 groups were compared. The experimental group exhibited significantly improved neurological function than the control group (P < .05). Furthermore, the heart rate in the experimental group was significantly lower than the control group (P < .05). However, no significant differences were observed in blood oxygen saturation, mean arterial pressure, central venous pressure, and systolic blood pressure between the 2 groups (P > 0.05). Moreover, the implementation of optimized nursing practices significantly reduced complications and improved the quality of life and satisfaction of post-CPR patients (P < .05). The integration of optimized emergency nursing practices in conjunction with CPR improves neurological outcomes in patients with cardiac arrest.

Factors affecting early childhood growth in hypoxic-ischemic encephalopathy treated with hypothermia

INTRODUCTION

There is an extensive body of research regarding neurological outcomes following neonatal hypoxic-ischemic encephalopathy (HIE) treated with therapeutic hypothermia (TH), with limited data on growth outcomes. We examined perinatal characteristics associated with postnatal growth in this population.

METHODS

Convenience cohort of 66 infants with HIE who underwent TH and participated in follow-up at 24 months of age were included. Regression modeling including perinatal anthropomorphics, markers of HIE, and systemic injury was used to evaluate growth at 24 months.

RESULTS

Birth head circumference was associated with weight (p = 0.036). MRI severity, pH at admission and birth head circumference were associated with height (p = 0.043, p = 0.015 and p = 0.043 respectively). MRI severity and length of intubation were associated with head circumference (p = 0.038 and p < 0.001 respectively).

CONCLUSION

There was a significant association between specific early factors and growth at 24 months among infants with HIE treated with TH.

Predictors of cardiac arrest in severe accidental hypothermia

STUDY OBJECTIVE

To indicate predictors of witnessed hypothermic cardiac arrest.

METHODS

We conducted a retrospective analysis of 182 patients with severe accidental hypothermia (i.e., with core body temperature of ≤28 °C) who presented with preserved spontaneous circulation at first contact with medical services. We divided the study population into two groups: patients who suffered hypothermic cardiac arrest (HCA) at any time between encounter with medical service and restoration of normothermia, and those who did not sustain HCA. The analyzed outcome was the occurrence of cardiac arrest prior to achieving normothermia. Hemodynamic and biochemical parameters were analyzed with regard to their association with the outcome.

RESULTS

Fifty-two (29%) patients suffered HCA. In a univariable analysis, four variables were significantly associated with the outcome, namely heart rate (p < 0.001), systolic blood pressure (p = 0.03), ventricular arrhythmia (p = 0.001), and arterial oxygen partial pressure (p = 0.002). In the multivariable logistic regression the best model predicting HCA included heart rate, PaO2, and Base Excess (AUROC = 0.78). In prehospital settings, when blood gas analysis is not available, other multivariable model including heart rate and occurrence of ventricular arrhythmia (AUROC = 0.74) can be used. In this study population, threshold values of heart rate of 43/min, temperature-corrected PaO2 of 72 mmHg, and uncorrected PaO2 of 109 mmHg, presented satisfactory sensitivity and specificity for HCA prediction.

CONCLUSIONS

In patients with severe accidental hypothermia, the occurrence of HCA is associated with a lower heart rate, hypoxemia, ventricular arrhythmia, lower BE, and lower blood pressure. These parameters can be helpful in the early selection of high-risk patients and their allocation to extracorporeal rewarming facilities.

Factors Influencing the Occurrence of Intraoperative Hypothermia in Patients Undergoing General Anesthesia Intervention: A Study in a Tertiary Care Hospital

BACKGROUND Intraoperative and postoperative hypothermia of patients can be caused by the use of anesthetic drugs and the complicated and time-consuming procedures of interventional surgery. This retrospective study included 184 patients to investigate the incidence and factors associated with hypothermia during intraoperative anesthesia in a single center in China between January and October 2023. MATERIAL AND METHODS A convenient sampling method was used to select 184 patients who underwent general anesthesia intervention in a tertiary hospital in Sichuan Province from January to October 2023 as the study population. The independent factors influencing the occurrence of intraoperative hypothermia were analyzed. A survey was conducted to collect 5 demographic factors, 4 preoperative-related factors, and 10 surgically related factors. According to the occurrence of intraoperative hypothermia, the independent influencing factors of unplanned hypothermia during perioperative period were further analyzed. RESULTS Among 184 patients, 64 (34.78%) experienced perioperative unplanned hypothermia, of which 5 (7.81%) cases occurred before the start of surgery, 7 (10.94%) occurred before the start of surgery after anesthesia, and 52 (81.25%) occurred during surgery. Logistic regression analysis showed that body temperature at the beginning of surgery (P<0.001), set operating room temperature (P<0.001), duration of anesthesia (P=0.006), and age (P=0.001) were independent influencing factors for unplanned hypothermia during perioperative period. CONCLUSIONS The incidence of intraoperative hypothermia is high in patients undergoing general anesthesia interventions. Age, duration of anesthesia, set operating room temperature, and body temperature at the beginning of the operation were independent influencing factors for the occurrence of unplanned hypothermia during the perioperative period.

Iatrogenic Shapiro syndrome: a case report

OBJECTIVES

Shapiro's syndrome (SS) is a rare condition characterized by spontaneous periodic hypothermia. The underlying pathophysiological mechanisms and etiology of this syndrome remain controversial, and fewer than 100 cases have been reported to date. The objective of this case report is to present a unique iatrogenic case of SS and contribute additional insights into the underlying etiology of this rare disorder.

METHODS

We conducted an analysis of existing medical literature and described a clinical case of SS secondary to a neurosurgical procedure.

RESULTS

To our knowledge, we present the first iatrogenic case of SS in a 53-year-old woman who underwent a partial right parieto-occipital lobectomy in 2003 as a treatment for refractory epilepsy. Several years after the surgical procedure, she began experiencing recurrent episodes of hypothermia. Brain magnetic resonance imaging (MRI) revealed the absence of the splenium of the corpus callosum (CC) and pituitary hyperplasia. After ruling out other potential causes of hypothermia, a diagnosis of SS was made.

DISCUSSION

The most plausible mechanism to explain the recurrent hypothermia associated with SS in our patient is a probable disruption of the pathways involved in thermoregulation through the CC as a consequence of the surgical procedure. This case report provides further insights into the etiology of this rare disorder.

Hypothermic Cardiac Arrest: A Case Report of an Unexpected Survivor Using Air Medical Transportation in Nepal

This is a case of a 34-year-old man surviving hypothermic cardiac arrest with excellent neurologic recovery in Nepal. After 3 days without communication at an altitude of approximately 6,000 m, the patient was located in a crevasse and retrieved by a helicopter-supported search and rescue team. At first contact, he was reported to be breathing and shivering with appropriate pupillary response. The patient was then flown to a local teaching hospital where he was assessed on arrival and found to be in cardiac arrest with absence of spontaneous breathing and a central pulse and bilaterally fixed and dilated pupils. An electrocardiogram demonstrated asystole, and his core temperature was unrecordably low on the available device. After resuscitation and return of spontaneous circulation, the patient received a secondary helicopter transfer to a major hospital in the capital, Kathmandu, where his recovery continued. The report discusses the physiological basis of the relatively favorable outcomes observed in hypothermic cardiac arrest and highlights the operations and capability of helicopter emergency medical services in a country on the United Nations list of least developed nations.

Transient changes in the ST-T waveform mimicking myocardial infarction in a child with near-drowning: a case report

Drowning is a common cause of childhood morbidity and mortality worldwide. Anoxia, hypothermia, and metabolic acidosis are mainly responsible for this morbidity. Drowning may lead to multiple organ damage, especially cardiac damage, in cases in which severe hypothermia and hypoxemia occur. We report a case of a 4-year-old girl who was admitted to our hospital's Emergency Department because of drowning. She had elevated troponin I concentrations and ST-segment elevation with T wave inversion. However, cardiovascular computed tomography showed no obvious abnormalities in the coronary arteries. We suggest that cardiac damage in this situation is caused by coronary artery spasms. To the best of our knowledge, this is the first case of cardiac damage with electrocardiographic changes after drowning in a preschool child.

Prolonged critical avalanche burial for nearly 23 h with severe hypothermia and severe frostbite with good recovery: a case report

BACKGROUND

Accidental hypothermia with severe frostbite is a rare combination of injuries with a high risk for long-term sequelae. There are widely accepted recommendations for the management of avalanche victims and for frostbite treatment, but no recommendation exists for the treatment of frostbite in severe hypothermic patients, specifically for the management of hypothermic avalanche victims presenting with frostbite.

