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)

When blood temperature is changed in closed system ('anaerobic') conditions, plasma pH and PCO2 vary but no titration by external CO2, acid or alkaline equivalents takes place. It is therefore assumed that the overall acid-base state undergoes no fundamental change. This is further justified by the constancy of osmotic relationships between plasma and red cells, and to a lesser extent of relative alkalinity and protein alpha imidazole (Reeves, 1972, 1976a, b). These considerations serve as a basis for a correction procedure of pH and PCO2 of blood in open systems in vivo to a standard temperature T* (25 degrees C, eventually 37 degrees C). The temperature-corrected values pH* and P*CO2, and the derived [HCO3]* can be represented on a temperature-independent bicarbonate-pH diagram. This permits an easier interpretation of blood acid-base changes occurring together with body temperature variations, such as in ectotherms, hibernators or in artificial hypothermia. Extension to intracellular pH is considered.
 ...
PMID:Blood acid-base state at a variable temperature. A graphical representation. 2 17

Sixteen cases of lactic acidosis are reported: 7 phenformin treated diabetes, 5 cardiovascular diseases (2 myocardial infractions, 2 pulmonary embolisms, 1 heart failure). In 2 patients no etiology was found. Concomittant renal failure or liver diseases were found in respectively 9 and 4 cases. Patients presented the usual criteria of lactic acidosis: clinical, polypnea, severe hypotension (9/16), peripheral symptoms of shock (12/16), hypothermia (9/16), abdominal pain (9/16): biologically, acidosis (pH = 6,99 +/- 0,01, HCO3- = 5,9 +/- 1,5 mmol), hyperlactatemia (14,1 +/- 3,6 mmol/l) with hig lactate/pyruvate ratio (105 +/- 73), and anion gap (24,3 +/- 4,2 mmol/l). Sodium bicarbonate infusion was performed in all cases (2,5 to 42 mmol/kg). Few cases required volhemic expansion or furosemid induced diuresis. One patient was treated with extrarenal dialysis. 13 patients were alkalinised with less than 185% of estimated deficit measured from alkalin reserve: 12 died. 3 patients received 185% more than this deficit, associated with furosemid (1,8 to 12,5 mg/kg): only one patient died ten days after by casual disease, with lactatemia of 3,2 mmol/l. In spite of the small number of patients, these findings suggest that an early and massive alkalinisation, with large doses of furosemid, can improve the severe lactic acidosis prognosis.
 ...
PMID:[Lactic acidosis and intensive care. 16 cases (author's transl)]. 23 77

Acid-base terminology including the sue of SI units is reviewed. The historical reasons why nomograms have been particularly used in acid-base work are discussed. The theoretical basis of the Henderson-Hasselbalch equation is considered. It is emphasized that the solubility of CO2 in plasma and the apparent first dissociation constant of carbonic acid are not chemical constants when applied to media of uncertain and varying composition such as blood plasma. The use of the Henderson-Hasselbalch equation in making hypothermia corrections for PCO2 is discussed. The Astrup system for the in vitro determination of blood gases and derived parameters is described and the theoretical weakness of the base excess concept stressed. A more clinically-oriented approach to the assessment of acid-base problems is presented. Measurement of blood [H+] and PCO2 are considered to be primary data which should be recorded on a chart with in vivo CO2-titration lines (see below). Clinical information and results of other laboratory investigations such as plasma bicarbonate, PO2,P50 are then to be considered together with the primary data. In order to interpret this combined information it is essential to take into account the known ventilatory response to metabolic acidosis and alkalosis, and the renal response to respiratory acidosis and alkalosis. The use is recommended of a chart showing the whole-body CO2-titration points obtained when patients with different initial levels of non-respiratory [H+] are ventilated. A number of examples are given of the use of this [H+] and PCO2 in vivo chart in the interpretation of acid-base data. The aetiology, prognosis and treatment of metabolic alkalosis is briefly reviewed. Treatment with intravenous acid is recommended for established cases. Attention is drawn to the possibility of iatrogenic production of metabolic alkalosis. Caution is expressed over the use of intravenous alkali in all but the severest cases of metabolic acidosis. The role of 2,3-diphosphoglycerate on tissue oxygenation is stressed and use of intravenous sodium phosphate as an alternative to intravenous bicarbonate is mentioned.
 ...
PMID:The physiological assessment of acid-base balance. 23 27

