Therapeutic Hypothermia and Temperature Management

Fever Prevention and Neurological Recovery in In-Hospital Cardiac Arrest Survivors at a Limited-Resource Setting
Bakhsh A, Bakhashwain W, Alhazmi M, Bahwireth S, Binmahfooz S, Alghamdi R, Bakhribah A and Alsufyani H
Temperature management plays a critical role in the neurological recovery of cardiac arrest survivors. While advanced device-based temperature control systems are prevalent in high-resource settings, their implementation in low-resource environments remains a challenge. This study aimed to examine the impact of fever prevention on neurological outcomes in cardiac arrest survivors managed without device-based temperature control. We conducted a retrospective study of adult in-hospital cardiac arrest survivors at an academic institution from 2013 to 2020. Patients were included if they were ≥18 years old, survived for at least 72 hours post-return of spontaneous circulation (ROSC), and experienced cardiac arrest in inpatient wards, intensive care units, or the emergency department. Fever was defined as a rectal temperature ≥37.5°C, and neurological outcomes were assessed using the Cerebral Performance Category (CPC) scale at 1 month post-ROSC. A good neurological outcome was defined as CPC 1 or 2. Statistical analyses included chi-square tests and logistic regression to identify predictors of outcomes. Of the 427 patients included, 58.8% experienced fever, and 12.8% achieved a good neurological outcome. Patients with fever were significantly less likely to have favorable outcomes ( < 0.01). Logistic regression revealed that each 1°C increase in body temperature beyond 37.5°C was associated with a 31% reduction in the likelihood of a good outcome ( < 0.01). Other predictors of poor outcomes included prolonged low-flow states and higher pre-arrest frailty scores. Fever is strongly associated with poor neurological outcomes in cardiac arrest survivors, particularly in low-resource settings without device-based temperature management. Effective fever prevention strategies, such as intravenous antipyretics and physical cooling methods, should be prioritized to improve outcomes.
Predictive Model for Histological Chorioamnionitis Risk in Parturients with Intrapartum Fever
Shao X, Lv B, Xiu Y, Wang L, Zhang J and Pan M
This study aimed to analyze the causative factors of histological chorioamnionitis (HCA) in parturients with intrapartum fever, assess the implications for maternal and neonatal outcomes, and develop a predictive model to enhance clinical decision-making. A retrospective analysis was performed on 408 parturients with intrapartum fever at Fujian Provincial Maternal and Child Health Hospital from January 2022 to June 2023. Based on post-delivery placental pathology, the data were categorized into HCA (249 cases) and non-HCA groups (159 cases). Variables were first screened using univariate analysis, followed by multivariate logistic regression to identify high-risk factors and develop a predictive model. The model's accuracy was validated using Bootstrap resampling and receiver operating characteristic (ROC) curve analysis. Significant differences were found between the HCA and non-HCA groups in terms of duration of premature rupture of membranes (≥24 hours), peak body temperature during labor (≥38°C), and levels of white blood cell count and C-reactive protein (CRP) at the onset of fever ( < 0.05). The predictive model showed strong accuracy, with an ROC area under the curve of 0.715. Intrapartum fever linked with HCA markedly exacerbates maternal and neonatal outcomes. Key risk factors for HCA include a peak labor temperature ≥38°C, CRP levels at fever onset, and grade III contamination of amniotic fluid. The developed model accurately predicts the HCA risk, enabling enhanced clinical interventions.
Impact and Contributing Factors of Maternal Pyrexia Peaks During Labor on Maternal and Neonatal Outcomes
Shao XF, Lin P, Xiu YL, Ren KH and Lv BQ
This study aims to equip clinicians with the necessary insights for identifying and managing pregnant women experiencing elevated maternal pyrexia during labor. It examines maternal and neonatal outcomes along with the factors associated with varying peak temperatures. A retrospective analysis was conducted on 319 pregnant women presenting with maternal pyrexia during labor. Participants were categorized into two groups based on peak temperature: Group A ( = 180, temperature <38°C) and Group B ( = 139, temperature ≥38°C). Basic characteristics, blood markers, and maternal and neonatal outcomes were compared between the two groups. (1) Group B exhibited a higher percentage of neutrophilic granulocytes (NE%) and C-reactive protein to lymphocyte ratio (CLR) compared with Group A ( < 0.05). (2) The rates of meconium-stained amniotic fluid, histological chorioamnionitis, hospitalization of neonates, and infections in neonates were greater in Group B than in Group A ( < 0.05). (3) Logistic regression analysis identified elevated CLR levels as a risk factor for peak temperatures exceeding 38°C, indicating that CLR could serve as a reliable predictor of maternal pyrexia above 38°C during labor. Higher maternal pyrexia peaks may exacerbate adverse maternal and neonatal outcomes, emphasizing the importance of timely clinical intervention. NE% and CLR could serve as valuable indicators for identifying underlying causes and predicting peak maternal pyrexia during labor.
