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Query: UMLS:C0022116 (ischemia)
 91,303 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Experiments were performed on 19 mongrel dogs. Changes of transplantation antigens by anesthesia and by brain ischemia were identified in cytotoxic tests. Brain ischemia was responsible for the significant alterations in 5 antigens, anesthesia alone induced significant changes in 3 antigens.
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PMID:[Changes in transplantation antigens of the dog due to cerebral ischemia and their demonstration using the cytotoxic test]. 120 24

A 12 lead electrocardiogram (ECG) has been recommended for adult patients before operations involving general or regional anesthesia. However, there is a growing consensus that it is of little benefit and ECG should be done only in selected subsets of patients with cardiac signs and symptoms or older patients. We prospectively surveyed 1,013 patients before operation, 395 patients were 40 years or more, ECG abnormalities were present in 130/395 (32.9%), significant ECG abnormalities in 31/395 (7.9%) and ECG with management change in 10/395 (2.5%). Old or questionable myocardial infarction were found in 8 (4.0%) and acute ischemia or injury in 4 (2.0%). The frequency of ECG abnormalities increased with age in males but not in females. Abnormal physical examination could predict only 20 per cent of abnormal ECG. The variables which could predict ECG abnormalities were age and irregular pulse. The frequency of ECG abnormalities, significant ECG abnormalities and ECG abnormalities which led to management change in those patients with normal physical examination were 31.7, 6.4 and 2.2 per cent respectively. In conclusion we propose that preoperative ECG may be indicated in both men and women aged > or = 40 years.
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PMID:The impact of routine preoperative electrocardiogram in patients age > or = 40 years in Srinagarind Hospital. 129 56

The feature of correlation between functional activity of the brain tissue and structural-functional characteristics of the vascular system after sensory deprivation by the removal of whiskers in newborn animals were studied in nembutal-anaesthetized rats in comparison to the animals under d-tubocurarine with local anesthesia. It has been shown that there are major changes of EP parameters and ECoG in the sensory-deprived brain area and diminution of brain cortex thickness. Changes in the vascular system are mainly structural, what are revealed as disorganization in angioarchitecture of radial arteries. At the same time, differences in the blood circulation intensity are found in d-tubocurarine animals only. The largest volume of the local blood circulation is observed in intact hemisphere of sensory-deprived animal. Thus, it can be concluded that sensory-deprived model is the alternative to the ischemia model. This model can be used in studies of physiology of brain blood circulation, and the "structure-function" correlation, in particular.
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PMID:[The characteristics of the correlation of the functional activity, blood supply and structural organization in the sensory-deprived cerebral cortex in rats]. 130 18

Increased extracellular concentrations of glutamate during episodes of cerebral ischemia may be due in part to a positive glutaminergic feedback loop. We evaluated the effect of selective AMPA or NMDA receptor antagonists on hippocampal extracellular concentrations of excitatory amino acids during ischemia and reperfusion. Thirteen New Zealand white rabbits were subjected to 10 min of global cerebral ischemia produced by neck tourniquet inflation (20 psi) combined with systemic hypotension during halothane (1-1.5%) anesthesia. Hippocampal extracellular concentrations of glutamate, aspartate, and glycine were monitored using in vivo microdialysis. NBQX (a selective AMPA receptor antagonist), MK801 (a noncompetitive NMDA receptor antagonist), or 5% dextrose was administered starting 1 h before ischemia. The NBQX group (n = 4) received 5 mg.kg-1 of NBQX intravenously (dissolved in 5% dextrose) over 5 min followed by an infusion of 5 mg.kg-1.h-1. The 5% dextrose group (n = 4) received an equivalent volume of 5% dextrose. The peak concentrations of glutamate, aspartate, and glycine in the early reperfusion period were 5-8-fold, 9-10-fold, and 4-5-fold higher than preischemic values, respectively. There were no significant differences, however, among the three groups in the concentrations of glutamate, aspartate, or glycine at any time during the study. These results do not support the existence of a positive feedback loop for glutamate mediated via AMPA or NMDA autoreceptors in the hippocampus during transient global ischemia or reperfusion.
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PMID:AMPA and NMDA receptor antagonists do not decrease hippocampal glutamate concentrations during transient global ischemia. 135 5

