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Tan YL, Tey SM, Ho HK. Moderate Hypothermia Effectively Alleviates Acetaminophen-Induced Liver Injury With Prolonged Action Beyond Cooling. Dose Response 2020; 18:1559325820970846. [PMID: 33239997 PMCID: PMC7675884 DOI: 10.1177/1559325820970846] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 10/11/2020] [Accepted: 10/13/2020] [Indexed: 12/19/2022] Open
Abstract
Acetaminophen (APAP) overdose accounts for the highest incidence of acute liver failure, despite the availability of an antidote i.e. N-acetylcysteine. This calls for alternative strategies to manage APAP-induced liver injury (AILI). Therapeutic hypothermia has been explored in past studies for hepatoprotection, but these phenomenal reports lack clarification of its optimal window for application, and mechanistic effects in specific AILI. Hence, we conducted an in vitro study with transforming growth factor-α transgenic mouse hepatocytes cell line, TAMH, and human liver hepatocytes cell line, L-02, where cells were conditioned with deep (25°C) or moderate (32°C) hypothermia before, during or after APAP toxicity. Cell viability was evaluated as a hallmark of cytoprotection, along with cell death. Simultaneously, cold shock proteins (CSPs) and heat shock proteins expressions were monitored; key liver functions including drug-metabolizing ability and hepatic clearance were also investigated. Herein, we demonstrated significant hepatoprotection with 24-hour moderate hypothermic conditioning during AILI and this effect sustained for at least 24 hours of rewarming. Such liver preservation was associated with a CSP—RNA-binding motif protein 3 (RBM3) as its knockdown promptly abolished the cytoprotective effects of hypothermia. With mild and reversible liver perturbations, hypothermic therapy appears promising and its RBM3 involvement deserves future exploration.
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Affiliation(s)
- Yeong Lan Tan
- Department of Pharmacy, Faculty of Science, National University of Singapore, Singapore.,NUS Graduate School for Integrative Sciences & Engineering, Centre for Life Sciences, National University of Singapore, Singapore
| | - Siew Min Tey
- Department of Pharmacy, Faculty of Science, National University of Singapore, Singapore
| | - Han Kiat Ho
- Department of Pharmacy, Faculty of Science, National University of Singapore, Singapore.,NUS Graduate School for Integrative Sciences & Engineering, Centre for Life Sciences, National University of Singapore, Singapore
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New application of a traditional vasoactive agent, sodium nitroprusside, in targeted temperature management during cardiac arrest and resuscitation. Crit Care Med 2015; 43:924-5. [PMID: 25768362 DOI: 10.1097/ccm.0000000000000844] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Holzer M. Therapeutic hypothermia following cardiac arrest. Best Pract Res Clin Anaesthesiol 2014; 27:335-46. [PMID: 24054512 DOI: 10.1016/j.bpa.2013.07.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2013] [Accepted: 07/23/2013] [Indexed: 11/19/2022]
Abstract
More than 10 years ago, the randomised studies of therapeutic hypothermia after cardiac arrest showed significant improvement of neurological outcome and survival. Since then, it has become clear that most of the possible adverse events of therapeutic hypothermia are mild and can easily be controlled by proper administration of intensive care. Although implementation of this effective therapy is quite successful, many questions of the exact treatment protocol still remain unanswered. Therapeutic hypothermia treatment therefore must be tailored to the specific patient's needs. Hence, the exact level of target temperature, duration of cooling, rewarming, timing of the therapy and concomitant medication to facilitate therapeutic hypothermia will be important in the future. Additionally, the use of a post-resuscitation treatment bundle (specialised cardiac-arrest centres including intensive post-resuscitation care, appropriate haemodynamic and respiratory management, therapeutic hypothermia and percutaneous coronary intervention) could further improve treatment of cardiac arrest.
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Affiliation(s)
- Michael Holzer
- Department of Emergency Medicine, Medical University of Vienna, Vienna, Austria.