Mild Hypothermia Therapy Reduces the Incidence of Early Cerebral Herniation and Decompressive Craniectomy after Mechanical Thrombectomy for Acute Ischemic Stroke with Large Infarction
Tan G, Wang J, Duan J, Li L, Pan F, He C and Xing W
The application value of mechanical thrombectomy (MT) in acute large-vessel occlusion cerebral infarction has been confirmed, but considering the poor prognosis of large-core infarction (LCI), the current guidelines and practices are based on anterior circulation small-core infarction. Reducing the perioperative complications of thrombectomy in LCIs is the key to saving more patients previously considered unsuitable for thrombectomy. Patients with acute anterior circulation cerebral infarction who were admitted to Suining Central Hospital of Sichuan Province from January 2022 to December 2023 and whose Alberta Stroke Program Early Computed Tomography Score value was 3-5 (the score range was 0-10, and the lower the score was, the larger the infarct area) or whose infarct core volume was ≥70 mL and who received MT were enrolled consecutively. The patients were grouped based on whether they were treated with mild hypothermia (mild hypothermia treatment group vs. conventional treatment group). Patients who were evaluated preoperatively for large-core cerebral infarction and underwent mild hypothermia treatment were performed immediately after MT. The clinical data of the patients were collected. The primary outcome events were the incidence of cerebral hernia within one week after the operation and the rate of requiring decompressive craniectomy (%). The secondary outcome was the modified Rankin scale (mRS) score at 90 days (the score range was 0-6, and the higher the score was, the greater the degree of functional disability). A total of 64 patients were included. Twenty-nine patients were assigned to the mild hypothermia treatment group, and 35 patients were assigned to the conventional treatment group. There was no significant difference in the baseline data between the two groups. The proportions of cerebral hernia and the need for decompressive craniectomy within one week after the operation were significantly lower in the mild hypothermia treatment group than in the conventional treatment group (31% vs. 57.1%, odds ratio [OR] 0.338, 95% confidence interval [CI] 0.120-0.948; = 0.037). The proportion of patients who underwent decompressive craniectomy in the mild hypothermia treatment group was significantly lower (13.8% vs. 42.8%, OR 0.213, 95% CI 0.061-0.745, = 0.011). There was no significant difference in the mRS score between the two groups at 90 days (4.31 ± 1.75 vs. 4.48 ± 1.57, = 0.456) or in the proportion of patients with a good prognosis (mRS 0-3) between the two groups (OR 0.569, 95% CI 0.18-1.793, = 0.333). Mild hypothermia treatment can reduce the incidence of early cerebral hernia and the need for decompressive craniectomy in patients with acute large-core cerebral infarction after MT; this treatment can be used as an important adjuvant treatment after thrombectomy for LCI, but may not change the long-term prognosis.
A Systematic Review and Meta-Analysis of Therapeutic Hypothermia and Pharmacological Cotherapies in Animal Models of Ischemic Stroke
Suerte ACC, Liddle LJ, Abrahart A, Khiabani E and Colbourne F
Therapeutic hypothermia (TH) lessens ischemic brain injury. Cytoprotective agents can augment protection, although it is unclear which combinations are most effective. The objective of this study is to identify which cytoprotective drug works best with delayed TH. Following PRISMA guidelines, a systematic review (PubMed, Web of Science, MEDLINE, Scopus) identified controlled experiments that used an focal ischemic stroke model and evaluated the efficacy of TH (delay of ≥1 hour) coupled with cytoprotective agents. This combination was our main intervention compared with single treatments with TH, drug, or no treatment. Endpoints were brain injury and neurological impairment. The CAMARADES checklist for study quality and the SYRCLE's risk of bias tool gauged study quality. Twenty-five studies were included. Most used young, healthy male rats, with only one using spontaneously hypertensive rats. Two studies used mice models, and six used adult animals. Study quality was moderate (median score = 6), and risk of bias was high. Pharmacological agents provided an additive effect on TH for all outcomes measured. Magnesium coupled with TH had the greatest impact compared with other agent-TH combinations on all outcomes. Longer TH durations improved both behavioral and histological outcomes and had greater cytoprotective efficacy than shorter durations. Anti-inflammatories were the most effective in reducing infarction (standardized mean difference [SMD]: -1.64, confidence interval [CI]: [-2.13, -1.15]), sulfonylureas reduced edema the most (SMD: -2.32, CI: [-3.09, -1.54]), and antiapoptotic agents improved behavioral outcomes the most (normalized mean difference: 52.38, CI: [45.29, 59.46]). Statistically significant heterogeneity was observed ( = 82 - 98%, all < 0.001), indicating that studies wildly differ in their effect size estimates. Our results support the superiority of adding cytoprotective therapies with TH (vs. individual or no therapy). Additional exploratory and confirmatory studies are required to identify and thoroughly assess combination therapies owing to limited work and inconsistent translational quality.
