Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0020672 (hypothermia)
 17,327 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Moderate hypothermia (30 degrees C) induced before circulatory arrest is known to improve neurologic outcome. We explored, for the first time in a reproducible dog outcome model, moderate hypothermia induced during reperfusion after cardiac arrest (resuscitation). In three groups of six dogs each (N = 18), normothermic ventricular fibrillation cardiac arrest (no blood flow) of 17 minutes was reversed by cardiopulmonary bypass--normothermic in control group I (37.5 degrees C) and hypothermic to 3 hours in groups II (32 degrees C) and III (28 degrees C). Defibrillation was achieved in less than or equal to 5 minutes and partial bypass was continued to 4 hours, controlled ventilation to 20 hours, and intensive care to 96 hours. All 18 dogs survived. Electroencephalographic activity returned significantly earlier in groups II and III. Mean +/- SD best neurologic deficit between 48 and 96 hours was 44 +/- 8% in group I, 38 +/- 12% in group II, and 35 +/- 7% in group III (differences not significant). Best overall performance category 2 (good outcome) between 48 and 96 hours was achieved in none of the six dogs in group I and in four of the 12 dogs in the combined hypothermic groups II and III (difference not significant). Mean +/- SD brain total histologic damage score was 130 +/- 22 in group I, 93 +/- 28 in group II (p = 0.05), and 80 +/- 26 in group III (p = 0.03). Gross myocardial damage was greater in groups II and III than in group I--numerically higher overall and significantly higher in group III for the right ventricle alone (p = 0.02). Moderate hypothermia after prolonged cardiac arrest may or may not improve cerebral outcome slightly and can worsen myocardial damage.
 ...
PMID:Moderate hypothermia after cardiac arrest of 17 minutes in dogs. Effect on cerebral and cardiac outcome. 223 54

We previously found mild hypothermia (34-36 degrees C), induced before cardiac arrest, to improve neurologic outcome. In this study we used a reproducible dog model to evaluate mild hypothermia by head cooling during arrest, continued with systemic cooling (34 degrees C) during recirculation and for 1 h after arrest. In four groups of dogs, ventricular fibrillation (no flow) of 12.5 min at 37.5 degrees C was reversed with cardiopulmonary bypass and defibrillation in less than or equal to 5 min, and followed by controlled ventilation to 20 h and intensive care to 96 h. In Study A we resuscitated with normotension and normal hematocrit; Control Group A-I (n = 12) was maintained normothermic, while Treatment Group A-II (n = 10) was treated with hypothermia. In Study B we resuscitated with hypertension and hemodilution. Control Group B-I (n = 12) was maintained normothermic (6 of 12 were not hemodiluted), while Treatment Group B-II (n = 10) was treated with hypothermia. Best overall performance categories (OPCs) achieved between 24 and 96 h postarrest were in Group A-I: OPC 1 (normal) in 0 of 12 dogs, OPC 2 (moderate disability) in 2, OPC 3 (severe disability) in 7, and OPC 4 (coma) in 3 dogs. In Group A-II, OPC 1 was achieved in 5 of 10 dogs (p less than 0.01), OPC 2 in 4 (p less than 0.001), OPC 3 in 1, and OPC 4 in 0 dogs. In Group B-I, OPC 1 was achieved in 0 of 12 dogs, OPC 2 in 6, OPC 3 in 5, and OPC 4 in 1 dog. In Group B-II, OPC 1 was achieved in 6 of 10 dogs (p less than 0.01), OPC 2 in 4 (p less than 0.05), and OPC 3 or 4 in 0 dogs. Mean neurologic deficit and brain histopathologic damage scores showed similar significant group differences. Morphologic myocardial damage scores were the same in all four groups. We conclude that mild brain cooling during and after insult improves neurologic outcome after cardiac arrest.
 ...
PMID:Mild cerebral hypothermia during and after cardiac arrest improves neurologic outcome in dogs. 229 37

Early deaths from trauma are often caused by exsanguinating hemorrhage from injuries that appear "irreparable." We explored the limits of deep hypothermic circulatory arrest induced during hemorrhagic shock to enable repair of these injuries in a bloodless field. In 15 dogs, after 30 minutes of hemorrhagic shock (mean arterial pressure, 40 mm Hg), cardiopulmonary bypass (CPB) was used to cool to 15 degrees C in 13-37 minutes. After circulatory arrest of 60 (Group 1), 90 (Group 2), or 120 (Group 3) minutes, reperfusion and rewarming were accomplished by CPB. All dogs survived greater than 72 hours. Best neurologic deficit scores (ND) (0% = normal, 100% = brain death) were 0 +/- 0% (normal) in Group 1, 10 +/- 8% (mild disability) in Group 2, and 27 +/- 24% in Group 3. Outcome in Group 3 dogs ranged from near-normal to comatose. After perfusion-fixation sacrifice, brain histopathologic damage scores correlated with insult time, as did ND scores. Deep hypothermia can allow 60-90 min of circulatory arrest with good neurologic recovery, even after a period of severe hemorrhagic shock. This technique may allow repair of otherwise lethal injuries and survival without brain damage.
 ...
PMID:Therapeutic deep hypothermic circulatory arrest in dogs: a resuscitation modality for hemorrhagic shock with 'irreparable' injury. 238 Oct 1

