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Hypothermia
Kinds of Hypothermia Terms modified by Hypothermia Selected AbstractsHypothermia treatment potentiates ERK1/2 activation after traumatic brain injuryEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 4 2007Coleen M. Atkins Abstract Traumatic brain injury (TBI) results in significant hippocampal pathology and hippocampal-dependent memory loss, both of which are alleviated by hypothermia treatment. To elucidate the molecular mechanisms regulated by hypothermia after TBI, rats underwent moderate parasagittal fluid-percussion brain injury. Brain temperature was maintained at normothermic or hypothermic temperatures for 30 min prior and up to 4 h after TBI. The ipsilateral hippocampus was assayed with Western blotting. We found that hypothermia potentiated extracellular signal-regulated kinase 1/2 (ERK1/2) activation and its downstream effectors, p90 ribosomal S6 kinase (p90RSK) and the transcription factor cAMP response element-binding protein. Phosphorylation of another p90RSK substrate, Bad, also increased with hypothermia after TBI. ERK1/2 regulates mRNA translation through phosphorylation of mitogen-activated protein kinase-interacting kinase 1 (Mnk1) and the translation factor eukaryotic initiation factor 4E (eIF4E). Hypothermia also potentiated the phosphorylation of both Mnk1 and eIF4E. Augmentation of ERK1/2 activation and its downstream signalling components may be one molecular mechanism that hypothermia treatment elicits to improve functional outcome after TBI. [source] Surface Cooling for Rapid Induction of Mild Hypothermia After Cardiac Arrest: Design Determines EfficacyACADEMIC EMERGENCY MEDICINE, Issue 4 2010Thomas Uray MD Abstract Objectives:, Recently, a novel cooling pad was developed for rapid induction of mild hypothermia after cardiac arrest. The aim of this study was to evaluate the cooling efficacy of three different pad designs for in-hospital cooling. Methods:, Included in this prospective interventional study were patients with esophageal temperature (Tes) > 34°C on admission. The cooling pad consists of multiple cooling units, filled with a combination of graphite and water, which is precooled to ,18°C (design A) or to ,9°C (designs B and C) before use. The designs of the cooling pad differed in number, shape, and thickness of the cooling units, with weights of 9.7 kg (design A), 5.3 kg (design B), and 6.2 kg (design C). All three designs were tested in sequential order and were changed according to the results found in the previous trial. Cooling was started after admission until Tes = 34°C, when the cooling pad was removed. The target temperature of Tes = 32,34°C was maintained for 24 hours. Data are presented as medians and interquartile ranges (IQRs = 25%,75%) or proportions. Results:, Cooling rates were 3.4°C/hour (IQR = 2.5,3.7) with design A (n = 12), 2.8°C/hour (IQR = 1.6,3.3) with design B (n = 7), and 2.9°C/hour (IQR = 1.9,3.6) with design C (n = 10; p = 0.5). To reach 34°C, the cooling pad had to be exchanged with a new one due to melting and therefore depleting cooling capacity in three patients with design A, in five patients with design B, and in no patient with design C (p = 0.004). Conclusions:, With adequate design and storage temperature, the cooling pad proved to be efficient for rapid in-hospital cooling of patients resuscitated from cardiac arrest. ACADEMIC EMERGENCY MEDICINE 2010; 17:360,367 © 2010 by the Society for Academic Emergency Medicine [source] The Association Between Hypothermia, Prehospital Cooling, and Mortality in Burn VictimsACADEMIC EMERGENCY MEDICINE, Issue 4 2010Adam J. Singer MD Abstract Objectives:, Hypothermia is associated with increased morbidity and mortality in trauma victims. The prognostic value of hypothermia on emergency department (ED) presentation in burn victims is not well known. The objective of this study was to determine the incidence of hypothermia in burn victims and its association with mortality and hospital length of stay (LOS). The study also examined the potential causative role of prehospital cooling in hypothermic burn patients. Methods:, This was a retrospective review of a county trauma registry. The county was both suburban and rural, with a population of 1.5 million and with one burn center. Burn patients between 1994 and 2007 who met trauma registry criteria were included. Demographic and clinical data including prehospital cooling, burn size and depth, and presence of inhalation injury were collected. Hypothermia was defined as a core body temperature of less than or equal to 35°C. Data analysis consisted of univariate associations between patient characteristics and hypothermia. Results:, There were 1,215 burn patients from 1994 to 2007. Mean age (±standard deviation [±SD]) was 29 (±24) years, 67% were male, 248 (26.7%) had full-thickness burns, and 24 (2.6%) had inhalation injury. Only 17 (1.8%) had a burn larger than 70% total body surface area (TBSA). A total of 929 (76%) patients had an initial ED temperature recorded. Only 15/929 (1.6%) burn patients had hypothermia on arrival, and all were mild (lowest temperature was 32.6°C). There was no association between sex, year, and presence of inhalation injury with hypothermia. Hypothermic patients were older (44 years vs. 29 years, p = 0.01), and median Injury Severity Score (ISS) was higher (25 vs. 4, p = 0.002) than for nonhypothermic patients. Hypothermia was present in 6/17 (35%) patients with a TBSA of 70% or greater and in 8/869 (0.9%) patients with a TBSA of <70% (p < 0.001). Mortality was higher in hypothermic patients (60% vs. 3%, p < 0.001). None of the hypothermic patients received prehospital cooling. Conclusions:, Hypothermia on presentation to the ED was noted in 1.6% of all burn victims in this trauma registry. Hypothermia was more common in very large burns and was associated with high mortality. In this series, prehospital cooling did not appear to contribute to hypothermia. ACADEMIC EMERGENCY MEDICINE 2010; 17:456,459 © 2010 by the Society for Academic Emergency Medicine [source] Intranasal cooling with or without intravenous cold fluids during and after cardiac arrest in pigsACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 4 2010L. COVACIU Background: Intranasal balloon catheters circulated with cold saline