CASE PRESENTATION

We present a case of a previously healthy, 53-year-old male skier who was critically buried by an avalanche at 2300 m of altitude at an ambient temperature of - 8 °C for nearly 23 h. The victim was found with the right hand out of the snow and an air connection to outside. He was somnolent with Glasgow Coma Scale 11 (Eye 4, Verbal 2, Motor 5) and spontaneously breathing, in a severely hypothermic state with an initial core temperature of 23.1 °C and signs of cold injuries in all four extremities. After rescue and active external forced air rewarming in the intensive care unit, the clinical signs of first-degree frostbite on both feet and the left hand vanished, while third- to fourth-degree frostbite injuries became apparent on all fingers of the right hand. After reaching a core body temperature of approximately 36 °C, aggressive frostbite treatment was started with peripheral arterial catheter-directed thrombolysis with alteplase, intravenous iloprost, ibuprofen, dexamethasone and regional sympathicolysis with a right-sided continuous axillary block. After ten months, the patient had no tissue loss but needed neuropathic pain treatment with pregabalin.

CONCLUSION

The combination of severe accidental hypothermia and severe frostbite is rare and challenging, as drug metabolism is unpredictable in a hypothermic patient and no recommendations for combined treatment exist. There is general agreement to give hypothermia treatment the priority and to begin frostbite treatment as early as possible after full rewarming of the patient. More evidence is needed to identify the optimal dosage and time point to initiate treatment of frostbite in severely hypothermic patients. This should be taken into consideration by future treatment recommendations.

Whole-Blood Gene Expression Profile After Hypoxic-Ischemic Encephalopathy

Importance

Induced hypothermia, the standard treatment for hypoxic-ischemic encephalopathy (HIE) in high-income countries (HICs), is less effective in the low-income populations in South Asia, who have the highest disease burden.

Objective

To investigate the differences in blood genome expression profiles of neonates with HIE from an HIC vs neonates with HIE from South Asia.

Design, Setting, and Participants

This case-control study analyzed data from (1) a prospective observational study involving neonates with moderate or severe HIE who underwent whole-body hypothermia between January 2017 and June 2019 and age-matched term healthy controls in Italy and (2) a randomized clinical trial involving neonates with moderate or severe HIE in India, Sri Lanka, and Bangladesh recruited between August 2015 and February 2019. Data were analyzed between October 2020 and August 2023.

Exposure

Whole-blood RNA that underwent next-generation sequencing.

Main Outcome and Measures

The primary outcomes were whole-blood genome expression profile at birth associated with adverse outcome (death or disability at 18 months) after HIE in the HIC and South Asia cohorts and changes in whole-genome expression profile during the first 72 hours after birth in neonates with HIE and healthy controls from the HIC cohort. Blood samples for RNA extraction were collected before whole-body hypothermia at 4 time points (6, 24, 48, and 72 hours after birth) for the HIC cohort. Only 1 blood sample was drawn within 6 hours after birth for the South Asia cohort.

Results

The HIC cohort was composed of 35 neonates (21 females [60.0%]) with a median (IQR) birth weight of 3.3 (3.0-3.6) kg and gestational age of 40.0 (39.0-40.6) weeks. The South Asia cohort consisted of 99 neonates (57 males [57.6%]) with a median (IQR) birth weight of 2.9 (2.7-3.3) kg and gestational age of 39.0 (38.0-40.0) weeks. Healthy controls included 14 neonates (9 females [64.3%]) with a median (IQR) birth weight of 3.4 (3.2-3.7) kg and gestational age of 39.2 (38.9-40.4) weeks. A total of 1793 significant genes in the HIC cohort and 99 significant genes in the South Asia cohort were associated with adverse outcome (false discovery rate <0.05). Only 11 of these genes were in common, and all had opposite direction in fold change. The most significant pathways associated with adverse outcome were downregulation of eukaryotic translation initiation factor 2 signaling in the HIC cohort (z score = -4.56; P < .001) and aldosterone signaling in epithelial cells in the South Asia cohort (z score = null; P < .001). The genome expression profile of neonates with HIE (n = 35) at birth, 24 hours, 48 hours, and 72 hours remained significantly different from that of age-matched healthy controls in the HIC cohort (n = 14).

Conclusions and Relevance

This case-control study found that disease mechanisms underlying HIE were primarily associated with acute hypoxia in the HIC cohort and nonacute hypoxia in the South Asia cohort. This finding might explain the lack of hypothermic neuroprotection.

Analysis of surgical site infection and tumour-specific survival rate in patients with renal cell carcinoma after laparoscopic radical nephrectomy

Surgical site infections (SSIs) may pose a significant risk to patients undergoing surgery. This study aims to explore the risk factors for SSIs in patients undergoing laparoscopic radical nephrectomy for renal cell carcinoma and the impact of infection on tumour-specific survival (CSS) after nephrectomy for renal cell carcinoma. To explore the risk factors for SSIs in patients undergoing laparoscopic radical nephrectomy for renal cell carcinoma and the impact of infection on tumour-specific survival (CSS) after nephrectomy for renal cell carcinoma. A retrospective analysis was conducted on 400 patients in our hospital from June 2021 to June 2023. This study divided patients into two groups: those with SSI and those without SSI. Collect general data and information related to the operating room. Clearly defined inclusion and exclusion criteria. Select surgical time, laminar mobile operating room use, and intraoperative hypothermia as observation indicators. Perform statistical analysis using SPSS 25.0 software, including univariate, multivariate, and survival analyses of wound-infected and uninfected patients. Out of 400 patients, 328 had no SSIs, 166 died during follow-up, 72 had SSIs, and 30 died during follow-up. There was no statistically significant difference (p > 0.05) in comparing primary data between individuals without SSIs and those with SSIs. There were statistically significant differences (p < 0.05) in surgical time, nonlaminar flow operating room use, and intraoperative hypothermia. The postoperative survival time of SSI patients with a tumour diameter of 7.0-9.9 cm was significantly longer than that of SSI patients, and the difference was statistically significant (p < 0.05). The occurrence of severe infection in patients with other tumour diameters did not affect postoperative survival, and the difference was not statistically significant (p > 0.05). After multiple factor analysis, it was found that severe infection can prolong the postoperative survival of patients with tumour diameter exceeding 7 cm (HR = 0.749, p < 0.05). This study identified nonlaminar flow operating rooms, prolonged surgical time, and intraoperative hypothermia as significant risk factors for SSIs. After nephrectomy for renal cell carcinoma patients with a tumour diameter of 7-9.9 μ m, perioperative infection can prolong their survival. However, it has no significant effect on patients with other tumour diameters.

Trauma-induced coagulopathy: What you need to know

ABSTRACT

Trauma-induced coagulopathy (TIC) is a global inflammatory state accompanied by coagulation derangements, acidemia, and hypothermia, which occurs after traumatic injury. It occurs in approximately 25% of severely injured patients, and its incidence is directly related to injury severity. The mechanism of TIC is multifaceted; proposed contributing factors include dysregulation of activated protein C, increased tPA, systemic endothelial activation, decreased fibrinogen, clotting factor consumption, and platelet dysfunction. Effects of TIC include systemic inflammation, coagulation derangements, acidemia, and hypothermia. Trauma-induced coagulopathy may be diagnosed by conventional coagulation tests including platelet count, Clauss assay, international normalized ratio, thrombin time, prothrombin time, and activated partial thromboplastin time; viscoelastic hemostatic assays such as thrombelastography and rotational thrombelastography; or a clinical scoring system known as the Trauma Induced Coagulopathy Clinical Score. Preventing TIC begins in the prehospital phase with early hemorrhage control, blood product resuscitation, and tranexamic acid therapy. Early administration of prothrombin complex concentrate is also being studied in the prehospital environment. The mainstays of TIC treatment include hemorrhage control, blood and component transfusions, and correction of abnormalities such as hypocalcemia, acidosis, and hypothermia.

LEVEL OF EVIDENCE

Therapeutic/Care Management; Level III.

Impact of Intraoperative Hypothermia on Incidence of Infection in Implant-Based Breast Reconstruction

BACKGROUND

Infection following implant-based breast reconstruction can lead to devastating complications. Risk factors for infection include smoking, diabetes, and obesity. Intraoperative hypothermia may represent another modifiable risk factor. This study analyzed the effect of hypothermia in postmastectomy immediate implant-based reconstruction on postoperative surgical-site infection (SSI).

METHODS

This was a retrospective review of 122 patients with intraoperative hypothermia, defined as less than 35.5°C, and 106 normothermic patients who underwent postmastectomy implant-based reconstruction between 2015 and 2021. Demographics, comorbidities, smoking status, hypothermia (and its duration), and length of surgery were collected. The primary outcome was SSI. Secondary outcomes included reoperation and delayed wound healing.