Twenty-nine female northern sea lions (Eumetopias jubatus) were immobilized using Telazol in dosages ranging from 1.8 to 8.1 mg/kg. Best results were achieved with Telazol dosages ranging between 1.8 and 2.5 mg/kg which resulted in smooth induction and recovery. Optimal injection location was in the muscle mass of the lower back and hip. Dosages greater than 3.5 mg/kg resulted in a tendency toward hypothermia. Six mortalities occurred which were partially caused by the location of drug injection and perhaps the high dosage.
 ...
PMID:Use of Telazol to immobilize female northern sea lions (Eumetopias jubatus) in Alaska. 276 Oct 7

A theoretical model of heat balance is presented that could clarify the matching of babies' wrapping with their environments. Best estimates of metabolic heat input and heat loss by all known routes are defined for 22 parts of the body surface. The variation of these with core temperature, posture, skin vasodilatation, and the onset of sweating are calculated: first, by using presumed skin temperatures and second, by following iterative calculation of the skin temperature and the consequent total heat losses. Calculation of the highest tolerable ambient temperature (HTAT) for a given set of clothes, underbedding, and covers shows that a well-wrapped baby lying face down could have an HTAT 10 degrees C lower than if he/she were lying supine. Representative values for highest and lowest tolerable temperatures (defined in text) are presented for the first 6 mo of life. Retrospective estimation of thermal balance from death-scene data on clothing and bedding can permit assessment of hyperthermia or hypothermia as a contributing cause of death. Recommendations are made on the avoidance of hyperthermia.
 ...
PMID:Thermal balance in infants. 880 35

We postulate that mitigating the multifactorial pathogenesis of postischemic encephalopathy requires multifaceted treatments. In preparation for expensive definitive studies, we are reporting here the results of small exploratory series, compared with historic controls with the same model. We hypothesized that the brain damage mitigating effect of mild hypothermia after cardiac arrest can be enhanced with thiopental loading, and even more so with the further addition of phenytoin and methylprednisolone. Twenty-four dogs (four groups of six dogs each) received VF 12.5 min no-flow, reversed with brief cardiopulmonary bypass (CPB), controlled ventilation to 20 h, and intensive care to 96 h. Group 1 with normothermia throughout and randomized group 2 with mild hypothermia (from reperfusion to 2 h) were controls. Then, group 3 received in addition, thiopental 90 mg/kg i.v. over the first 6 h. Then, group 4 received, in addition to group 2 treatment, thiopental 30 mg/kg i.v. over the first 90 min (because the larger dose had produced cardiopulmonary complications), plus phenytoin 15 mg/kg i.v. at 15 min after reperfusion, and methylprednisolone 130 mg/kg i.v. over 20 h. All dogs survived. Best overall performance categories (OPC) achieved (OPC 1 = normal, OPC 5 = brain death) were better in group 2 than group 1 (< 0.05) and numerically better in groups 3 or 4 than in groups 1 or 2. Good cerebral outcome (OPC 1 or 2) was achieved by all six dogs only in group 4 (P < 0.05 group 4 vs. 2). Best NDS were 44 +/- 3% in group 1; 20 +/- 14% in group 2 (P = 0.002); 21 +/- 15% in group 3 (NS vs. group 2); and 7 +/- 8% in group 4 (P = 0.08 vs. group 2). Total brain histologic damage scores (HDS) at 96 h were 156 +/- 38 in group 1; 81 +/- 12 in group 2 (P < 0.001 vs. group 1); 53 +/- 25 in group 3 (P = 0.02 vs. group 2); and 48 +/- 5 in group 4 (P = 0.02 vs. group 2). We conclude that after prolonged cardiac arrest, the already established brain damage mitigating effect of mild immediate postarrest hypothermia might be enhanced by thiopental, and perhaps then further enhanced by adding phenytoin and methylprednisolone.
 ...
PMID:Thiopental combination treatments for cerebral resuscitation after prolonged cardiac arrest in dogs. Exploratory outcome study. 1095 Mar 20