The Warming Management Measures May Need to Be Further Enhanced During Scoliosis Correction and Internal Fixation Surgery: A Retrospective Cohort Study
Zhou H, Li L, Li Q, Guo X, Xu N, Zheng Q and Fu Q
The incidence of intraoperative hypothermia (IPH) exceeds 70% during spinal surgery, which can lead to many adverse outcomes, including increased intraoperative blood loss/transfusion and delayed recovery. We aimed to evaluate the comprehensive efficiency of a kind of enhanced warming measure on patients undergoing spinal surgery. A retrospective analysis was conducted on the clinical data, surgical procedures, and outcomes of consecutive patients admitted to the department of orthopedics of a hospital from December 2019 to May 2023 and undergoing spinal surgery (scoliosis correction and internal fixation surgery). The impact of the perioperative warming measures on surgical temperature variation and postoperative recovery was analyzed. The surgical patients who received normal active warming measures (quilt, blood transfusion and infusion warming, flushing fluid warming) were the control group (Normal Warming Group [NWG], = 199), and the enhanced active warming measures (NWG and forced air warming) were the experimental group (Enhanced Warming Group [EWG], = 201). Incidence of IPH was the primary endpoint of this study. EWG exhibited a significantly reduced incidence of IPH and average frequency of hypothermia per patient compared with NWG (respectively, < 0.01) and demonstrated notable reductions in intraoperative blood loss, urine output, anesthesia recovery time, and duration of arousal (respectively, < 0.05, < 0.01, and < 0.001). Postoperatively, EWG showed a significantly reduced incidence of shivering ( < 0.001) and had lower costs for postoperative antibiotic use and albumin administration (respectively, < 0.05 and < 0.01). So we infer that the occurrence of hypothermia during spinal surgery may seem unavoidable, but EWG can effectively lower the occurrence of IPH and its adverse outcomes, and then somewhat alleviate the postoperative treatment burden. However, given that this study is a retrospective cohort study, it is not yet possible to definitively prove the above conclusions, so we will design relevant prospective clinical studies to prove that the optimization of temperature management may be crucial to ensure optimal overall recovery outcomes.
Use of the Delphi Method in the Construction of the Temperature Chain Management Scheme for Da Vinci Robot-Assisted Urological Surgical Patients
Chen F, Li H, Liang X and Liu T
The study aimed to construct a temperature chain management scheme in patients undergoing Da Vinci Robot-assisted surgery in urological surgical patients by the Delphi method, providing a reference for the prevention and treatment of the inadvertent perioperative hypothermia. First, instructing by the Joanna Briggs Institute (JBI) Evidence-Based Healthcare model and systematically reviewing literature related to the prevention and treatment of perioperative hypothermia in Da Vinci robot-assisted surgery patients in the urological surgical patients from guideline-related websites and professional association websites. Second, carrying out the qualitative interviews, which were conducted with medical staff in the urology department and the Da Vinci robot-assisted surgery team in a teaching hospital. Third, a temperature chain management scheme draft was obtained by a panel meeting. Finally, using the Delphi method to evaluate the draft, demonstrating its scientificity and feasibility, and obtaining the final scheme. The temperature chain management scheme constructed by a Delphi method, embraced seven links from preoperative ward, preoperative transfer, anesthesia waiting room, operating room, postanesthesia recovery room, postoperative transfer, and postoperative ward. The enthusiasm degree of both rounds of expert consultation was 100%, with expert authority levels of 0.875 and 0.888, respectively, indicating good representativeness and authority. Kendall's coefficient in two rounds was 0.220 and 0.400, respectively, indicating a trend toward consensus among experts, which indicated the scheme had a high degree of credibility and feasibility. The temperature chain management scheme for Da Vinci robot-assisted surgery patients in the urology department, constructed by the Delphi method, is both scientific and feasible.
