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Persson O, Valerianova A, Bělohlávek J, Cronberg T, Nielsen N, Englund E, Mlček M, Friberg H. Hypothermia After Cardiac Arrest in Large Animals (HACA-LA): Study protocol of a randomized controlled experimental trial. Resusc Plus 2024; 19:100704. [PMID: 39040822 PMCID: PMC11261465 DOI: 10.1016/j.resplu.2024.100704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2024] [Accepted: 06/17/2024] [Indexed: 07/24/2024] Open
Abstract
Background Induced hypothermia post-cardiac arrest is neuroprotective in animal experiments, but few high-quality studies have been performed in larger animals with human-like brains. The neuroprotective effect of postischemic hypothermia has recently been questioned in human trials. Our aim is to investigate whether hypothermia post-cardiac arrest confers a benefit compared to normothermia in large adult animals. Our hypothesis is that induced hypothermia post cardiac arrest is neuroprotective and that the effect diminishes when delayed two hours. Methods Adult female pigs were anesthetized, mechanically ventilated and kept at baseline parameters including normothermia (38 °C). All animals were subjected to ten minutes of cardiac arrest (no-flow) by induced ventricular fibrillation, followed by four minutes of cardiopulmonary resuscitation with mechanical compressions, prior to the first countershock. Animals with sustained return of spontaneous circulation (systolic blood pressure >60 mmHg for ten minutes) within fifteen minutes from start of life support were included and randomized to three groups; immediate or delayed (2 h) intravenous cooling, both targeting 33 °C, or intravenously controlled normothermia (38 °C). Temperature control was applied for thirty hours including cooling time, temperature at target and controlled rewarming (0.5 °C/h). Animals were extubated and kept alive for seven days. The primary outcome measure is histological brain injury on day seven. Secondary outcomes include neurological and neurocognitive recovery, and the trajectory of biomarkers of brain injury. Conclusion High-quality animal experiments in clinically relevant large animal models are necessary to close the gap of knowledge regarding neuroprotective effects of induced hypothermia after cardiac arrest.Trial registration:Preclinicaltrials.eu (PCTE0000272), published 2021-11-03.
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Affiliation(s)
- Olof Persson
- Department of Clinical Sciences, Anaesthesiology and Intensive Care, Lund University, Lund, Sweden
- Department of Intensive and Perioperative Care, Skåne University Hospital, Lund, Sweden
| | - Anna Valerianova
- Third Department of Internal Medicine, General University Hospital, Charles University, Prague, Czech Republic
- Institute of Physiology, First Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Jan Bělohlávek
- Second Department of Medicine – Department of Cardiovascular Medicine, First Faculty of Medicine, Charles University and General University Hospital, Prague, Czech Republic
| | - Tobias Cronberg
- Department of Clinical Sciences, Neurology, Lund University, Lund, Sweden
- Department of Neurology, Skåne University Hospital, Lund, Sweden
| | - Niklas Nielsen
- Department of Clinical Sciences, Anaesthesiology and Intensive Care, Lund University, Lund, Sweden
| | - Elisabet Englund
- Department of Clinical Sciences, Pathology, Lund University, Lund, Sweden
- Department of Genetics, Pathology and Molecular Diagnostics, Skåne University Hospital, Lund, Sweden
| | - Mikuláš Mlček
- Institute of Physiology, First Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Hans Friberg
- Department of Clinical Sciences, Anaesthesiology and Intensive Care, Lund University, Lund, Sweden
- Department of Intensive and Perioperative Care, Skåne University Hospital, Malmö, Sweden
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梁 国, 郑 汝, 菅 洪, 张 旻, 袁 慧, 洪 睫, 武 钢. [A new method for establishing a ventricular fibrillation model by TCEI in Tibetan miniature pig]. NAN FANG YI KE DA XUE XUE BAO = JOURNAL OF SOUTHERN MEDICAL UNIVERSITY 2019; 39:1370-1375. [PMID: 31852641 PMCID: PMC6926077 DOI: 10.12122/j.issn.1673-4254.2019.11.16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 05/12/2019] [Indexed: 11/24/2022]
Abstract
OBJECTIVE To explore an economical, convenient, safe and efficient method for establishing a Tibetan miniature pig model of cardiac arrest (CA). METHODS Cardiac puncture was performed in 12 Tibetan miniature pigs using two acupuncture needles. One needle was inserted into the fourth intercostal near the right side of the sternum about 3 cm in depth at an angle of 30° to 60° between the chest and the needle, and the depth was adjusted until the handle of the needle vibrated with the heartbeat without premature ventricular contraction on the electrocardiogram; the other was inserted into the subcutaneous tissue of the left armpit about 3 cm in depth without damaging important organs. The handles of the two needles were connected with 9V dry batteries to form a circuit and generate direct current stimulation. Ventricular fibrillation was produced in the pigs to induce CA by stimulation of transcutaneous electrical induction (TCEI) for 3 s, and the success rate of modeling was recorded. After an interval of 4 min without intervention, cardiopulmonary resuscitation (CPR) was performed using the standard Utstein style, and the survival of the pigs after recovery was observed. RESULTS The success rate of ventricular fibrillation modeling was 91.67% (11/12) using this method, and CPR achieved a success rate of 45.45% (5/11) in these models. The subsequent survival of the pigs was 100% (5/5) at 24 h and 80% (4/5) at 72 h. After observation for 72 h, the resuscitated Tibetan miniature pigs were dissected, and no significant damage was found in the vital organs in the thoracic or abdominal cavities. CONCLUSIONS We successfully established a model of CA using acupuncture needles and dry batteries in Tibetan miniature pigs, and this method is economical, convenient, safe and efficient.
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Affiliation(s)
- 国栋 梁
- 南方医科大学南方医院急诊科,广东 广州 510515Department of Emergency Medicine, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China
| | - 汝钢 郑
- 南方医科大学第五附属医院急诊科,广东 广州 510900Department of Emergency Medicine, Fifth Affiliated Hospital of Southern Medical University, Guangzhou 510900, China
| | - 洪健 菅
- 南方医科大学南方医院急诊科,广东 广州 510515Department of Emergency Medicine, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China
| | - 旻海 张
- 南方医科大学南方医院急诊科,广东 广州 510515Department of Emergency Medicine, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China
| | - 慧琼 袁
- 南方医科大学南方医院急诊科,广东 广州 510515Department of Emergency Medicine, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China
| | - 睫敏 洪
- 南方医科大学南方医院急诊科,广东 广州 510515Department of Emergency Medicine, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China
| | - 钢 武
- 南方医科大学南方医院急诊科,广东 广州 510515Department of Emergency Medicine, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China
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Idelchik GM, Varon J. Normal saline versus colloid solutions for induction of hypothermia: the effect of specific heat capacity on cooling. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2014; 18:123. [PMID: 25029562 PMCID: PMC4056667 DOI: 10.1186/cc13771] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The prevention of ischemic injury to preserve both end-organ function and improve neurological recovery by the implementation of therapeutic hypothermia has been well established in the literature. However, not only the means by which body temperature is cooled but also the rate by which target temperature is attained remains an area of continued interest and research. The induction of therapeutic hypothermia to begin the process of body temperature lowering through the infusion of a cold solution intravenously into the body may be one variable that influences not only rapidity of cooling but also subsequent clinical outcome. In a recent issue of Critical Care, Skulec and colleagues compared the induction of therapeutic hypothermia by cold normal saline versus cold colloid solution containing hydroxyethyl starch in a porcine animal model of cardiac arrest, assessing both the rate of temperature change and target temperature achieved, in addition to changes in intracranial pressure.
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