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Abstract
Full cerebral recovery after cardiopulmonary resuscitation is still a rare event. Unfortunately, up to now, no specific and outcome-improving therapy was available after such events. From several cases it is known that low body and brain temperature during a cardiocirculatory arrest improves the neurological outcome following these events. As it is not possible in acute events to induce hypothermia beforehand, whether cooling after the insult could also be protective was evaluated. After animal studies in the 1990s and first clinical pilot trials of mild therapeutic and induced hypothermia, two randomized trials of hypothermic therapy after successful resuscitation after cardiac arrest were conducted. These studies demonstrated that hypothermia after cardiac arrest could improve neurological outcome as well as overall mortality.
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Affiliation(s)
- Michael Holzer
- Department of Emergency Medicine, University of Vienna, Universitätsklinik für Notfallmedizin, AKH--Wien, Austria.
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Application of mild therapeutic hypothermia on stroke: a systematic review and meta-analysis. Stroke Res Treat 2012; 2012:295906. [PMID: 22567539 PMCID: PMC3329674 DOI: 10.1155/2012/295906] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2011] [Accepted: 12/06/2011] [Indexed: 11/18/2022] Open
Abstract
Background. Stroke occurs due to an interruption in cerebral blood supply affecting neuronal function. Body temperature on hospital admission is an important predictor of clinical outcome. Therapeutic hypothermia is promising in clinical settings for stroke neuroprotection. Methods. MEDLINE/PubMed, CENTRAL, Stroke Center, and ClinicalTrials.gov were systematically searched for hypothermia intervention induced by external or endovascular cooling for acute stroke. NIH Stroke Scale (NIHSS) and modified Rankin Scale (mRS) were the main stroke scales used, and mortality was also reported. A meta-analysis was carried out on stroke severity and mortality. Results. Seven parallel-controlled clinical trials were included in the meta-analysis. Sample sizes ranged from 18 to 62 patients, yielding a total of 288. Target temperature (∼33°C) was reached within 3-4 hours. Stroke severity (Cohen's d = −0.17, 95% CI: −0.42 to 0.08, P = 0.32; I2 = 73%; Chi2 = 21.89, P = 0.0001) and mortality (RR = 1.60, 95% CI: 0.93 to 2.78, P = 0.11; I2 = 0%; Chi2 = 2.88, P = 0.72) were not significantly affected by hypothermia. Discussion. Hypothermia does not significantly improve stroke severity; however, this finding should be taken with caution due to the high heterogeneity and limited number of included studies. No impact on mortality was observed.
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Yu T, Barbut D, Ristagno G, Cho JH, Sun S, Li Y, Weil MH, Tang W. Survival and neurological outcomes after nasopharyngeal cooling or peripheral vein cold saline infusion initiated during cardiopulmonary resuscitation in a porcine model of prolonged cardiac arrest. Crit Care Med 2010; 38:916-21. [PMID: 20081534 DOI: 10.1097/ccm.0b013e3181cd1291] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE We have previously demonstrated that nasopharyngeal cooling initiated during cardiopulmonary resuscitation improves the success of resuscitation. In this study, we compared the effects of nasopharyngeal cooling with cold saline infusion initiated during cardiopulmonary resuscitation on resuscitation outcome in a porcine model of prolonged cardiac arrest. We hypothesized that nasopharyngeal cooling initiated during cardiopulmonary resuscitation would yield better resuscitation outcome when compared with cold saline infusion. DESIGN Randomized, prospective animal study. SETTING University-affiliated research laboratory. SUBJECTS Yorkshire-X domestic pigs (Sus scrofa). INTERVENTIONS Ventricular fibrillation was induced in 14 pigs weighing 38 +/- 2 kg. After 15 mins of untreated ventricular fibrillation, cardiopulmonary resuscitation was performed for 5 mins before defibrillation. Coincident with the start of cardiopulmonary resuscitation, animals were randomly assigned to receive nasopharyngeal cooling with the aid of the RhinoChill Device (BeneChill, San Diego, CA) or cold saline infusion with 30 mL/kg 4 degrees C saline. One hour after restoration of spontaneous circulation, surface cooling was begun with the aid of a water blanket in both groups and maintained for 4 hrs. MEASUREMENTS AND MAIN RESULTS Jugular vein temperature significantly decreased in animals subjected to nasopharyngeal cooling in comparison with those receiving cold saline infusion (p < .01). Core temperature, however, decreased only in animals receiving cold saline infusion (p < .01). Coronary perfusion pressure was significantly higher in the animals treated with nasopharyngeal cooling (p = .02). All seven animals treated with nasopharyngeal cooling were successfully resuscitated in contrast to only two animals resuscitated in the cold saline infusion group (p = .02). CONCLUSION In this model, nasopharyngeal cooling initiated during cardiopulmonary resuscitation improved the success of resuscitation compared to cooling with cold saline infusion.
