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Kuzmiszyn AK, Selli AL, Furuholmen M, Smaglyukova N, Kondratiev T, Fuskevåg OM, Sager G, Dietrichs ES. Moderate but not severe hypothermia increases intracellular cyclic AMP through preserved production and reduced elimination. Cryobiology 2023; 110:18-23. [PMID: 36649914 DOI: 10.1016/j.cryobiol.2023.01.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Revised: 01/12/2023] [Accepted: 01/12/2023] [Indexed: 01/15/2023]
Abstract
Rewarming from accidental hypothermia could be complicated by acute cardiac dysfunction but providing supportive pharmacotherapy at low core temperatures is challenging. Several pharmacological strategies aim to improve cardiovascular function by increasing cAMP in cardiomyocytes as well as cAMP and cGMP levels in vascular smooth muscle, but it is not clear what effects temperature has on cellular elimination of cAMP and cGMP. We therefore studied the effects of differential temperatures from normothermia to deep hypothermia (37 °C-20 °C) on cAMP levels in embryonic H9c2 cardiac cells and elimination of cAMP and cGMP by PDE-enzymes and ABC-transporter proteins. Our experiments showed significant elevation of intracellular cAMP in H9c2-cells at 30 °C but not 20 °C. Elimination of both cAMP and cGMP through ABC transport-proteins and PDE-enzymes showed a temperature dependent reduction. Accordingly, the increased cardiomyocyte cAMP-levels during moderate hypothermia appears an effect of preserved production and reduced elimination at 30 °C. This correlates with earlier in vivo findings of a positive inotropic effect of moderate hypothermia.
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Affiliation(s)
- Adrina Kalasho Kuzmiszyn
- Experimental and Clinical Pharmacology, Department of Medical Biology, UiT - the Arctic University of Norway, Tromsø, Norway; Norwegian Air Ambulance Foundation, Research and Development Department, Oslo, Norway; Division of Surgical Medicine and Intensive Care, University Hospital of North Norway, Tromsø, Norway
| | - Anders Lund Selli
- Experimental and Clinical Pharmacology, Department of Medical Biology, UiT - the Arctic University of Norway, Tromsø, Norway
| | - Markus Furuholmen
- Experimental and Clinical Pharmacology, Department of Medical Biology, UiT - the Arctic University of Norway, Tromsø, Norway
| | - Natalia Smaglyukova
- Experimental and Clinical Pharmacology, Department of Medical Biology, UiT - the Arctic University of Norway, Tromsø, Norway
| | - Timofei Kondratiev
- Anesthesia and Critical Care Research Group, Department of Clinical Medicine, UiT - the Arctic University of Norway, Tromsø, Norway
| | - Ole-Martin Fuskevåg
- Department of Laboratory Medicine, Division of Diagnostic Services, University Hospital of North Norway, Tromsø, Norway
| | - Georg Sager
- Experimental and Clinical Pharmacology, Department of Medical Biology, UiT - the Arctic University of Norway, Tromsø, Norway
| | - Erik Sveberg Dietrichs
- Experimental and Clinical Pharmacology, Department of Medical Biology, UiT - the Arctic University of Norway, Tromsø, Norway; Center for Psychopharmacology, Diakonhjemmet Hospital, Oslo, Norway.
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2
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Vedantam A, Jimsheleishvili G, Harrop JS, Alberga LR, Ahmad FU, Murphy RK, Jackson JB, Rodgers RB, Levi AD. A prospective multi-center study comparing the complication profile of modest systemic hypothermia versus normothermia for acute cervical spinal cord injury. Spinal Cord 2022; 60:510-515. [PMID: 35013548 DOI: 10.1038/s41393-021-00747-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 12/24/2021] [Accepted: 12/29/2021] [Indexed: 11/09/2022]
Abstract
STUDY DESIGN Prospective multi-center trial. OBJECTIVES To characterize the complication profile associated with modest systemic hypothermia after acute cervical SCI in a prospective multi-center study. SETTING Five trauma centers in the United States. METHODS We analyzed data from a prospective, multi-center trial on the use of modest systemic hypothermia for acute cervical SCI. Patients with acute cervical SCI were assigned to receive modest systemic hypothermia (33 C) or standard of care medical treatment. Patients in the hypothermia group were cooled to 33 C and maintained at the target temperature for 48 h. Complication profile and the rate of complications within the first 6 weeks after injury were compared between the two groups. Multiple regression analysis was performed to determine risk factors for complications after injury. RESULTS Fifty patients (hypothermia: 27, control: 23) were analyzed for this study. Median age was significantly lower in the hypothermia arm (39 vs 59 years, p = 0.02). Respiratory complications were the most common (hypothermia: 55.6% vs control: 52.2%, p = 0.81). The rate of deep vein thrombosis was not significantly different between the two groups (hypothermia: 14.8% vs control 17.4%, p = 0.71). The rate of complications was not statistically different between the two groups. CONCLUSION In this prospective multi-center controlled trial, preliminary data show that modest systemic hypothermia was not associated with increased risk of complications within the first 6 weeks after acute cervical SCI. TRIAL INFORMATION The study is registered on clinicaltrials.gov NCT02991690. University of Miami IRB (Central IRB) approval No.: 20160758. Emory University IRB #IRB00093786.
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Affiliation(s)
- Aditya Vedantam
- Department of Neurosurgery, Medical College of Wisconsin, Milwaukee, WI, USA
| | - George Jimsheleishvili
- The Miami Project to Cure Paralysis, Miami, FL, USA.,Department of Neurological Surgery, University of Miami/Jackson Health System, Miami, FL, USA
| | - James S Harrop
- Department of Neurosurgery, Thomas Jefferson University, Philadelphia, PA, USA
| | | | - Faiz U Ahmad
- Department of Neurological Surgery, Emory University School of Medicine, Atlanta, GA, USA
| | - Rory K Murphy
- Barrow Brain and Spine and Honor Health, Phoenix, AZ, USA
| | - J Benjamin Jackson
- Department of Orthopedic Surgery, University of South Carolina, Columbia, SC, USA
| | | | - Allan D Levi
- The Miami Project to Cure Paralysis, Miami, FL, USA. .,Department of Neurological Surgery, University of Miami/Jackson Health System, Miami, FL, USA.
