Mild hypothermia, as a common means of intraoperative nerve protection, has been used in clinical practice. Compared with the traditional methods such as freezing helmet and nasopharyngeal cooling, hypothermic blood perfusion is considered to be a promising treatment for mild hypothermia, but it lacks experimental and theoretical verification of its cooling effect. In this study, the commercial finite element simulation software COMSOL combined the Pennes equation with the cerebrovascular network model to construct a new simplified human brain model, which was further used to simulate the cooling process of cerebral hypothermic blood perfusion. When the hypothermic blood perfusion was 33 ℃, the human brain could enter the mild hypothermic state within 4 minutes. By comparing with helmet cooling, the feasibility and efficiency of the blood perfusion scheme were verified. By comparing with the calculation results based on Pennes equation, the rationality of the model constructed in this study were verified. This model can non-intrusively predict the changes of brain temperature during surgery, and provide a reference for the setting of treatment parameters such as blood temperature, so as to provide personalized realization of safer and more effective mild hypothermia neuro protection.
Humans ; Hypothermia, Induced/methods* ; Hypothermia ; Hemoperfusion ; Brain/physiology* ; Body Temperature

BACKGROUNDTherapeutic hypothermia has been recommended for the treatment of cardiac arrest patients who remain comatose after the return of spontaneous circulation. The aim of this study was to evaluate the effectiveness and safety of mild hypothermia on patients with cardiac arrest by conducting a meta-analysis.

METHODSThe relevant trials were searched in Cochrane Library, PubMed, Web of Science, Embase, CNKI and Wan Fang Data from the date of their establishment to October 2014. Thereafter, the studies retrieved were screened based on predefined inclusion and exclusion criteria. Data were extracted, and the quality of the included studies was evaluated. A meta-analysis was conducted using the Cochrane Collaboration Review Manager 5.2 software.

RESULTSSix randomized controlled trials involving 531 cases were included, among which 273 cases were assigned to the treatment group and the other 258 cases to the control group. The meta-analysis indicated that mild hypothermia therapy after cardiac arrest produced significant differences in survival rate (relative risk [RR] =1.23, 95% confidence interval [CI]: 1.02-1.48, P = 0.03) and neurological function (RR = 1.33, 95% CI: 1.08-1.65, P = 0.007) after 6 months compared with normothermia therapy. However, no significant differences were observed in the survival to the hospital discharge (RR = 1.35, 95% CI: 0.87-2.10, P = 0.18), favorable neurological outcome at hospital discharge (RR = 1.53, 95% CI: 0.95-2.45, P = 0.08) and adverse events.

CONCLUSIONSThe meta-analysis demonstrated that mild hypothermia can improve the survival rate and neurological function of patients with cardiac arrest after 6 months. On the other hand, regarding the survival to hospital discharge, favorable neurological outcome at hospital discharge, and adverse events, our meta-analysis produced nonsignificant results.

Cardiopulmonary Resuscitation ; Heart Arrest ; therapy ; Humans ; Hypothermia, Induced ; methods

PURPOSE: This study compared nursing frequency, nursing time, and nursing intervention priorities depending on the method of neonatal induced hypothermia. METHODS: We observed 15 neonatal subjects receiving therapeutic hypothermia for 3 days each. Forty-five nurses experienced with nursing neonatal patients under therapeutic hypothermia provided responses about nursing intervention priorities. Analyses with the chi-square, the Fisher exact test, the paired t-test, the Wilcoxon signed rank test, and the Wilcoxon rank-sum test were performed on the data using SAS version 9.4. RESULTS: The frequency of nursing activities was higher for selective head therapeutic hypothermia (SHTH) than for systemic therapeutic hypothermia (STH), and nursing time was also significantly longer. In terms of nursing intervention priorities, there were priority differences in “risk for ineffective thermoregulation” and “risks for impaired skin integrity” for SHTH compared to STH . CONCLUSION: Since SHTH for neonatal therapeutic hypothermia requires more nursing time and frequent nursing activities than STH, STH is therefore recommended if the therapeutic efficacy is similar. Appropriate nursing personnel should be allocated for neonatal SHTH nursing. Nurses should be aware of nursing interventions for therapeutic hypothermia as the priorities are different for different methods of neonatal therapeutic hypothermia.
Head ; Humans ; Hypothermia ; Hypothermia, Induced* ; Infant, Newborn ; Methods* ; Neonatal Nursing ; Nursing* ; Skin