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Affiliation(s)
- Tao Yu
- Weil Institute of Critical Care Medicine, Rancho Mirage, CA, USA
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Meade AJ, Meloni BP, Mastaglia FL, Knuckey NW. The application of cell penetrating peptides for the delivery of neuroprotective peptides/proteins in experimental cerebral ischaemia studies. ACTA ACUST UNITED AC 2009. [DOI: 10.6030/1939-067x-2.1.21] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Abella BS, Rhee JW, Huang KN, Vanden Hoek TL, Becker LB. Induced hypothermia is underused after resuscitation from cardiac arrest: a current practice survey. Resuscitation 2005; 64:181-6. [PMID: 15680527 DOI: 10.1016/j.resuscitation.2004.09.014] [Citation(s) in RCA: 179] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2004] [Revised: 09/06/2004] [Accepted: 09/06/2004] [Indexed: 12/12/2022]
Abstract
BACKGROUND Important recent work has demonstrated that the use of induced hypothermia can improve survival and neurologic recovery after cardiac arrest. We wished to ascertain the extent to which physicians were using this treatment, and what opinions are held by clinicians regarding its use. METHODS An internet-based survey of physicians was conducted, with physicians chosen at random from published directories of the Society for Academic Emergency Medicine, the American Thoracic Society, and the American Heart Association. Physicians were questioned regarding use of therapeutic hypothermia, methods employed, and/or reasons why they had not incorporated hypothermia into their care of cardiac arrest patients. RESULTS Completed surveys were collected from 265 physicians, including those practicing emergency medicine (41%), critical care (13%), and cardiology (24%). Respondents were geographically well distributed and the majority (94%) were at post-training level. Most respondents (78%) practiced at either larger referral hospitals or academic medical centers. When asked if they had ever used hypothermia following cardiac arrest, 87% said they had not. Among reasons cited for non-use, 49% felt that there were not enough data, 32% mentioned lack of incorporation of hypothermia into advanced cardiovascular life support (ACLS) protocols, and 28% felt that cooling methods were technically too difficult or too slow. CONCLUSION Despite compelling data supporting its use, hypothermia has yet to be broadly incorporated into physician practice. This highlights the need for improved awareness and education regarding this treatment option, as well as the need to consider hypothermia protocols for inclusion in future iterations of ACLS.
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Affiliation(s)
- Benjamin S Abella
- Emergency Resuscitation Center, Section of Emergency Medicine, University of Chicago Hospitals, 5841 S. Maryland Avenue, MC 5068 Chicago, IL 60637, USA.