Acute Kidney Injury after Hypoxic Ischemic Encephalopathy in Neonates Treated with Passive Versus Active Total Body Cooling
Bamaga AK, Alwassia HK, Al-Khotani AA, Al-Bal'awi Y, Kobeisy S, Alsubaie MA and Alyazidi AS
Hypoxic-ischemic encephalopathy (HIE) affects 1-2 per 1000 term live births, often resulting in severe long-term disabilities. Therapeutic hypothermia (TH) is the standard care in developed countries, but high costs of modern cooling devices necessitate low-cost alternatives. This study compares passive cooling with active machine cooling regarding short-term renal outcomes, specifically acute kidney injury (AKI), in neonates with HIE. This retrospective study was conducted at Dr. Soliman Fakeeh Hospital's neonatal intensive care unit from 2019 to 2023. The study analyzed patient demographics, clinical outcomes, and laboratory data (sodium, potassium, urea, and creatinine) to assess AKI. Treatment involved whole-body cooling at 33.5-34.5°C for 72 hours, followed by gradual rewarming. A total of 39 neonates were included in the study. Both cooling methods showed similar short-term renal outcomes, with no statistically significant differences in creatinine levels between the groups at baseline, 24 hours, 72 hours, or discharge. A trend of higher creatinine levels in the passive cooling group was observed, but it did not reach statistical significance. The median length of hospital stay was longer in the passive cooling group, though this difference was marginally nonsignificant. Long-term follow-up revealed no significant differences in chronic kidney disease incidence or neurodevelopmental outcomes between the groups. This study found no significant differences in both short-term renal outcomes and long-term effects between passive and active cooling methods in neonates with HIE. However, the trend of higher creatinine levels in the passive cooling group suggests the need for further investigation with larger sample sizes and extended follow-up to clarify the long-term effects of cooling methods on renal and neurodevelopmental outcomes in neonates with HIE.
Intraoperative Hypothermia Versus Normothermia in Breast Reconstruction: A Systematic Review and Meta-Analysis
Putra TN, Sayudo IF, Sudarman JP, Krish K, Vellaichamy S, Nadila I and Filho MO
Despite advancements in breast reconstruction, the precise impact of intraoperative hypothermia on postoperative complications remains unclear. Recent literature suggests that intraoperative hypothermia is a risk factor for impaired wound healing and increases the incidence of surgical site infections. This study examines the effect of intraoperative hypothermia on postoperative outcomes in breast reconstruction. We searched PubMed, Embase, and Cochrane Library for studies comparing hypothermia with normothermia in breast reconstruction. A meta-analytical method was employed to estimate the risk of postoperative complications among patients undergoing breast reconstruction. Data synthesis employed the random-effects models, presenting the results as risk ratio (RR) with corresponding 95% confidence intervals (CIs). Statistical analysis was performed using Review Manager 5.4 (Cochrane Collaboration), and heterogeneity was assessed using I statistics. Four studies meeting our inclusion criteria were included in the meta-analysis, comprising 871 participants. The average age and body mass index were 52.98 years and 27.76 kg/m, with a follow-up duration of 3-6 months. In our analysis, intraoperative hypothermia was associated with an increase in the incidence of wound healing complications in breast reconstruction (RR 1.68; 95% CI 1.24 to 2.27; = 0.0008). Despite lower incidence of infection, hematoma, seroma, and necrosis in the hypothermia group, no significant differences were observed. Our meta-analysis assessing intraoperative hypothermia in breast reconstruction indicates that hypothermia is a significant risk factor for wound healing complications.
Hypothermia and Influence of Rewarming Rates on Survival Among Patients Admitted to Intensive Care with Bloodstream Infection: A Multicenter Cohort Study
White KC, Quick L, Ramanan M, Tabah A, Shekar K, Senthuran S, Edwards F, Attokaran AG, Kumar A, Meyer J, McCullough J, Blank S, Smart C, Garrett P and Laupland KB
Although critically ill patients with bloodstream infections (BSIs) who present with hypothermia are at the highest risk for death, it is not known how rewarming rates may influence the outcomes. The objective of this study was to identify the occurrence and determinants of hypothermia among patients admitted to intensive care units (ICUs) with BSI and assess how the rate of temperature correction may influence 90-day all-cause case-fatality. A cohort of 3951 ICU admissions associated with BSI was assembled. The lowest temperature measured within the first 24 hours of admission was identified, and among those who were hypothermic (<36°C), the rewarming rate [(time difference between lowest and subsequent first temperature ≥36°C) divided by hypothermia severity (difference between lowest measured and 36°C)] was determined. Within the first 24 hours of admission to the ICU, 329 (8.4%) and 897 (22.7%) subjects had the lowest temperature measurements ranging <34.9°C and 35-35.9°C, respectively. Patients with lower temperatures were more likely to be admitted to tertiary care ICUs, have more comorbid illnesses, have greater severity of illness, and have a higher need for organ-supportive therapies. The 90-day all-cause case-fatality rate was 22.9% overall and was 45.3%, 24.8%, and 19.6% for those with the lowest 24 hours temperatures of <35°C, 35-35.9°C, and ≥36°C, respectively ( < 0.001). Among 1133 hypothermic patients with documented temperatures corrected to the normal range while admitted to the ICU, the median rate of temperature increase was 0.24 (interquartile range, 0.13-0.45)C/hour. After controlling for the severity of illness and comorbidity, a faster rewarming rate was associated with significantly lower 90-day case-fatality. Hypothermia is a significant risk factor associated with death among critically ill patients with BSI that faster rates of rewarming may modify.