RESULTS

A total of 185 patients (81%) underwent staged reconstruction with tissue expander placement and 43 patients (18.9%) had a direct-to-implant procedure. Over half (53%) of the patients experienced intraoperative hypothermia. In the hypothermic group, a higher proportion of patients had SSIs (34.4% versus 17% of normothermic patients; P < 0.05) and wound healing complications (27.9% versus 16%; P < 0.05). Intraoperative hypothermia predicted SSI (OR, 2.567; 95% CI, 1.367 to 4.818; P < 0.05) and delayed wound healing (OR, 2.023; 95% CI, 1.053 to 3.884; P < 0.05). Longer duration of hypothermia significantly correlated with SSI, with an average 103 minutes versus 77 minutes ( P < 0.05).

CONCLUSIONS

This study demonstrates that intraoperative hypothermia is a significant risk factor for postoperative infection in postmastectomy implant-based breast reconstruction. Maintaining strict normothermia during implant-based breast reconstruction procedures may improve patient outcomes by reducing the risk of postoperative infection and delayed wound healing.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Risk, II.

CTRP6 promotes the macrophage inflammatory response, and its deficiency attenuates LPS-induced inflammation

Macrophages play critical roles in inflammation and tissue homeostasis, and their functions are regulated by various autocrine, paracrine, and endocrine factors. We have previously shown that CTRP6, a secreted protein of the C1q family, targets both adipocytes and macrophages to promote obesity-linked inflammation. However, the gene programs and signaling pathways directly regulated by CTRP6 in macrophages remain unknown. Here, we combine transcriptomic and phosphoproteomic analyses to show that CTRP6 activates inflammatory gene programs and signaling pathways in mouse bone marrow-derived macrophages (BMDMs). Treatment of BMDMs with CTRP6 upregulated proinflammatory, and suppressed the antiinflammatory, gene expression. We also showed that CTRP6 activates p44/42-MAPK, p38-MAPK, and NF-κB signaling pathways to promote inflammatory cytokine secretion from BMDMs, and that pharmacologic inhibition of these signaling pathways markedly attenuated the effects of CTRP6. Pretreatment of BMDMs with CTRP6 also sensitized and potentiated the BMDMs response to lipopolysaccharide (LPS)-induced inflammatory signaling and cytokine secretion. Consistent with the metabolic phenotype of proinflammatory macrophages, CTRP6 treatment induced a shift toward aerobic glycolysis and lactate production, reduced oxidative metabolism, and elevated mitochondrial reactive oxygen species production in BMDMs. Importantly, in accordance with our in vitro findings, BMDMs from CTRP6-deficient mice were less inflammatory at baseline and showed a marked suppression of LPS-induced inflammatory gene expression and cytokine secretion. Finally, loss of CTRP6 in mice also dampened LPS-induced inflammation and hypothermia. Collectively, our findings suggest that CTRP6 regulates and primes the macrophage response to inflammatory stimuli and thus may have a role in modulating tissue inflammatory tone in different physiological and disease contexts.

[Hypothermia in elderly patients]

Hypothermia in older patients is a serious symptom, with high morbidity and mortality, and often an atypical presentation of an underlying problem. The most common causes are an infection and exposure to extreme cold ('accidental hypothermia'), but there are other, less common causes. These two cases show hypothermia as one of the symptoms in atypical presentations of underlying conditions. It is important to run diagnostics for infectious diseases and other underlying causes, and start antibiotics promptly. If there is no response to antibiotics and diagnostics do not reveal evidence of an infection, clinicians need to consider other causes of hypothermia.

Peripheral BDNF Regulates Somatosensory-Sympathetic Coupling in Brachial Plexus Avulsion-Induced Neuropathic Pain

Brachial plexus avulsion (BPA) is a combined injury involving the central and peripheral nervous systems. Patients with BPA often experience severe neuropathic pain (NP) in the affected limb. NP is insensitive to the existing treatments, which makes it a challenge to researchers and clinicians. Accumulated evidence shows that a BPA-induced pain state is often accompanied by sympathetic nervous dysfunction, which suggests that the excitation state of the sympathetic nervous system is correlated with the existence of NP. However, the mechanism of how somatosensory neural crosstalk with the sympathetic nerve at the peripheral level remains unclear. In this study, through using a novel BPA C7 root avulsion mouse model, we found that the expression of BDNF and its receptor TrκB in the DRGs of the BPA mice increased, and the markers of sympathetic nervous system activity including α1 and α2 adrenergic receptors (α1-AR and α2-AR) also increased after BPA. The phenomenon of superexcitation of the sympathetic nervous system, including hypothermia and edema of the affected extremity, was also observed in BPA mice by using CatWalk gait analysis, an infrared thermometer, and an edema evaluation. Genetic knockdown of BDNF in DRGs not only reversed the mechanical allodynia but also alleviated the hypothermia and edema of the affected extremity in BPA mice. Further, intraperitoneal injection of adrenergic receptor inhibitors decreased neuronal excitability in patch clamp recording and reversed the mechanical allodynia of BPA mice. In another branch experiment, we also found the elevated expression of BDNF, TrκB, TH, α1-AR, and α2-AR in DRG tissues from BPA patients compared with normal human DRGs through western blot and immunohistochemistry. Our results revealed that peripheral BDNF is a key molecule in the regulation of somatosensory-sympathetic coupling in BPA-induced NP. This study also opens a novel analgesic target (BDNF) in the treatment of this pain with fewer complications, which has great potential for clinical transformation.

Modified intraoperative temperature management prevents prolonged length of stay after head and neck surgery with free flap reconstruction

The present study aimed to investigate the association between intraoperative body temperature and prolonged length of stay (PLOS) after free flap reconstruction. A total of 753 patients who underwent head and neck surgery with free flap reconstruction were collected and randomly assigned into primary and validation cohorts. In the primary cohort, univariable and multivariable analyses were conducted to evaluate associations between intraoperative time-weighted (TW) temperature (TW average [TWA] temperature, TW hypothermia and TW hyperthermia) and PLOS. Nomograms were developed with and without intraoperative TW temperature, and validated in the validation cohort. Severe intraoperative TW hypothermia (OR = 1.004; 95% CI: 1.000, 1.007; p = 0.032) was identified as an independent risk factor for PLOS. Intraoperative TWA temperature and TW hypothermia showed linear related predictive effect for PLOS. The nomogram incorporating intraoperative TW temperature showed higher C-index (0.652, 95% CI: 0.591, 0.713) and improved net reclassification improvement for non-event (0.277, 95% CI: 0.118, 0.435; p < 0.001). Lower TWA temperature with mild TW hypothermia had a preventive effect on PLOS with a linear association, which may provide a modified range for intraoperative temperature management. The proposed nomogram incorporating intraoperative TW temperature could be used to develop personalized preventive strategies for PLOS after free flap reconstruction. IRB NUMBER: SYSEC-KY-KS-2022-037. CLINICAL TRIAL REGISTRATION NUMBER: Not applicable.

Association of EEG Background and Neurodevelopmental Outcome in Neonates With Hypoxic-Ischemic Encephalopathy Receiving Hypothermia

BACKGROUND AND OBJECTIVES

Predicting neurodevelopmental outcome for neonates with hypoxic-ischemic encephalopathy (HIE) is important for clinical decision-making, care planning, and parent communication. We examined the relationship between EEG background and neurodevelopmental outcome among children enrolled in a trial of erythropoietin or placebo for neonates with HIE treated with therapeutic hypothermia.

METHODS

Participants had EEG recorded throughout hypothermia. EEG background was classified as normal, discontinuous, or severely abnormal (defined as burst suppression, low voltage suppressed, or status epilepticus) at 5 1-hour epochs: onset of recording, 24, 36, 48, and 72 hours after birth. The predominant background pattern during the entire continuous video EEG monitoring recording was calculated using the arithmetic mean of the 5 EEG background ratings (normal = 0; discontinuous = 1; severely abnormal = 2) as follows: "predominantly normal" (mean = 0), "normal/discontinuous" (0 < mean<1), "predominantly discontinuous" (mean = 1), "discontinuous/severely abnormal" (1 < mean<2), or "predominantly severely abnormal" (mean = 2). Primary outcome was death or neurodevelopmental impairment (NDI) defined as cerebral palsy, Gross Motor Function Classification Score ≥1, or cognitive score <90 on Bayley Scales of Infant Toddler Development, third edition at age 2 years. Neurodevelopment was also categorized into a 5-level ordinal measure: no, mild, moderate, severe NDI, or death for secondary analysis. We used generalized linear regression models with robust standard errors to assess the relative risk of death or NDI by EEG background in both unadjusted and adjusted analyses controlling for the effects of treatment group, sex, HIE severity, and study recruitment site.

RESULTS

Among 142 neonates, the predominant background EEG pattern was predominantly normal in 35 (25%), normal/discontinuous in 68 (48%), predominantly discontinuous in 11 (7.7%), discontinuous/severely abnormal in 16 (11%), and predominantly severely abnormal in 12 (8.5%). Increasing severity of background across monitoring epochs was associated with increasingly worse clinical outcomes. Children with severe EEG background abnormality at any time point (n = 36, 25%) were significantly more likely to die or have severe NDI at 2 years (adjusted relative risk: 7.95, 95% CI 3.49-18.12).