Neonatal hypoxic-ischemic encephalopathy (HIE) is a common disease that affects brain function in neonates. At present, mild hypothermia and hyperbaric oxygen therapy are the main methods for the treatment of neonatal HIE; however, they are independent of each other and cannot be combined for synchronous treatment, without monitoring of brain function-related physiological information. In addition, parameter setting of hyperbaric oxygen chamber and mild hypothermia mattress relies on the experience of the medical practitioner, and the parameters remain unchanged throughout the medical process. This article proposes a new device for the treatment of neonatal HIE, which has the modules of hyperbaric oxygen chamber and mild hypothermic mattress, so that neonates can receive the treatment of hyperbaric oxygen chamber and/or mild hypothermic mattress based on their conditions. Meanwhile, it can realize the real-time monitoring of various physiological information, including amplitude-integrated electroencephalogram, electrocardiogram, and near-infrared spectrum, which can monitor brain function, heart rate, rhythm, myocardial blood supply, hemoglobin concentration in brain tissue, and blood oxygen saturation. In combination with an intelligent control algorithm, the device can intelligently regulate parameters according to the physiological information of neonates and give recommendations for subsequent treatment.
Infant, Newborn ; Humans ; Hypothermia, Induced/methods* ; Hypothermia/therapy* ; Hyperbaric Oxygenation ; Brain ; Electroencephalography ; Hypoxia-Ischemia, Brain/therapy*

AIMIn order to study airway rewarming method and rewarming devices for hypothermia, hypothermic dog model was established.

METHODSThe anesthetized dog was immersed in cold water at 16.7 degrees C until the esophageal temperature (Te) of the dog decreased to 34.0 degrees C, the core temperature and skin temperature were monitored by using a 12-channel scanning thermometers. Atracurium besylate, a skeletal muscle relaxant, was injected intravenously when the core temperature of the dog was basically steady after the dog was out of the cold water, the hypothermic dog model was established.

RESULTSRectal and esophageal temperature could stand for the core temperature of the hypothermic dog model, but mixing with each other was prohibited because of leading to mistakes. Administering of atracurium besylate could eliminate the effect of shivering on airway rewarming alone, hypothermic dog model in which shivering was inhibited could be used in determination of airway rewarming technique and rewarming devices for hypothermia.

CONCLUSIONHypothermic dog model in which shivering was inhibited can abolish the interference of shivering, experimental repeatability is good, experimental method quite simple, and the model appropriate for application and dissemination.

Animals ; Body Temperature ; Cold Temperature ; Disease Models, Animal ; Dogs ; Hypothermia ; therapy ; Hypothermia, Induced ; Male ; Respiratory System ; Rewarming ; methods ; Shivering

Targeted temperature management (TTM) has been partially applied in patients with restoration of spontaneous circulation (ROSC) after cardiac arrest (CA). In the 2020 American Heart Association (AHA) cardiopulmonary resuscitation (CPR) guidelines, TTM is used as advanced life support after ROSC for the treatment of patients with CPR. TTM has a protective effect on cardiac function after CA, but the specific mechanism of its protective effect on cardiac function remains unclear. In this paper, the basic experimental progress, clinical trial progress and development prospect of TTM on the protective mechanism of cardiac function after CA are reviewed.
United States ; Humans ; Cardiopulmonary Resuscitation/methods* ; Temperature ; Heart Arrest/therapy* ; Hypothermia, Induced/methods* ; Body Temperature