Iloprost has been shown to minimize skeletal muscle necrosis when administered before the onset of ischemia in animal experiments, possibly by preventing neutrophil activation. Since patients with acute limb ischemia are seen after the process has begun, we investigated whether iloprost can be protective when given only during reperfusion. After anesthesia, 18 adult mongrel dogs underwent a standard isolated gracilis muscle preparation. In six control animals (group I) the gracilis muscle was subjected to 6 hours of ischemia followed by 48 hours of reperfusion. Group II animals (n = 6) received intravenous infusion of iloprost at a dose of 0.45 microgram/kg/hr beginning 1 hour before the onset of muscle ischemia and throughout the experiment (6 hours of ischemia and 1 hour of reperfusion). In addition to the continuous infusion, they received 0.45 microgram/kg intravenous boluses of iloprost 10 minutes before the induction of ischemia and 10 minutes before reperfusion. Group III animals (n = 6) had a similar ischemic interval, but were given a bolus of iloprost of 0.45 microgram/kg at end ischemia followed by continuous infusion of 0.45 microgram/kg/hr for 48 hours during reperfusion. Muscle biopsies were obtained at baseline and after 1 hour of reperfusion in all groups. Additional biopsies were obtained at 48 hours of reperfusion in groups I and III. Myeloperoxidase activity, a marker of neutrophil activation, was measured in all muscle biopsies. At the end of reperfusion, the gracilis muscle was harvested in all animals and weighed. Muscle necrosis was estimated by serial transection, nitroblue tetrazolium histochemical staining followed by computerized planimetry.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:The value and limitation of iloprost infusion in decreasing skeletal muscle necrosis. 137 47

The use of a pneumatic ankle tourniquet applied to the supramalleolar ankle region is a useful method of obtaining a bloodless field in surgery of the foot. The pneumatic ankle tourniquet allows for more accurate and reproducible control of circumferential compression than the standard Esmarch bandage, when used in conjunction with the regional ankle block. Between March 1987 and October 1990, 84 foot surgeries were performed using the pneumatic tourniquet and ankle block technique on 76 patients by one surgeon. Tourniquet ischemia lasted from 30 to 105 min. Tourniquet pressure was set to 100 to 150 mm of mercury above systolic blood pressure without exceeding 325 mm of mercury. Two patients reported mild pain directly beneath the tourniquet after 45 and 70 min, respectively. Neither patient required deflation of the tourniquet to complete the procedure. The clinical and electrophysiologic evidence showed that no neurologic or vascular damage occurs. The use of the pneumatic tourniquet in conjunction with regional ankle block anesthesia provides a reasonable alternative to the standard thigh tourniquet for surgery of the foot.
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PMID:The pneumatic ankle tourniquet with ankle block anesthesia for foot surgery. 139 64

We performed local anesthesia of the knee for arthroscopic surgery in 1,000 patients who were diagnosed of meniscopathy, chondropathy, or block of the knee. We established two anesthetic times. The first consisted of an intraarticular administration of 40 ml of a mixture containing bupivacaine 0.5%, lidocaine 0.5% or prilocaine 1%, and adrenaline 1:200,000. The second was extraarticular and consisted of a local infiltration at the sites of entrance of the arthroscope or instrumental material with lidocaine 0.5% or prilocaine 1%, with adrenaline 1:100,000. We kept a latency period of 10 to 15 min, time required for setting up the arthroscopic procedure. Ischemia was systematically avoided. With this technique the following surgical treatments were performed: meniscectomy, curettage of articular cartilage, synovectomy, plica sections, and extraction of free bodies. Tolerance to surgery was excellent in 32.3% cases, good in 46.5%, regular in 16%, and bad in 5.2%. In no cases more complex anesthetic techniques were undertaken. We conclude that the anesthetic technique used in this study is appropriate for arthroscopic surgery of the knee and allows to perform ambulatory surgery. The procedure is not useful in cases of ligament reconstruction, regional infection, and rupture of the articular capsula. Although the anesthetic technique is easy some factors should be considered before indication of the procedure such as a careful selection of the patient, skillfulness of the surgeon in performing the arthroscopy, and the accuracy of the preoperative diagnosis.
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PMID:[Local anesthesia of the knee for arthroscopic surgery. Our experience in 1,000 cases]. 141 Jul 54

The tourniquet is widely used in upper and lower extremity surgery in orthopedic practice. However, safe working guidelines for the application of the tourniquet are not clearly defined. The use of a tourniquet is an important step in performing total knee arthroplasty, and it seems plausible that mechanical damage is directly related to the height and the duration of the pressure of the tourniquet applied. Even the tourniquet pressure which is widely accepted in clinical practice, if it is applied for several hours, would permanently damage not only tissues directly under the tourniquet but also the muscles and the nerves distal to the tourniquet. The resultant ischemia to limb produces local changes including hypoxemia, acidosis and hyperkalemia. Relatively little is known about the systemic effects of tourniquet release when the patient is undergoing total knee replacement surgery under a general anesthesia. Therefore, we studied the systemic effects. The results were as follows: 1) Approximately five minutes after the tourniquet was released there was a statistically significant increase in mean heart rate.: 2) Serum potassium levels tended to increase significantly until five minutes while the serum sodium level rose significantly only one minute, and the lactate level rose significantly for only two minutes after tourniquet released; 3) PaCO2 increased for five minutes after tourniquet release and remained elevated for 30 minutes; 4) PaO2 did not change significantly two minutes after tourniquet release; 5) The mean pH dropped to 7.34 and remained low for over five minutes.
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PMID:Blood gas and electrolyte changes after tourniquet application in total knee replacement surgery. 141 92

