PubMed Health⌕ Search

Biomedical subjects

B Mets

Publications and source records attributed to B Mets.

48 records · Page 3Linked to original sources
PubMed1992

Continuous intravenous propofol with nitrous oxide for ocular surgery. A comparison with etomidate, alfentanil, nitrous oxide and isoflurane.

Propofol, administered intravenously for induction and as a continuous maintenance anaesthetic with nitrous oxide, was compared, in a group of elderly patients scheduled for ophthalmic surgery, with an anaesthetic technique (etomidate, alfentanil, nitrous oxide and isoflurane) specifically chosen to be haemodynamically stable and evanescent in action. Both techniques resulted in similar effects on blood pressure after induction, intubation and surgical incision, but propofol did not prevent increases in heart rate as effectively at these times. Furthermore, during maintenance anaesthesia, cardiovascular stability and anaesthetic depth were more easily achieved in the group where etomidate, alfentanil and isoflurane were used. Propofol decreased intra-ocular pressure after intubation, while in both groups recovery was rapid with no significant complications. A subgroup of patients receiving alpha-methyldopa had significantly longer post-anaesthetic recovery times.

Aged↗
PubMed1992

Intravenous sedation for ocular surgery under local anaesthesia.

Anterior segment ophthalmic surgery is commonly performed under local anaesthesia. In order to improve patient comfort, a variety of sedation techniques has been employed in the past. The object of this study was, firstly, to determine whether continuous intravenous sedation during surgery offered any advantages in patients premedicated with temazepam and metoclopramide, and, secondly, to compare midazolam to propofol for this purpose. Forty nine patients were randomly allocated to receive no intravenous sedation (n = 15), continuous propofol infusion (n = 17), or continuous intravenous midazolam infusion (n = 17) after peribulbar anaesthesia. Each technique provided cardiovascular and respiratory stability and allowed early recovery with minimal postoperative sequelae. Unexpected ocular field movement occurred more commonly in the patients receiving intravenous sedation, although statistical significance was not shown (p = 0.06). Significantly more patients in the intravenous sedation groups reported amnesia (p = 0.03). Patient acceptability was good irrespective of the technique used. This study suggests that continuous sedation using propofol or midazolam is not beneficial and should be avoided in ophthalmic patients who have received a simple premedication.

Aged↗
PubMed1992

Lidocaine and bupivacaine cardiorespiratory toxicity is additive: a study in rats.

The purpose of this study was to determine whether equipotent solutions of lidocaine, bupivacaine, or a mixture of these compounds infused at a fixed rate in anesthetized rats resulted in equivalent lethal cardiorespiratory toxicity and to establish whether the lethality of the individual drugs was additive. This was assessed by comparing the time to respiratory and circulatory arrest, determining the lethal doses of administered local anesthetic in each group, and ascertaining the concentration of lidocaine or bupivacaine, or both, at the time of circulatory arrest. The times to respiratory and circulatory arrest were similar in rats receiving either lidocaine (2%) or bupivacaine (0.5%) or a mixture of 1% lidocaine and 0.25% bupivacaine. The mean lidocaine-to-bupivacaine cumulative lethal dose ratio (3.36) and concentration ratio (2.33) were determined and used to calculate lidocaine equivalent values for bupivacaine data. Lidocaine equivalent cumulative lethal doses and plasma concentrations were similar in all three groups studied. This work suggests that the lethal cardiorespiratory toxicity of lidocaine and bupivacaine associated with intravenous infusion is additively toxic in rats.

Animals↗
PubMed1992

The effects of inhibition of plasma cholinesterase and hepatic microsomal enzyme activity on cocaine, benzoylecgonine, ecgonine methyl ester, and norcocaine blood levels in pigs.

We measured the blood levels of cocaine and its three major metabolites, benzoylecgonine, ecgonine methyl ester, and norcocaine, in three groups of male pigs weighing about 26 kg (25.75 +/- 0.25 kg) to determine the effects of inhibition of plasma cholinesterase and hepatic microsomal enzyme activity on cocaine metabolism. In addition, systemic elimination half-life, volume of distribution, and clearance of cocaine were calculated for the three groups. Group 1 pigs (n = 4) were pretreated with normal saline solution, group 2 pigs (n = 4) were pretreated with tetraisopropyl pyrophosphoramide, a specific plasma cholinesterase inhibitor, and group 3 pigs (n = 4) were pretreated with cimetidine, a hepatic microsomal enzyme inhibitor, all administered intramuscularly. Pigs were anesthetized with intravenous sodium thiopental; a carotid arterial cannula and an external jugular catheter were then inserted for the administration of cocaine and for blood sampling. Forty-five minutes later, when pigs were again completely awake, cocaine 3 mg/kg was given intravenously. Arterial blood samples were collected for the analysis of cocaine and cocaine metabolite levels just before and at 5, 10, 15, 30, 45, 60, 120, 180, and 1440 minutes after the administration of cocaine. Cocaine and cocaine metabolite blood levels were analyzed with high-pressure liquid chromatography methods and plasma cholinesterase activity was measured with a colorimetric method. The blood levels of cocaine and cocaine metabolites were significantly different among the three groups (p less than 0.05, analysis of variance). Statistically significant differences in half-life, volume of distribution and clearance were also seen among the three groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Midazolam-induced benzodiazepine withdrawal syndrome.

A case history of a patient who developed severe anxiety and agitation on two occasions after discontinuation of a midazolam infusion is presented. The withdrawal symptoms interfered with effective mechanical ventilation and the patient required the reintroduction of a long-acting benzodiazepine to treat the withdrawal state and to facilitate weaning from mechanical ventilation.

Akathisia, Drug-Induced↗
PubMed1988

Cardiovascular and respiratory effects of oral premedication with trimeprazine and droperidol in children.

The systolic blood pressure, pulse rate and respiratory rate were assessed in 112 children before and after receiving premedication consisting of trimeprazine (3 mg/kg) and droperidol (0.2 mg/kg) by mouth. A mild (10%) drop in blood pressure was shown, but no statistical difference was found in the other parameters measured. The premedication is highly efficacious, 70% of patients being asleep in the preanaesthetic room; 27% were calm and only 3% were distressed or crying.

Administration, Oral↗
PubMedDate not supplied

Alcohol pretreatment does not affect bupivacaine pharmacokinetics in the pig.

We investigated whether alcohol pretreatment sufficient to cause fatty liver change would affect the disposition of bupivacaine after i.v. administration in pigs. Twelve male pigs (22-26 kg) were randomly divided into two groups of six each. Group A received ethanol (1 g kg-1 day-1) via an intragastric tube for 16 days. Group D received an equal volume of isocaloric dextrose 44% in water for this period. On day 17, left internal jugular and carotid cannulae were placed under thiopentone anaesthesia. On recovery from anesthesia, a blood sample was taken for the determination of liver function indices and then bupivacaine hydrochloride (1.2 mg kg-1) was administered over one minute and samples for plasma bupivacaine analysis taken from the arterial cannulae over the next five hours. Right liver lobe biopsies were taken and animals were killed under general anaesthesia. Blind evaluation of liver biopsies confirmed fatty liver changes only in alcohol-pretreated livers. Despite this there were no differences in bupivacaine disposition and liver function indices between the two groups.

Anesthetics, Local↗