Randomized controlled trials have demonstrated the safety and efficacy of mild hypothermia in the treatment of neonatal hypoxic-ischemic encephalopathy (HIE), which can reduce mortality or the incidence of severe neurological sequelae. Mild hypothermia has been used in the neonatal intensive care unit (NICU) as a routine treatment method for neonatal HIE in many developed countries, and it is increasingly applied in some NICUs in China. However, 40%-50% of the neonates treated with mild hypothermia die or develop severe neurological disability. Thus, to achieve the best neuroprotective effect, issues such as selection of patients with indications for mild hypothermia, cooling method, optimal time for mild hypothermia, duration of mild hypothermia, optimal target temperature, and the safety and long-term effects of mild hypothermia combined with other therapies, need to be further discussed. This article reviews the latest progress in clinical research on these issues.
Humans ; Hypothermia, Induced ; adverse effects ; methods ; Hypoxia-Ischemia, Brain ; therapy ; Infant, Newborn

Adolescent ; Adult ; Child ; Child, Preschool ; Electrocoagulation ; methods ; Female ; Humans ; Hypothermia, Induced ; Male ; Middle Aged ; Prospective Studies ; Tonsillectomy ; methods ; Young Adult

BACKGROUNDLarge animal cardiopulmonary bypass (CPB) models are expensive, and prevent assessment of neurocognitive function, and difficulties with long-term recovery. The purpose of this study was to establish a novel rat model of cardiopulmonary bypass for deep hypothermic circulatory arrest without blood priming.

METHODSTwenty adult male Sprague-Dawley rats weighing 450-560 g were randomized to CPB with deep hypothermic circulatory arrest (DHCA) and control groups, with 10 rats each. The experimental protocols, including blood and crystalloid fluid administration, anesthesia, orotracheal intubation, ventilation, cannulation, and heparinization were identical in both groups. After inducing cardiac arrest, the circuit was turned off and rats were left in a DHCA state for 15 minutes. Rats were rewarmed to 34°C to 35°C over a period of 36 to 42 minutes using CPB-assisted rewarming, a heating blanket, and a heating lamp along with administration of 0.1 mEq of sodium bicarbonate and 0.14 mEq of calcium chloride. The remaining priming volume was reinfused and animals were weaned from CPB.

RESULTSAll CPB with DHCA processes were successfully achieved. Blood gas analysis and hemodynamic parameters were in the normal range. The vital signs of all rats were stable.

CONCLUSIONSOur CPB circuit has several novel features, including a small priming volume, active cooling/rewarming processes, vacuum-assisted venous drainage, peripheral cannulation without thoracotomy or sternotomy, and an accurate means of monitoring peripheral tissue oxygenation.

Animals ; Cardiopulmonary Bypass ; methods ; Circulatory Arrest, Deep Hypothermia Induced ; methods ; Male ; Models, Animal ; Rats ; Rats, Sprague-Dawley ; Rats, Wistar

OBJECTIVE: To compare the outcomes of temperature-controlled radiofrequency-assisted endoscopic tonsillectomy and adenoidectomy (rT + A) and conventional tonsillectomy and adenoidectomy (cT + A) in children. METHOD: Forty-seven children who were with hypertrophy of both tonsils and adenoid and underwent tonsillectomy and adenoidectomy were retrospectively studied. There are 24 patients underwent rT + A and 23 patients underwent cT+A. Data of surgery time, bleeding volume, duration of postoperative pain and duration of postoperative pseudomembrane were collected and analysed. Hearing and disease-specific quality-of-life questionnaire (OSA-18) were analysed. RESULT: Surgery times of rT + A are statistically shorter than those of cT + A, bleeding volumes of rT + A are significantly less than those of cT + A. There are no differences of the duration of postoperative pain and duration of pseudomembrane between these two groups. Hearings were increased to normal in all conductive hearing loss patients. OSA-18 scores were declined significantly in rT + A group than cT + A. CONCLUSION Temperature-controlled radiofrequency-assisted endoscopic operation can reduce bleeding volume and shorten surgery time without more pain or injury to patients, and the effect is satisfactory.
Adenoidectomy ; methods ; Child ; Child, Preschool ; Endoscopy ; Female ; Humans ; Hypothermia, Induced ; Male ; Retrospective Studies ; Tonsillectomy ; methods ; Treatment Outcome