Search PubMed⌕ Search

Biomedical subjects

Z E Vieira

Publications and source records attributed to Z E Vieira.

13 recordsLinked to original sources
PubMed1994

Evaluation of fentanyl and sufentanil on the diameter of the common bile duct by ultrasonography in man: a double blind, placebo controlled study.

Narcotic mu-agonists have been shown to increase the common bile duct pressure. With a recently introduced non-invasive ultrasonographic technique, we have demonstrated that morphine caused constriction of the common bile duct. We have now investigated the effect of highly potent, widely used mu-agonists, fentanyl and sufentanil on the diameter of the common bile duct using this technique in a double-blind, randomized study in 17 patients undergoing cholecystectomy. After premedication with midazolam and glycopyrrolate, anesthesia was induced by midazolam, 50 micrograms.kg-1 and thiopental, 3.0-5.0 mg.kg-1. Tracheal intubation was facilitated by succinyl-choline, 1.0 mg.kg-1 and muscle relaxation maintained with vecuronium. Anesthesia was maintained with enflurane or isoflurane and nitrous oxide in oxygen. The diameter of the common bile duct was determined before and at 4 and 8 minutes after the administration of the study drugs. One way analysis of variance and paired t-test were used for statistical analysis. P < 0.05 was considered significant. No significant change in common bile duct diameter was observed after i.v. placebo, nor were there any significant changes after fentanyl or sufentanil administration. Since the baseline common bile duct diameters were not significantly different among the three groups, fentanyl or sufentanil in the doses used had no more effect than a placebo on common bile duct diameter. It is concluded that fentanyl and sufentanil caused no effect on the common bile duct, therefore, these mu-agonists seem to be safe in patients in whom spasm of the common bile ducts should be avoided.

Adult↗
PubMed1993

Double-blind placebo-controlled ultrasonographic confirmation of constriction of the common bile duct by morphine.

Although the increase in the common bile duct pressure in response to morphine has been repeatedly reported in experimental animals and humans, this is the first double-blind non-invasive, ultrasonographic study designed to demonstrate constriction of the common bile duct caused by i.v. administration of morphine in surgical patients. In a double-blind, placebo-controlled, randomized study, 12 patients undergoing open cholecystectomy were enrolled. No opioids were allowed for 12 hours prior to the study. After premedication with midazolam and glycopyrrolate, anesthesia was induced by midazolam, 50 micrograms/kg-1 and thiopental, 3.0-5.0 mg/kg-1. Tracheal intubation was facilitated by succinylcholine, 1.0 mg/kg-1 and muscle relaxation was maintained with vecuronium. Anesthesia was maintained with enflurane and nitrous oxide in oxygen. After imaging the common bile duct by ultrasonography, placebo or morphine, 0.2 mg/kg-1 was injected intravenously. The diameter of the common bile duct was measured before and 4 and 8 minutes after the drug. Student t-test was utilized for statistical analysis. P < 0.05 was considered significant. No significant change in common bile duct diameter was observed after placebo administration. Morphine caused a significant reduction in the diameter of the common bile duct. Before morphine, the mean +/- SD diameter was 9.5 +/- 3.3 mm; after morphine at 4 and 8 minutes, 7.2 +/- 2.1 and 5.8 +/- 2.1 mm, respectively. It is concluded that ultrasonography in a double-blind placebo-controlled design has proven to be a valid method for the evaluation of the effect of drugs on the common bile duct.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Double-blind comparison of butorphanol and nalbuphine on the common bile duct by ultrasonography in man.

Butorphanol and nalbuphine, narcotic agonist-antagonists were shown to cause no increase in biliary pressure in contrast to morphine in dogs or men. A non-invasive, ultrasonographic technique confirmed that morphine caused constriction of the common bile duct while placebo caused no effect. To prove the lack of constrictive effect of butorphanol and nalbuphine on the common bile duct, the changes in its diameter were measured following placebo or the two agonist-antagonists by ultrasonography. In a double-blind, randomized study, 17 patients undergoing open cholecystectomy were evaluated. No morphine or opioids were allowed for 12 hours prior to the study. After premedication with midazolam and glycopyrrolate, anesthesia was induced by midazolam, 50 micrograms.kg-1 and thiopental, 3.0-5.0 mg.kg-1. Tracheal intubation was facilitated by succinylcholine 1.0 mg.kg-1 and muscle relaxation was maintained with vecuronium. Anesthesia was maintained with isoflurane or enflurane and nitrous oxide in oxygen. After imaging the common bile duct by ultrasonography, placebo, nalbuphine 0.3 mg.kg-1 or butorphanol 40 micrograms.kg-1 were injected intravenously. The diameter of the common bile duct was measured before and at 4 and 8 minutes after drug administration. One-way analysis of variance and paired t-test were utilized for statistical analysis. P < 0.05 was considered significant. No significant changes in the common bile duct diameter was observed after placebo administration, nor was any change observed after either nalbuphine or butorphanol as compared to the baseline. The comparison of three groups of patients showed no statistically significant difference.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1984

Closed circuit anesthesia in infants and children.

A closed-system low-flow technique with enflurane, halothane, or isoflurane as the sole anesthetic was used in three groups of ten children each. Anesthesia was induced by injection into the expiratory limb of a priming standard dose of the liquid anesthetic, followed by additional doses at 15, 30, 60, and 90 sec, and 2, 3, and 4 min. Further injections following the "square root of time" sequence were used for maintenance. Volumes of anesthetics used averaged 3.7 +/- 1.1 ml for enflurane, 2.3 +/- 1.1 ml for halothane, and 3.0 +/- 0.9 ml for isoflurane. These volumes were higher than predicted on theoretical grounds, as was the frequency with which anesthetics had to be injected. Closed-system low-flow anesthesia is a practical, economical, and nonpolluting technique in pediatric patients. Complications associated with isoflurane suggest, however, that isoflurane is not as satisfactory as enflurane or halothane when using this technique in infants and children.

Anesthesia, Inhalation↗
PubMedDate not supplied

1,001 subclavian perivascular brachial plexus blocks: success with a nerve stimulator.

BACKGROUND AND OBJECTIVES: Among the supraclavicular approaches to the brachial plexus, the subclavian perivascular technique is a well-established method of anesthesia of the upper extremity. Ever since Kulenkampf described his technique, eliciting a paresthesia has been almost mandatory ("no paresthesia, no anesthesia"). Lately, nerve stimulators have become more popular. However, up to the present time, clinical studies involving the nerve stimulator have failed to show success rates comparable to paresthesia techniques. METHODS: Data from 1,001 consecutive, subclavian perivascular blocks were prospectively gathered over 2.5 years. All blocks were performed according to Winnie's technique, but using a nerve stimulator instead of a paresthesia. When an adequate response was obtained, 35 to 40 mL of local anesthetic solution was injected. RESULTS: Nine hundred seventy-three blocks (97.2%) were completely successful; 16 blocks (1.6%) were incomplete and needed supplementation; and 12 blocks (1.2%) failed and required general anesthesia, giving a success rate for regional anesthesia of 98.8%. CONCLUSIONS: The subclavian perivascular block consistently provides an effective block for surgery on the upper extremity. At the site of injection with this technique, the plexus is reduced to its smallest components and the sheath is reduced to its smallest volume, which explains in great part the success obtained with this block. We believe that we have demonstrated a nerve stimulator technique that is both highly successful and safe; no clinical pneumothorax was found nor did any other major complications develop.

Adolescent↗