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3
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Tveita T, Sieck GC. Physiological Impact of Hypothermia: The Good, the Bad and the Ugly. Physiology (Bethesda) 2021; 37:69-87. [PMID: 34632808 DOI: 10.1152/physiol.00025.2021] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Hypothermia is defined as a core body temperature of < 35°C, and as body temperature is reduced the impact on physiological processes can be beneficial or detrimental. The beneficial effect of hypothermia enables circulation of cooled experimental animals to be interrupted for 1-2 h without creating harmful effects, while tolerance of circulation arrest in normothermia is between 4 and 5 min. This striking difference has attracted so many investigators, experimental as well as clinical, to this field, and this discovery was fundamental for introducing therapeutic hypothermia in modern clinical medicine in the 1950's. Together with the introduction of cardiopulmonary bypass, therapeutic hypothermia has been the cornerstone in the development of modern cardiac surgery. Therapeutic hypothermia also has an undisputed role as a protective agent in organ transplantation and as a therapeutic adjuvant for cerebral protection in neonatal encephalopathy. However, the introduction of therapeutic hypothermia for organ protection during neurosurgical procedures or as a scavenger after brain and spinal trauma has been less successful. In general, the best neuroprotection seems to be obtained by avoiding hyperthermia in injured patients. Accidental hypothermia occurs when endogenous temperature control mechanisms are incapable of maintaining core body temperature within physiologic limits and core temperature becomes dependent on ambient temperature. During hypothermia spontaneous circulation is considerably reduced and with deep and/or prolonged cooling, circulatory failure may occur, which may limit safe survival of the cooled patient. Challenges that limit safe rewarming of accidental hypothermia patients include cardiac arrhythmias, uncontrolled bleeding, and "rewarming shock".
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Affiliation(s)
- Torkjel Tveita
- Anesthesia and Critical Care Research Group, Department of Clinical Medicine, UiT The Arctic University of Norway, Tromsø, Norway.,Division of Surgical Medicine and Intensive Care, University Hospital of North Norway, Tromsø, Norway
| | - Gary C Sieck
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota, United States
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4
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Mohyuddin R, Dietrichs ES, Sundaram P, Kondratiev T, Figenschou MF, Sieck GC, Tveita T. Cardiovascular Effects of Epinephrine During Experimental Hypothermia (32°C) With Spontaneous Circulation in an Intact Porcine Model. Front Physiol 2021; 12:718667. [PMID: 34552506 PMCID: PMC8450451 DOI: 10.3389/fphys.2021.718667] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Accepted: 06/25/2021] [Indexed: 01/05/2023] Open
Abstract
Aims: Rewarming from accidental hypothermia and therapeutic temperature management could be complicated by cardiac dysfunction. Although pharmacologic support is often applied when rewarming these patients, updated treatment recommendations are lacking. There is an underlying deficiency of clinical and experimental data to support such interventions and this prevents the development of clinical guidelines. Accordingly, we explored the clinical effects of epinephrine during hypothermic conditions. Materials and methods: Anesthetized pigs were immersion cooled to 32°C. Predetermined variables were compared at temperature/time-point baseline, after receiving 30 ng/kg/min and 90 ng/kg/min epinephrine infusions: (1) before and during hypothermia at 32°C, and after rewarming to 38°C (n = 7) and (2) a time-matched (5 h) normothermic control group (n = 5). Results: At 32°C, both stroke volume and cardiac output were elevated after 30 ng/kg/min administration, while systemic vascular resistance was reduced after 90 ng/kg/min. Epinephrine infusion did not alter blood flow in observed organs, except small intestine flow, and global O2 extraction rate was significantly reduced in response to 90 ng/kg/min infusion. Electrocardiographic measurements were unaffected by epinephrine infusion. Conclusion: Administration of both 30 ng/kg/min and 90 ng/kg/min at 32°C had a positive inotropic effect and reduced afterload. We found no evidence of increased pro-arrhythmic activity after epinephrine infusion in hypothermic pigs. Our experiment therefore suggests that β₁-receptor stimulation with epinephrine could be a favorable strategy for providing cardiovascular support in hypothermic patients, at core temperatures >32°C.
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Affiliation(s)
- Rizwan Mohyuddin
- Anesthesia and Critical Care Research Group, Department of Clinical Medicine, UiT, The Arctic University of Norway, Tromsø, Norway
| | - Erik Sveberg Dietrichs
- Experimental and Clinical Pharmacology Research Group, Department of Medical Biology, UiT, The Arctic University of Norway, Tromsø, Norway.,Center for Psychopharmacology, Diakonhjemmet Hospital, Oslo, Norway
| | - Predip Sundaram
- Anesthesia and Critical Care Research Group, Department of Clinical Medicine, UiT, The Arctic University of Norway, Tromsø, Norway
| | - Timofey Kondratiev
- Anesthesia and Critical Care Research Group, Department of Clinical Medicine, UiT, The Arctic University of Norway, Tromsø, Norway
| | - Marie Fjellanger Figenschou
- Anesthesia and Critical Care Research Group, Department of Clinical Medicine, UiT, The Arctic University of Norway, Tromsø, Norway.,Division of Surgical Medicine and Intensive Care, University Hospital of North Norway, Tromsø, Norway
| | - Gary C Sieck
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, MI, United States
| | - Torkjel Tveita
- Anesthesia and Critical Care Research Group, Department of Clinical Medicine, UiT, The Arctic University of Norway, Tromsø, Norway.,Division of Surgical Medicine and Intensive Care, University Hospital of North Norway, Tromsø, Norway.,Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, MI, United States
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Myrka A, Buck L. Cytoskeletal Arrest: An Anoxia Tolerance Mechanism. Metabolites 2021; 11:metabo11080561. [PMID: 34436502 PMCID: PMC8401981 DOI: 10.3390/metabo11080561] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 08/13/2021] [Accepted: 08/14/2021] [Indexed: 12/16/2022] Open
Abstract
Polymerization of actin filaments and microtubules constitutes a ubiquitous demand for cellular adenosine-5′-triphosphate (ATP) and guanosine-5′-triphosphate (GTP). In anoxia-tolerant animals, ATP consumption is minimized during overwintering conditions, but little is known about the role of cell structure in anoxia tolerance. Studies of overwintering mammals have revealed that microtubule stability in neurites is reduced at low temperature, resulting in withdrawal of neurites and reduced abundance of excitatory synapses. Literature for turtles is consistent with a similar downregulation of peripheral cytoskeletal activity in brain and liver during anoxic overwintering. Downregulation of actin dynamics, as well as modification to microtubule organization, may play vital roles in facilitating anoxia tolerance. Mitochondrial calcium release occurs during anoxia in turtle neurons, and subsequent activation of calcium-binding proteins likely regulates cytoskeletal stability. Production of reactive oxygen species (ROS) formation can lead to catastrophic cytoskeletal damage during overwintering and ROS production can be regulated by the dynamics of mitochondrial interconnectivity. Therefore, suppression of ROS formation is likely an important aspect of cytoskeletal arrest. Furthermore, gasotransmitters can regulate ROS levels, as well as cytoskeletal contractility and rearrangement. In this review we will explore the energetic costs of cytoskeletal activity, the cellular mechanisms regulating it, and the potential for cytoskeletal arrest being an important mechanism permitting long-term anoxia survival in anoxia-tolerant species, such as the western painted turtle and goldfish.