have previously been used for the induction and maintenance of selective brain cooling in pigs with normal circulation. In the present study, we investigated the feasibility of therapeutic hypothermia initiation, maintenance and rewarming using such intranasal balloon catheters with or without addition of intravenous ice-cold fluids during and after cardiac arrest treatment in pigs. Material and methods: Cardiac arrest was induced in 20 anaesthetised pigs. Following 8 min of cardiac arrest and 1 min of cardiopulmonary resuscitation (CPR), cooling was initiated after randomisation with either intranasal cooling (N) or combined with intravenous ice-cold fluids (N+S). Hypothermia was maintained for 180 min, followed by 180 min of rewarming. Brain and oesophageal temperatures, haemodynamic variables and intracranial pressure (ICP) were recorded. Results: Brain temperatures reductions after cooling did not differ (3.8 ± 0.7 °C in the N group and 4.3 ± 1.5 °C in the N+S group; P=0.47). The corresponding body temperature reductions were 3.6 ± 1.2 °C and 4.6 ± 1.5 °C (P=0.1). The resuscitation outcome was similar in both groups. Mixed venous oxygen saturation was lower in the N group after cooling and rewarming (P=0.024 and 0.002, respectively) as compared with the N+S group. ICP was higher after rewarming in the N group (25.2 ± 2.9 mmHg; P=0.01) than in the N+S group (15.7 ± 3.3 mmHg). Conclusions: Intranasal balloon catheters can be used for therapeutic hypothermia initiation, maintenance and rewarming during CPR and after successful resuscitation in pigs. [source] Effectiveness of cutaneous warming systems on temperature control: meta-analysisJOURNAL OF ADVANCED NURSING, Issue 6 2010Cristina Maria Galvão galvão c.m., liang y. & clark a.m. (2010) Effectiveness of cutaneous warming systems on temperature control: meta-analysis. Journal of Advanced Nursing,66(6), 1196,1206. Abstract Title.,Effectiveness of cutaneous warming systems on temperature control: meta-analysis. Aim., This paper is a report of a meta-analysis to identify the effectiveness of different types of cutaneous warming systems in temperature control for patients undergoing elective surgery. Background., Hypothermia is a common and serious complication of surgery. Different cutaneous warming systems are used to prevent hypothermia during surgery but there have been no previous meta-analyses of the effectiveness of different warming systems in controlling temperature. Data sources., We conducted a search of the CINAHL (2000 to April 2009), Medline (2000 to April 2009), Embase (2000 to April 2009) and the Cochrane Register of Controlled Trials (2000 to April 2009) databases for randomized controlled trials published in English, Spanish and Portuguese. The primary outcome measure of interest was core body temperature. Methods., A systematic review incorporating meta-analysis was carried out. Results., From 329 papers, 23 trials compared warming systems. Forced-air warming systems had a strong tendency towards superior temperature control over passive insulation via cotton blankets (mean difference: 0·29°C; 95% confidence interval: ,0·02 to 0·59, three trials 292 patients) and radiant warming systems (mean difference: 0·16°C; 95% confidence interval: ,0·01 to 0·33, three trials, 161 patients). However, circulating water garments tended to be more effective than forced-air warming systems (mean difference: ,0·73°C; 95% confidence interval: ,1·51 to 0·05, I2 = 97%; four trials, 198 patients). Pooled results approached statistical significance and indicated clinically meaningful differences in temperature control. Conclusion., Current evidence suggests that circulating water garments offer better temperature control than forced-air warming systems, and both are more effective than passive warming devices. [source] Active cooling in traumatic brain-injured patients: a questionable therapy?ACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 10 2009P.-O. GRÄNDE Hypothermia is shown to be beneficial for the outcome after a transient global brain ischaemia through its neuroprotective effect. Whether this is also the case after focal ischaemia, such as following a severe traumatic brain injury (TBI), has been investigated in numerous studies, some of which have shown a tendency towards an improved outcome, whereas others have not been able to demonstrate any beneficial effect. A Cochrane report concluded that the majority of the trials that have already been published have been of low quality, with unclear allocation concealment. If only high-quality trials are considered, TBI patients treated with active cooling were more likely to die, a conclusion supported by a recent high-quality Canadian trial on children. Still, there is a belief that a modified protocol with a shorter time from the accident to the start of active cooling, longer cooling and rewarming time and better control of blood pressure and intracranial pressure would be beneficial for TBI patients. This belief has led to the instigation of new trials in adults and in children, including these types of protocol adjustments. The present review provides a short summary of our present knowledge of the use of active cooling in TBI patients, and presents some tentative explanations as to why active cooling has not been shown to be effective for outcome after TBI. We focus particularly on the compromised circulation of the penumbra zone, which may be further reduced by the stress caused by the difference in thermostat and body temperature and by the hypothermia-induced more frequent use of vasoconstrictors, and by the increased risk of contusional bleedings under hypothermia. We suggest that high fever should be reduced pharmacologically. [source] Deep Hypothermia and Circulatory Arrest in the Surgical Management of Renal Tumors with Cavoatrial ExtensionJOURNAL OF CARDIAC SURGERY, Issue 6 2009Panagiotis Dedeilias M.D. Their intraluminar extension to the cardiac cavities occurs with a tumor-thrombus formation at a percentage of 1%. The aim of this study is to present the principles of "radical" management that should be targeted to excision of the kidney together with the cavoatrial tumor-thrombus. Material: From 2003 through 2008, we treated six patients with renal-cell carcinoma involving the IVC and/or the right cardiac chambers. The