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)

The effects of diltiazem, a sarcolemmal Ca2+ channel blocker, and ryanodine, an inhibitor of sarcoplasmic reticulum function, were investigated in isolated newborn rabbit hearts (2 to 5 days old) subjected to ischemia and reperfusion. After cardioplegic arrest with St. Thomas' Hospital solution, global ischemia was induced at 37 degrees C (normothermia) for 45 minutes or at 20 degrees C (hypothermia) for 180 minutes. The hearts were then reperfused at 37 degrees C for 30 minutes. Diltiazem or ryanodine, at concentrations that have minimal to moderately negative inotropic effects under nonischemic conditions, was added to the cardioplegic solution. After normothermic ischemia, reperfusion of untreated hearts resulted in recovery of left ventricular developed pressure to 52.9% +/- 2.5% of the preischemic level. In hearts treated with diltiazem, recovery of left ventricular developed pressure was significantly improved (84.2% +/- 2.9% at 3 x 10(-8) mol/L; p < 0.01). Comparable improvement was achieved with ryanodine (90.5% +/- 4.1% at 10(-9) mol/L; p < 0.01). Creatine kinase leakage and structural derangement of mitochondria were also reduced by both agents. With hypothermic ischemia, left ventricular developed pressure recovered in untreated hearts to 72.7% +/- 3.3% of preischemic values. Treatment with diltiazem improved the recovery of left ventricular developed pressure to 96.9% +/- 3.5% at 3 x 10(-8) mol/L and reduced creatine kinase leakage and mitochondrial damage. Ryanodine also improved the recovery of left ventricular developed pressure and attenuated ultrastructural damage. These findings suggest that Ca2+ handling by the sarcoplasmic reticulum, like transsarcolemmal Ca2+ influx, plays an important role in the pathogenesis of myocardial ischemia-reperfusion injury in the neonatal heart despite the morphologic and functional immaturity of the sarcoplasmic reticulum in the neonate.
 ...
PMID:Protective effects of diltiazem and ryanodine against ischemia-reperfusion injury in neonatal rabbit hearts. 832 Oct 5

When activated neutrophils are recruited and bind to endothelial tissues, they release leukotrienes, proteolytic enzymes, and free radicals. The latter has been implicated in myocardial stunning following periods of ischemia and reperfusion, as may occur following cardiopulmonary bypass (CPB). The neutrophil surface complex CD11/CD18 promotes the neutrophil-endothelial adhesion process. Monoclonal antibodies have been developed that can block neutrophil adhesion to the endothelium by preventing CD11/CD18 binding to adhesion molecules (ICAM-1 or ELAM-1) located on endothelial cells. We used monoclonal IgG antibody 60.3 to block neutrophil adherence and thereby potentially reduce myocardial stunning. Pretreatment of rabbits subjected to myocardial ischemia/reperfusion with either monoclonal 60.3 or saline resulted in only a small increase in the rate of recovery of preload recruitable stroke work index during reperfusion. More severe occlusion may have been needed to see significant results. We also evaluated the effects of anti-neutrophil therapy in animal models of CPB. Rhesus monkeys were subjected to deep hypothermia and CPB, followed by 24 hours of fluid resuscitation. Animals receiving monoclonal 60.3 (N = 3) showed less weight gain, less infused resuscitative fluid, and higher terminal hematocrit and PaO2 than controls (N = 3). Antineutrophil therapy may prevent multiorgan system failure in certain high risk patients.
 ...
PMID:Potential role of neutrophil anti-adhesion therapy in myocardial stunning, myocardial infarction, and organ dysfunction after cardiopulmonary bypass. 846 23

Surgical treatment of acute aortic dissection involving the segment of transverse aortic arch is difficult and often associated with a high mortality and morbidity. The high mortality and morbidity are primarily related to anatomic features and techniques of cerebral protection employed during the period of aortic branch occlusion needed for reconstruction. This study reports our experience of 20 consecutive cases of acute type A aortic dissection treated by repair or replacement of the transverse aortic arch during emergency operation. Ages of the patients ranged from 56 to 76 years. All patients were referred to us within 2 weeks of onset (mean time, 58 hours). Selective cerebral perfusion or deep hypothermia with complete circulatory arrest was employed during the period of aortic branch occlusion. Duration of cerebral perfusion, circulatory arrest, myocardial ischemia, and cardiopulmonary bypass averaged 106 minutes, 32 minutes, 127 minutes, and 248 minutes, respectively. There were three operative deaths. All three dissections were ruptured ones, and the patients died of hemorrhage, deep coma, or multiple organ failure. One patient died of infection 3 months after operation. The remaining patients are alive and well without any detectable neurological deficit 1 month to 4 years postoperatively. This experience emphasizes that repair or replacement of acute type A aortic dissection involving the aortic arch can be performed safely by adequate selection of patients, supportive measures, and operative methods.
 ...
PMID:Replacement of the transverse aortic arch for type A acute aortic dissection. 846 31