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Affiliation(s)
- Alexander Myrka
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON M5S 3G5, Canada;
| | - Leslie Buck
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON M5S 3G5, Canada;
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, ON M5S 3G5, Canada
- Correspondence: ; Tel.: +1-416-978-3506
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6
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Nilsen JH, Schanche T, Kondratiev TV, Hevrøy O, Sieck GC, Tveita T. Maintaining intravenous volume mitigates hypothermia-induced myocardial dysfunction and accumulation of intracellular Ca 2. Exp Physiol 2021; 106:1196-1207. [PMID: 33728692 DOI: 10.1113/ep089397] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Accepted: 03/11/2021] [Indexed: 11/08/2022]
Abstract
NEW FINDINGS What is the central question of this study? Detailed guidelines for volume replacement to counteract hypothermia-induced intravascular fluid loss are lacking. Evidence suggests colloids might have beneficial effects compared to crystalloids. Are central haemodynamic function and level of hypothermia-induced calcium overload, as a marker of cardiac injury, restored by fluid substitution during rewarming, and are colloids favourable to crystalloids? What is the main finding and its importance? Infusion with crystalloid or dextran during rewarming abolished post-hypothermic cardiac dysfunction, and partially mitigated myocardial calcium overload. The effects of volume replacement to support haemodynamic function are comparable to those using potent cardio-active drugs. These findings underline the importance of applying intravascular volume replacement to maintain euvolaemia during rewarming. ABSTRACT Previous research exploring pathophysiological mechanisms underlying circulatory collapse after rewarming victims of severe accidental hypothermia has documented post-hypothermic cardiac dysfunction and hypothermia-induced elevation of intracellular Ca2+ concentration ([Ca2+ ]i ) in myocardial cells. The aim of the present study was to examine if maintaining euvolaemia during rewarming mitigates cardiac dysfunction and/or normalizes elevated myocardial [Ca2+ ]i . A total of 21 male Wistar rats (300 g) were surface cooled to 15°C, then maintained at 15°C for 4 h, and subsequently rewarmed to 37°C. The rats were randomly assigned to one of three groups: (1) non-intervention control (n = 7), (2) dextran treated (i.v. 12 ml/kg dextran 70; n = 7), or (3) crystalloid treated (24 ml/kg 0.9% i.v. saline; n = 7). Infusions occurred during the first 30 min of rewarming. Arterial blood pressure, stroke volume (SV), cardiac output (CO), contractility (dP/dtmax ) and blood gas changes were measured. Post-hypothermic changes in [Ca2+ ]i were measured using the method of radiolabelled Ca2+ (45 Ca2+ ). Untreated controls displayed post-hypothermic cardiac dysfunction with significantly reduced CO, SV and dP/dtmax . In contrast, rats receiving crystalloid or dextran treatment showed a return to pre-hypothermic control levels of CO and SV after rewarming, with the dextran group displaying significantly better amelioration of post-hypothermic cardiac dysfunction than the crystalloid group. Compared to the post-hypothermic increase in myocardial [Ca2+ ]i in non-treated controls, [Ca2+ ]i values with crystalloid and dextran did not increase to the same extent after rewarming. Volume replacement with crystalloid or dextran during rewarming abolishes post-hypothermic cardiac dysfunction, and partially mitigates the hypothermia-induced elevation of [Ca2+ ]i .
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Affiliation(s)
- Jan Harald Nilsen
- Anesthesia and Critical Care research group, Department of Clinical Medicine, UiT, Arctic University of Norway, Tromsø, Norway.,Department of Research and Education, Norwegian Air Ambulance Foundation, Drøbak, Norway.,Division of Surgical Medicine and Intensive Care, University Hospital of North Norway, Tromsø, Norway
| | - Torstein Schanche
- Anesthesia and Critical Care research group, Department of Clinical Medicine, UiT, Arctic University of Norway, Tromsø, Norway.,Department of Physiology & Biomedical Engineering, Mayo Clinic, Rochester, MN, USA
| | - Timofei V Kondratiev
- Anesthesia and Critical Care research group, Department of Clinical Medicine, UiT, Arctic University of Norway, Tromsø, Norway
| | - Olav Hevrøy
- Department of Anesthesiology and Intensive Care, Haukeland University Hospital, Bergen, Norway
| | - Gary C Sieck
- Department of Physiology & Biomedical Engineering, Mayo Clinic, Rochester, MN, USA
| | - Torkjel Tveita
- Anesthesia and Critical Care research group, Department of Clinical Medicine, UiT, Arctic University of Norway, Tromsø, Norway.,Division of Surgical Medicine and Intensive Care, University Hospital of North Norway, Tromsø, Norway.,Department of Physiology & Biomedical Engineering, Mayo Clinic, Rochester, MN, USA
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Impact of Donor Core Body Temperature on Graft Survival After Heart Transplantation. Transplantation 2019; 102:1891-1900. [PMID: 29994980 DOI: 10.1097/tp.0000000000002337] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
BACKGROUND A previous donor intervention trial found that induction of mild therapeutic hypothermia in the brain-dead donor reduced the dialysis requirement after kidney transplantation. Consequences on the performance of cardiac allografts after transplantation were not explored to date. METHODS Cohort study investigating 3-year heart allograft survival according to spontaneous core body temperature (CBT) assessed on the day of organ procurement. The study is nested in the database of the randomized trial of donor pretreatment with low-dose dopamine (ClinicalTrials.gov identifier: NCT000115115). RESULTS Ninety-nine heart transplant recipients who had received a cardiac allograft from a multiorgan donor enrolled in the dopamine trial were grouped by tertiles of the donor's CBT assessed by a mere temperature reading 4 to 20 hours before procurement (lowest, 32.0-36.2°C; middle, 36.3-36.8°C; highest, 36.9-38.8°C). Baseline characteristics considering demographics of donors and recipients, concomitant donor treatments, donor hemodynamic, and respiratory parameters as well as underlying cardiac diseases in recipients, pretransplant hemodynamic assessments, including pretransplant inotropic/mechanical support, urgency, and waiting time were similar. A lower CBT was associated with inferior heart allograft survival (hazard ratio, 0.53; 95% confidence interval, 0.31-0.93, per tertile; P = 0.02, and hazard ratio, 0.68; 95% confidence interval, 0.50-0.93°C; P = 0.02) when CBT was included as continuous explanatory variable in the Cox regression analysis. CONCLUSIONS A lower CBT in the brain-dead donor before procurement may associate with an unfavorable clinical course after heart transplantation. More research is required, before therapeutic hypothermia can routinely be used in multiorgan donors when a cardiac transplantation is intended.
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Kakizaki R, Bunya N, Uemura S, Odagiri A, Kasai T, Narimatsu E. Takotsubo cardiomyopathy developed during rewarming of accidental hypothermia with extracorporeal membrane oxygenation. Acute Med Surg 2019; 6:201-205. [PMID: 30976450 PMCID: PMC6442525 DOI: 10.1002/ams2.399] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Accepted: 01/30/2019] [Indexed: 11/09/2022] Open
Abstract
Background We here present the first case report of takotsubo cardiomyopathy that developed during rewarming of a patient with severe accidental hypothermia with extracorporeal membrane oxygenation. Case A 74-year-old woman was found unresponsive outdoors and suffered cardiopulmonary arrest during transfer to our hospital. On arrival, she was still in cardiopulmonary arrest. Veno-arterial extracorporeal membrane oxygenation was initiated for resuscitation and rewarming. After admission to the intensive care unit, her blood pressure suddenly dropped, and coronary angiography on day 2 indicated intact coronary arteries. Left ventriculography showed typical takotsubo-like dysfunction in the end-systolic phase, which led to the diagnosis of takotsubo cardiomyopathy. Left ventricular wall motion gradually improved, and echocardiography on day 6 revealed that abnormalities in the left ventricular wall motion had almost disappeared. Conclusion Takotsubo cardiomyopathy might arise during rewarming of patients with severe accidental hypothermia.
