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Biomedical subjects

S Muravchick

Publications and source records attributed to S Muravchick.

31 records · Page 2Linked to original sources
PubMed1981

Isobaric tetracaine spinal anesthesia and the lithotomy position.

The extent and pattern of anesthesia produced by hyperbaric and by isobaric 0.5% tetracaine spinal anesthesia were compared in this blind-observer, randomized study of 103 spinal anesthetics performed in 98 patients having genitourinary surgery in the lithotomy position. Pinprick stimulation showed no significant differences in maximum segmental sensory levels, times to maximum level, or duration of anesthesia for isobaric as compared to hyperbaric tetracaine. No parameters were significantly altered by barbotage of isobaric tetracaine solutions. With injections given to patients in the sitting position and with patients subsequently maintained in a horizontal lithotomy position before being put in the lithotomy position, the addition of dextrose to tetracaine solutions injected at room temperature into the subarachnoid space does not significantly alter the cephalad spread of spinal anesthesia.

Adult↗
PubMed1981

Density of normal human cerebrospinal fluid and tetracaine solutions.

Density and specific gravity (SG) were determined at two or more temperatures between 23 and 37 C for 15 samples of normal human cerebrospinal fluid (CSF) and CSF mixed with tetracaine, and for tetracaine solutions commonly used for spinal anesthesia. Density was determined from measured weight and volume, and SG was calculated using the density of water at the same temperature. With 95% confidence limits, SG of normal human CSF at 37 C ranges from 1.0063 to 1.0075, less variation than previously reported. Changes in temperature altered the densities of dextrose, tetracaine, and CSF, alone or in combination, in a parallel manner, but SG remained constant for each solution over the observed temperature range.

Adult↗
PubMed1980

Peripheral temperature monitoring during cardiopulmonary bypass operation.

Almost one-third of 24 adult patients undergoing hypothermic cardiopulmonary bypass (CPB) for elective cardiac operation were found to have upper extremity skin and muscle temperatures of 30.0 degrees C or less at termination of CPB despite the return of nasopharyngeal temperature to normal values. Within 45 minutes, the mean nasopharyngeal temperature of these patients fell spontaneously from 37.1 degrees +/- 0.3 degrees C (+/- standard deviation) to 35.1 degrees +/- 0.4 degrees C, a significantly greater fall (p less than 0.005) than was observed for patients with extremity temperatures greater than 30.0 degrees C. Persistent hypothermia of the upper extremities correlated statistically with large body mass; it appears that these patients incur disproportionately large caloric debts during hypothermic CPB. Inadvertent hypothermia after CPB can be minimized if both core and extremity temperatures are utilized to provide an assessment of the adequacy of warming prior to return to spontaneous circulation.

Adult↗
PubMed1980

Preoperative pharmacology and anesthetic risk.

Chronic or preoperative drug therapy may contribute to the overall risk of anesthesia by modifying organ function directly, or by altering the response of the patient to anesthetic agents or adjuvants. Many drug-patient and drug-drug interactions can be predicted from analysis of their expected effects upon the neurohumoral control systems that normally maintain physiological homeostasis, especially those involving the release or termination of action of catecholamines or acetylcholine. Current concepts of biotransformation, especially as regards hepatic microsomal function, are so broad that estimates of the toxic potential of the metabolites of anesthetic drugs still require an empirical approach for each agent considered.

Anesthetics↗
PubMed1979

Glycopyrrolate and cardiac dysrhythmias in geriatric patients after reversal of neuromuscular blockade.

The increase in cardiac muscarinic activity following injection of anticholinesterases can be minimized by the long-acting anticholinergic drug glycopyrrolate. In a series of 50 patients 65 years of age or older who had received glycopyrrolate (0.88 +/- 0.15 mg) mixed with neostigmine (4.40 +/- 0.66 mg) or pyridostigmine (17.46 +/- 2.92 mg) to antagonize neuromuscular blockade, the incidence of new postoperative cardiac dysrhythmias was 16 per cent. All dysrhythmias occurred in patients with pre-existing cardiovascular disease. There was no statistically significant relationship between the incidence of cardiac dysrhythmias and the choice of anaesthetic technique or anticholinesterase drug.

Aged↗
PubMed1979

Pentolinium for control of reflex hypertension in spinal cord injured patients.

Ganglioplegia was produced by intravenous infusion of pentolinium tartrate 5 mg to control reflex hypertension in 29 patients with chronic spinal cord injuries undergoing 32 elective surgical procedures. The patient group with lesions above the first thoracic segment (T1) demonstrated significant but moderate intraoperative elevation of both systolic and diastolic pressure whether pentolinium was given prior to or during surgical stimulation. Patients with lesions below T1 had no significant pressure elevations with either mode of therapy. Pentolinium ganglioplegia can safely maintain blood pressure within reasonable limits in these patients; some increase in dosage may be required in patients with lesions above T1.

Adolescent↗
PubMed1976

Adrenergic receptors and vascular resistance in cerebral circulation of the cat.

Infusion of catecholamines and pharmacologic blockade were used to demonstrate the presence of an adrenergic receptor system with both alpha and beta components inthe feline cerebral vasculature. For this purpose, the anatomically isolated brain preparation was perfused under controlled constant-pressure conditions to eliminate active autoregulatory changes and passive fluctuations in calculated cerebral vascular resistance (CVR) secondary to alterations of perfusion pressure. Alpha adrenergic activity was demonstrated as substantial cerebral vasoconstriction in response to infusions of l-norepinephrine and epinephrine; cerebral blood flow (CBF) was decreased by mean values of 25% and 29%, respectively, with calculated increases in CVR of 82% and 62%, respectively. Marked reductions in the vasoconstriction produced by these two catecholamines followed the use of the alpha receptor blocking drug, phenoxybenzamine. Isoproterenol consistently produced cerebral vasodilation (mean CVR decrease of 22%), and this vasodilation was blocked during infusion of a specific beta adrenergic blocking agent, propranolol. Histamine vasodilation (mean CBF increase 49%) appeared to be independent of the classic adrenergic mechanisma. The observed responses are explained on the basis of a functionally significant cerebrovascular adrenergic system having high specificity and demonstrating considerable potency. The data also indicate a predominance of alpha over beta adrenergic cerebrovascular reception.

Animals↗
PubMedDate not supplied

An unusual complication of lumbosacral plexus block: a case report.

Lumbosacral plexus block is a valuable anesthetic technic in the hands of an experineced anesthesiologist. However, as illustrated by this case report, anesthetic dosage must be selected with great care, and patients unable to describe paresthesias should be excluded from use of this procedure.

Aged↗