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Hagioka S, Takeda Y, Takata K, Morita K. Nasopharyngeal cooling selectively and rapidly decreases brain temperature and attenuates neuronal damage, even if initiated at the onset of cardiopulmonary resuscitation in rats. Crit Care Med 2003; 31:2502-8. [PMID: 14530758 DOI: 10.1097/01.ccm.0000084845.76762.f4] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To determine the effectiveness of nasopharyngeal cooling for selective brain cooling and neuroprotection from ischemia. DESIGN Prospective animal study. SETTING Experimental laboratory in a university hospital. SUBJECTS Male Wistar rats (n = 28). INTERVENTIONS In study 1, hippocampal temperature was decreased to 31 degrees C under spontaneous circulation. In the nasopharyngeal cooling group, physiologic saline (5 degrees C) was infused to the bilateral nasal cavities at the rate of 100 mL.min-1.kg weight-1. In the whole body cooling group, a fan and a water blanket (5 degrees C) were used. In study 2, ischemia and resuscitation were performed in normothermic and nasopharyngeal cooling (initiated with resuscitation after 5 mins of ischemia and continued for 20 mins) groups. MEASUREMENTS AND MAIN RESULTS The hippocampal temperature was decreased to 31 degrees C in 7 +/- 2 mins without any change in the rectal temperature in the nasopharyngeal cooling group, whereas a decrease in hippocampal temperature to 31 degrees C took 33 +/- 1 mins in the whole body cooling group. Although skull base region was cooled by nasopharyngeal cooling, the epidural temperature of the parietal region was lower than the hippocampal temperature, indicating that brain temperature was hematogenously lowered. There was no difference between changes in cerebral blood flow or between the ratios of oxygen extraction from arterial blood in the head region in the nasopharyngeal cooling and whole body cooling groups. In the second study, all animals were successfully resuscitated, and the times required for recovery of mean arterial blood pressure (60 mm Hg) after resuscitation in the nasopharyngeal cooling and normothermic groups were the same. The histologic damage was significantly attenuated in the nasopharyngeal cooling group (33 +/- 21% cell death in the hippocampus) compared with that in the normothermic group (73 +/- 11%). CONCLUSIONS Nasopharyngeal cooling enables rapid and selective reductions in cortical and subcortical temperatures without disturbing the recovery of systemic circulation after resuscitation.
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Affiliation(s)
- Shingo Hagioka
- Department of Anesthesiology and Resuscitology, Okayama Medical School, Japan
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Takeda Y, Namba K, Higuchi T, Hagioka S, Takata K, Hirakawa M, Morita K. Quantitative evaluation of the neuroprotective effects of hypothermia ranging from 34 degrees C to 31 degrees C on brain ischemia in gerbils and determination of the mechanism of neuroprotection. Crit Care Med 2003; 31:255-60. [PMID: 12545025 DOI: 10.1097/00003246-200301000-00040] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE The present study was designed to determine whether the predominant factor responsible for neuroprotection of hypothermia ranging from 31 to 34 degrees C is prolongation of onset of ischemic depolarization or suppression of neuronal injury during ischemic depolarization and to quantitatively determine the neuroprotective effects of hypothermia of 34 degrees C and 31 degrees C. DESIGN Prospective animal study. SETTING A university research laboratory. SUBJECTS Eighty-nine gerbils. INTERVENTIONS Bilateral common carotid arteries were occluded for 3-20 mins. The brain temperature was set at 37 degrees C, 34 degrees C, or 31 degrees C before and during ischemic depolarization. MEASUREMENTS AND MAIN RESULTS DC potentials were measured in the CA1 region, where histologic evaluation was performed 7 days later. Onset times of ischemic depolarization were 1.3 +/- 0.2, 1.6 +/- 0.4, and 2.4 +/- 0.7 mins at 37 degrees C, 34 degrees C, and 31 degrees C, respectively. The logistic regression curve demonstrated a close relationship between duration of ischemic depolarization and neuronal damage and showed a rightward shift by lowering the brain temperature. In the 37 degrees C, 34 degrees C, and 31 degrees C groups, the durations of ischemic depolarization causing 50% neuronal damage were estimated to be 8.0, 14.2, and 26.0 mins, respectively, and the ischemia times causing 50% neuronal damage were estimated to be 4.9, 8.1, and 14.2 mins, respectively. CONCLUSIONS The onset of ischemic depolarization was prolonged in the 34 degrees C and 31 degrees C groups by only 0.3 and 1.1 mins, respectively, compared with that in the 37 degrees C group. Most of the neuroprotection by hypothermia was attributed to the suppression of neuronal injury during ischemic depolarization, suggesting that hypothermia has neuroprotective effects if it is initiated during the ischemic depolarization period. The results also indicate that the neuroprotective effect at 31 degrees C is about three times greater than that at 34 degrees C and that neuronal cells can withstand 2.9 times longer duration of ischemia at 31 degrees C than at 37 degrees C.