Biochemical disorders accompanying posttransfusion shock in cats under protection by selective cerebral hypothermia, by our own method was studied in cats. In 11 of 22 cats, selective cerebral hypothermia was performed before transfusion of human group A blood. In 11 control cats, transfusions were made without prior selective cerebral hypothermia. The following parameters were determined in venous blood: pH, pCO2, HCO3, content and excess of buffer bases. Selective cerebral hypothermia diminished mortality in cats in posttransfusion shock and reduced the intensity of the biochemical changes accompanying shock.
 ...
PMID:Some biochemical indices of posttransfusion shock induced under protection by selective hypothermia of the brain. 23 89

With its chronic administration in a dose of 100 mg/kg lithium carbonate inhibited shaking of the head induced in mice with 5-hydroxytryptophan (5-HTP). This effect did not differ from the action following a single injection of lithium, when the interval between injection of lithium and of 5-HTP was one hour. With the interval lengthened to 24 hours the frequency of shaking diminished only under the effect of chronic administration. At the 5th, 10th and 21st day of a daily administration lithium failed to produce any effect on the hypothermal action of a reserpine-like agent Po 4-1284, but would reduce the protective action of imipramine in a ptosis test. A single injection of lithium made against the background of a chronic injection of water produced an opposite effect, viz. it significantly reduced the protective action of imipramine in hypothermia, but did not affect it with reference to ptosis. Hence, chronic administration of lithium leads to potentiation in its action of the serotonin-negative and central adreno-negative componets and to extenuating the peripheral adreno-negative component.
 ...
PMID:[Effect of lithium on the central serotonin- and adrenergic processes after its chronic administration]. 108 64

1. Two hours of exposure to heat stress, resulted in hyperthermia in rabbits (Oryctolagus cuniculus). 2. This was accompanied by a severe hypocapnia, partly compensated for by a significant decrease in bicarbonate (HCO3-) concentration. 3. The severest hyperthermia (Tb = 43.5 degrees) was followed by a sharp decreased in both PaCO2 (to 20.2 torr) and HCO3- (to 9.2 mM/l), resulting in extreme metabolic acidosis (pH = 7.290). 4. The significant increase in serum osmolality (27%) is interpreted by the cumulative effect of increased electrolyte and metabolite concentrations. 5. The elevation in blood BUN, creatinine, globulin and GOT levels point to a possible damage to muscle cells by hypothermia. 6. The stable cholesterol and alkaline phosphatase levels, suggest that liver tissue was not damaged. 7. The dramatic increase in glucose from 103.8 to 348.8 mg%, and the significant increase (from 22.0 to 39.9 mg%) in BUN, suggest a possible disability of the cells to metabolize carbohydrates, accompanied by a progressive proteolysis as an alternative process for energy production. 8. The data suggest that the emergence of muscle cell damage, severe hyperglycemia and acidosis under heat stress, precedes and amplifies the deteriorating effects of high Tb in heat stressed rabbits, which often lead to mortality.
 ...
PMID:The effect of heat exposure on blood chemistry of the hyperthermic rabbit. 198 37