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Affiliation(s)
- Ryuichiro Kakizaki
- Department of Emergency Medicine Sapporo Medical University Hokkaido Japan
| | - Naofumi Bunya
- Department of Emergency Medicine Sapporo Medical University Hokkaido Japan
| | - Shuji Uemura
- Department of Emergency Medicine Sapporo Medical University Hokkaido Japan
| | - Arisa Odagiri
- Department of Emergency Medicine Sapporo Medical University Hokkaido Japan
| | - Takehiko Kasai
- Emergency and Critical Care Center Hakodate Municipal Hospital Hokkaido Japan
| | - Eichi Narimatsu
- Department of Emergency Medicine Sapporo Medical University Hokkaido Japan
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9
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Zhang R, Chen X, Xiao Y. The effects of a forced-air warming system plus electric blanket for elderly patients undergoing transurethral resection of the prostate: A randomized controlled trial. Medicine (Baltimore) 2018; 97:e13119. [PMID: 30407328 PMCID: PMC6250554 DOI: 10.1097/md.0000000000013119] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
BACKGROUND Perioperative inadvertent hypothermia in elderly urology patients undergoing transurethral resection of the prostate (TURP) is a well-known serious complication, as it increases the risk of myocardial ischemia, blood loss, and surgical wound infection. We conducted this prospective randomized controlled trial to evaluate the combined effect of a forced-air warming system and electric blanket in elderly TURP patients. METHODS Between January 2015 and October 2017, we recruited 443 elderly male patients undergoing elective TURP with subarachnoid blockade (SAB). These were randomly divided into 3 groups: group E (intraoperative warming using electric blankets set to 38°C; n = 128); group F (intraoperative warming using a forced-air warmer set to 38°C; n = 155) and group FE (intraoperative warming using a forced-air warmer plus electric blankets, both set to 38°C; n = 160). The primary outcome was shivering and their grades. Hemodynamic changes, esophageal temperature, recovery time, incidences of adverse effects, and patient and surgeon satisfaction were also recorded. RESULTS Baseline characteristics showed no significant differences when compared across the 3 groups (P >.05). Compared with groups E and F, both HR and mean arterial pressure (MAP) in group FE were significantly decreased from T6 to T10 (P <.05). Compared with groups E and F, esophageal temperature in group FE increased significantly from T5 to T10 (P <.05). Compared with group E, esophageal temperature in group F was significantly increased from T5 to T10 (P <.05). Compared with groups F and FE, post-anesthesia care unit (PACU) recovery time was longer in group E, while compared with group F, PACU recovery time was shorter in group FE (P <.05). Compared to patients in groups E and F, those in group FE had a significantly lower incidence of arrhythmia and shivering (P <.05). The number of patients with shivering grades 0 to 3 was higher in group E than in other groups, while the number of patients with shivering grade 2 was significantly higher in group F than in group FE (P <.05). Patient and surgeon satisfaction scores were higher in group FE than in groups E and F (P <.05). CONCLUSIONS Use of a forced-air warming system combined with an electric blanket was an effective method with which to retain warmth among elderly TURP patients.
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Functional recovery after dantrolene-supplementation of cold stored hearts using an ex vivo isolated working rat heart model. PLoS One 2018; 13:e0205850. [PMID: 30312353 PMCID: PMC6185861 DOI: 10.1371/journal.pone.0205850] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Accepted: 10/02/2018] [Indexed: 11/19/2022] Open
Abstract
The ryanodine receptor antagonist dantrolene inhibits calcium release from the sarcoplasmic reticulum and reduces cardiac ischaemia-reperfusion injury (IRI) in global warm ischaemia models however the cardioprotective potential of dantrolene under hypothermic conditions is unknown. This study addresses whether the addition of dantrolene during cardioplegia and hypothermic storage of the donor heart can improve functional recovery and reduce IRI. Using an ex vivo isolated working heart model, Wistar rat (3 month and 12 month) hearts were perfused to acquire baseline haemodynamic measurements of aortic flow, coronary flow, cardiac output, pulse pressure and heart rate. Hearts were arrested and stored in Celsior preservation solution supplemented with 0.2–40 μM dantrolene for 6 hours at 4°C, then reperfused (15 min Langendorff, 30 min working mode). In 3-month hearts, supplementation with 1 μM dantrolene significantly improved aortic flow and cardiac output compared to unsupplemented controls however lactate dehydrogenase (LDH) release and contraction bands were comparable. In contrast, 40 μM dantrolene-supplementation yielded poor cardiac recovery, increased post-reperfusion LDH but reduced contraction bands. All 3-month hearts stored in dantrolene displayed significantly reduced cleaved-caspase 3 intensities compared to controls. Analysis of cardioprotective signalling pathways showed no changes in AMPKα however dantrolene increased STAT3 and ERK1/2 signaling in a manner unrelated to functional recovery and AKT activity was reduced in 1 μM dantrolene-stored hearts. In contrast to 3-month hearts, no significant improvements were observed in the functional recovery of 12-month hearts following prolonged storage in 1 μM dantrolene. Conclusions: Dantrolene supplementation at 1 μM during hypothermic heart preservation improved functional recovery of young, but not older (12 month) hearts. Although the molecular mechanisms responsible for dantrolene-mediated cardioprotection are unclear, our studies show no correlation between improved functional recovery and SAFE and RISK pathway activation.
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11
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Microcirculation-mediated preconditioning and intracellular hypothermia. Med Hypotheses 2018; 115:8-12. [PMID: 29685204 DOI: 10.1016/j.mehy.2018.03.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2018] [Accepted: 03/19/2018] [Indexed: 01/08/2023]
Abstract
Microcirculation is a network of perfused capillaries that connects macrocirculation with the cells. Although research has provided insight into microcirculatory blood flow, our knowledge remains limited. In this article, we propose a new role of microcirculation in physiological and shock states. In healthy individuals, microcirculation maintains cellular homeostasis via preconditioning. When blood volume decreases, the ensuing microcirculatory changes result in heterogeneity of perfusion and tissue oxygenation. Initially, this is partly compensated by the preserved autoregulation and the increase in the metabolism rate of cells, but at later stages, the loss of autoregulation activates the cascade of intracellular hypothermia.