main symptoms leading to the diagnosis were hematuria, dyspnea, or lower limb edema. The extension of the tumor was type IV in three cases, type III in two, and type II in one case. Method: Extracorporeal circulation combined with a short period of hypothermic circulatory arrest was the method used. Radical nephrectomy combined with cavotomy and atriotomy was performed to an "en-block" extirpation of the tumor-thrombus and allowed oncologic surgical clearance of the disease. Results: There was no operative death. The mean postoperative course duration was 11 days, apart from one obese patient who presented postoperative pancreatitis and died on the 44th postoperative day due to respiratory failure. During the cumulative postoperative follow-up of 171 months the patients remain free of recurrence. Conclusions: The use of extracorporeal circulation and deep hypothermic circulatory arrest provides a good method for radical excision of renal carcinomas involving the IVC with satisfactory morbidity and long-term survival results. Cooperation of urologists and cardiac surgeons is necessary for this type of operation. [source] A systematic review of the effectiveness of cutaneous warming systems to prevent hypothermiaJOURNAL OF CLINICAL NURSING, Issue 5 2009Cristina M Galvão Aims., To retrieve and critique recent randomised trials of cutaneous warming systems used to prevent hypothermia in surgical patients during the intraoperative period and to identify gaps in current evidence and make recommendations for future trials. Background., Hypothermia affects up to 70% of anaesthetised surgical patients and is associated with several significant negative health outcomes. Design., Systematic review using integrative methods. Methods., We searched CINAHL, EMBASE, Cochrane Register of Controlled Trials and Medline databases (January 2000,April 2007) for recent reports on randomised controlled trials of cutaneous warming systems used with elective patients during the intraoperative period. Inclusion criteria., We included randomised control trials examining the effects of cutaneous warming systems used intraoperatively on patients aged 18 years or older undergoing non-emergency surgery. Studies published in English, Spanish or Portuguese with a comparison group that consisted of either usual care or active cutaneous warming systems without prewarming were reviewed. Results., Of 193 papers initially identified, 14 studies met the inclusion criteria. There was moderate evidence to indicate that carbon-fibre blankets and forced-air warming systems are equally effective and that circulating-water garments are most effective for maintaining normothermia during the intraoperative period. Few trials reported costs. Conclusions., Carbon-fibre blankets and forced-air warming systems are effective and circulating-water garments may be preferable. Future research should measure the direct and indirect costs associated with competing systems. Relevance to clinical practice., Nurses can use this review to inform their selection of warming interventions in perioperative nursing practice. They can also assess other factors such as nursing workload, staff training and equipment maintenance, which should be incorporated into future research. [source] Scandinavian Clinical practice guidelines for therapeutic hypothermia and post-resuscitation care after cardiac arrestACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 3 2009M. CASTRÉN Background and aim: Sudden cardiac arrest survivors suffer from ischaemic brain injury that may lead to poor neurological outcome and death. The reperfusion injury that occurs is associated with damaging biochemical reactions, which are suppressed by mild therapeutic hypothermia (MTH). In several studies MTH has been proven to be safe, with few complications and improved survival, and is recommended by the International Liaison of Committee on Resuscitation. The aim of this paper is to recommend clinical practice guidelines for MTH treatment after cardiac arrest from the Scandinavian Society of Anaesthesiology and Intensive Care Medicine (SSAI). Methods: Relevant studies were identified after two consensus meetings of the SSAI Task Force on Therapeutic Hypothermia (SSAITFTH) and via literature search of the Cochrane Central Register of Controlled Trials and Medline. Evidence was assessed and consensus opinion was used when high-grade evidence (Grade of Recommendation, GOR) was unavailable. A management strategy was developed as a consensus from the evidence and the protocols in the participating countries. Results and conclusion: Although proven beneficial only for patients with initial ventricular fibrillation (GOR A), the SSAITFTH also recommend MTH after restored spontaneous circulation, if active treatment is chosen, in patients with initial pulseless electrical activity and asystole (GOR D). Normal ethical considerations, premorbid status, total anoxia time and general condition should decide whether active treatment is required or not. MTH should be part of a standardized treatment protocol, and initiated as early as possible after indication and treatment have been decided (GOR E). There is insufficient evidence to make definitive recommendations among techniques to induce MTH, and we do not know the optimal target temperature, duration of cooling and rewarming time. New studies are needed to address the question as to how MTH affects, for example, prognostic factors. [source] Optimal Body Temperature in Transitional Extremely Low Birth Weight Infants Using Heart Rate and Temperature as IndicatorsJOURNAL OF OBSTETRIC, GYNECOLOGIC & NEONATAL NURSING, Issue 1 2010Robin B. Knobel ABSTRACT Objective: To explore body temperature in relationship to heart rate in extremely low birth weight (ELBW) infants during their first 12 hours to help identify the ideal set point for incubator control of body temperature. Design: Within subject, multiple-case design. Setting: A tertiary neonatal intensive care unit (NICU) in North Carolina. Participants: Ten infants born at fewer than 29 weeks gestation and weighing 400 to 1,000 g. Methods: Heart rate and abdominal body temperature were measured at 1-minute intervals for 12 hours. Heart rates were considered normal if they were between the 25th and 75th percentile for each infant. Results: Abdominal