DISCUSSION

EEG background is strongly associated with NDI at age 2 years. These results can be used to assist health care providers to plan follow-up care and counsel families for decision-making related to goals of care.

Short-term neurological injury in newborns infants with overcooling in passive hypothermia and transferred to reference hospital in Colombia

AIM

The aim of the study was to determine whether overcooling (temperature <33°C) during passive hypothermia when transporting neonates with perinatal asphyxia increased the risk of short-term neurological injury.

METHODS

A retrospective observational study was performed. Newborns transferred to the LaCardio neonatal unit between January 2021 and April 2022 with moderate and severe perinatal asphyxia and who received passive hypothermia during transport were included. A temperature of <33°C was considered overcooling. A composite outcome of neurological injury was defined by the presence of abnormalities on brain magnetic resonance imaging, video telemetry, seizure before discharge or both.

RESULTS

The study included 101 newborns. A total of 18 neonates had a temperature <33°C after transportation. Neurological injuries were present in 21.8% of the temperature <33°C group and 78.2% of the temperature ≥33°C group. Temperature <33°C at the end of transport (aOR 9.2, 95% CI 1.1-77.3) were associated with neurological injury before discharge from the unit.

CONCLUSION

During transportation, overcooling in neonates with asphyxia increases the risk of neurological injury before discharge from the neonatal unit. It is important to qualify the transport team with adequate training and equipment for therapeutic hypothermia.

Mechanisms for hypothermia during anaphylactic hypotension in awake rats

Hypothermia develops during systemic anaphylaxis in rodents. The aim of this study was to elucidate the mechanism for the hypothermia by assessing the roles of locomotor activity, tail heat dissipation, heat production in the brown adipose tissue (BAT) activity, and chemical mediators during ovalbumin-induced anaphylactic hypotension in awake rats. We measured the core body temperature (Tcore) and mean blood pressure (MBP), along with the surface temperature of the interscapular region (TiScap), an indirect measure of BAT activity, and the tail (Ttail). During anaphylaxis, MBP decreased to the nadir of 53 ± 2 mmHg at 8 min with recovery toward baseline. Tcore began to decrease at 7.5 min with the nadir of 36.1 ± 0.2°C at 30 min from the baseline of 38.0 ± 0.1°C. TiScap also significantly decreased, but its onset was preceded by that of Tcore. Ttail decreased after antigen, suggesting the absence of increased heat dissipation from the tail. The physical activity, as evaluated by moved distances, did not decrease until 20 min after antigen, followed by a progressive decrease. Reduced movement using a restraint maneuver not only reduced Tcore in nonsensitized rats but also augmented the anaphylactic hypothermia in the early phase (1.5-18 min) in sensitized rats. Combined antagonism against platelet-activating factor (PAF) and histamine H1 receptors abolished antigen-induced hypotension but only attenuated hypothermia. In conclusion, decreased locomotor activity, but not tail heat dissipation or decreased BAT activity, may at least in part contribute to this hypothermia. PAF and histamine are involved mainly in hypotension but only partly in hypothermia during rat anaphylaxis.NEW & NOTEWORTHY Anaphylactic shock is a life-threatening systemic hypotension. Hypothermia is observed during systemic anaphylaxis of rats. We determined the mechanism as follows: decreased locomotor activity, but not tail heat dissipation or decreased BAT activity, may at least in part contribute to this hypothermia. PAF and histamine are involved mainly in hypotension, but only partly in hypothermia during rat anaphylaxis.

Perinatal asphyxia and hypothermic treatment from the endocrine perspective

Introduction

Perinatal asphyxia is one of the three most important causes of neonatal mortality and morbidity. Therapeutic hypothermia represents the standard treatment for infants with moderate-severe perinatal asphyxia, resulting in reduction in the mortality and major neurodevelopmental disability. So far, data in the literature focusing on the endocrine aspects of both asphyxia and hypothermia treatment at birth are scanty, and many aspects are still debated. Aim of this narrative review is to summarize the current knowledge regarding the short- and long-term effects of perinatal asphyxia and of hypothermia treatment on the endocrine system, thus providing suggestions for improving the management of asphyxiated children.

Results

Involvement of the endocrine system (especially glucose and electrolyte disturbances, adrenal hemorrhage, non-thyroidal illness syndrome) can occur in a variable percentage of subjects with perinatal asphyxia, potentially affecting mortality as well as neurological outcome. Hypothermia may also affect endocrine homeostasis, leading to a decreased incidence of hypocalcemia and an increased risk of dilutional hyponatremia and hypercalcemia.

Conclusions

Metabolic abnormalities in the context of perinatal asphyxia are important modifiable factors that may be associated with a worse outcome. Therefore, clinicians should be aware of the possible occurrence of endocrine complication, in order to establish appropriate screening protocols and allow timely treatment.

Predictors of neurologic outcomes and mortality in physically abused and unintentionally injured children: a retrospective observation study

OBJECTIVES

This study aimed to identify the predictors of neurologic outcomes and mortality in physically abused and unintentionally injured children admitted to intensive care units (ICUs).

METHODS

All maltreated children were admitted to pediatric, neurosurgical, and trauma ICUs between 2001 and 2019. Clinical factors, including age, sex, season of admission, identifying settings, injury severity score, etiologies, length of stay in the ICU, neurologic outcomes, and mortality, were analyzed and compared between the physically abused and unintentionally injured groups. Neurologic assessments were conducted using the Pediatric Cerebral Performance Category scale. The study was approved by the Institutional Review Board of Chang Gung Memorial Hospital and the Ethics Committee waived the requirement for informed consent because of the anonymized nature of the data.

RESULTS

A total of 2481 children were investigated; of them, there were 480 (19.3%) victims admitted to the ICUs, including 156 physically abused and 324 unintentionally injured. Age, history of prematurity, clinical outcomes, head injury, neurosurgical interventions, clinical manifestations, brain computed tomography findings, and laboratory findings significantly differed between them (all p < 0.05). Traumatic brain injury was the major etiology for admission to the ICU. The incidence of abusive head trauma was 87.1% among the physically abused group. Only 46 (29.4%) and 268 (82.7%) cases achieved favorable neurologic outcomes in the physically abused and unintentionally injured groups, respectively. Shock within 24 h, spontaneous hypothermia (body temperature, < 35 °C), and post-traumatic seizure were strongly associated with poor neurologic outcomes and mortality in both groups.

CONCLUSIONS

Initial presentation with shock, spontaneous hypothermia at ICU admission, and post-traumatic seizure were associated with poor neurologic outcomes and mortality in physically abused and unintentionally injured children.

Maintaining normothermia immediately after birth in preterm infants <34 weeks' gestation: A systematic review and meta-analysis

AIM

To evaluate delivery room (DR) interventions to prevent hypothermia and improve outcomes in preterm newborn infants <34 weeks' gestation.

METHODS

Medline, Embase, CINAHL and CENTRAL were searched till 22nd July 2022. Randomized controlled trials (RCTs), non-RCTs and quality improvement studies were considered. A random effects meta-analysis was performed, and the certainty of evidence was evaluated using GRADE guidelines.

RESULTS

DR temperature of ≥23 °C compared to standard care improved temperature outcomes without an increased risk of hyperthermia (low certainty), whereas radiant warmer in servo mode compared to manual mode decreased mean body temperature (MBT) (moderate certainty). Use of a plastic bag or wrap (PBW) improved normothermia (low certainty), but with an increased risk of hyperthermia (moderate certainty). Plastic cap improved normothermia (moderate certainty) and when combined with PBW improved MBT (low certainty). Use of a cloth cap decreased moderate hypothermia (low certainty). Though thermal mattress (TM) improved MBT, it increased risk of hyperthermia (low certainty). Heated-humidified gases (HHG) for resuscitation decreased the risk of moderate hypothermia and severe intraventricular hemorrhage (very low to low certainty). None of the interventions was shown to improve survival, but sample sizes were insufficient.

CONCLUSIONS

DR temperature of ≥23 °C, radiant warmer in manual mode, use of a PBW and a head covering is suggested for preterm newborn infants <34 weeks' gestation. HHG and TM could be considered in addition to PBW provided resources allow, in settings where hypothermia incidence is high. Careful monitoring to avoid hyperthermia is needed.