Evaluation of the Effect of Surgical Drapes on Intraoperative Hypothermia: A Randomized Clinical Trial
Ilkaz N and Iyigun E
Many patients experience unintended hypothermia in intraoperative processes. This randomized clinical trial aims to investigate the impact of surgical drapes on hypothermia during the intraoperative period. A randomized clinical trial was conducted from April 2019 to November 2020 in the Department of Anesthesiology and Reanimation/Operating Rooms at an education and research hospital. Out of 205 patients assessed for eligibility, 74 underwent elective abdominal surgery and were randomized into two groups: nonwoven surgical drapes and woven surgical drapes. The study had two stages: preoperative and intraoperative. Preoperative data were collected using information and evaluation forms, while intraoperative assessment involved forms for wetness and weight. Tympanic and esophageal temperatures were recorded every 15 minutes, and surgical drapes were weighed with a precision scale before and after surgery. There was no significant difference between the two groups in terms of body mass index, irrigation amount, surgery duration, gender, and preoperative shivering ( > 0.05). A statistically significant difference was found in preoperative body temperature (36°C), type of surgery, and intraoperative hypothermia ( < 0.05). Both types of surgical drapes were wet, but this difference was not statistically significant between the nonwoven group (mean ± SD [1368 ± 607]) and the woven group (mean ± SD [1335 ± 636], = 0.824). This study demonstrated that neither woven nor nonwoven surgical drapes, nor the wetness of the surgical drapes, had a significant effect on intraoperative hypothermia. However, there is a need for randomized controlled trials involving uniform types of surgery related to the topic.
Progress of Brain Hypothermia Treatment for Severe Subarachnoid Hemorrhage-177 Cases Experienced and a Narrative Review
Kobata H
The benefits of hypothermia for the treatment of subarachnoid hemorrhage (SAH) remain controversial. In 1999, we initiated brain hypothermia treatment (BHT) in the hyperacute phase to mitigate the evolution of early brain injury in patients with World Federation of Neurological Surgeons (WFNS) grade V SAH. In June 2014, we introduced endovascular cooling to maintain normothermia for seven days following the initial BHT period. Immediately after the decision to treat the sources of bleeding, cooling was initiated, with a target temperature of 33-34°C. Bleeding sources were extirpated primarily by clipping with decompressive craniectomy. Patients were rewarmed at a rate of ≤1°C/day after ≥48 hours of surface cooling. After being rewarmed to 36°C, temperatures were controlled with antipyretic (chronologically divided into groups A-C with 47, 46, and 46 patients, respectively) or endovascular (group D, 38 patients) cooling. Overall, 177 patients (median age, 62 [52-68] years; 94 [53.1%] women; onset-to-arrival time, 36 minutes [28-50]) were included. The median Glasgow Coma Scale (GCS) score upon admission was 4 (3-6). Median core body temperature was 36 (35.3-36.6)°C on arrival, 34.6 (34.0-35.3)°C on entering the operating room, 33.8 (33.4-34.3)°C upon starting the microsurgical or interventional radiology procedure, and 33.7 (33.3-34.2)°C upon admission to the intensive care unit. There were no significant differences in age, sex, GCS score, pupillary findings, location of bleeding sources, or treatment methods. There were 69 (39.0%) overall favorable outcomes (modified Rankin Scale score of 0-3) at 6 months and 11 (23.4%), 18 (39.1%), 17 (37.0%), and 23 (60.5%) in groups A-D, respectively ( = 0.0065). The outcomes of patients with WFNS grade V SAH improved over time. Herein, we report our experience using BHT for severe SAH through a narrative review.