temperatures were low throughout the 12-hour study period (mean 35.17-36.68 °C). Seven of 10 infants had significant correlations between abdominal temperature and heart rate. Heart rates above the 75th percentile were associated with low and high abdominal temperatures; heart rates less than the 25th percentile were associated with very low abdominal temperatures. The extent to which abdominal temperature was abnormally low was related to the extent to which the heart rate trended away from normal in 6 of the 10 infants. Optimal temperature control point that maximized normal heart rate observations for each infant was between 36.8 °C and 37 °C. Conclusions: Hypothermia was associated with abnormal heart rates in transitional ELBW infants. We suggest nurses set incubator servo between 36.8 °C and 36.9 °C to optimally control body temperature for ELBW infants. [source] Thermoregulation and Heat Loss Prevention After Birth and During Neonatal Intensive-Care Unit Stabilization of Extremely Low-Birthweight InfantsJOURNAL OF OBSTETRIC, GYNECOLOGIC & NEONATAL NURSING, Issue 3 2007Robin Knobel Extremely low-birthweight infants have inefficient thermoregulation due to immaturity and may exhibit cold body temperatures after birth and during their first 12 hours of life. Hypothermia in these infants can lead to increased morbidity and mortality. Anecdotal notes made during our recent study revealed extremely low-birthweight infants' temperatures decreased with caregiver procedures such as umbilical line insertion, intubations, obtaining chest x-rays, manipulating intravenous lines, repositioning, suctioning, and taking vital signs during the first 12 hours of life. Therefore, nursing interventions should be undertaken to prevent heat loss during these caregiver procedures. Nurses can improve the thermal environment for extremely low-birthweight infants by prewarming the delivery room and placing the infant in a plastic bag up to the neck during delivery room stabilization to prevent heat loss. JOGNN, 36, 280-287 ; 2007. DOI: 10.1111/J.1552-6909.2007.00149.x [source] Sex Differences in Ethanol-Induced Hypothermia in Ethanol-Naïve and Ethanol-Dependent/Withdrawn RatsALCOHOLISM, Issue 1 2009Anna N. Taylor Background:, Human and animal findings indicate that males and females display major differences in risk for and consequences of alcohol abuse and alcoholism. These differences are in large part mediated by sex-specific hormonal environments. Gonadal and adrenal secretory products are known to modulate the neurobehavioral responses of ethanol (EtOH) dependence and withdrawal. However, the effects of these steroids on physiological adaptations, such as thermoregulation, are less well established. To study the role of sex-related hormones in mediating sex differences in the hypothermic response to acute challenge with EtOH, we compared the EtOH-induced hypothermic responses of EtOH-naïve male and female rats and EtOH-dependent (on the third day of withdrawal) male and female rats before (intact) and after depletion of all gonadal and adrenal steroids by gonadectomy (GDX) with or without adrenalectomy (ADX). Methods:, Intact and GDX male and female rats, with or without ADX, were fed an EtOH-containing liquid diet for 15 days while control (EtOH-naïve) rats were pairfed the isocaloric liquid diet without EtOH or fed normal rat chow and water. On the third day of withdrawal from the EtOH diet we tested the hypothermic response to EtOH challenge (1.5 g/kg BWt, ip). Blood alcohol content (BAC) and corticosterone (CORT) content were analyzed in a separate series of intact and GDX males and females with and without ADX in response to the EtOH challenge. Results:, Ethanol-induced hypothermia was significantly greater and its duration significantly longer in intact males than females when subjects were EtOH-naïve. EtOH-induced hypothermia was significantly greater in intact females than males by the third day of withdrawal from EtOH dependence. GDX in males significantly shortened the duration of the hypothermic response and tended to blunt EtOH-induced hypothermia while response duration was significantly extended by GDX in females that tended to enhance EtOH-hypothermia. EtOH-induced hypothermia was significantly enhanced and its duration significantly lengthened by combined GDX and ADX in EtOH-naïve and -withdrawn males and by combined GDX and ADX in EtOH-naïve but not EtOH-withdrawn females. These differential EtOH-induced hypothermic responses did not appear to be caused by differences in EtOH handling among the groups. The absence of adrenal activation by EtOH in the GDX,ADX males and females contributes to their enhanced EtOH-induced hypothermic responses. Conclusions:, These results implicate the direct and indirect effects of removal of gonadal and adrenal secretory products as mediators of the thermoregulatory actions of EtOH. [source] Fetal Learning With Ethanol: Correlations Between Maternal Hypothermia During Pregnancy and Neonatal Responsiveness to Chemosensory Cues of the DrugALCOHOLISM, Issue 5 2004Paula Abate Abstract: Background: Fetuses learn about ethanol odor when the drug is present in the amniotic fluid. Prenatal learning comprising ethanol's chemosensory cues also suggests an acquired association between ethanol's chemosensory and postabsorptive properties. Ethanol-related thermal disruptions have been implicated as a significant component of the drug's unconditioned properties. In the present study, ethanol-induced thermal changes were analyzed in pregnant rats subjected to a moderate ethanol dose. This thermal response was later tested for its correlation with the responsiveness of the progeny to ethanol and nonethanol chemosensory stimuli. Methods: During gestational day (GD) 14, pregnant rats were subjected to a minor surgical procedure to place a subcutaneous telemetric thermal sensor in the nape of the neck. During GDs 17 to 20, females received a daily intragastric administration of ethanol (2 g/kg) or water, using solutions kept at room temperature. Maternal body temperatures were recorded before and after (4 consecutive hours) the administration of water or ethanol. Newborns representative of both prenatal treatments were tested in terms of behavioral activity elicited by the smell of ethanol or of a novel odorant (cineole). A third