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Affiliation(s)
- Yoshimasa Takeda
- Department of Anesthesiology and Resuscitation, Okayama University Medical School, Okayama City, Japan.
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Feigin VL, Anderson CS, Rodgers A, Anderson NE, Gunn AJ. The emerging role of induced hypothermia in the management of acute stroke. J Clin Neurosci 2002; 9:502-7. [PMID: 12383404 DOI: 10.1054/jocn.2001.1072] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Current treatment of acute stroke remains unsatisfactory. This review presents experimental and clinical data which suggest that mild induced hypothermia could be a potent and practicable neuroprotective treatment of acute ischaemic stroke and intracerebral haemorrhage. Hypothermia, if proven to be safe, effective and widely practicable in patients with acute stroke, could have an enormous positive impact on reducing the burden of stroke worldwide. Critical issues that will need to be considered in a well designed randomised controlled trial of induced hypothermia in acute stroke patients are discussed.
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Affiliation(s)
- Valery L Feigin
- Clinical Trials Research Unit, University of Auckland, Auckland, New Zealand.
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Behringer W, Safar P, Wu X, Nozari A, Abdullah A, Stezoski SW, Tisherman SA. Veno-venous extracorporeal blood shunt cooling to induce mild hypothermia in dog experiments and review of cooling methods. Resuscitation 2002; 54:89-98. [PMID: 12104113 DOI: 10.1016/s0300-9572(02)00046-1] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Mild hypothermia (33-36 degrees C) might be beneficial when induced during or after insults to the brain (cardiac arrest, brain trauma, stroke), spinal cord (trauma), heart (acute myocardial infarction), or viscera (hemorrhagic shock). Reaching the target temperature rapidly in patients inside and outside hospitals remains a challenge. This study was to test the feasibility of veno-venous extracorporeal blood cooling for the rapid induction of mild hypothermia in dogs, using a simple pumping-cooling device. Ten custom-bred hunting dogs (21-28 kg) were lightly anesthetized and mechanically ventilated. In five dogs, two catheters were inserted through femoral veins, one peripheral and the other into the inferior vena cava. The catheters were connected via a coiled plastic tube as heat exchanger (15 m long, 3 mm inside diameter, 120 ml priming volume), which was immersed in an ice-water bath. A small roller-pump produced a veno-venous flow of 200 ml/min (about 10% of cardiac output). In five additional dogs (control group), a clinically practiced external cooling method was employed, using alcohol over the skin of the trunk and fanning plus ice-bags. During spontaneous normotension, veno-venous cooling delivered blood into the vena cava at 6.2 degrees C standard deviation (SD 1.4) and decreased tympanic membrane (Tty) temperature from 37.5 to 34.0 degrees C at 5.2 min (SD 0.7), and to 32.0 degrees C at 7.9 min (SD 1.3). Skin surface cooling decreased tympanic temperature from 37.5 to 34.0 degrees C at 19.9 min (SD 3.7), and to 32.0 degrees C at 29.9 (SD 5.1) (P=0.001). Heart rates at Tty 34 and 32 degrees C were significantly lower than at baseline in both groups, but within physiological range, without difference between groups. There were no arrhythmias. We conclude that in large dogs the induction of mild systemic hypothermia with extracorporeal veno-venous blood shunt cooling is simple and four times more rapid than skin surface cooling.
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Affiliation(s)
- Wilhelm Behringer
- Safar Center for Resuscitation Research, Departments of Anesthesiology and Critical Care Medicine, University of Pittsburgh, 3434 Fifth Avenue, Pittsburgh, PA 15260, USA.