Association Between the Rewarming Duration and Neurological Outcomes after Extracorporeal Cardiopulmonary Resuscitation Followed by Targeted Temperature Management for Out-of-Hospital Cardiac Arrests: A Secondary Analysis of the SAVE-J II Study
Miyamoto S, Hifumi T, Komori A, Iriyama H, Abe T, Inoue A, Sakamoto T, Kuroda Y, Otani N and
There are no studies examining the association between rewarming durations and neurological outcomes after extracorporeal cardiopulmonary resuscitation (ECPR) followed by targeted temperature management (TTM) for patients with out-of-hospital cardiac arrest (OHCA). This study aimed to examine the association between rewarming durations and neurological outcomes after ECPR with TTM for patients with OHCA. This was a secondary analysis of the Advanced Life Support Study Registry for Ventricular Fibrillation with Extracorporeal Circulation in Japan study, a retrospective, multicenter study. Patients with OHCA who underwent ECPR and completed a TTM of 34°C and <34°C were included. Favorable neurological outcomes (cerebral performance categories 1-2) and survival upon hospital discharge were the primary outcomes. In total, 407 patients were included, with favorable neurological outcomes upon hospital discharge in 106 patients. The numbers of patients with rewarming durations of <24 hours, 24 hours, and >24 hours were 178, 133, and 96, respectively. In the multivariable analysis, a rewarming duration of <24 hours was not significantly associated with favorable neurological outcomes [odds ratio (OR): 1.06, 95% confidence interval (CI): 0.60-1.87, = 0.84] or survival (OR: 0.96, 95% CI: 0.58-1.57, = 0.86) compared with that of 24 hours, and that of <24 hours was not significantly associated with favorable neurological outcomes (OR: 0.74, 95% CI: 0.40-1.71, = 0.56) or survival (OR: 0.74, 95% CI: 0.42-1.28, = 0.38) than that of >24 hours. A rewarming duration of <24 hours in TTM after ECPR for OHCA was not significantly associated with favorable neurological outcomes or survival than that of 24 hours or >24 hours.
Impact of Time to Initiation of Targeted Temperature Management Among Patients with Out-of-Hospital Cardiac Arrest Undergoing Percutaneous Coronary Intervention
Kovach CP, Leonard J, Messenger JC, Waldo SW and Perman SM
Delays in initiation of targeted temperature management (TTM) have been observed in randomized trials evaluating immediate or delayed coronary angiography among survivors of ventricular tachycardia (VT) or ventricular fibrillation (VF) out-of-hospital cardiac arrest (OHCA), but whether delays are associated with adverse clinical outcomes is unknown. Resuscitated survivors of VT/VF OHCA who received TTM between April 2011 and June 2015 were identified and time to TTM initiation was described. The association between TTM initiation <2 versus ≥2 hours, neurologically favorable, and overall survival to hospital discharge was assessed. In a propensity-weighted analysis of 2954 patients, a significantly larger proportion of patients undergoing percutaneous coronary intervention (PCI) had TTM initiation ≥2 hours (48.6%) as compared to patients undergoing angiography (41.4%) or those who did not undergo a procedure (33.0%; < 0.001 for all comparisons). In this cohort, the odds of neurologically favorable survival (odds ratios [OR]: 0.88, 95% confidence intervals [CI] = 0.75-1.02) and overall survival (OR: 0.92, 95% CI = 0.83-1.03) to hospital discharge were similar among ST-elevation myocardial infarction (STEMI) patients who underwent PCI with TTM initiation <2 versus ≥2 hours. Patients without STEMI who underwent PCI with TTM initiation ≥2 hours and did not have a "do not resuscitate" order or withdrawal of life-sustaining care had decreased odds of neurologically favorable survival to hospital discharge (OR: 0.45, 95% CI = 0.22-0.93) compared to TTM initiation <2 hours. PCI was associated with delays in TTM initiation ≥2 hours among resuscitated survivors of VT/VF OHCA. Delays in TTM initiation ≥2 hours were associated with decreased odds of neurologically favorable survival among patients without STEMI who underwent PCI.