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12
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Role of superoxide ion formation in hypothermia/rewarming induced contractile dysfunction in cardiomyocytes. Cryobiology 2018; 81:57-64. [PMID: 29458041 DOI: 10.1016/j.cryobiol.2018.02.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Revised: 02/12/2018] [Accepted: 02/13/2018] [Indexed: 01/24/2023]
Abstract
Rewarming following accidental hypothermia is associated with circulatory collapse due primarily to impaired cardiac contractile (systolic) function. Previously, we found that reduced myofilament Ca2+ sensitivity underlies hypothermia/rewarming (H/R)-induced cardiac contractile dysfunction. This reduced Ca2+ sensitivity is associated with troponin I (cTnI) phosphorylation. We hypothesize that H/R induces reactive oxygen species (ROS) formation in cardiomyocytes, which leads to cTnI phosphorylation and reduced myofilament Ca2+ sensitivity. To test this hypothesis, we exposed isolated rat cardiomyocytes to a 2-h period of severe hypothermia (15 °C) followed by rewarming (35 °C) with and without antioxidant (TEMPOL) treatment. Simultaneous measurements of cytosolic Ca2+ ([Ca2+]cyto) and contractile (sarcomere shortening) responses indicated that H/R-induced contractile dysfunction and reduced Ca2+ sensitivity was prevented in cardiomyocytes treated with TEMPOL. In addition, TEMPOL treatment blunted H/R-induced cTnI phosphorylation. These results support our overall hypothesis and suggest that H/R disrupts excitation-contraction coupling of the myocardium through a cascade of event triggered by excessive ROS formation during hypothermia. Antioxidant treatment may improve successful rescue of accidental hypothermia victims.
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Fukaya H, Piktel JS, Wan X, Plummer BN, Laurita KR, Wilson LD. Arrhythmogenic Delayed Afterdepolarizations Are Promoted by Severe Hypothermia But Not Therapeutic Hypothermia. Circ J 2018; 82:62-70. [DOI: 10.1253/circj.cj-17-0145] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Hidehira Fukaya
- The Heart and Vascular Research Center, MetroHealth Campus, Case Western Reserve University
- Department of Cardiovascular Medicine, Kitasato University School of Medicine
| | - Joseph S. Piktel
- The Heart and Vascular Research Center, MetroHealth Campus, Case Western Reserve University
- Department of Emergency Medicine, MetroHealth Campus, Case Western Reserve University
| | - Xiaoping Wan
- The Heart and Vascular Research Center, MetroHealth Campus, Case Western Reserve University
| | - Bradley N. Plummer
- The Heart and Vascular Research Center, MetroHealth Campus, Case Western Reserve University
| | - Kenneth R. Laurita
- The Heart and Vascular Research Center, MetroHealth Campus, Case Western Reserve University
| | - Lance D. Wilson
- The Heart and Vascular Research Center, MetroHealth Campus, Case Western Reserve University
- Department of Emergency Medicine, MetroHealth Campus, Case Western Reserve University
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Dietrichs ES, Håheim B, Kondratiev T, Traasdahl E, Tveita T. Effects of hypothermia and rewarming on cardiovascular autonomic control in vivo. J Appl Physiol (1985) 2017; 124:850-859. [PMID: 29357499 DOI: 10.1152/japplphysiol.00317.2017] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Rewarming from accidental hypothermia is associated with cardiovascular dysfunction that complicates rewarming and contributes to a high mortality rate. We investigated autonomic cardiovascular control, as well as the separate effects of cooling, hypothermia, and rewarming on hemodynamic function, aiming to provide knowledge of the pathophysiology causing such complications in these patients. A rat model designed for circulatory studies during cooling, hypothermia (15°C), and rewarming was used. Spectral analysis of diastolic arterial pressure and heart rate allowed assessment of the autonomic nervous system. Hemodynamic variables were monitored using a conductance catheter in the left ventricle and a pressure transducer connected to the left femoral artery. Sympathetic cardiovascular control was reduced after rewarming. Stroke volume increased during cooling but decreased during stable hypothermia and did not normalize during rewarming. Despite autonomic dysfunction, total peripheral resistance increased during cooling and did not normalize after rewarming. The present data show that sympathetic cardiovascular control is reduced by hypothermia and rewarming. A simultaneous systolic dysfunction is seen in rewarmed animals, caused by reduced filling of the left ventricle and impaired contractile function, in the presence of normal diastolic function. These findings show that dysfunction of the efferent sympathetic nervous system could be instrumental in development of rewarming shock. NEW & NOTEWORTHY The present study shows impaired autonomic control of cardiovascular function after rewarming from severe hypothermia. In victims of accidental hypothermia, rewarming shock is a much feared and lethal complication. The pathophysiology causing such cardiovascular collapse appears complex. Our findings indicate that dysfunction of the autonomic nervous system is an important part of the pathophysiology. Thus the present study gives novel information, important for further development of treatment strategies in this patient group.
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Affiliation(s)
- Erik Sveberg Dietrichs
- Anesthesia and Critical Care Research Group, Department of Clinical Medicine, UiT, The Arctic University of Norway , Tromsø , Norway.,Department of Research and Education, Norwegian Air Ambulance Foundation, Drøbak, Norway.,Department of Clinical Pharmacology, Division of Diagnostic Services, University Hospital of North Norway , Tromsø , Norway
| | - Brage Håheim
- Anesthesia and Critical Care Research Group, Department of Clinical Medicine, UiT, The Arctic University of Norway , Tromsø , Norway
| | - Timofei Kondratiev
- Anesthesia and Critical Care Research Group, Department of Clinical Medicine, UiT, The Arctic University of Norway , Tromsø , Norway
| | - Erik Traasdahl
- PET Imaging Center, Division of Diagnostic Services, University Hospital of North Norway , Tromsø , Norway
| | - Torkjel Tveita
- Anesthesia and Critical Care Research Group, Department of Clinical Medicine, UiT, The Arctic University of Norway , Tromsø , Norway.,Division of Surgical Medicine and Intensive Care, University Hospital of North Norway , Tromsø , Norway
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15
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Dietrichs ES, Sager G, Tveita T. Altered pharmacological effects of adrenergic agonists during hypothermia. Scand J Trauma Resusc Emerg Med 2016; 24:143. [PMID: 27919274 PMCID: PMC5139099 DOI: 10.1186/s13049-016-0339-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2016] [Accepted: 11/29/2016] [Indexed: 01/02/2023] Open
Abstract
Rewarming from accidental hypothermia is often complicated by hypothermia-induced cardiac dysfunction, calling for immediate pharmacologic intervention. Studies show that although cardiac pharmacologic support is applied when rewarming these patients, a lack of updated treatment recommendations exist. Mainly due to lack of clinical and experimental data, neither of the international guidelines includes information about pharmacologic cardiac support at temperatures below 30 °C. However, core temperature of accidental hypothermia patients is often reduced below 30 °C. Few human studies exploring effects of adrenergic drugs during hypothermia have been published, and therefore prevailing information is collected from pre-clinical studies. The most prominent finding in these studies is an apparent depressive effect of adrenaline on cardiac function when used in doses which elevate cardiac output during normothermia. Also noradrenaline and isoprenaline largely lacked positive cardiac effects during hypothermia, while dopamine is a more promising drug for supporting cardiac function during rewarming. Data and information from these studies are in support of the prevailing notion; not to use adrenergic drugs at core temperatures below 30 °C.