Seizures Cause Prolonged Impairment of Ventilation, CO2 Chemoreception and Thermoregulation

Sudden unexpected death in epilepsy (SUDEP) has been linked to respiratory dysfunction, but the mechanisms underlying this association remain unclear. Here we found that both focal and generalized convulsive seizures (GCSs) in epilepsy patients caused a prolonged decrease in the hypercapnic ventilatory response (HCVR; a measure of respiratory CO2 chemoreception). We then studied Scn1a R1407X/+ (Dravet syndrome; DS) and Scn8a N1768D/+ (D/+) mice of both sexes, two models of SUDEP, and found that convulsive seizures caused a postictal decrease in ventilation and severely depressed the HCVR in a subset of animals. Those mice with severe postictal depression of the HCVR also exhibited transient postictal hypothermia. A combination of blunted HCVR and abnormal thermoregulation is known to occur with dysfunction of the serotonin (5-hydroxytryptamine; 5-HT) system in mice. Depleting 5-HT with para-chlorophenylalanine (PCPA) mimicked seizure-induced hypoventilation, partially occluded the postictal decrease in the HCVR, exacerbated hypothermia, and increased postictal mortality in DS mice. Conversely, pretreatment with the 5-HT agonist fenfluramine reduced postictal inhibition of the HCVR and hypothermia. These results are consistent with the previous observation that seizures cause transient impairment of serotonergic neuron function, which would be expected to inhibit the many aspects of respiratory control dependent on 5-HT, including baseline ventilation and the HCVR. These results provide a scientific rationale to investigate the interictal and/or postictal HCVR as noninvasive biomarkers for those at high risk of seizure-induced death, and to prevent SUDEP by enhancing postictal 5-HT tone.SIGNIFICANCE STATEMENT There is increasing evidence that seizure-induced respiratory dysfunction contributes to the pathophysiology of sudden unexpected death in epilepsy (SUDEP). However, the cellular basis of this dysfunction has not been defined. Here, we show that seizures impair CO2 chemoreception in some epilepsy patients. In two mouse models of SUDEP we found that generalized convulsive seizures impaired CO2 chemoreception, and induced hypothermia, two effects reported with serotonergic neuron dysfunction. The defects in chemoreception and thermoregulation were exacerbated by chemical depletion of serotonin and reduced with fenfluramine, suggesting that seizure-induced respiratory dysfunction may be due to impairment of serotonin neuron function. These findings suggest that impaired chemoreception because of transient inhibition of serotonergic neurons may contribute to the pathophysiology of SUDEP.

Neurosteroid pathway derangement in asphyctic infants treated with hypothermia: an untargeted metabolomic approach

BACKGROUND

The pathobiological mechanisms associated with perinatal asphyxia and hypoxic-ischemic encephalopathy are complex and poorly understood. The metabolic effects of therapeutic hypothermia have been partially explored.

METHODS

We conducted a single-center longitudinal study to investigate the metabolic effects of perinatal asphyxia and hypoxic-ischemic encephalopathy on the urinary metabolome of a group of 12 asphyctic infants over time compared to 22 matched healthy newborns, using untargeted metabolomics based on mass spectrometry.

FINDINGS

Over-representation pathway analysis identified the steroidogenesis pathway as being significantly disrupted, with reduced steroid levels in the first three days of life despite treatment with hypothermia. Comparison with matched healthy newborns showed that the urinary steroid content was lower in asphyctic infants before hypothermia. The lysine degradation and carnitine synthesis pathways were also significantly affected.

INTERPRETATION

Steroidogenesis is significantly disrupted in asphyctic infants compared to healthy newborns. Given how neurosteroids are involved in neuromodulation and neuroprotection, translational research is warranted on the potential role of neurosteroid-based intervention in asphyctic infants.

FUNDING

None.

Takotsubo Cardiomyopathy Following Complete Avalanche Burial: A Case Report

Libersa, Marie, Louis Marxer, Ken Zafren, Stephane Oggier, Lorenzo Pucci, and Mathieu Pasquier. Takotsubo cardiomyopathy following complete avalanche burial: a case report. High Alt Med Biol. 24:149-151, 2023.-Takotsubo cardiomyopathy is a transient left ventricular dyskinesia triggered by a stressful physical or emotional event. We report a case of mid-ventricular Takotsubo stress cardiomyopathy in an avalanche victim. The patient was a 41-year-old woman who was completely buried under 1.2 m of snow for 30 minutes. On arrival at the hospital, she was conscious and hypothermic (core temperature 33.7°C). Her ECG showed rapid atrial fibrillation (142 beats/min) that converted to sinus rhythm after rewarming and administration of crystalloids. Echocardiography showed akinesia of the left mid-ventricle with a left ventricular ejection fraction of 41%. At 48-hour follow-up, echocardiography showed an almost complete recovery. During her hospital stay the patient was diagnosed with an acute stress disorder with symptoms of dissociation. She was discharged home after 5 days. At 2-week follow-up echocardiography was normal. Psychological follow-up was normal at 7 months. The physical and psychological stress of the avalanche, as well as hypothermia, were all possible triggers of Takotsubo cardiomyopathy.

Impact of Intraoperative Hypothermia on Autologous Breast Reconstruction

OBJECTIVE

Studies have identified perioperative hypothermia as a risk factor for impaired wound healing, increased hospital length of stay, and surgical site infection. This study examines the effect of intraoperative hypothermia on postoperative outcomes in autologous microvascular free flap breast reconstruction.

METHODS

This was a retrospective review of 55 patients who experienced intraoperative hypothermia, defined as less than 35.0°C core body temperature and 99 normothermic patients who underwent autologous-based microvascular free flap breast reconstruction from 2013 to 2021. Demographics, comorbidities, smoking status, intraoperative warming devices, type of autologous reconstruction, hypothermia (and its duration), and length of surgery were collected. The outcomes assessed were infection rate, reoperation within 90 days, skin necrosis, wound healing complications, hematoma, seroma, and readmission within 90 days.

RESULTS

In the study population of 154 consecutive patients, 8.4% had type 1 or type 2 diabetes and 3.2% were current smokers. A total of 90.3% of patients (139) underwent deep inferior epigastric perforator flap reconstruction, 7.1% (11) superficial inferior epigastric artery flap reconstruction, and 4 (2.6%) another free flap type. A total of 35.7% of the patients (55) experienced intraoperative hypothermia defined as less than 35.0°C. In the hypothermic group, a higher proportion of patients had wound healing complications (52.7% vs 29.3%, P < 0.05), hematoma (16.4% vs 5.1%, P < 0.05), and readmission for postoperative complications (34.5% vs 14.1%, P < 0.05). There was also a trend toward higher incidence of seroma (7.3% vs 5.1%), surgical site infection (12.7% vs 9.1%), skin necrosis (12.7% vs 9.1%), and unplanned reoperation within 90 days (10.9% vs 7.1%). Further analysis via Firth logistic regression demonstrated intraoperative hypothermia predicted postoperative hematoma (odds ratio [OR], 3.68; 95% confidence interval [CI], 1.17-11.60; P < 0.05), readmission within 90 days (OR, 3.20; 95% CI, 1.45-7.08; P < 0.05), and wound healing complications (OR, 2.69; 95% CI, 1.36-5.33; P < 0.05).

CONCLUSIONS

This study demonstrates that intraoperative hypothermia is a significant risk factor for postoperative wound healing complications, hematoma, and readmission within 90 days in autologous breast reconstruction. Because of a finite amount of donor sites, it is important to find ways to minimize the risk of postoperative complications. Our results support that maintaining strict normothermia during autologous breast reconstruction can significantly improve patient outcomes and reduce morbidity.

Selected environmental factors in mothers of newborns subjected to the therapeutic hypothermia - a case control study

OBJECTIVES

Hypothermia is an established method of treating severe forms of perinatal hypoxia in newborns. Some of them develop neonatal encephalopathy, which is associated with high morbidity and mortality. Therefore, prophylaxis of this pathology is important as well as determining environmental factors in mothers of newborns affected by this pathology. The aim of the study was to assess of selected environmental factors in mothers of newborns qualified for hypothermia.

MATERIAL AND METHODS

The material consisted of 102 subjects, including 51 mothers of newborns with hypoxic-ischemic encephalopathy referred for hypothermia treatment (group I) and 51 mothers of newborns without signs of hypoxia (group II). The case-control study was carried out in the third level reference centre. It is 1 of 20 centers of therapeutic hypothermia for newborn in Poland. Data was collected based on a data collection sheet. Study groups were compared in terms of demographic and environmental data. The odds ratio (OR) was determined and the logistic regression analysis of univariate and multivariate regression was used to determine the probability of the need for hypothermia in the study group.

RESULTS

The groups did not differ in terms of age, BMI and place of living. The need to use hypothermia increased in pregnant women living together with their parents (OR = 6.8, 95% CI: 2.4-19.6) also in case of exposure to factors at the workplace, i.e., noise (OR = 4.1, 95% CI: 1.1-15.5).

CONCLUSIONS

Based on the results of our case-control study we postulate to pay attention during preconception care to proper preparation for pregnancy especially in younger women exposed to nuisance in the work environment and at home. In this area postulated activities should include education programs, in close cooperation occupational medicine practitioners and obstetricians even before the conception as a part of pre-conception counseling. Int J Occup Med Environ Health. 2023;36(1):59-68.