There are numerous physiological effects of spinal anaesthesia. This chapter focuses on the physiological effects that are of clinical relevance to the anaesthesiologist, and provides suggestions for successful management of this simple and popular technique. The mechanisms and clinical significance of spinal-anaesthesia-induced hypotension, bradycardia and cardiac arrest are reviewed. The increasing popularity of ambulatory spinal anaesthesia requires knowledge that long-acting local anaesthetics, such as bupivacaine, impair the ability to void far longer than short-acting local anaesthetics, such as lidocaine. The importance of thermoregulation during spinal anaesthesia, and the clinical consequences of spinal-anaesthesia-induced hypothermia are reviewed. Effects of spinal anaesthesia on ventilatory mechanics are also highlighted. Lastly, the sedative and minimum-alveolar-concentration-sparing effects of spinal anaesthesia are discussed to reinforce the need for the judicious use of sedation in the perioperative setting.
Best Pract Res Clin Anaesthesiol 2003 Sep
PMID:Physiology of spinal anaesthesia and practical suggestions for successful spinal anaesthesia. 1452 3

Perioperative hypothermia is common in high-risk surgical patients. Anaesthesia impairs central thermoregulation, allowing re-distribution of body heat. Cool ambient temperatures and high-volume fluid administration accelerate loss of heat to the environment. Randomized, controlled trials have proven that mild hypothermia increases the incidence of wound infection and prolongs hospitalization, increases the incidence of morbid cardiac events and ventricular tachycardia, and impairs coagulation. Other complications include enhanced anaesthetic drugs effects, prolonged recovery room stays, shivering, and impaired immune function. There is compelling animal evidence for cerebral protection by mild hypothermia. However, evidence for protection in surgical patients is not yet available. The most effective means of preventing perioperative hypothermia is active pre-warming. High ambient temperatures, warmed intravenous fluids and active cutaneous warming are useful intra-operatively, while active cutaneous warming and intravenous pethidine abolish post-operative shivering. Proper thermal management may reduce complications and improve the outcome in high-risk surgical patients.
Best Pract Res Clin Anaesthesiol 2003 Dec
PMID:Perioperative hypothermia in the high-risk surgical patient. 1466 53

Malignant hyperthermia (MH) is an uncommon, life-threatening, acute pharmacogenetic disorder of the skeletal muscle cell. It manifests in susceptible individuals as a hypermetabolic response on exposure to halogenated volatile anaesthetics and depolarizing muscle relaxants. There may also be a relationship between susceptibility to MH, heat stroke and exercise-induced rhabdomyolysis. The pathophysiology of the crisis involves an uncontrolled release of cytoplasmic free calcium from the sarcoplasmic reticulum leading to activation of energy-producing biochemical pathways. Organ system failure and rhabdomyolysis may occur as a result of high fever, hyperkalaemia and acidosis. The ryanodine receptor, the calcium-release channel of the sarcoplasmic reticulum, is the primary locus for malignant hypothermia susceptibility. Multiple mutations in the gene for the ryanodine receptor protein are causative. Other genes may also be involved. A classical fulminant crisis presents with a rising end-tidal carbon dioxide, skeletal muscle rigidity, tachycardia, hyperthermia and acidosis. Mortality may be as high as 70% if the syndrome is not recognized and treated. Immediate discontinuation of triggering agents, oxygenation, and correction of acidosis and electrolyte abnormalities, cooling and dantrolene are essential for treatment of the syndrome. Thanks to clinical and research investigations, widespread education and the introduction of dantrolene sodium, the mortality from MH is less than 5%. This chapter provides an overview and an update of MH.
Best Pract Res Clin Anaesthesiol 2003 Dec
PMID:Malignant hyperthermia. 1466 55

Perioperative hypothermia triples the incidence of adverse myocardial outcomes in high-risk patients. Mild hypothermia significantly increases blood loss and augments allogeneic transfusion requirement, but the molecular pathophysiology of this effect remains to be elucidated. Only 1.9 degrees C core hypothermia triples the incidence of surgical wound infection following colon resection and increases the duration of hospitalization by 20%. Hypothermia adversely affects antibody- and cell-mediated immune defences, as well as the oxygen availability in the peripheral wound tissues. Mild perioperative hypothermia changes the kinetics and action of various anaesthetic and paralysing agents, increases thermal discomfort, and is associated with delayed post-anaesthetic recovery. Finally, mild core hypothermia influences pulse oximetry monitoring and various electrophysiological indices of the nervous system, with questionable clinical significance, as yet.
Best Pract Res Clin Anaesthesiol 2003 Dec
PMID:Consequences of inadvertent perioperative hypothermia. 1466 56


1 2 3 4 5 Next >>