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Affiliation(s)
- Erik Sveberg Dietrichs
- Anesthesia and Critical Care Research Group, Department of Clinical Medicine, UiT, The Arctic University of Norway, 9037, Tromsø, Norway. .,Department of Research and Education, Norwegian Air Ambulance Foundation, 1441, Drøbak, Norway.
| | - Georg Sager
- Experimental and Clinical Pharmacology, Department of medical biology, UiT, The Arctic University of Norway, 9037, Tromsø, Norway
| | - Torkjel Tveita
- Anesthesia and Critical Care Research Group, Department of Clinical Medicine, UiT, The Arctic University of Norway, 9037, Tromsø, Norway.,Division of Surgical Medicine and Intensive Care, University Hospital of North Norway, 9038, Tromsø, Norway
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16
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Schaible N, Han YS, Hoang T, Arteaga G, Tveita T, Sieck G. Hypothermia/rewarming disrupts excitation-contraction coupling in cardiomyocytes. Am J Physiol Heart Circ Physiol 2016; 310:H1533-40. [PMID: 26993227 DOI: 10.1152/ajpheart.00840.2015] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Accepted: 03/16/2016] [Indexed: 12/25/2022]
Abstract
Hypothermia/rewarming (H/R) is poorly tolerated by the myocardium; however, the underlying intracellular basis of H/R-induced cardiac dysfunction remains elusive. We hypothesized that in cardiomyocytes, H/R disrupts excitation-contraction coupling by reducing myofilament Ca(2+) sensitivity due to an increase in cardiac troponin I (cTnI) phosphorylation. To test this hypothesis, isolated rat cardiomyocytes (13-15 cells from 6 rats per group) were electrically stimulated to evoke both cytosolic Ca(2+) ([Ca(2+)]cyto) and contractile (sarcomere shortening) responses that were simultaneously measured using an IonOptix system. Cardiomyocytes were divided into two groups: 1) those exposed to hypothermia (15°C for 2 h) followed by rewarming (35°C; H/R); or 2) time-matched normothermic (35°C) controls (CTL). Contractile dysfunction after H/R was indicated by reduced velocity and extent of sarcomere length (SL) shortening compared with time-matched controls. Throughout hypothermia, basal [Ca(2+)]cyto increased and the duration of evoked [Ca(2+)]cyto transients was prolonged. Phase-loop plots of [Ca(2+)]cyto vs. contraction were shifted rightward in cardiomyocytes during hypothermia compared with CTL, indicating a decrease in Ca(2+) sensitivity. Using Western blot, we found that H/R increases cTnI phosphorylation. These results support our overall hypothesis and suggest that H/R disrupts excitation-contraction coupling of cardiomyocytes due to increased cTnI phosphorylation and reduced Ca(2+) sensitivity.
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Affiliation(s)
- Niccole Schaible
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota; and
| | - Young Soo Han
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota; and
| | - Thuy Hoang
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota; and
| | - Grace Arteaga
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota; and
| | - Torkjel Tveita
- Departments of Anesthesiology and Physiology, University of Tromsø-The Arctic University of Norway, Tromsø, Norway
| | - Gary Sieck
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota; and
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Darocha T, Sobczyk D, Kosiński S, Jarosz A, Gałązkowski R, Nycz K, Drwiła R. New diastolic cardiomyopathy in patients with severe accidental hypothermia after ECMO rewarming: a case-series observational study. Cardiovasc Ultrasound 2015; 13:31. [PMID: 26174320 PMCID: PMC4502559 DOI: 10.1186/s12947-015-0027-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2015] [Accepted: 07/09/2015] [Indexed: 01/22/2023] Open
Abstract
Introduction Accidental hypothermia is a condition associated with significant morbidity and mortality. Hypothermia has been reported to affect left ventricular systolic and diastolic function. However, most of the data come from animal experimental studies. Aim of the study The purpose of the present study was to assess the impact of severe accidental hypothermia on systolic and diastolic ventricular function in patients treated using veno-arterial extracorporeal membrane oxygenation (ECMO). Methods We prospectively assessed nine hypothermic patients (8 male, age 25–78 years) who were transferred to the Severe Accidental Hypothermia Center and treated with ECMO. Transthoracic echocardiography was performed on admission (in patients without cardiac arrest) and on discharge from ICU after achieving cardiovascular stability. Cardiorespiratory stability and full neurologic recovery was achieved in all patients. Results Biomarkers of myocardial damage (CK, CKMB, hsTnT) were significantly elevated in all study patients. Admission echocardiography performed in patients in sinus rhythm, revealed moderate-severe bi-ventricular systolic dysfunction and moderate bi-ventricular diastolic dysfunction. Discharge echocardiography showed persistent mild bi-ventricular diastolic dysfunction, although systolic function of both ventricles returned to normal. Discharge echocardiography in patients admitted with cardiac arrest showed normal (5 patients) or moderately impaired (1 patient) global LV systolic function on discharge. However, mild or moderate LV diastolic dysfunction was observed in all 6 patients. Discharge RV systolic function was normal, whereas mild RV diastolic dysfunction was present in these patients. Conclusion After severe accidental hypothermia bi-ventricular diastolic dysfunction persists despite systolic function recovery in survivors treated with ECMO.
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Affiliation(s)
- Tomasz Darocha
- Department of Anesthesiology and Intensive Care, The John Paul II Hospital, Medical College of Jagiellonian University, Cracow, Poland.
| | - Dorota Sobczyk
- Department of Interventional Cardiology, The John Paul II Hospital, Pradnicka 80, 31 202, Cracow, Poland.
| | - Sylweriusz Kosiński
- Department of Anesthesiology and Intensive Care, Pulmonary Hospital, Zakopane, Poland. .,Tatra Mountain Rescue Service, Zakopane, Poland.
| | - Anna Jarosz
- Department of Anesthesiology and Intensive Care, The John Paul II Hospital, Medical College of Jagiellonian University, Cracow, Poland.
| | - Robert Gałązkowski
- Department of Emergency Medical Services, Medical University of Warsaw, Polish Medical Air Rescue, Warsaw, Poland.
| | - Krzysztof Nycz
- Department of Interventional Cardiology, The John Paul II Hospital, Pradnicka 80, 31 202, Cracow, Poland.
| | - Rafał Drwiła
- Department of Anesthesiology and Intensive Care, The John Paul II Hospital, Medical College of Jagiellonian University, Cracow, Poland.