Liver and spleen phagocytic clearance of blood-borne microparticulate tissue debris and products of intravascular coagulation after trauma and surgical injury is an important mechanism to limit the deposition of debris in the pulmonary vascular bed. Plasma fibronectin (pFn) modulates this clearance process. We evaluated the effect of a localized peripheral ischemia and reperfusion injury on liver and spleen phagocytic function. Male rats (250 to 350 g) underwent 4 hours of tourniquet-induced bilateral hindlimb ischemia, followed by 18 hours of reperfusion after release of the tourniquet. Rats subjected to ether anesthesia alone or anesthesia followed by groin incision without ischemia were the control and sham groups, respectively. Reticuloendothelial (RE) phagocytic function was assessed at 15 minutes and 18 hours after the start of reperfusion by the in vivo liver and spleen removal of blood-borne iodine 125 (125I)-test microparticles, which were coated with gelatin (denatured collagen) to enhance their interaction with pFn. Liver and spleen particle uptake in control and sham rats was similar. In contrast, after 4 hours of ischemic injury with 15 minutes of reperfusion, we observed a 30% to 40% decrease (p less than 0.05) in liver and spleen particle uptake as compared with sham controls with partial restoration of this removal mechanism by 18 hours. This depression in liver and spleen phagocytic function was associated with a significant (p less than 0.05) increase in the deposition of the 125I-test particles in the lung. RE depression was not due to a deficiency of pFn; indeed, a marked elevation (588 +/- 12 micrograms/mL versus 1,083 +/- 40 micrograms/mL) of pFn was observed by immunoassay over the 18-hour reperfusion interval. Comparative bioassay of humoral (opsonic) versus cellular (Kupffer's cell) activity revealed that Kupffer's cells in livers from controls or ischemia-reperfusion rats exhibited normal phagocytic function when incubated in plasma harvested from either control or 4-hour ischemic rats. The opsonic activity of plasma harvested after ischemia and reperfusion was also more than adequate, consistent with the immunoassay analysis. Thus, the impaired liver and spleen clearance mechanism after peripheral ischemia and reperfusion injury did not appear to be due to either a macrophage cellular deficit or a lack of pFn. This clearance depression may be mediated by splanchnic malperfusion, which is known to develop after peripheral ischemia and reperfusion and associated soft tissue injury.
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PMID:Liver and spleen phagocytic depression after peripheral ischemia and reperfusion. 141 24

This study was designed to determine whether the end-systolic pressure-length relationship (ESPLR) reflects changes in regional contractility during the imposition of graded ischemia, and whether it is modified by diltiazem during propofol anesthesia. Seven beagles were anesthetized and instrumented to measure left ventricular pressure and subendocardial segment lengths (sonomicrometry) in the region of the left anterior descending (LAD) and circumflex (LC) arteries. Afterload was increased by the tightening of a snare around the descending thoracic aorta. Pressure-length loops were constructed and the slope of the ESPLR and the x-axis intercept, Lo, were calculated. Graded ischemia of the apical myocardium only was accomplished by the tightening of a micrometer-controlled snare around the LAD to produce Critical Constriction (CC), Ischemia 1 and 2 (I1, I2), and Total Occlusion (TO). In the basal LC region, LAD ischemia had no effect on either the ESPLR slope or Lo. In contrast, the ESPLR slope in the LAD area was decreased by ischemia at I1 (-40%), increased at TO (+69%), and unchanged at CC and I2, and was reduced by diltiazem at CC and I2 (-31% and -36%, respectively). The LAD ESPLR Lo was increased by ischemia by 64% and 61% at I2, and 91% and 122% at TO, before and after diltiazem, respectively. In the LC region, diltiazem decreased systolic shortening and the ESPLR slope. These results indicate that diltiazem has negative inotropic properties in both ischemic and nonischemic areas. Also, Lo is not a constant and must always be redetermined for every intervention. In the absence of ischemia, the ESPLR may be a reliable measure of myocardial contractility.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Canine end-systolic pressure-length relationships: depressed by diltiazem, invalidated by ischemia. 142 Oct 71


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