group of pups were tested in response to unscented air stimulation. Results: Ethanol administration during late gestation induced reliable maternal hypothermia, a thermal disruption greater than that observed in water-treated females. It was systematically observed that maternal ethanol-induced hypothermia negatively correlated with neonatal motor reactivity elicited by ethanol olfactory stimulation. No other significant correlations were observed in terms of responsiveness to cineole or to unscented air in animals prenatally exposed to ethanol or water. Conclusions: In conjunction with prior research, the present results indicate that fetal ethanol exposure may yield learning of an association between ethanol's sensory and unconditioned properties. Ethanol-induced hypothermia during late gestation seems to represent a significant component of ethanol's unconditioned consequences. Specifically, ethanol-related thermal disruptions in the womb are highly predictive of neonatal responsiveness to ethanol's chemosensory cues that are known to be processed by the near-term fetus. [source] Recombinant activated factor VII efficacy and safety in a model of bleeding and thrombosis in hypothermic rabbits: a blind studyJOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 2 2007A. GODIER Summary.,Background:,Recombinant activated factor VII (rFVIIa) is increasingly used to secure hemostasis in hemorrhagic situations in trauma and surgical patients. Hypothermia is often observed in these clinical settings. Objective:,To study the efficacy and safety of rFVIIa in hypothermia in a rabbit model of bleeding and thrombosis. Methods:,Sixty-nine rabbits were anesthetized, ventilated and monitored for blood pressure, temperature and carotid flow. The Folts model was used: a stenosis (75%) and an injury were carried out on the carotid artery, inducing thrombosis. Blood flow decreased as thrombus size increased until the pressure gradient was such that the thrombus was released and local arterial blood flow was suddenly restored. This is known as a cyclic flow reduction (CFR). After counting baseline CFRs during a 20-min period (P1), rabbits were randomized blindly to one of four groups: normothermic (NT) placebo or rFVIIa (150 ,g kg,1), hypothermic (HT) (34 °C) placebo or rFVIIa. Then CFRs were recorded over a second period (P2). At the end of the experiment, a hepato-splenic section was performed and the amount of blood loss was recorded. After each period, the following were measured: ear immersion bleeding time (BT), hemoglobin, platelet count, prothrombin time (PT), activated partial thromboplastin time (aPTT) and fibrinogen. Results:,Hypothermia increased BT and blood loss. These effects were reversed by rFVIIa. In NT rabbits, rFVIIa shortened BT but did not reduce blood loss. rFVIIa-treated rabbits bled similarly regardless of temperature. The incidence of CFRs was higher in treated than placebo animals regardless of temperature. rFVIIa decreased PT and aPTT without modifying platelet count or fibrinogen level. Conclusion:,Hemostatic efficacy of rFVIIa was maintained in hypothermia. However, the number of CFRs was higher in the rFVIIa-treated group than in the placebo groups, whether for NT or HT rabbits. [source] Retrospective Study of Streptokinase Administration in 46 Cats with Arterial ThromboembolismJOURNAL OF VETERINARY EMERGENCY AND CRITICAL CARE, Issue 4 2000Kari E. Moore DVM Summary A retrospective evaluation was performed on 46 cats with arterial thromboembolism (ATE) that were treated with streptokinase (SK). Significant heart disease was diagnosed in 45/46 cats, and 21/46 cats had congestive heart failure. Variable dosing schemes of streptokinase were administered within 1,20 hours following the onset of clinical signs (median = 5.5 hours). There was no difference between survivors (S) and non-survivors (NS), based on time of administration of SK after onset of clinical signs. Twenty-five (54%) of the cats had return of pulses within 2,24 hours of treatment. Fourteen (30%) of the cats had return of motor function between 9 hours and 6 days. Fifteen of the cats (33%) were discharged from the hospital, 18 (39%) died in the hospital, and 13 (28%) cats were euthanized due to complications or poor response to treatment. Four of 5 cats (80%) with single limb dysfunction survived to hospital discharge. Life threatening hyperkalemia was diagnosed in 16 cats (35%) after SK administration. Hyperkalemia was more likely to occur with the longer duration of SK infusion. Eleven cats (24%) developed clinical signs of bleeding following SK administration and 3 of these cats required a blood transfusion. Laboratory testing documented coagulopathy following SK administration in 11 out of 17 cats tested. Hypothermia and azotemia prior to SK administration and the development of hyperkalemia were negatively associated with survival. [source] Mild hypothermia inhibits IL-10 production in peripheral blood mononuclear cellsACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 2 2004T. Matsui Background:, Hypothermia is often associated with compromised host defenses and infections. Deterioration of immune functions related to hypothermia have been investigated, but the involvement of cytokines in host defense mechanisms and in infection remains unclear. Therefore, we determined whether mild hypothermia affects the production of several types of cytokines in peripheral blood mononuclear cells (PBMCs), and the balance between pro-inflammatory and anti-inflammatory states. Methods:, PBMCs obtained from 12 healthy humans were cultured with phytohemagglutinin (PHA) in normothermic (37°C: control) or hypothermic (33°C) conditions for 24 h. The production levels of tumor necrosis factor (TNF)-,, the interleukins (ILs) IL-6, IL-8 and IL-10, and interferon (IFN)-, in the culture supernatants were measured by means of enzyme-linked immunosorbent assay (ELISA). Results:, Under hypothermic conditions (33°C), PHA-induced production of IL-10 and IFN-, in PBMCs was significantly lower, by 34% and 84%, respectively, when compared with controls, while production of TNF-,, IL-6 and IL-8 did not change. The magnitude of reduction of IL-10 in hypothermic conditions resulted in IL-10/pro-inflammatory cytokine ratios decreasing to approximately 30,45% of those of controls. Conclusions:, The