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Negative inotropic effects of epinephrine in the presence of increased β-adrenoceptor sensitivity during hypothermia in a rat model. Cryobiology 2014; 70:9-16. [PMID: 25445571 DOI: 10.1016/j.cryobiol.2014.10.012] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Revised: 10/21/2014] [Accepted: 10/29/2014] [Indexed: 11/22/2022]
Abstract
BACKGROUND Animal studies show reduced inotropic effects of cardiac β-adrenoceptor agonists like epinephrine (Epi) during hypothermia and rewarming, while drugs targeting other pharmacological mechanisms have positive effects. This study therefore aimed to determine β-adrenoceptor sensitivity in isolated cardiomyocytes and investigate hemodynamic effects of Epi and its ability to stimulate cardiac β-adrenoceptors at different temperatures in vivo. METHODS Isolated rat myocardial cells were incubated with the radioactive β-adrenoceptor ligand [(3)H]-CGP12177 and propranolol, used as a displacer. Cells were subjected to normothermia (37 °C) or hypothermia (15 °C). After incubation, radioactivity was measured to estimate β-adrenoceptor affinity for propranolol (IC50), as a measure of β-adrenoceptor sensitivity. In separate in vivo experiments, Epi (1.25 μg/min) was administered the last 5min of experiments in normothermic (37 °C, 5h), hypothermic (4h at 15 °C) and rewarmed rats (4h at 15 °C, and subsequently rewarmed to 37 °C). Hemodynamic parameters were monitored during infusion. Hearts were thereafter freeze-clamped and tissue cAMP was measured. RESULTS In vitro measurements of IC50 for propranolol showed a hypothermia-induced increase in β-adrenoceptor sensitivity at 15 °C. Corresponding in vivo experiments at 15 °C showed decreased cardiac output and stroke volume, whereas total peripheral resistance (TPR) increased during Epi infusion, simultaneous with a 4-fold cAMP increase. CONCLUSIONS This experiment shows a hypothermia-induced in vivo and in vitro increase of cardiac β-adrenoceptor sensitivity, and simultaneous lack of inotropic effects of Epi in the presence of increased TPR. Our findings therefore indicate that hypothermia-induced reduction in inotropic effects of Epi is due to substantial elevation of TPR, rather than β-adrenoceptor dysfunction.
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19
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Bondke Persson A, Persson PB. Extreme environments. Acta Physiol (Oxf) 2014; 212:189-90. [PMID: 25042108 DOI: 10.1111/apha.12347] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- A. Bondke Persson
- Institute of Vegetative Physiology; Charité-Universitaetsmedizin Berlin; Berlin Germany
| | - P. B. Persson
- Institute of Vegetative Physiology; Charité-Universitaetsmedizin Berlin; Berlin Germany
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20
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Dietrichs ES, Håheim B, Kondratiev T, Sieck GC, Tveita T. Cardiovascular effects of levosimendan during rewarming from hypothermia in rat. Cryobiology 2014; 69:402-10. [PMID: 25280932 DOI: 10.1016/j.cryobiol.2014.09.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2014] [Revised: 09/18/2014] [Accepted: 09/22/2014] [Indexed: 10/24/2022]
Abstract
BACKGROUND Previous research aimed at ameliorating hypothermia-induced cardiac dysfunction has shown that inotropic drugs, that stimulate the cAMP, - PKA pathway via the sarcolemmal β-receptor, have a decreased inotropic effect during hypothermia. We therefore wanted to test whether levosimendan, a calcium sensitizer and dose-dependent phosphodiesterase 3 (PDE3) inhibitor, is able to elevate stroke volume during rewarming from experimental hypothermia. METHODS A rat model designed for circulatory studies during experimental hypothermia (4h at 15°C) and rewarming was used. The following three groups were included: (1) A normothermic group receiving levosimendan, (2) a hypothermic group receiving levosimendan the last hour of stable hypothermia and during rewarming, and (3) a hypothermic placebo control group. Hemodynamic variables were monitored using a Millar conductance catheter in the left ventricle (LV), and a pressure transducer connected to the left femoral artery. In order to investigate the level of PKA stimulation by PDE3 inhibition, myocardial Ser23/24-cTnI phosphorylation was measured using Western-blot. RESULTS After rewarming, stroke volume (SV), cardiac output (CO) and preload recruitable stroke work (PRSW) were restored to within pre-hypothermic values in the levosimendan-treated animals. Compared to the placebo group after rewarming, SV, CO, PRSW, as well as levels of Ser23/24-cTnI phosphorylation, were significantly higher in the levosimendan-treated animals. CONCLUSION The present data shows that levosimendan ameliorates hypothermia-induced systolic dysfunction by elevating SV during rewarming from 15°C. Inotropic treatment during rewarming from hypothermia in the present rat model is therefore better achieved through calcium sensitizing and PDE3 inhibition, than β-receptor stimulation.
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Affiliation(s)
- Erik Sveberg Dietrichs
- Dept. of Research and Education, Norwegian Air Ambulance Foundation, 1441 Drøbak, Norway; Anesthesia and Critical Care Research Group, Institute of Clinical Medicine, UiT, The Arctic University of Norway, 9037 Tromsø, Norway.
| | - Brage Håheim
- Anesthesia and Critical Care Research Group, Institute of Clinical Medicine, UiT, The Arctic University of Norway, 9037 Tromsø, Norway; Dept. of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine, Rochester, MN 55905, USA.
| | - Timofei Kondratiev
- Anesthesia and Critical Care Research Group, Institute of Clinical Medicine, UiT, The Arctic University of Norway, 9037 Tromsø, Norway.
| | - Gary C Sieck
- Dept. of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine, Rochester, MN 55905, USA; Anesthesia and Critical Care Research Group, Institute of Clinical Medicine, UiT, The Arctic University of Norway, 9037 Tromsø, Norway.
| | - Torkjel Tveita
- Anesthesia and Critical Care Research Group, Institute of Clinical Medicine, UiT, The Arctic University of Norway, 9037 Tromsø, Norway; Division of Surgical Medicine and Intensive Care, University Hospital of North Norway, 9038 Tromsø, Norway.
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Dietrichs ES, Kondratiev T, Tveita T. Milrinone ameliorates cardiac mechanical dysfunction after hypothermia in an intact rat model. Cryobiology 2014; 69:361-6. [PMID: 25224046 DOI: 10.1016/j.cryobiol.2014.09.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Revised: 08/21/2014] [Accepted: 09/02/2014] [Indexed: 11/17/2022]
Abstract
BACKGROUND Rewarming from hypothermia is often complicated by cardiac dysfunction, characterized by substantial reduction in stroke volume. Previously we have reported that inotropic agents, working via cardiac β-receptor agonism may exert serious side effects when applied to treat cardiac contractile dysfunction during rewarming. In this study we tested whether Milrinone, a phosphodiesterase III inhibitor, is able to ameliorate such dysfunction when given during rewarming. METHODS A rat model designed for circulatory studies during experimental hypothermia with cooling to a core temperature of 15°C, stable hypothermia at this temperature for 3h and subsequent rewarming was used, with a total of 3 groups: (1) a normothermic group receiving Milrinone, (2) a hypothermic group receiving Milrinone the last hour of hypothermia and during rewarming, and (3) a hypothermic saline control group. Hemodynamic function was monitored using a conductance catheter introduced to the left ventricle. RESULTS After rewarming from 15°C, stroke volume and cardiac output returned to within baseline values in Milrinone treated animals, while these variables were significantly reduced in saline controls. CONCLUSIONS Milrinone ameliorated cardiac dysfunction during rewarming from 15°C. The present results suggest that at low core temperatures and during rewarming from such temperatures, pharmacologic efforts to support cardiovascular function is better achieved by substances preventing cyclic AMP breakdown rather than increasing its formation via β-receptor stimulation.