[Craniocerebral hypothermia in the acute period of ischemic stroke]

OBJECTIVE

To determine the effect of craniocerebral hypothermia (CCH) on neurological deficit regression, hemodynamics, fever and functional outcome of therapy in patients with moderate ischemic stroke (IS).

MATERIAL AND METHODS

This study included 60 patients with IS (the first day). The main group consisted of 30 patients who underwent CCH, and the comparison (control) group consisted of 30 patients without CCH. The National Institutes of Health Stroke Scale (NIHSS), the Glasgow Coma Scale (GCS), the modified Rankin Scale (mRs) were used. Recorded parameters were mortality, heart rate (HR), blood pressure (BP), axial temperature, cerebral temperature of the frontal cortex. Cerebral temperature was obtained noninvasively by using a RTM-01-RES radiothermometer (Russia). CCH (for 24 hours) in the main group was implemented by ATG-01 device (Russia). Results were recorded on the day of admission, after 24 hours and at discharge. In both groups, basic neuroprotective, hypotensive, antiplatelet and antiedemic therapy was administered.

RESULTS

No fatal outcomes were reported in both groups. Side-effects and complications of CCH were not recorded. In the main group, neurological deficit assessed by NIHSS decreased by 75% after the CCH procedure and by 93.75% at the time of discharge from the hospital. In patients of the comparison group, regression of neurological deficit was 35% on the second day and 55% at the day of discharge. The use of CCH suppressed systemic and cerebral hyperthermia. Functional outcome of therapy in the main group was higher compared to the comparison one. The dynamics in blood pressure and heart rate didn't differ in both groups.

CONCLUSION

A pronounced positive effect of CCH on the course of the acute period and therapy results in patients with IS was demonstrated.

Deep Versus Moderate Hypothermia in Acute Type A Aortic Dissection: A Propensity-Matched Analysis

BACKGROUND

The ideal temperature for hypothermic circulatory arrest (HCA) during acute type A aortic dissection (ATAAD) repair has yet to be determined. We examined the clinical impact of different degrees of hypothermia during dissection repair.

METHODS

Out of 240 cases of ATAAD between June 2014 and December 2019, 228 patients were divided into two groups according to lowest intraoperative temperature: moderate hypothermic circulatory arrest (MHCA) (20-28°C) versus deep hypothermic circulatory arrest (DHCA) (<20°C). From this, 74 pairs of propensity-matched patients were analysed with respect to operative data and short-term clinical outcomes. Independent predictors of a composite outcome of 30-day mortality and stroke were identified.

RESULTS

Mean lowest temperature was 25.5±3.9°C in the MHCA group versus 16.0±2.9°C in DHCA. Overall 30-day mortality of matched cohort was 11.5% (17 deaths), there were no significant different between matched groups. Cardiopulmonary bypass (CPB) times were longer in DHCA (221.0±69.9 vs 190.7±74.5 mins, p=0.01). Antegrade cerebral perfusion (ACP) during HCA predicted a lower composite risk of 30-day mortality and stroke (OR 0.38). Female sex (OR 4.71), lower extremity ischaemia at presentation (OR 3.07), and CPB >235 minutes (OR 2.47), all portended worse postoperative outcomes.

CONCLUSIONS

A surgical strategy of MHCA is at least as safe as DHCA during repair of acute type A aortic dissection. ACP during HCA is associated with reduced 30-day mortality and stroke, whereas female sex, lower extremity ischaemia, and longer CPB times are all predictive of poorer short-term outcomes.

Hypothermic circulatory arrest versus aortic clamping in thoracic and thoracoabdominal aortic aneurysm repair

BACKGROUND

To compare perioperative and midterm outcomes in thoracic and thoraco-abdominal aortic aneurysm (TAA and TAAA) repair using hypothermic circulatory arrest (HCA) or aortic clamping (AC) with mild hypothermia.

METHODS

From 2012 to 2021 there were 180 open repairs of a TAA or TAAA, of which 90 (50%) were done with HCA and 90 (50%) with aortic clamping with mild hypothermia. The indications for HCA were arch aneurysm, TAA from chronic aortic dissection, and inability to clamp the aorta for proximal anastomosis.

RESULTS

Compared to AC, the HCA group had less prior descending aorta replacement/repair (9.1% vs. 32%, p = 0.0001). Intraoperatively, the HCA group had more TAAs (70% vs. 20%, p < 0.0001) while the AC group had more TAAAs (80% vs. 30%, p < 0.0001). HCA group had longer cardiopulmonary bypass times (242 vs. 181 min, p < 0.0001) but shorter cross-clamp time (39 vs. 120 min, p < 0.0001) and lower temperatures (18°C vs. 34°C, p < 0.0001). Postoperatively, the HCA group had longer intubation times (31 vs. 26 h, p = 0.002), but all other postoperative outcomes including paralysis (2.2% vs. 8.9%, p = 0.08), and operative mortality (4.4% vs. 2.2%, p = 0.68) were similar between HCA and AC groups. Patient age was an independent risk factor for postoperative paralysis (OR 1.07, p = 0.03) while HCA was not significant (OR 0.37, p = 0.21). Five-year survival was similar between HCA and AC groups (85% vs. 80%, p = 0.36).

CONCLUSIONS

Postoperative outcomes and midterm survival were acceptable in thoracic and thoracoabdominal aneurysm patients after HCA or AC. Both HCA and AC with mild hypothermia were valid approaches in TAA/A repair.

Antiplatelet Therapy in Acute Myocardial Infarction and Cardiogenic Shock: Insights From the National Cardiogenic Shock Initiative

BACKGROUND

Patients presenting with acute myocardial infarction complicated by cardiogenic shock (AMI-CS) are at high risk for impaired antiplatelet activity secondary to malabsorption, systemic hypoperfusion, hypothermia, need for mechanical ventilation, and high use of analgesics. The use of antiplatelet therapy in these high-risk patients is not well studied.

METHODS

Using the National Cardiogenic Shock Initiative database, we analyzed patients who presented with AMI-CS at 60 hospitals from March 2018 to December 2020. All patients were treated using a standard shock protocol. Herein, the patterns of antiplatelet use are described.

RESULTS

A total of 204 patients were included in the analysis, of which 174 (85.3%) presented with ST-segment elevation myocardial infarction (STEMI). The majority (84.3%) received antiplatelet therapy before percutaneous coronary intervention (PCI); of those who received antiplatelets, 77.9% received aspirin, 55.2% received an oral P2Y12 inhibitor, and 19.2% received intravenous (IV) antiplatelet therapy. Ticagrelor was the most common P2Y12 inhibitor administered (41.9%), followed by clopidogrel (12.2%) and prasugrel (1.2%). Only 18.6% of oral antiplatelet agents were crushed. Baseline characteristics of patients who received IV vs non-IV antiplatelet agents were similar. Thrombolysis in Myocardial Infarction (TIMI) 0 flow was present in 69.6% of patients before PCI and aspiration thrombectomy was performed in 24.5% of patients. The presence of STEMI, cardiac arrest, cardiopulmonary resuscitation, hypothermia, vasopressor use, elevated lactate levels, or number of vessels treated did not influence the use of IV antiplatelet agents.

CONCLUSIONS

The use of crushed and IV antiplatelet agents in AMI-CS is low. Further studies are needed in this high-risk population to assess whether more potent antiplatelet inhibition will improve outcomes.

Extracorporeal Life Support in Accidental Hypothermia with Cardiac Arrest-A Narrative Review

Severely hypothermic patients, especially suffering cardiac arrest, require highly specialized treatment. The most common problems affecting the recognition and treatment seem to be awareness, logistics, and proper planning. In severe hypothermia, pathophysiologic changes occur in the cardiovascular system leading to dysrhythmias, decreased cardiac output, decreased central nervous system electrical activity, cold diuresis, and noncardiogenic pulmonary edema. Cardiac arrest, multiple organ dysfunction, and refractory vasoplegia are indicative of profound hypothermia. The aim of these narrative reviews is to describe the peculiar pathophysiology of patients suffering cardiac arrest from accidental hypothermia. We describe the good chances of neurologic recovery in certain circumstances, even in patients presenting with unwitnessed cardiac arrest, asystole, and the absence of bystander cardiopulmonary resuscitation. Guidance on patient selection, prognostication, and treatment, including extracorporeal life support, is given.

Cardiopulmonary resuscitation in special circumstances

Cardiopulmonary resuscitation prioritises treatment for cardiac arrests from a primary cardiac cause, which make up the majority of treated cardiac arrests. Early chest compressions and, when indicated, a defibrillation shock from a bystander give the best chance of survival with a good neurological status. Cardiac arrest can also be caused by special circumstances, such as asphyxia, trauma, pulmonary embolism, accidental hypothermia, anaphylaxis, or COVID-19, and during pregnancy or perioperatively. Cardiac arrests in these circumstances represent an increasing proportion of all treated cardiac arrests, often have a preventable cause, and require additional interventions to correct a reversible cause during resuscitation. The evidence for treating these conditions is mostly of low or very low certainty and further studies are needed. Irrespective of the cause, treatments for cardiac arrest are time sensitive and most effective when given early-every minute counts.