present study clearly demonstrates that mild hypothermia (33°C) inhibits IL-10 and IFN-, production in cultured PBMCs. The profound inhibition of IL-10 and the pro-inflammatory reaction-dominated state induced suggests that the host defense mechanism against secondary infection may be maintained rather than inhibited in hypothermia. Thus, the reduction of IL-10 could be an important characteristic of immune responses in mild hypothermia. [source] Hypothermia during the infusion of cryopreserved autologous peripheral stem cell causes electrocardiographical changes: Report of two casesAMERICAN JOURNAL OF HEMATOLOGY, Issue 8 2006Fahri Sahin Abstract Currently, autologous peripheral stem cell transplantation used as a therapeutic modality in the treatment of various hematological malignancies is gaining more popularity day by day. In this method, the patient's own peripheral stem cells are collected by a proper method and stored at ,80°C until they are reinfused into the patient after being rewarmed in water bath at 37°C. A number of complications have been reported related to reinfusion of the cryopreserved cells into the patient. These may include noncardiovascular complications such as nausea, vomiting, flushing, abdominal pain, chest discomfort, and headache, as well as cardiovascular complications like arrhythmias, hypotension, and hypertension. Hypothermia related to rapid infusion has been reported as the main factor underlying the cardiovascular complications. Electrocardiographic findings of hypothermia include sinusal bradycardia, prolonged QT and PR intervals, widened QRS complexes, and J wave, which is a ECG abnormality characterized by supraventricular and ventricular arrhythmias. We here present two cases of giant J wave caused by hypothermia during infusion of cryopreserved autologous peripheral stem cell that is detected by ECG and regressed after infusion ceased. Am. J. Hematol. 81:627,630, 2006. © Wiley-Liss, Inc. [source] Hypothermia During Head and Neck Surgery,THE LARYNGOSCOPE, Issue 8 2003Nishant Agrawal MD Abstract Objective To determine the predictors and incidence of hypothermia in patients undergoing head and neck surgery. Study Design Retrospective analysis. Methods Patients were either not warmed (n = 43) or actively warmed with forced-air warming (n = 25). Clinical variables that were assessed as predictors of core body temperature included age, body mass, duration of procedure, estimated blood loss, amount of intravenous fluids administered, and the use of forced-air warming. The incidence of severe intraoperative hypothermia and potential hypothermia-related complications was also examined. Results The study demonstrated that advanced age is a risk factor for hypothermia and decreased body mass is associated with lower final body temperatures in the groups of patients that was not warmed. After adjusting for differences in the ages and weights between the two groups, the mean core body temperature was found to be 0.4°C lower in the patients who were not warmed. Severe intraoperative hypothermia occurred in 5 of 38 patients (11.6%) who were not warmed and 2 of 23 patients (8.0%) who were warmed. The complications associated with hypothermia included delayed time to extubation, the development of neck seromas, and flap dehiscence. Conclusions Patients undergoing head and neck surgery are at risk for the development of intraoperative hypothermia and require careful temperature monitoring. Elderly patients and patients with low body mass are more prone to develop low intraoperative core body temperatures. Active warming with forced-air warmers should be considered for patients at risk for intraoperative hypothermia and for patients who develop hypothermia intraoperatively, to avoid hypothermia-related complications. [source] Effects of desmopressin on platelet function under conditions of hypothermia and acidosis: an in vitro study using multiple electrode aggregometry,ANAESTHESIA, Issue 7 2010A. A. Hanke Summary Hypothermia and acidosis lead to an impairment of coagulation. It has been demonstrated that desmopressin improves platelet function under hypothermia. We tested platelet function ex vivo during hypothermia and acidosis. Blood samples were taken from 12 healthy subjects and assigned as follows: normal pH, pH 7.2, and pH 7.0, each with and without incubation with desmopressin. Platelet aggregation was assessed by multiple electrode aggregometry. Baseline was normal pH and 36 °C. The other samples were incubated for 30 min and measured at 32 °C. Acidosis significantly impaired aggregation. Desmopressin significantly increased aggregability during hypothermia and acidosis regardless of pH, but did not return it to normal values at low pH. During acidosis and hypothermia, acidosis should be corrected first; desmopressin can then be administered to improve platelet function as a bridge until normothermia can be achieved. [source] Inadvertent hypothermia and mortality in postoperative intensive care patients: retrospective audit of 5050 patientsANAESTHESIA, Issue 9 2009D. Karalapillai Summary We proposed that many Intensive Care Unit (ICU) patients would be hypothermic in the early postoperative period and that hypothermia would be associated with increased mortality. We retrospectively reviewed patients admitted to ICU after surgery. We recorded the lowest temperature in the first 24 h after surgery using tympanic membrane thermometers. We defined hypothermia as < 36 °C, and severe hypothermia as < 35 °C. We studied 5050 consecutive patients: 35% were hypothermic and 6% were severely hypothermic. In-hospital mortality was 5.6% for normothermic patients, 8.9% for all hypothermic patients (p < 0.001), and 14.7% for severely hypothermic patients (p < 0.001). Hypothermia was associated with in-hospital mortality: OR 1.83 for each degree Celsius (°C) decrease (95% CI: 1.2,2.60, p < 0.001). Given the evidence for improved outcome associated with active patient warming during surgery we suggest conducting prospective studies of active warming of patients admitted to ICU after surgery. [source] Hypothermia after cardiac arrest: feasible but is it therapeutic?ANAESTHESIA, Issue 8 2008G. C. Fisher No abstract is available for this article. [source] Antiapoptotic Cardioprotective Effect of Hypothermia Treatment Against