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Ebmeyer U, Keilhoff G, Wolf G, Röse W. Strain specific differences in a cardio-pulmonary resuscitation rat model. Resuscitation 2002; 53:189-200. [PMID: 12009223 DOI: 10.1016/s0300-9572(02)00003-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
An asphyxial cardiac arrest rat model, originally developed for Sprague-Dawley rats, was transferred to a Wistar rat model. Several strain specific life support adjustments, i.e. ventilator settings, anaesthesia, and drug requirements, were necessary to stabilize the model for Wistar rats. Despite these arrangements numerous resuscitation related variables appeared different. Three groups were evaluated and compared: a temperature monitored Wistar group 1 (n=34), a temperature controlled Wistar group 2 (n=26) and a temperature controlled Sprague-Dawley group 3 (n=7). Overall, Wistar rats seem to have more sensitive cardio-circulatory system evidenced by a more rapid development of cardiac arrest (164 vs. 201 s), requiring higher adrenaline/epinephrine doses (10 vs. 5 microg/kg) and requiring more time for recovery after resuscitation (i.e. for return of blood pressure and blood gases). Without strict temperature control (as in groups 2+3 rats) group 1 rats went into spontaneous mild to moderate hypothermia during the first 24 h after restoration of spontaneous circulation (ROSC). Spontaneous hypothermia delayed the development of overall visible CA1 neuronal damage 24-48 h, but did not prevent it; therefore the model seemed to be suitable for future studies. Neuronal damages in the CA1 region in Wistar rats appeared to be more as shrunken cell bodies and pyknotic nuclei before resorption took place, whereas in Sprague-Dawley rats appeared in the same region.
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Affiliation(s)
- U Ebmeyer
- Institute of Medical Neurobiology, Otto-von-Guericke University Magdeburg, Leipziger Strasse 44, 39120 Magdeburg, Germany.
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Eshel G, Reisler G, Berkovitch M, Shapira S, Grauer E, Barr J. Comparison of fast versus slow rewarming following acute moderate hypothermia in rats. Paediatr Anaesth 2002; 12:235-42. [PMID: 11903937 DOI: 10.1046/j.1460-9592.2002.00801.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND The aim of this study was to compare the biochemical and physiological responses of fast vs. slow rewarming from moderate hypothermia in anaesthetized rats. METHODS Anaesthetized rats were surface cooled to 28 degrees C, for 20 min, then rewarmed either quickly over 30 min or slowly over 120 min with monitoring of vital signs, systemic vascular resistance (SVR), cardiac output, biochemical changes and activity for 31 days. RESULTS At hypothermia, cardiac output decreased to 77 +/- 38 ml x min(-1) and lactate increased to 4.62 +/- 4.73 mmol x l(-)1. Fast rewarming caused an abrupt increase in cardiac output (270 +/- 24 ml x min(-1)) and a sharp drop in SVR (325.6 +/- 23.3 dyne x s(-1) x cm(-5)), compared with a smoother course with cardiac output (142 +/- 18 ml x min(-1), P < 0.01) and SVR (662.8 +/- 41.0 dyne x s(-1) x cm(-5), P < 0.01), measured during slow rewarming. Lactate failed to return to normal values (upon returning to normothermia) (2.5 +/- 0.75 mmol x l(-1)) only in the fast rewarming group. In both groups, activity in the open field was not different from control rats. CONCLUSIONS In rats, moderate hypothermia for 20 min does not appear to cause lasting biochemical or behavioural consequences, whether rewarming lasted over 30 or 120 min. However, there was a greater early change in cardiac output and heart rate, due to systemic vasodilatation in the fast rewarming animals. These acute changes may have consequences in patients with compromised cardiovascular reserves.