Hypothermia in the immediate postoperative period is associated with postoperative instability, prolonged recovery and increased risk of myocardial ischemia in the subsequent 24 h. This study examined the effect of irrigating-fluid temperature during transurethral resection of the prostate on perioperative temperature regulation. A randomized prospective study was conducted on twenty-eight consecutive patients undergoing transurethral resections of the prostate. The control group received room-temperature irrigant. The study group received irrigant warmed through the Abbott level-one fluid warmer or in the Ohio Servocare incubator. Fluid temperatures were 17 degrees C for unwarmed fluid, 37 degrees C for level-one fluid, and 35 degrees C for incubator fluid. The incidence of hypothermia (< or = 36 degrees C) in the immediate postoperative period was 95% in the cold-irrigant group and 38% in the warm-irrigant group (p = 0.001). The decrease from pre- to postoperative temperature was greater with cold (0.95 +/- 0.47 degrees C) than with warm (0.42 +/- 0.64 degrees C) irrigant (p = 0.01). The type of anesthesia (spinal versus general) and method of fluid warming (incubator versus level-one) did not have a significant effect on the perioperative temperature drop. Regression analysis demonstrated that the time of resection, amount of prostate resected, volume of irrigant fluid, and volume of intravenous fluid administered were not independent predictors of intraoperative temperature change.
 ...
PMID:Effect of irrigating fluid on perioperative temperature regulation during transurethral prostatectomy. 882 86

Both regional and general anesthesia markedly impair the normal precise regulation of core body temperature. Consequently, inadvertent perioperative hypothermia is common. Hypothermia develops because the typical operating room environment is cold; however it is anesthetic-induced impairment of thermoregulatory responses that contributes most. Internal redistribution of body heat is a surprisingly important factor, contributing more to core hypothermia than net heat loss in most patients. There is now convincing evidence that a typical degree of intraoperative hypothermia, say 2 degrees C, predisposes to numerous complications such as shivering, prolonged duration of action of several drugs, myocardial ischemia, coagulopathy and increased incidence of surgical wound infections, which alter patient outcome. Fortunately, effective methods such as convective warming are available for preventing hypothermia.
 ...
PMID:[Intraoperative hypothermia: pathophysiology and clinical sequelae]. 922 2

Anesthetized surgical patients frequently become hypothermic, because of decreased metabolic heat production, increased heat loss, surgical exposure, and dry respiration gases. Intraoperative hypothermia may trigger postoperative protein breakdown, shivering, myocardial ischemia, and many other problems. For that reason, heat conservation is a major anesthetic management. We determined the efficacy of Warm Touch warming system (Mallinckrodt Medical, Inc.) compared with that of a warming blanket. Sixteen patients undergoing oral and maxillo-facial surgery under neuroleptanesthesia were studied by measuring rectal and finger-tip skin temperature. Patients were divided in Warm Touch group (n = 8) using Warm Touch warming system Model 5100 and warming blanket group (n = 8) and the temperatures were measured every quarter over 60 minutes. Rectal temperature increased 0.62 degrees C after 60 minutes in the Warm Touch group, but significant changes were absent in warming blanket group. Temperature gradient between the rectum and finger-tip skin decreased markedly in the Warm Touch group. This study suggests that Warm Touch is useful to restore body temperature and to prevent postoperative problems arising from intraoperative hypothermia.
 ...
PMID:[Efficacy of Warm Touch warming system for hypothermia]. 945 89