Oxidative Stress InjuriesACADEMIC EMERGENCY MEDICINE, Issue 9 2009Chien-Hua Huang MD Abstract Objectives:, The effect of hypothermia on cardiomyocyte injury induced by oxidative stress remains unclear. The authors investigated the effects of hypothermia on apoptosis and mitochondrial dysfunction in cardiomyocytes exposed to oxidative stress. Methods:, Cardiomyocytes (H9c2) derived from embryonic rat heart cell culture were exposed to either normothermic (37°C) or hypothermic (31°C) environments before undergoing oxidative stress via treatment with hydrogen peroxide (H2O2). The degree of apoptosis was determined by annexin V and terminal deoxynucleotidyl transferase (TUNEL) staining. The amount of reactive oxygen species (ROS) was compared after H2O2 exposure between normo- and hypothermic-pretreated groups. Mitochondrial dysfunction in both groups was measured by differential reductase activity and transmembrane potential (,,m). Results:, Hydrogen peroxide induced significant apoptosis in both normothermic and hypothermic cardiomyocytes. Hypothermia ameliorated apoptosis as demonstrated by decreased annexin V staining (33 ± 1% vs. 49 ± 4%; p < 0.05) and TUNEL staining (27 ± 17% vs. 80 ±25%; p < 0.01). The amount of intracellular ROS increased after H2O2 treatment and was higher in the hypothermic group than that in the normothermic group (237.9 ± 31.0% vs. 146.6 ± 20.6%; p < 0.05). In the hypothermic group, compared with the normothermic group, after H2O2 treatment mitochondrial reductase activity was greater (72.0 ± 17.9% vs. 27.0 ± 13.3%; p < 0.01) and the mitochondria ,,m was higher (101.0 ± 22.6% vs. 69.7 ± 12.9%; p < 0.05). Pretreatment of cardiomyocytes with the antioxidant ascorbic acid diminished the hypothermia-induced increase in intracellular ROS and prevented the beneficial effects of hypothermia on apoptosis and mitochondrial function. Conclusions:, Hypothermia at 31°C can protect cardiomyocytes against oxidative stress,induced injury by decreasing apoptosis and mitochondrial dysfunction through intracellular ROS-dependent pathways. [source] Hemodialysis as a Treatment of Severe Accidental HypothermiaARTIFICIAL ORGANS, Issue 3 2010Rogier Caluwé Abstract We describe a case of severe accidental hypothermia (core body temperature 23.2°C) successfully treated with hemodialysis in a diabetic patient with preexisting renal insufficiency. Consensus exists about cardiopulmonary bypass as the treatment of choice in cases of severe accidental hypothermia with cardiac arrest. Prospective randomized controlled trials comparing the different rewarming modalities for hemodynamically stable patients with hypothermia, however, are lacking. In our opinion, the choice of a rewarming technique should be patient tailored, knowing that hemodialysis is an efficient, minimally invasive, and readily available technique with the advantage of providing electrolyte support. [source] Chlorpyrifos-Induced Hypothermia and Vasodilation in the Tail of the Rat: Blockade by Scopolamine,BASIC AND CLINICAL PHARMACOLOGY & TOXICOLOGY, Issue 1 2000Christopher J. Gordon Organophosphate pesticides such as chlorpyrifos reduce core temperature (Tc) in laboratory rodents. The mechanism(s) responsible for the chlorpyrifos-induced hypothermia are not well known. This study assessed the role of a key effector for thermoregulation in the rat, vasomotor control of heat loss from the tail, and its possible cholinergic control during chlorpyrifos-induced hypothermia. Tc and motor activity were monitored by telemetry in female Long-Evans rats maintained at an ambient temperature (Ta) of 25°. Tail skin temperature (Tsk(t)) was measured hourly. Rats were dosed with chlorpyrifos (0 or 25 mg/kg orally). Two hr later the rats were dosed with saline or scopolamine (1.0 mg/kg intraperitoneally). Two hr after chlorpyrifos treatment there was a marked elevation in Tsk(t) concomitant with a 0.5° reduction in Tc. Scopolamine administered to control rats led to a marked elevation in Tc with little change in Tsk(t). Rats treated with chlorpyrifos and administered scopolamine underwent a marked vasoconstriction and elevation in Tc. Vasodilation of the tail is an important thermoeffector to reduce Tc during the acute stages of chlorpyrifos exposure. The blockade of the response by scopolamine suggests that the hypothermic and vasodilatory response to chlorpyrifos is mediated via a cholinergic muscarinic pathway in the CNS. [source] Use of a Standardized Order Set for Achieving Target Temperature in the Implementation of Therapeutic Hypothermia after Cardiac Arrest: A Feasibility StudyACADEMIC EMERGENCY MEDICINE, Issue 6 2008J. Hope Kilgannon MD Abstract Objectives:, Induced hypothermia (HT) after cardiac arrest improved outcomes in randomized trials. Current post,cardiac arrest treatment guidelines advocate HT; however, utilization in practice remains low. One reported barrier to adoption is clinician concern over potential technical difficulty of HT. We hypothesized that using a standardized order set, clinicians could achieve HT target temperature in routine practice with equal or better efficiency than that observed in randomized trials. Methods:, After a multidisciplinary HT education program, we implemented a standardized order set for HT induction and maintenance including sedation and paralysis, intravenous cold saline infusion, and an external cooling apparatus, with a target temperature range of 33,34°C. We performed a retrospective analysis of a prospectively compiled and maintained registry of cardiac arrest patients with HT attempted (intent-to-treat) over the first year of implementation. The primary outcome measures were defined a priori by extrapolating treatment arm data from the largest and most efficacious randomized trial: 1) successful achievement of target temperature for ,85% of patients in the cohort and 2) median time from return of spontaneous circulation (ROSC) to achieving target temperature <8 hours. Results:, Clinicians attempted HT on 23 post,cardiac arrest patients (arrest location: 78% out-of-hospital, 22% in-hospital; initial rhythm: 26% ventricular fibrillation/tachycardia, 70% pulseless electrical activity or asystole) and achieved the target temperature in 22/23 (96%) cases. Median time from ROSC to target temperature was 4.4 (interquartile range 2.8,7.2) hours. Complication