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Biomedical subjects

J B Gunter

Publications and source records attributed to J B Gunter.

10 recordsLinked to original sources
PubMed1992

Thoracic epidural anesthesia via the caudal approach in children.

We investigated the feasibility of performing thoracic epidural anesthesia via the caudal approach in 20 children (age 62 +/- 38 months and weight 18.5 +/- 7.3 kg; mean +/- standard deviation). Based on external landmarks, a predetermined length of 24-G epidural catheter (Concord Portex 20/24 microcatheter system) with stylet was passed into the epidural space through a 20-G intravenous catheter inserted through the sacrococcygeal ligament, and a radiograph of the abdomen and chest was obtained. The radiographically determined catheter tip position was within two vertebrae of the target position in 17 of 20 subjects. In one subject, it was impossible to advance the catheter more than 10 cm. The other two malpositioned catheters were successfully reinserted. Intraoperative caudal anesthesia and postoperative pain relief were satisfactory in all 20 subjects. We have found it possible to use the caudal approach to thoracic epidural anesthesia in children as old as 10 yr. Ease of removal of the stylet, ease of injection, and negative aspiration and test doses predict successful placement and obviate the need for routine radiographic confirmation of catheter position.

Anesthesia, Caudal↗
PubMed1992

Comparison of vasoconstrictors for functional endoscopic sinus surgery in children.

Three different vasoconstricting agents were evaluated during functional endoscopic sinus surgery (FESS) in 57 children. Oxymetazoline hydrochloride 0.05%, phenylephrine hydrochloride 0.25%, or cocaine 4% was applied to the nasal mucosa in a prospective, randomized, double-blind fashion. Heart rate and blood pressure changes were recorded 5 and 10 minutes after application of the study vasoconstrictor to each nostril. The surgeon's subjective impressions of bleeding and visualization were recorded for each side of the nose, as were total blood loss and anesthesia time. Although all three vasoconstrictors were tolerated well by the children, there was a suggestion that heart rate decreased more at 5 minutes with phenylephrine than with oxymetazoline or cocaine (P = .08) and that blood pressure increased more at 10 minutes with phenylephrine than with oxymetazoline or cocaine (P = .1). No arrhythmias were noted. Subjective scoring for bleeding showed that children receiving oxymetazoline were less likely to receive scores of "more" bleeding than usual (3/38 vs. 10/34 for phenylephrine and 10/35 for cocaine, P less than .02). Subjective scoring for visualization showed that children receiving oxymetazoline were also less likely to receive scores of "worse" visualization than usual (3/38 vs. 12/38 for phenylephrine and 9/35 for cocaine, P less than .01). There was no difference in surgical bleeding or visualization between children receiving phenylephrine and children receiving cocaine. In our institution, 0.05% oxymetazoline is the preferred vasoconstrictor for FESS in children.

Blood Pressure↗
PubMed1991

Caudal epidural anesthesia in conscious premature and high-risk infants.

Twenty premature or high-risk infants received caudal epidural anesthesia for inguinal herniorrhaphy, orchiopexy, and circumcision. Mean gestational age at surgery was 48 +/- 12 weeks; mean weight at surgery was 4,100 +/- 1,400 g. Caudal anesthesia, performed with 1 mL/kg of 0.375% bupivacaine, was successful in 19 of 20 infants. Onset of anesthesia occurred in 14 +/- 1 minutes; duration of surgical anesthesia was 89 +/- 8 minutes. Surgical conditions were generally excellent and the infants tolerated anesthesia and surgery well. No postoperative complications were observed. Caudal epidural anesthesia is an acceptable alternative to general or spinal anesthesia in premature and high-risk infants.

Anesthesia, Caudal↗
PubMed1991

Optimum concentration of bupivacaine for combined caudal--general anesthesia in children.

Caudal epidural anesthesia has become widely accepted as a means of providing postoperative pain relief and intraoperative supplementation to general anesthesia for children. To determine the best concentration of bupivacaine for combined general-caudal anesthesia in children, 122 children aged 1-8 yr scheduled for outpatient inguinal herniorrhaphy were randomized to receive, in a double-blind fashion, caudal anesthesia with bupivacaine in one of six concentrations (0.125, 0.15, 0.175, 0.2, 0.225, or 0.25%). After incision, a programmed reduction in inspired halothane resulted, if tolerated by the subject, in an inspired halothane concentration of 0.5% 10 min after incision. End-tidal halothane concentration at hernia sac ligation for subjects receiving 0.175% bupivacaine (0.55 +/- 0.03%) was less than that for subjects receiving 0.15% bupivacaine (0.75 +/- 0.05%; P less than 0.05). Subjects receiving 0.175% bupivacaine also were discharged earlier from the postanesthesia care unit (PACU) (27 +/- 1 min) than were subjects receiving 0.15% bupivacaine (38 +/- 5 min; P = 0.05). Children receiving greater than or equal to 0.2% bupivacaine tended to complain more of leg weakness after surgery; however, the difference did not reach statistical significance (39 of 67 vs. 16 of 47; P = 0.057). The incidence of complaints of leg weakness and paresthesia was positively correlated with bupivacaine concentration (r = 0.706; P = 0.05). Subjects receiving 0.125% bupivacaine had higher pain scores on arrival to the PACU than did those receiving 0.2% bupivacaine (P = 0.05); there were no other differences in pain scores.(ABSTRACT TRUNCATED AT 250 WORDS)

Ambulatory Surgical Procedures↗
PubMed1990

Caudal epidural anesthesia reduces blood loss during hypospadias repair.

We studied 24 boys who were randomized to receive caudal epidural anesthesia with 0.33 ml.kg.-1 0.25% bupivacaine either before (group A) or after (group B) Mathieu repair of distal hypospadias. The 2 groups did not differ in regard to age or weight, and all boys received a standardized anesthetic with halothane and nitrous oxide in oxygen. Intraoperative blood loss was measured with sponge weights and microcalibrated suction canisters. Halothane requirements were reduced in group A (0.5 versus 1.1 plus or minus 0.1%, p less than 0.001). Measured blood loss was reduced in group A (16 plus or minus 10 ml. versus 31 plus or minus 17 ml., p less than 0.01). Operating time was reduced in group A (92 plus or minus 13 minutes versus 103 plus or minus 14 minutes, p less than 0.05). There was no apparent difference in postoperative pain relief between the 2 groups. We conclude that caudal epidural anesthesia can reduce blood loss and improve surgical conditions during hypospadias repair.

Anesthesia, Caudal↗
PubMed1979

Hydrogen transfer in catalysis by adenosylcobalamin-dependent diol dehydratase.

Studies [bachovchin, W. W., et al. (1978) Biochemistry 17, 2218] of the mechanism of inactivation of adenosylcobalamin-dependent diol dehydratase have led to the development of a general method to describe the kinetics of a reaction pathway containing a reservoir of mobile hydrogen. Analysis by this method of catalytic rate measurements for mixtures of 1,2-propanediol and 1,1-dideuterio-1,2-propanediol supports a mechanism involving an intermediate with three equivalent hydrogens, in which hydrogen transfer from this intermediate to product is the major rate-contributing step. Other results using tritium as a trace label [essenberg, M. K., et al. (1971) J. Am. Chem. Soc. 93, 1242] are considered in light of these deuterium isotope studies.

Cobamides↗