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Biomedical subjects

A A El-Etr

Publications and source records attributed to A A El-Etr.

13 recordsLinked to original sources
PubMed1979

Prolongation of pancuronium-induced neuromuscular blockade by intravenous infusion of nitroglycerin.

Based upon clinical observation of undue prolongation of pancuronium-induced blockade in the presence of intravenous infusion of nitroglycerin, neuromuscular blockades produced by pancuronium, succinylcholine and d-tubocurarine were studied in 51 cats using the sciatic-gastrocnemius nerve-muscle preparation. Pancuronium-induced blockade was found to be significantly prolonged (P less than 0.1) in the presence of a nitroglycerin infusion of 1 microgram/kg/min (65 vs. 127 min). Less, but still significant, prolongation occurred when nitroglycerin, 0.5 microgram/kg/min, was infused. The intravenous infusion of nitroglycerin must be started prior to the pancuronium injection for the block to be prolonged. Neuromuscular blocks produced by succinylcholine and d-tubocurarine were not altered by nitroglycerin. In experiments using the isolated rat diaphragm preparation, the depth of pancuronium-induced block was found not to be changed by nitroglycerin, suggesting an effect of nitroglycerin on the process of recovery from blockade. These findings indicate a selective pancuronium-nitroglycerin interaction.

Animals↗
PubMed1978

Serum epinephrine and norepinephrine during valve replacement and aorta-coronary bypass.

A comparison of the levels of serum epinephrine, norepinephrine and blood pressure was made in 25 patients undergoing aorta-coronary bypass or valve replacement who were anaesthetized with a nitrous oxide-narcotic technique. Serum epinephrine and norepinephrine were measured in arterial samples drawn pre-induction, post-induction, before cardiopulmonary bypass, two and eight minutes after initiation of cardiopulmonary bypass, 20 minutes before termination and after termination of cardiopulmonary bypass. In both patient groups significant increases in epinephrine and norepinephrine occurred befored cardiopulmonary bypass, with accompanying increase of blood pressure in the valve replacement patients. During cardiopulmonary bypass an initial hypotensive response (p less than 0.001) was recorded, followed by a significant increase in blood pressure and epinephrine in both groups. After cardiopulmonary bypass, aorta-coronary bypass patients had epinephrine, norepinephrine and blood pressure equal to levels before cardiopulmonary bypass. In contrast, serum epinephrine continued to rise in the valve replacement patients, with a gradual recovery of blood pressure to pre-bypass levels. These findings demonstrate significant differences in blood pressure and catecholamine response in patients with valvular disease from patients with coronary artery disease.

Adult↗
PubMed1976

Levels of circulating norepinephrine and epinephrine before, during, and after cardiopulmonary bypass in man.

Little information is available on the levels of circulating catecholamines during cardiac surgery. A study was undertaken to measure the serum levels of epinephrine and norepinephrine before, during, and after cardiopulmonary bypass in 16 patients. Sampling were drawn before induction, after intubation, before bypass, 2 and 8 minutes after initiation of the bypass, and 20 minutes after bypass. The findings of this study show that the initiation of cardiopulmonary bypass was associated with a significant but transient fall in mean blood pressure accompanied by an increased secretion of adrenal epinephrine and norepinephrine. The cause of the observed hypotension may be due to an initial hemodilution of the circulating catecholamines by the 2 L. pump-priming solution. The secretion of adrenal catecholamines appears to be a compensatory response to the lowered blood pressure as indicated by the rapid return of the blood pressure in the ensuing minutes. Twenty minutes after bypass, both the blood pressure and serum catecholamine levels were observed to have returned to preinduction levels.

Anesthesia, Inhalation↗
PubMedDate not supplied

The effects of ketamine and of Innovar anesthesia on digitalis tolerance in dogs.

In a comparison of digitalis tolerance in dogs anesthetized with ketamine, Innovar Vet, or pentobarbital, the dosage of ouabain needed to cause ventricular tachycardia was significantly higher, as was the LD50 of ouabain, with ketamine or Innovar than with pentobarbital. Ventricular tachycardia induced by ouabain was generally converted to sinus rhythm following administration of Innovar, ketamine, or droperidol but not after administration of fentayl alone or after pentobarbital.

Anesthesia, Inhalation↗
PubMedDate not supplied

The effect of enflurane, isoflurane, fluroxene, methoxyflurane and diethyl ether anesthesia on ouabain tolerance in the dog.

Digitalis tolerance in dogs anesthetized with enflurane, isoflurane, fluroxene, methoxyflurane, and diethyl ether was compared with that in dogs anesthetized with pentobarbital. Ouabain dosage needed to cause ventricular tachycardia was significantly higher than that of pentobarbital with all agents except fluroxene, as was the LD50. The relative potency of these anesthetics in converting ouabain-induced ventricular tachycardia to sinus rhythm, in order of descending effectiveness, was: diethyl ether, methoxyflurane, enflurane, fluroxene, isoflurane, pentobarbital.

Anesthesia, Inhalation↗
PubMedDate not supplied

Enflurane anesthesia for surgical removal of pheochromocytoma.

Four cases describing the use of enflurane as the main anesthetic during surgical removal of pheochromocytoma (PCC) are presented and the preoperative preparation and intraoperative management of the patients are discussed. Serum levels of epinephrine and norepinephrine were measured in 3 of the reported cases. Intraoperative values were extremely elevated during tumor manipulation, but there was only 1 minor episode of arrhythmias. Criteria for choosing anesthetic agents for surgical removal of PCC are outlined. The authors conclude from their experience and that of others that enflurane is as safe and effective an anesthetic as any now available for PCC excision.

Adult↗
PubMedDate not supplied

Amitriptyline therapy increases electrocardiographic changes during reversal of neuromuscular blockade.

Induction of anesthesia is associated with an increased incidence of cardiac arrhythmias in patients maintained on amitriptyline medication. This study presents additional evidence showing that, in experimental animals (cats), amitriptyline treatment also produces significant ST-T wave and conduction abnormalities during neostigmine reversal of neuromuscular blockade.

Amitriptyline↗