The Correlation Between Preoperative Perfusion Index and Intraoperative Hypothermia During Laparoscopic Radical Surgery for Urological Malignancies
Zhang Y, Li Y and Chen F
This study aimed to explore the relationship between preoperative baseline perfusion index (PI) and intraoperative hypothermia during general anesthesia. PI reflects the peripheral perfusion status, which may be associated with the decrease of core temperature during general anesthesia, as the redistribution of temperature from the core compartment to the peripheral compartment depends on the peripheral perfusion status. A total of 68 patients underwent radical surgery for urological malignancies in this study. The baseline PI value was measured upon entering the operating room. Core temperature was continuously monitored using a nasal pharyngeal probe from anesthesia induction to the end of surgery, with temperature data recorded every 15 minutes. Univariate and multivariate logistic regression analyses were used to identify risk factors for intraoperative hypothermia. Intraoperative hypothermia occurred in 26 patients, whose baseline PI (2.70 ± 0.73) was significantly lower than that of the normothermic group (3.65 ± 1.05), with <0.05. The baseline PI was independently associated with intraoperative hypothermia (PI: [OR] 0.375, 95% confidence interval [CI]: 1.584-6.876, = 0.001). This study suggests that low baseline PI is an independent factor associated with intraoperative hypothermia. In future studies, PI value could be considered as a predictor for the treatment of intraoperative hypothermia.
Prevalence of Pulmonary Hypertension During Therapeutic Hypothermia for Hypoxic Ischemic Encephalopathy and Evaluation of Short-Term Outcomes
Javed R, Hodson J and Gowda H
Infants with perinatal asphyxia and moderate-to-severe hypoxic ischemic encephalopathy (HIE) are currently treated with therapeutic hypothermia (TH) as part of a brain protective strategy. However, perinatal asphyxia is a risk factor for development of persistent pulmonary hypertension (PPHN). As such, the aim of this study was to quantify the risk of PPHN in infants undergoing TH and assess short-term outcomes in infants developing PPHN. All = 59 infants undergoing TH for moderate-to-severe HIE over a period of 3 years (January 2020-December 2022) at a single center were included. PPHN was diagnosed in = 10 (17%), with this deemed to have been exacerbated by TH in = 6 (10%). Only 50% (5/10) with PPHN required inhaled nitric oxide, and none of the infants received extracorporeal membrane oxygenation. PPHN was not found to be significantly associated with short-term outcomes, including the extent of HIE on brain magnetic resonance imagings, in-hospital mortality or requirement for nasogastric feeding at discharge. In conclusion, TH appears to be a safe and effective treatment for moderate-to-severe HIE with or without PPHN.
Exploratory Feasibility Study of Cerebral Cooling by Transpulmonary Cooling During Cardiac Arrest in a Swine Cardiac Arrest Model
Sakurai A, Kato Y, Uki H, Yagi K, Watanabe A, Sato J, Nakagawa K, Nakabayashi H and Kinoshita K
Studies on targeted temperature management for postcardiac arrest syndrome have shown no difference in outcomes between normothermia and hypothermia in patients with postcardiac arrest brain injury. Therefore, further development of therapeutic methods for temperature control in cardiac arrest patients is desirable. Although animal studies have shown that inducing hypothermia during cardiac arrest improves outcomes, no clinically effective method has yet been reported. We investigated whether intra-arrest lung cooling (IALC) effectively lowers brain temperature. A device capable of cooling oxygen was developed. The pigs were subjected to cardiac arrest using the device, ventilated, cooled during cardiopulmonary resuscitation, and resuscitated for 1 hour, with changes in brain temperature closely monitored. A device capable of cooling oxygen to -30°C was used to cool the lungs during cardiac arrest. Through this approach, IALC successfully reduced the brain temperature. Optimal cooling efficiency was observed when chest compressions and ventilation were synchronized at a ratio of 5:1, resulting in an approximate brain temperature reduction of 1.5°C/h. Our successful development of an oxygen-cooling device underscores the potential for lowering brain temperature through IALC using inhaled oxygen cooling.
The Association Between Neonatal Intensive Care Unit Arrival Temperatures and Short-Term Outcomes of Neonates with Moderate and Severe Hypoxic-Ischemic Encephalopathy
Arslan Z, Okbay Gunes A, Deveci MF, Unal Yuksekgonul A and Kasali K
Therapeutic hypothermia (TH) is the only treatment method that is known to reduce mortality and neurological sequela rates in newborns with moderate and severe hypoxic-ischemic encephalopathy (HIE). We aimed to evaluate the relationship between rectal temperatures measured upon arrival to our unit and short-term outcomes in newborns with HIE/TH. This was a retrospective study conducted between January 2022 and January 2023. The neonates were divided into three groups according to their rectal temperatures measured upon arrival at our unit as follows: Group 1) <33°C, Group 2) 33-34°C (group arriving at target temperature), and Group 3) >34°C. Short-term outcomes and mortality were compared between the groups. Group 1 consisted of 17 (19.8%) neonates, Group 2 consisted of 34 (39.5%) neonates, and Group 3 consisted of 35 (40.7%) neonates who had HIE and an indication for TH. Rectal temperature on arrival to the unit was not related to the rate of clinical convulsions, rates of abnormal attenuated electroencephalography and magnetic resonance imaging findings, rate of pulmonary hypertension, duration of mechanical ventilation and length of hospital stay. Although the mortality rate was 29% in Group 1, it was 3% and 6% in Groups 2 and 3, respectively ( = 0.016). No relationship was found between the rectal temperature upon arrival to the NICU and the short-term outcomes in HIE/TH neonates. However, the mortality rate in those who were overcooled was significantly higher compared with the other groups.