A 69 year-old male with ischemic heart disease indicated for coronary artery bypass grafting was scheduled for carotid microendoarterectomy. We induced mild hypothermia technique with vasodilation and surface cooling by convecting warming device. We examined hemodynamics by pulmonary artery catheter. Anesthesia was induced with thiamylal, fentanyl, midazolam and isoflurane in nitrous oxide and oxygen. Following administration of vecuronium, trachea was intubated. Pulmonary artery catheter was inserted from the femoral vein. Dopamine, dobutamine 3-5 micrograms.kg-1.min-1 and PGE1 5-10 ng.kg-1.min-1 were continuously administered to keep peripheral blood circulation and cardiac output (CO). Systemic vascular resistance decreased from 1800 to 591 dyne.s.cm-5 and CO increased from 2.8 to 6.9 l.min-1. The occlusion of blood flow of the right carotid artery for 40 min at 34.5 degrees C of rectal temperature did not cause any neurological deficits. No other complications such as arrhythmia, myocardial ischemia and bleeding tendency were observed. Keeping peripheral blood circulation and uniform cooling and warming are important in inducing mild hypothermia safely in a patient with ischemic heart disease.
 ...
PMID:[Mild hypothermia anesthesia for carotid microendoarterectomy in a patient with ischemic heart disease]. 951 37

The majority of pediatric cardiosurgery centers make use of cardiopulmonary bypass (CPB) with low hematocrit, and therefore we deemed it interesting to investigate the pathological effects of hemodilution on patients. Specifically, we studied the effect of hemodilution on aerobic and water metabolism in children with congenital heart disease subjected to CPB. Two groups of patients were examined. In the studied group (n = 12, mean age 7.1 +/- 1.1 years) the blood-fluid ratio in primary filling of the CPB device was 1:6.2 +/- 0.7 and minimal hematocrit during myocardial ischemia 18 +/- 0.7%. Control group consisted of 7 patients aged 8.3 +/- 0.6 years, with the above values 1:2.8 +/- 0.4 and 22 +/- 1.6%, respectively. The groups were similar as regards the initial status of patients, level of hypothermia, and duration of myocardial ischemia. Gas content in venous blood was the criterion of aerobic metabolism. Fluid accumulation in the extravasal space during and after surgery was assessed by bioelectroimpedance measurements of the total extracellular extravasal fluid (EEF). Monitoring showed a decrease of hematocrit during CPB to 18 +/- 0.7%, saturation of venous blood with oxygen within 70-75%, and oxygen content 37-43 mm Hg. In the main group a manifest increase of EEF was observed as early as during the early postperfusion period; this increase is probably one of the main components in the detrimental effect of hemodilution. Redistribution of fluid after CPB leads to expressed interstitial edemas and impairs the function of vital organs. That is why signs of cardiorespiratory failure were observed in the main group. Thus, one of the main problems in CPB with low hematocrit is fluid accumulation in the extravasal space.
 ...
PMID:[The effect of hemodilution on the indices of aerobic metabolism and water metabolism in children with congenital heart defects operated on under artificial circulation]. 955 60

This study was undertaken to determine the factors that influence the final outcome after the operation of acute aortic dissection. Twenty-one patients, the median age was 59 years (range 44 to 81), were operated at acute phase in 92 admitted into our hospital during the 13-year period between May 1985 and Jan. 1998. Preoperative complications included cardiac in 5 and ruptured with shock in 7, myocardial ischemia in 3 and stroke in 4. The ascending aortic reconstruction (9, 43%), ascending aorta and arch reconstruction (7, 33%) and other procedures (4, 19%) were performed using cardiopulmonary bypass with deep hypothermia and circulatory arrest or selective cerebral perfusion. The 30-day operative deaths were 6 (29%) and 5 (24%) late death occurred. Three out of 5 were aneurysm related deaths. The cause specific survival rates were 61% at 5 years and 51% at 8 years. The multivariably determined risk factors for death were as follows (p < 0.05): preoperative FDP; bleeding volume; postoperative renal complications; postoperative stroke.
 ...
PMID:[Early and long-term outcome for surgical treatment of acute aortic dissection]. 974 94

Thermoregulation is impaired during anesthesia for cardiac surgery. Redistribution of body heat and heat loss to the environment result in mild hypothermia before cardiopulmonary bypass. Maintenance of normothermia, rather than hypothermia, may facilitate early tracheal extubation. Hypothermia alters the distribution and decreases the metabolism of most drugs, including anesthetic drugs and muscle relaxants, thus prolonging recovery. Postoperative shivering increases metabolic rate and potentially leads to myocardial ischemia; prevention is therefore critical to the success of early tracheal extubation after cardiac surgery. Coagulopathies, increased incidence of surgical wound infection, and perioperative cardiac morbidity are other potential risk factors identified in noncardiac patients. Hypothermia, however, does have potential benefits to the patient, including protection from cerebral ischemia and hypoxemia. Mild core hypothermia (approximately 34 degrees C) may represent the optimal balance between risks and benefits for fast-track patients.
 ...
PMID:The implications of hypothermia for early tracheal extubation following cardiac surgery. 991 65


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>