Delivery Room Interventions for Hypothermia in Preterm Neonates: A Systematic Review and Network Meta-analysis

Importance

Prevention of hypothermia in the delivery room is a cost-effective, high-impact intervention to reduce neonatal mortality, especially in preterm neonates. Several interventions for preventing hypothermia in the delivery room exist, of which the most beneficial is currently unknown.

Objective

To identify the delivery room thermal care intervention that can best reduce neonatal hypothermia and improve clinical outcomes for preterm neonates born at 36 weeks' gestation or less.

Data Sources

MEDLINE, the Cochrane Central Register of Controlled Trials, Embase, and CINAHL databases were searched from inception to November 5, 2020.

Study Selection

Randomized and quasi-randomized clinical trials of thermal care interventions in the delivery room for preterm neonates were included. Peer-reviewed abstracts and studies published in non-English language were also included.

Data Extraction and Synthesis

Data from the included trials were extracted in duplicate using a structured proforma. A network meta-analysis with bayesian random-effects model was used for data synthesis.

Main Outcomes and Measures

Primary outcomes were core body temperature and incidence of moderate to severe hypothermia on admission or within the first 2 hours of life. Secondary outcomes were incidence of hyperthermia, major brain injury, and mortality before discharge. The 9 thermal interventions evaluated were (1) plastic bag or plastic wrap covering the torso and limbs with the head uncovered or covered with a cloth cap; (2) plastic cap covering the head; (3) skin-to-skin contact; (4) thermal mattress; (5) plastic bag or plastic wrap with a plastic cap; (6) plastic bag or plastic wrap along with use of a thermal mattress; (7) plastic bag or plastic wrap along with heated humidified gas for resuscitation or for initiating respiratory support in the delivery room; (8) plastic bag or plastic wrap along with an incubator for transporting from the delivery room; and (9) routine care, including drying and covering the body with warm blankets, with or without a cloth cap.

Results

Of the 6154 titles and abstracts screened, 34 studies that enrolled 3688 neonates were analyzed. Compared with routine care alone, plastic bag or wrap with a thermal mattress (mean difference [MD], 0.98 °C; 95% credible interval [CrI], 0.60-1.36 °C), plastic cap (MD, 0.83 °C; 95% CrI, 0.28-1.38 °C), plastic bag or wrap with heated humidified respiratory gas (MD, 0.76 °C; 95% CrI, 0.38-1.15 °C), plastic bag or wrap with a plastic cap (MD, 0.62 °C; 95% CrI, 0.37-0.88 °C), thermal mattress (MD, 0.62 °C; 95% CrI, 0.33-0.93 °C), and plastic bag or wrap (MD, 0.56 °C; 95% CrI, 0.44-0.69 °C) were associated with greater core body temperature. Certainty of evidence was moderate for 5 interventions and low for plastic bag or wrap with a thermal mattress. When compared with routine care alone, a plastic bag or wrap with heated humidified respiratory gas was associated with less risk of major brain injury (risk ratio, 0.23; 95% CrI, 0.03-0.67; moderate certainty of evidence) and a plastic bag or wrap with a plastic cap was associated with decreased risk of mortality (risk ratio, 0.19; 95% CrI, 0.02-0.66; low certainty of evidence).

Conclusions and Relevance

Results of this study indicate that most thermal care interventions in the delivery room for preterm neonates were associated with improved core body temperature (with moderate certainty of evidence). Specifically, use of a plastic bag or wrap with a plastic cap or with heated humidified gas was associated with lower risk of major brain injury and mortality (with low to moderate certainty of evidence).

Hypothermia in Trauma

Hypothermia in trauma patients is a common condition. It is aggravated by traumatic hemorrhage, which leads to hypovolemic shock. This hypovolemic shock results in a lethal triad of hypothermia, coagulopathy, and acidosis, leading to ongoing bleeding. Additionally, hypothermia in trauma patients can deepen through environmental exposure on the scene or during transport and medical procedures such as infusions and airway management. This vicious circle has a detrimental effect on the outcome of major trauma patients. This narrative review describes the main factors to consider in the co-existing condition of trauma and hypothermia from a prehospital and emergency medical perspective. Early prehospital recognition and staging of hypothermia are crucial to triage to proper care to improve survival. Treatment of hypothermia should start in an early stage, especially the prevention of further cooling in the prehospital setting and during the primary assessment. On the one hand, active rewarming is the treatment of choice of hypothermia-induced coagulation disorder in trauma patients; on the other hand, accidental or clinically induced hypothermia might improve outcomes by protecting against the effects of hypoperfusion and hypoxic injury in selected cases such as patients suffering from traumatic brain injury (TBI) or traumatic cardiac arrest.

Thiazoline-related innate fear stimuli orchestrate hypothermia and anti-hypoxia via sensory TRPA1 activation

Thiazoline-related innate fear-eliciting compounds (tFOs) orchestrate hypothermia, hypometabolism, and anti-hypoxia, which enable survival in lethal hypoxic conditions. Here, we show that most of these effects are severely attenuated in transient receptor potential ankyrin 1 (Trpa1) knockout mice. TFO-induced hypothermia involves the Trpa1-mediated trigeminal/vagal pathways and non-Trpa1 olfactory pathway. TFOs activate Trpa1-positive sensory pathways projecting from trigeminal and vagal ganglia to the spinal trigeminal nucleus (Sp5) and nucleus of the solitary tract (NTS), and their artificial activation induces hypothermia. TFO presentation activates the NTS-Parabrachial nucleus pathway to induce hypothermia and hypometabolism; this activation was suppressed in Trpa1 knockout mice. TRPA1 activation is insufficient to trigger tFO-mediated anti-hypoxic effects; Sp5/NTS activation is also necessary. Accordingly, we find a novel molecule that enables mice to survive in a lethal hypoxic condition ten times longer than known tFOs. Combinations of appropriate tFOs and TRPA1 command intrinsic physiological responses relevant to survival fate.

Unrecognized platelet physiology is the cause of rewarming deaths in accidental hypothermia and neonatal cold injury

BACKGROUND

The lack of improvement in prognosis of accidental hypothermia and neonatal cold injury suggests that a major cause of mortality has not been appreciated.

AIM OF THE ARTICLE

To show that thrombocytopenia that deepens on rewarming under certain conditions is that missing factor.

SCIENTIFIC BASIS

Below 34 °C the first stage of aggregation is accentuated, the platelets are more sensitive to ADP and aggregation studies show an increased response "first stage hyper aggregation". We have confirmed that the irreversible second stage of platelet aggregation does not occur below 34 °C. On rewarming, the first stage of aggregation is followed by disaggregation. When platelets are warmed to 34 °C the potential exists for the platelets to undergo an irreversible second stage of aggregation "second stage platelet hyper aggregation" that can cause a further drop in platelet count and a bleeding diathesis. This only occurs if the platelets have been sufficiently primed when cold and may not be appreciated if platelet counts are not followed.

SIGNIFICANCE OF THIS DATA AND CORRELATION WITH THE LITERATURE

This thesis explains many other open questions. Why has the overall prognosis remained without improvement over the last half century? Why hypothermic cardiac surgery is free of this problem? Why the depth of hypothermia is alone not prognostic? Has following platelet counts been associated with improved prognosis? Why cardiac arrest does not affect prognosis? Why some patients die suddenly after recovering from hypothermia? Why are so many different rewarming techniques used? Why is the prognosis better in hypothermic suicide attempts? What is the pathophysiological explanation for reversible sequestration of platelets to the liver and spleen in hypothermia? Is DIC (diffuse intravascular coagulation) a problem in hypothermia? And how this new approach could improve prognosis?

CONCLUSION

Prognosis can be improved by following platelet counts during rewarming. In patients with prolonged hypothermia, this will show a life-threatening drop in such counts easily treated by platelet infusion.

Temperature management in acute brain injury: A systematic review of clinical evidence

Temperature alterations in neurocritical care settings are common and have a striking effect on brain metabolism leading to or exacerbating neuronal injury. Hyperthermia worsens acute brain injury (ABI) patients outcome. However conclusive evidence linking control of temperature to improved outcome is still lacking. This review article report an update -results from clinical studies published between March 2006 and March 2020- on the relationship between hyperthermia or Target Temperature Management and functional outcome or mortality in ABI patients.

MATERIALS AND METHODS

A systematic search of articles in PubMed and EMBASE database was accomplished. Only complete studies, published in English in peer-reviewed journals were included.