rates were low. Conclusions:, Using a standardized order set, clinicians can achieve HT target temperature in routine practice. [source] Hypothermia after Cardiac Arrest: We Can Do ThisACADEMIC EMERGENCY MEDICINE, Issue 6 2008Alan E. Jones MD No abstract is available for this article. [source] Using diffusion MRI for measuring the temperature of cerebrospinal fluid within the lateral ventriclesACTA PAEDIATRICA, Issue 2 2010LR Kozak Abstract Aim:, Hypothermia is often induced to reduce brain injury in newborns, following perinatal hypoxic,ischaemic events, and in adults following traumatic brain injury, stroke or cardiac arrest. We aimed to devise a method, based on diffusion-weighted MRI, to measure non-invasively the temperature of the cerebrospinal fluid in the lateral ventricles. Methods:, The well-known temperature dependence of the water diffusion constant was used for the estimation of temperature. We carried out diffusion MRI measurements on a 3T Philips Achieva Scanner involving phantoms (filled with water or artificial cerebrospinal fluid while slowly cooling from 41 to 32°C) and healthy adult volunteers. Results:, The estimated temperature of water phantoms followed that measured using a mercury thermometer, but the estimates for artificial cerebrospinal fluid were 1.04°C lower. After correcting for this systematic difference, the estimated temperature within the lateral ventricles of volunteers was 39.9°C. Using diffusion directions less sensitive to cerebrospinal fluid flow, it was 37.7°C, which was in agreement with the literature. Conclusion:, Although further improvements are needed, measuring the temperature within the lateral ventricles using diffusion MRI is a viable method that may be useful for clinical applications. We introduced the method, identified sources of error and offered remedies for each. [source] Cool heads: ethical issues associated with therapeutic hypothermia for newbornsACTA PAEDIATRICA, Issue 2 20092Article first published online: 1 DEC 200, Dominic J Wilkinson Abstract Hypothermia is the first treatment for newborns with hypoxic-ischaemic encephalopathy (HIE) with consistent evidence of a reduction in the risk of death or severe disability. This paper addresses a number of ethical and practical issues faced by clinicians as cooling moves from an experimental treatment into practice. These issues are not unique to therapeutic hypothermia. They include the extrapolation of evidence from trials to clinical care, as well as the impact of hypothermia on prognosis and withdrawal of life-sustaining treatment. Conclusion: Hypothermia is a promising new therapy, but further research will be necessary to help resolve some of the ethical concerns associated with its use in newborns with HIE . [source] Use of plastic bags to prevent hypothermia at birth in preterm infants-do they work at lower gestations?ACTA PAEDIATRICA, Issue 2 2009CPH Ibrahim Abstract Background: Hypothermia at birth is strongly associated with mortality and morbidity in preterm infants. Occlusive wrapping of preterm infants during resuscitation, including polythene bags have been shown to prevent hypothermia. Objectives: To evaluate the effectiveness of the introduction of polythene bags at resuscitation of infants born below 30 weeks gestation in a large tertiary neonatal centre. Methods: Retrospective audit of admission temperatures of all infants born below 30 weeks gestation for two years before and two years after the introduction of polythene bags. Hypothermia was defined as admission axillary temperature < 36°C. Results: A total of 334 eligible infants were born during the study period. Two hundred and fifty-three (75.8%) had admission temperatures recorded. The incidence of hypothermia fell from 25% to 16%(p = 0.098) for the whole group since the introduction of polythene bags. The main reduction in hypothermia was seen in infants born above 28 weeks gestation (19.4% vs. 3.9%, p = 0.017). There was no significant effect in infants born between 28 weeks and 30 weeks (29.3% vs. 24.8%, p = 0.58). Conclusions Polythene bags are effective in reducing the incidence of hypothermia at admission in infants born below 30 weeks gestation. The benefit in infants born below 28 weeks gestation was only marginal. This is in contrast to previously published studies. This may be related to the comparatively low incidence of hypothermia at the study centre even prior to introduction of polythene bags. [source] Comparison of the Effects of Hypothermia at 33°C or 35°C after Cardiac Arrest in RatsACADEMIC EMERGENCY MEDICINE, Issue 4 2007Eric S. Logue BS Abstract Objectives: Hypothermia of 32°C,34°C induced after resuscitation from cardiac arrest improves neurologic recovery, but the optimal depth of cooling is unknown. Using a rat model, the authors tested the hypothesis that cooling to 35°C between hours 1 and 24 after resuscitation would improve neurologic outcome as much as cooling to 33°C. Methods: Halothane-anesthetized rats (n= 38) underwent 8 minutes of asphyxial cardiac arrest and resuscitation. Cranial temperature was maintained at 37°C before, during, and after arrest. Between one and 24 hours after resuscitation, cranial temperature was maintained at 33°C, 35°C, or 37°C using computer-controlled cooling fans and heating lamps. Neurologic scores were measured daily, and rats were killed at 14 days for histologic analysis. Neurons per high-powered field were counted in the CA1 region of the anterior hippocampus using neuronal nuclear antigen staining. Results: After 14 days, 12 of 12 rats (100%) cooled to 33°C, 11 of 12 rats (92%) cooled to 35°C, and ten of 14 rats (71%) cooled to 37°C survived, with hazard of death greater in the rats cooled to 37°C than in the combined hypothermia groups. Neurologic scores were worse in the rats cooled to 37°C than in the hypothermia groups on days 1, 2, and 3. Numbers of surviving neurons were similar between the groups cooled to 33°C and 35°C and were higher than in the group cooled to 37°C. Conclusions: These data illustrate that hypothermia of 35°C or 33°C over the first day of recovery improves neurologic scores and neuronal survival after cardiac arrest in rats. The benefit of induced hypothermia of 35°C appears to be similar to the benefit of 33°C. [source] | |||||||||||||||||||||||||||||||||||||