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Affiliation(s)
- Erik Sveberg Dietrichs
- Department of Research and Education, Norwegian Air Ambulance Foundation, 1441 Drøbak, Norway; Anesthesia and Critical Care Research Group, Institute of Clinical Medicine, UiT, The Arctic University of Norway, 9037 Tromsø, Norway.
| | - Timofei Kondratiev
- Anesthesia and Critical Care Research Group, Institute of Clinical Medicine, UiT, The Arctic University of Norway, 9037 Tromsø, Norway.
| | - Torkjel Tveita
- Anesthesia and Critical Care Research Group, Institute of Clinical Medicine, UiT, The Arctic University of Norway, 9037 Tromsø, Norway; Division of Surgical Medicine and Intensive Care, University Hospital of North Norway, 9019 Tromsø, Norway.
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Polderman KH. Of ions and temperature: the complicated interplay of temperature, fluids, and electrolytes on myocardial function. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2013; 17:1018. [PMID: 24313967 PMCID: PMC4056327 DOI: 10.1186/cc13139] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
This article discusses the potential of levosimendan to treat calcium-induced myocardial dysfunction associated with deep hypothermia. Moderate hypothermia (30 to 34°C) usually improves myocardial contractility and stabilizes heart rhythm, but deep hypothermia can cause severe myocardial dysfunction, which is mediated by intracellular calcium overload. In experimental studies, levosimendan appears effective in reversing this. Clinical studies are needed to confirm these findings and to determine whether levosimendan could also be used for accidental hypothermia and perhaps to mitigate diastolic dysfunction under moderate hypothermia.
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23
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A cardioprotective preservation strategy employing ex vivo heart perfusion facilitates successful transplant of donor hearts after cardiocirculatory death. J Heart Lung Transplant 2013; 32:734-43. [PMID: 23796155 DOI: 10.1016/j.healun.2013.04.016] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2013] [Revised: 04/20/2013] [Accepted: 04/30/2013] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Ex vivo heart perfusion (EVHP) has been proposed as a means to facilitate the resuscitation of donor hearts after cardiocirculatory death (DCD) and increase the donor pool. However, the current approach to clinical EVHP may exacerbate myocardial injury and impair function after transplant. Therefore, we sought to determine if a cardioprotective EVHP strategy that eliminates myocardial exposure to hypothermic hyperkalemia cardioplegia and minimizes cold ischemia could facilitate successful DCD heart transplantation. METHODS Anesthetized pigs sustained a hypoxic cardiac arrest and a 15-minute warm ischemic standoff period. Strategy 1 hearts (S1, n = 9) underwent initial reperfusion with a cold hyperkalemic cardioplegia, normothermic EVHP, and transplantation after a cold hyperkalemic cardioplegic arrest (current EVHP strategy). Strategy 2 hearts (S2, n = 8) underwent initial reperfusion with a tepid adenosine-lidocaine cardioplegia, normothermic EVHP, and transplantation with continuous myocardial perfusion (cardioprotective EVHP strategy). RESULTS At completion of EVHP, S2 hearts exhibited less weight gain (9.7 ± 6.7 [S2] vs 21.2 ± 6.7 [S1] g/hour, p = 0.008) and less troponin-I release into the coronary sinus effluent (4.2 ± 1.3 [S2] vs 6.3 ± 1.5 [S1] ng/ml; p = 0.014). Mass spectrometry analysis of oxidized pleural in post-transplant myocardium revealed less oxidative stress in S2 hearts. At 30 minutes after wean from cardiopulmonary bypass, post-transplant systolic (pre-load recruitable stroke work: 33.5 ± 1.3 [S2] vs 19.7 ± 10.9 [S1], p = 0.043) and diastolic (isovolumic relaxation constant: 42.9 ± 6.7 [S2] vs 65.2 ± 21.1 [S1], p = 0.020) function were superior in S2 hearts. CONCLUSION In this experimental model of DCD, an EVHP strategy using initial reperfusion with a tepid adenosine-lidocaine cardioplegia and continuous myocardial perfusion minimizes myocardial injury and improves short-term post-transplant function compared with the current EVHP strategy using cold hyperkalemic cardioplegia before organ procurement and transplantation.
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Rungatscher A, Hallström S, Giacomazzi A, Linardi D, Milani E, Tessari M, Luciani GB, Scarabelli TM, Mazzucco A, Faggian G. Role of calcium desensitization in the treatment of myocardial dysfunction after deep hypothermic circulatory arrest. Crit Care 2013; 17:R245. [PMID: 24138817 PMCID: PMC4056352 DOI: 10.1186/cc13071] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2013] [Accepted: 09/17/2013] [Indexed: 11/10/2022] Open
Abstract
Introduction Rewarming from deep hypothermic circulatory arrest (DHCA) produces calcium desensitization by troponin I (cTnI) phosphorylation which results in myocardial dysfunction. This study investigated the acute overall hemodynamic and metabolic effects of epinephrine and levosimendan, a calcium sensitizer, on myocardial function after rewarming from DHCA. Methods Forty male Wistar rats (400 to 500 g) underwent cardiopulmonary bypass (CPB) through central cannulation and were cooled to a core temperature of 13°C to 15°C within 30 minutes. After DHCA (20 minutes) and CPB-assisted rewarming (60 minutes) rats were randomly assigned to 60 minute intravenous infusion with levosimendan (0.2 μg/kg/min; n = 15), epinephrine (0.1 μg/kg/min; n = 15) or saline (control; n = 10). Systolic and diastolic functions were evaluated at different preloads with a conductance catheter. Results The slope of left ventricular end-systolic pressure volume relationship (Ees) and preload recruitable stroke work (PRSW) recovered significantly better with levosimendan compared to epinephrine (Ees: 85 ± 9% vs 51 ± 11%, P<0.003 and PRSW: 78 ± 5% vs 48 ± 8%, P<0.005; baseline: 100%). Levosimendan but not epinephrine reduced left ventricular stiffness shown by the end-diastolic pressure-volume relationship and improved ventricular relaxation (Tau). Levosimendan preserved ATP myocardial content as well as energy charge and reduced plasma lactate concentrations. In normothermia experiments epinephrine in contrast to Levosimendan increased cTnI phosphorylation 3.5-fold. After rewarming from DHCA, cTnI phosphorylation increased 4.5-fold in the saline and epinephrine group compared to normothermia but remained unchanged with levosimendan. Conclusions Levosimendan due to prevention of calcium desensitization by cTnI phosphorylation is more effective than epinephrine for treatment of myocardial dysfunction after rewarming from DHCA.
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25
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Chalkias A, Xanthos T. Postcardiac arrest syndrome: second thoughts regarding therapeutic hypothermia. Acta Physiol (Oxf) 2013; 207:324-5. [PMID: 23057649 DOI: 10.1111/apha.12029] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- A. Chalkias
- Department of Anatomy, Medical School; National and Kapodistrian University of Athens; Athens; Greece
| | - T. Xanthos
- Department of Anatomy, Medical School; National and Kapodistrian University of Athens; Athens; Greece
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