The cellular response to hypotonic stimulation was studied with videometric methods in 266 proximal renal tubules dissected from Carassius auratus (goldfish). In hypotonic solutions (low NaCl), cells underwent rapid swelling followed by gradual shrinking toward isotonic volume (volume-regulatory decrease phase, VRD). Hypothermia (8 degrees C), increased extracellular potassium (15, 25, and 40 mM), quinine (0.1 mM), barium (0.5 mM), 4,4'-diisothio-cyanostilbene-2,2'-disulfonic acid (DIDS; 0.02 mM), acetazolamide (0.1 mM), decrements in extracellular bicarbonate, and increases in extracellular chloride impaired VRD. Ouabain (1.0 mM), furosemide (0.1 mM), and the chloride channel blocker 5-nitro-2-(3-phenylpropylalanine) benzoate (NPPB; 0.001 mM) had no effect. While VRD occurred in the absence of extracellular calcium influx, addition of the calcium ionophore A23187 (0.01 mM) in the presence of ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid (EGTA; 2.0 mM) impaired this process both in acidic and alkaline media. Trifluoroperazine (0.01 mM) reversibly inhibited VRD. The effect of this calmodulin inhibitor could not be overridden with the cationic ionophore gramicidin (0.5 microM). The data suggest that Carassius proximal renal tubular cells volume regulate in hypotonic solutions by the loss of KCl and osmotically obligated water. We postulate that the main efflux of potassium is through a calcium-gated potassium channel with its counter ion extruded through a calmodulin-regulated Cl(-)-HCO3- exchanger.
 ...
PMID:Possible role of basolateral cell membrane in proximal renal tubule osmoregulation. 233 Oct 23

The effect of the administration of secretin and bethanechol on exocrine pancreatic secretion was studied in rabbits subjected to temperature changes; these involved a drop from 38 degrees C +/- 1 to 28 degrees C +/- 1 (hypothermia) and a subsequent return to 38 degrees C +/- 1 (normothermia). It was observed that hypothermia does not depress the action of secretin on the secretion of fluid, HCO3- and Cl-. Neither was the action of bethanechol on the enzyme secretion affected by changes in body temperature.
 ...
PMID:Exocrine pancreatic response to secretin and bethanechol in rabbits under hypothermia. 289 36

Effects of ischemia and reperfusion on acid-base changes in relation to myocardial contractility, and the effects of correcting H+ were studied by lowering PCO2 or increasing HCO3- levels. The hearts were perfused by working heart mode and whole heart ischemia was induced by use of a one way valve followed by myocardial warming (37 degrees C, normothermia), cooling (18 degrees C, hypothermia) or warming plus 2.1 mM NaHCO3 for 15 min. The hearts were then reperfused for 20 min. Coronary effluent was collected through pulmonary artery cannulation and used for the measurement of acid-base changes. There were close correlations between the decrease in coronary flow and LV pressure, LV dP/dt. Close correlations were also observed between the decline in LV pressure and the rise in PCO2, H+, and the decline in HCO3-. A highly significant correlation was seen between H+ and lactate production. Myocardial contractility decreased to the same extent in 3 groups during ischemia, whereas its recovery rate in both the hypothermia and HCO3- -treated groups were significantly higher than in the normothermia group. The increment of H+ was significantly less in both the hypothermia and HCO3- -treated groups than in normothermia. These results indicate that lactate production is the major H+ producing source and the correction of H+ could minimize the ischemic insult and at the same time contribute to the reperfusion injury.
 ...
PMID:Acid-base changes in ischemic myocardium and intervention with hypothermia or bicarbonate. 314 55

Resuscitation of a neonate requires both immediate cardiopulmonary resuscitation and extended intensive care. Initial resuscitation of the neonate, as for adults, must include support of the airway, breathing and circulation. Because of the unique physiology of a newborn infant, some aspects of drug therapy differ significantly from their counterparts in the resuscitation of adults, and hypoglycemia and hypothermia pose special threats to a distressed neonate. Epinephrine and atropine can be administered via an endotracheal tube, but vascular access, which is most easily obtained by cannulating an umbilical vessel, is required for administering other drugs. Initial drug therapy, including glucose, oxygen and bicarbonate, is intended to restore metabolic homeostasis. Bicarbonate administration must be preceded by adequate alveolar ventilation. Drugs used to increase cardiac output early in resuscitation include those that increase heart rate, increase preload or improve myocardial function. Other drugs used in extended intensive care may also improve cardiac output, alter the distribution of the circulation or alter pulmonary function or gas exchange. These agents will be reviewed in a subsequent article.
 ...
PMID:The pharmacology of neonatal resuscitation and cardiopulmonary intensive care. Part I--Immediate resuscitation. 372 30


1 2 3 Next >>