The Effect of Temperature Chain Management Scheme During Robot-Assisted Radical Prostatectomy
Pan L, Chen F, Hu J and Zhang Y
The study aimed to explore the effect of the temperature chain management scheme on preventing hypothermia in patients undergoing robot-assisted radical prostatectomy (RARP). The patients were randomized to receive either intraoperative warming only (control group, Group C) or the temperature chain management (experimental group, Group T). We compared the core temperature, inadvertent perioperative hypothermia (IPH) rates, the incidence of shivering, and thermal comfort between the two groups. The perioperative core temperature of the Group T was higher than that of the Group C, and the incidence of IPH, the incidence of shivering in the postanesthesia care unit (PACU), and the length of stay in PACU were lower than those of the control group. The thermal comfort of Group T scored higher than that of Group C when leaving the PACU, all above have a statistically significant difference ( < 0.05). The temperature chain management scheme could decrease the IPH rates and reduce postoperative complications in RARP patients. The Clinical Trials Registration number is 2023IIT034.
Case Report of the Use of an Intravascular Cooling Device in the Management of Malignant Hyperthermia
Von Schweinitz B and Gros BJ
Malignant hyperthermia (MH) is a rare, life-threatening condition caused by alterations in skeletal muscle calcium channels inherited through an autosomal dominant pattern. The use of specific agents in anesthesia such as inhaled anesthetics and succinylcholine can precipitate a hyperthermic crisis. Patients experience a rapid increase in muscle rigidity, secondary to skeletal muscle calcium dysregulation, leading to acute rhabdomyolysis and possible hyperthermia. Providers must have a high index of suspicion of this disease process because early diagnosis is critical to mortality reduction. Management centers around removal of the offending agent, dantrolene, and supportive care including cooling if hyperthermic. Intravascular cooling devices have been used in thermodynamic regulation after cardiac arrest and have shown to be more effective than dermal cooling techniques; however, they have not been well described in other disease processes. The following case report is the first to describe a patient suffering from MH to undergo invasive intravenous cooling in order to counteract the effects of this life-threatening disease.
The Effectiveness of Target Temperature Management on Poor-Grade Aneurysmal Subarachnoid Hemorrhage: A Systematic Review and Meta-Analysis
Liu Y, Xu M, Zhang P and Feng G
The effectiveness of target temperature management (TTM) in poor-grade aneurysmal subarachnoid hemorrhage (aSAH) remains a topic of debate. In order to assess the clinical efficacy of TTM in patients with poor-grade aSAH, we conducted a systematic review and meta-analysis. This research was registered in PROSPERO (CRD42023445582) and included all relevant publications up until October 2023. We compared the TTM groups with the control groups in terms of unfavorable outcomes (modified Rankin scale [mRS] score > 3), mortality, delayed cerebral ischemia (DCI), cerebral vasospasm (CVS), and specific complications. Subgroup analyses were performed based on country, study type, follow-up time, TTM method, cooling maintenance period, and rewarming rate. Effect sizes were calculated as relative risk (RR) using random-effect or fixed-effect models. The quality of the articles was assessed using the methodological index for non-randomized studies scale. Our analysis included a total of 5 clinical studies (including 1 randomized controlled trial) and 219 patients (85 in the TTM group and 134 in the control group). Most of the studies were of moderate quality. TTM was found to be associated with a statistically significant improvement in mortality (mRS score 6) rates compared with the control group (RR = 0.61, 95% confidence interval [CI]: 0.40-0.94, = 0.026). However, there was no statistically significant difference in unfavorable outcomes (mRS 4-6) between the TTM and control groups (RR = 0.94, 95% CI: 0.71-1.26, = 0.702). The incidence of adverse events, including DCI, CVS, pneumonia, cardiac complications, and electrolyte imbalance, did not significantly differ between the two groups. In conclusion, our overall results suggest that TTM does not significantly reduce unfavorable outcomes in poor-grade aSAH patients. However, TTM may decrease mortality rates. Preoperative TTM may cause patients to miss the opportunity for surgery, although it temporarily protects the brain. Furthermore, the incidence of adverse events was similar between the TTM and control groups.