RESULTS

A total of 63 articles into 5 subchapters are presented: acute ischemic stroke (17), subarachnoid hemorrhage (14), brain trauma (14), intracranial hemorrhage (8), and mixed acute brain injury (10). This evidence confirm and extend the negative impact of hyperthermia in ABI patients on worse functional outcome and higher mortality. In particular "early hyperthermia" in AIS patients seems to have a protective role have as promoting factor of clot lysis but no conclusive evidence is available. Normothermic TTM seems to have a positive effect on TBI patients in a reduced mortality rate compared to hypothermic TTM.

CONCLUSIONS

Hyperthermia in ABI patients is associated with worse functional outcome and higher mortality. The use of normothermic TTM has an established indication only in TBI; further studies are needed to define the role and the indications of normothermic TTM in ABI patients.

Inadvertent Perioperative Hypothermia Risks and Postoperative Complications: A Retrospective Study

Inadvertent perioperative hypothermia is a widely known patient condition that is associated with postoperative complications. This retrospective comparative study of 298 surgical patients was conducted at a single hospital site in the midwestern United States. Our aims were to describe risk factors and outcomes associated with perioperative hypothermia. We compared the type and frequency of patient factors, clinical factors, and postoperative complications during the inpatient stay of the sample patients to determine whether there were factors or complications associated with perioperative hypothermia. Significant factors associated with the occurrence of perioperative hypothermia included older age and type of surgery. Hypothermia in patients was associated with a higher rate of postoperative complications when compared with normothermic patients. Nurses and perioperative leaders should understand the risk factors and complications associated with perioperative hypothermia to collaboratively develop and test evidence-based initiatives, improve care, and promote optimal patient outcomes.

Cardiac Arrest Secondary to Accidental Hypothermia: Who Should We Resuscitate?

Cardiac arrest with a degree of concurrent hypothermia is not a rare presentation. This presentation, often in remote areas, poses a challenge for the prehospital physician because the cause of the arrest will significantly alter decision making and prognostication. Survival from cardiac arrest secondary to accidental hypothermia is significantly greater than that of normothermic arrests when appropriate triage and management decisions are made. The complexity of this decision benefits from a specific algorithm to follow in the event of such a casualty presenting. This article systematically reviews the literature on cardiac arrest secondary to accidental hypothermia and provides recommendations in addition to a novel algorithm to aid the responding prehospital clinician in deciding if a hypothermic resuscitation standard operating procedure should be implemented.

Cardiac Arrest Secondary to Accidental Hypothermia: The Physiology Leading to Hypothermic Arrest

Cardiac arrest secondary to accidental hypothermia is rare in the United Kingdom. However, some evidence suggests that it is under-reported; furthermore, recognizing hypothermia as the cause of death is difficult in the postmortem setting. Urban and rural residents are exposed to cold winter conditions both at home and while undertaking recreational activities. Understanding the physiology underpinning hypothermic cardiac arrest is crucial in order to make informed clinical decisions in regard to triage and management by air ambulance services and in prevention of this rare presentation. This article discusses the epidemiology and pathophysiology of accidental hypothermic to explain how personnel can survive after 8 hours 40 minutes of cardiac arrest.

Admission Body Temperature in Critically Ill Patients as an Independent Risk Predictor for Overall Outcome

INTRODUCTION

Body temperature (BT) abnormalities are frequently observed in critically ill patients. We aimed to assess admission BT in a heterogeneous critically ill patient population admitted to an intensive care unit (ICU) as a prognostic parameter for intra-ICU and long-term mortality.

METHODS

A total of 6,514 medical patients (64 ± 15 years) admitted to a German ICU between 2004 and 2009 were included. A follow-up of patients was performed retrospectively. The association of admission BT with both intra-ICU and long-term mortality was investigated by logistic regression.

RESULTS

Patients with hypothermia (<36°C BT) were clinically worse and had more pronounced signs of multi-organ failure. Admission BT was associated with adverse overall outcome, with a 2-fold increase for hyperthermia (mortality 12%; odds ratio [OR] 1.80, 95% confidence interval [CI] 1.43-2.26; p < 0.001), and a 4-fold increase for the risk of hypothermia (mortality 24%; OR 4.05, 95% CI 3.38-4.85; p < 0.001) with respect to intra-ICU and long-term mortality. Moreover, hypothermia was even more harmful than hyperthermia, and both were strongly associated with intra-ICU mortality, especially in patients admitted with acute coronary syndrome (hypothermia: hazard ratio 6.12, 95% CI 4.12-9.11; p < 0.001; hyperthermia: OR 2.70, 95% CI 1.52-4.79; p< 0.001).

CONCLUSION

Admission BT is an independent risk predictor for both overall intra-ICU and long-term mortality in critically ill patients admitted to an ICU. Therefore, BT at admission might not only serve as a parameter for individual risk stratification but can also influence individual therapeutic decision-making.

The 6-hydroxychromanol derivative SUL-109 ameliorates renal injury after deep hypothermia and rewarming in rats

Background

Mitochondrial dysfunction plays an important role in kidney damage in various pathologies, including acute and chronic kidney injury and diabetic nephropathy. In addition to the well-studied ischaemia/reperfusion (I/R) injury, hypothermia/rewarming (H/R) also inflicts acute kidney injury. Substituted 6-hydroxychromanols are a novel class of mitochondrial medicines that ameliorate mitochondrial oxidative stress and protect the mitochondrial network. To identify a novel 6-hydroxychromanol that protects mitochondrial structure and function in the kidney during H/R, we screened multiple compounds in vitro and subsequently assessed the efficacy of the 6-hydroxychromanol derivatives SUL-109 and SUL-121 in vivo to protect against kidney injury after H/R in rats.

Methods

Human proximal tubule cell viability was assessed following exposure to H/R for 48/4 h in the presence of various 6-hydroxychromanols. Selected compounds (SUL-109, SUL-121) or vehicle were administered to ketamine-anaesthetized male Wistar rats (IV 135 µg/kg/h) undergoing H/R at 15°C for 3 h followed by rewarming and normothermia for 1 h. Metabolic parameters and body temperature were measured throughout. In addition, renal function, renal injury, histopathology and mitochondrial fitness were assessed.

Results

H/R injury in vitro lowered cell viability by 94 ± 1%, which was counteracted dose-dependently by multiple 6-hydroxychomanols derivatives. In vivo, H/R in rats showed kidney injury molecule 1 expression in the kidney and tubular dilation, accompanied by double-strand DNA breaks and protein nitrosylation. SUL-109 and SUL-121 ameliorated tubular kidney damage, preserved mitochondrial mass and maintained cortical adenosine 5'-triphosphate (ATP) levels, although SUL-121 did not reduce protein nitrosylation.

Conclusions

The substituted 6-hydroxychromanols SUL-109 and SUL-121 ameliorate kidney injury during in vivo H/R by preserving mitochondrial mass, function and ATP levels. In addition, both 6-hydroxychromanols limit DNA damage, but only SUL-109 also prevented protein nitrosylation in tubular cells. Therefore SUL-109 offers a promising therapeutic strategy to preserve kidney mitochondrial function.

Accidental Hypothermia Treated by Hemodialysis in the Acute Phase: Three Case Reports and a Review of the Literature

Accidental hypothermia is defined as a core body temperature <35°C. Even with the use of multiple active rewarming methods, it has a high mortality rate. No standard treatment strategy for moderate or severe hypothermia in the absence of cardiac arrest has yet been established. We herein report three patients with severe or moderate accidental hypothermia who were treated by hemodialysis in the acute phase. This case report with a literature review describes the usefulness of hemodialysis for the treatment of moderate and severe accidental hypothermia without cardiac arrest.

The Impact of Intraoperative Fluid Therapy and Body Temperature on Surgical Site Infection - Re-Assessment of a Randomized Trial

Background: Use of supplemental oxygen during surgery to reduce the incidence of SSI was investigated in the PROXI trial, which found no reduced frequency of SSI. Subsequently, it has been suggested that a restrictive fluid regimen and hypothermia in some patients could explain why no beneficial effect of supplemental oxygen was found. We evaluated the association between the occurrence of SSI and two perioperative factors, volume of infused fluid and body temperature (BT). Methods: We used data from the PROXI trial including 1,386 patients undergoing laparotomy randomly assigned to receive 80% or 30% oxygen during surgery. A fluid infusion index (FII) was calculated for each patient as the volume of infused fluids/body weight/duration of surgery. Results: SSI occurred in 18.9% of the patients in the lower FII tertile group (OR=0.86; P=0.41), in 20.4% in the upper FII tertile group (OR=1.49; P=0.05), in 19.7% of the patients with hypothermia (OR=1.28; P=0.25) and in 25.0% with hyperthermia (OR=1.26; P=0.52). An increased risk of SSI (OR=3.15; P=0.01) was found in patients having both hypothermia and emergency surgery.

CONCLUSION

A trend towards an increased risk of SSI was seen in patients who received a greater volume of intravenous fluid. No association was found between BT and SSI.