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Affiliation(s)
- Gideon Eshel
- Pediatric Intensive Care Unit, Assaf Harofeh Medical Center, Sackler Faculty of Medicine, Tel-Aviv University, Zerifin, Israel
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Leonov Y, Safar P, Sterz F, Stezoski SW. Extending the golden hour of hemorrhagic shock tolerance with oxygen plus hypothermia in awake rats. An exploratory study. Resuscitation 2002; 52:193-202. [PMID: 11841888 DOI: 10.1016/s0300-9572(01)00453-1] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
In a previous study of volume-controlled hemorrhagic shock (HS) in awake rats, without fluid resuscitation, either breathing of 100% oxygen or moderate hypothermia while breathing air, increased survival time. We hypothesized that combining oxygen and hypothermia can maximally extend the "golden hour" of HS from which resuscitation can be successful in terms of survival rate. Rats were prepared under light general anesthesia, breathing spontaneously via face mask, and then awakened for 2 h. Then, 3.25 ml arterial blood/100 g were withdrawn over 20 min. At the end of HS of 30, 60, 90 or 180 min duration, the shed blood was reinfused. Breathing was spontaneous. Survival endpoint was 24 h or earlier death. HS of 30 or 60 min was used for preliminary experiments; HS of 90 or 180 min for 35 definitive experiments. Control groups A-1 and B-1 had normothermia (rectal temperature 37.5 degrees C) and were breathing air. Treatment groups A-2 and B-2 had total body surface cooling during HS to rectal temperature 32 degrees C and were breathing 100% O(2). Arterial pressure during HS was higher in the hypothermia-O(2) groups. With HS of 90 min, in the normothermia-air group A-1 (n=10), none of the 10 rats survived to 3 h; while in the hypothermia-O(2) group A-2 (n=5), all rats survived to 24 h (P<0.001). With HS of 180 min, in the normothermia-air group B-1 (n=10), three of 10 rats survived to 3 h and 24 h (hypotension during HS in these three survivors was less severe than in the non-survivors); and in the hypothermia-O(2) group B-2 (n=10) all 10 rats survived to 24 h (P<0.003). We conclude that moderate hypothermia (32 degrees C) plus 100% oxygen inhalation during volume-controlled HS in awake rats mitigates hypotension and increases the chance of survival. It enables survival even after 3 h of moderate HS.
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Affiliation(s)
- Yuval Leonov
- Safar Center for Resuscitation Research (SCRR), Department of Anesthesiology and Critical Care Medicine, University of Pittsburgh Medical Center, 3434 Fifth Avenue, Pittsburgh, PA 15260, USA
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Abstract
This article is adapted from a presentation given at the 1999 SAEM annual meeting by Dr. Peter Safar. Dr. Safar has been involved in resuscitation research for 44 years, and is a distinguished professor and past initiating chairman of the Department of Anesthesiology and Critical Care Medicine at the University of Pittsburgh. He is the founder and director of the Safar Center for Resuscitation Research at the University of Pittsburgh, and has been the research mentor of many critical care and emergency medicine research fellows. Here he presents a brief history of past accomplishments, recent findings, and future potentials for resuscitation research. Additional advances in resuscitation, from acute terminal states and clinical death, will build upon the lessons learned from the history of reanimatology, including optimal delivery by emergency medical services of already documented cardiopulmonary cerebral resuscitation, basic-advanced-prolonged life support, and future scientific breakthroughs. Current controversies, such as how to best educate the public in life-supporting first aid, how to restore normotensive spontaneous circulation after cardiac arrest, how to rapidly induce mild hypothermia for cerebral protection, and how to minimize secondary insult after cerebral ischemia, are discussed, and must be resolved if advances are to be made. Dr. Safar also summarizes future technologies already under preliminary investigation, such as ultra-advanced life support for reversing prolonged cardiac arrest, extending the "golden hour" of shock tolerance, and suspended animation for delayed resuscitation.
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Affiliation(s)
- P Safar
- Safar Center for Resuscitation Research, University of Pittsburgh, PA 15260, USA.
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Abstract
Despite its proven clinical application for protection-preservation of the brain and heart during cardiac surgery, hypothermia research has fallen in and out of favor many times since its inception. Since the 1980s, there has been renewed research and clinical interest in therapeutic hypothermia for resuscitation of the brain after cardiac arrest or TBI and for preservation-resuscitation of extracerebral organs, particularly the abdominal viscera in low-flow states such as HS. Although some of the fears regarding the side effects of hypothermia are warranted, others are not. Without further laboratory and clinical studies, the significance of these effects cannot be determined and ways to overcome these problems cannot be developed. Currently, at the turn of the century, there are significant data demonstrating the benefit of mild-to-moderate hypothermia in animals and humans after cardiac arrest or TBI and in animals during and after HS. The clinical implications of uncontrolled versus controlled hypothermia in trauma patients and the best way to assure poikilothermia for cooling without shivering are still unclear. It is time to consider a prospective trial of therapeutic, controlled hypothermia for patients during traumatic HS and resuscitation. The authors believe that the new millennium will witness remarkable advantages of the use of controlled hypothermia in trauma. Starting in the prehospital phase, mild hypothermia will be induced in hypovolemic patients, which will not only decrease the immediate mortality rate but perhaps also will protect cells and reduce the likelihood of secondary inflammatory response syndrome, multiple organ failure, and late deaths. The most futuristic applications will be hypothermic strategies to achieve prolonged suspended animation for delayed resuscitation in traumatic exsanguination cardiac arrest.
