Articles: anesthetics.
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Randomized Controlled Trial Clinical Trial
Bicarbonate-buffered lidocaine-epinephrine-hyaluronidase for eyelid anesthesia.
A double-masked, randomized clinical trial was conducted to determine if subcutaneous eyelid injections of a bicarbonate-buffered lidocaine-epinephrine-hyaluronidase mixture were less painful than unbuffered injections. Twenty-one patients received both buffered (pH = 7.4) and unbuffered (pH = 4.6) injections. ⋯ Seventeen (81%) of 21 patients ranked the buffered injection less painful. Use of a bicarbonate-buffered lidocaine-epinephrine-hyaluronidase mixture is effective in making ophthalmic anesthesia less painful.
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J Dermatol Surg Oncol · Nov 1990
Effect of the topical anesthetic EMLA on the efficacy of pulsed dye laser treatment of port-wine stains.
EMLA cream (Eutectic Mixture of Local Anesthetics) is a new topical anesthetic composed of 25 mg lidocaine and 25 mg prilocaine in an oil-in-water emulsion cream. It has been found to be very effective for local anesthesia prior to venepuncture, minor surgical procedures, and pulsed dye laser (PDL) therapy for port-wine stains (PWS) in children. However, since EMLA may cause vasoconstriction of cutaneous vessels, we tried to determine whether pretreatment with EMLA decreases the efficacy of subsequent PDL treatment. ⋯ The other site, in the same area of the PWS and patient's body, was not pretreated with EMLA. The test sites were compared 6-8 weeks later to determine whether EMLA decreased the degree of lightening of the PWS compared to the non-EMLA-treated site. We conclude that EMLA is an effective topical anesthetic for PDL treatment of PWS and does not adversely affect the efficacy of the treatment.
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Clin. Exp. Pharmacol. Physiol. · Nov 1990
Effects of halothane, ketamine, propofol and alfentanil anaesthesia on circulatory control in rabbits.
1. We have made a within-rabbit comparison of the effects of four general anaesthetic regimens on the haemodynamic response to acute reduction in central blood volume and on baroreflex control of heart rate. 2. Acute haemorrhage was simulated by gradually inflating a cuff on the inferior vena cava in order to cause cardiac output to fall at a constant rate of 8.5%/min while the responses of systemic vascular resistance, arterial pressure and heart rate were measured. ⋯ This effect of alfentanil appeared to be mediated centrally, since it could be reproduced by injecting small doses (1.5-7.5 micrograms) into the fourth ventricle. All four anaesthetic agents and nitrous oxide attenuated the baroreceptor control of heart rate. The effect was least with nitrous oxide and alfentanil, greatest with halothane.
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The determination of MAC values (minimum alveolar concentrations) for inhalation anesthetics and, correspondingly, of MIR values (minimum infusion rates) for i.v. anesthetics necessarily requires the use of therapeutically ineffective doses so that reactions to skin incision can be observed. EEG feedback-controlled dosing systems for i.v. anesthetics make it possible to determine dose requirement curves, allowing the definition of effective therapeutic infusion rates (ETI). During total i.v. anesthesia in 11 patients treated with fentanyl the mean effective infusion rate for methohexitone was found to be 4.68 +/- 1.39 mg/min, while for propofol the mean ETI in 11 volunteers was determined at 9.90 +/- 2.46 mg/min. The implications of feedback-controlled dosing systems for the study of clinico-pharmacologic problems in anesthesia are discussed.