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Affiliation(s)
- S A Tisherman
- Safar Center for Resuscitation Research, University of Pittsburgh, Pennsylvania, USA.
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Schwab S, Schwarz S, Spranger M, Keller E, Bertram M, Hacke W. Moderate hypothermia in the treatment of patients with severe middle cerebral artery infarction. Stroke 1998; 29:2461-6. [PMID: 9836751 DOI: 10.1161/01.str.29.12.2461] [Citation(s) in RCA: 377] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND PURPOSE Animal research and clinical studies in head trauma patients suggest that moderate hypothermia may improve outcome by attenuating the deleterious metabolic processes in neuronal injury. Clinical studies on moderate hypothermia in the treatment of acute ischemic stroke patients are still lacking. METHODS Moderate hypothermia was induced in 25 patients with severe ischemic stroke in the middle cerebral artery (MCA) territory for therapy of postischemic brain edema. Hypothermia was induced within 14+/-7 hours after stroke onset and achieved by external cooling with cooling blankets, cold infusions, and cold washing. Patients were kept at 33 degreesC body-core temperature for 48 to 72 hours, and intracranial pressure (ICP), cerebral perfusion pressure, and brain temperature were monitored continuously. Outcome at 4 weeks and 3 months after the stroke was analyzed with the Scandinavian Stroke Scale (SSS) and Barthel index. The side effects of induced moderate hypothermia were analyzed. RESULTS Fourteen patients survived the hemispheric stroke (56%). Neurological outcome according to the SSS score was 29 (range, 25 to 37) 4 weeks after stroke and 38 (range 28 to 48) 3 months after stroke. During hypothermia, elevated ICP values could be significantly reduced. Herniation caused by a secondary rise in ICP after rewarming was the cause of death in all remaining patients. The most frequent complication of moderate hypothermia was pneumonia in 10 of the 25 patients (40%). Other severe side effects of hypothermia could not be detected. CONCLUSIONS Moderate hypothermia in the treatment of severe cerebral ischemia is not associated with severe side effects. Moderate hypothermia can help to control critically elevated ICP values in severe space-occupying edema after MCA stroke and may improve clinical outcome in these patients.
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Affiliation(s)
- S Schwab
- Department of Neurology, University of Heidelberg, Heidelberg, Germany.
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Abstract
Non-invasive brain temperature measurements using proton magnetic resonance spectroscopy were used to test the hypothesis that localized head cooling would reduce brain temperature in 10 normal adult humans. Temperature reductions of the head surface to 15.8+/-3.5 degrees C did not reduce brain temperature measured in the superficial cortex (36.8+/-0.5 degrees C) or thalamus (36.6+/-0.7 degrees C), as compared to measurements obtained with a head surface temperature of 34.7+/-1.6 degrees C (37.0+/-0.6 degrees C and 36.6+/-0.4 degrees C, respectively). There was no change in the temperature gradient from the superficial to deep brain locations in the presence or absence of head cooling, and brain temperature did not decrease as a function of the duration of head cooling for periods up to 50 min. There was no correlation between the scalp surface (range: 10-38 degrees C) and brain temperature at either the deep or superficial locations.
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Affiliation(s)
- R J Corbett
- Ralph Rogers and Mary Nell Magnetic Resonance Center, Department of Radiology, University of Texas Southwestern Medical Center at Dallas, 75235-9085, USA
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