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D J Buggy

Publications and source records attributed to D J Buggy.

30 records · Page 2Linked to original sources
PubMed2000

Nimodipine premedication and induction dose of propofol.

UNLABELLED: Antagonists at the L-type voltage sensitive calcium channel (L-VSCC) potentiate anesthetic potency in experimental models, suggesting that it may be a target site for IV anesthetics. Nimodipine is a 1, 4-dihydro- pyridine antagonist of L-VSCC which crosses the blood-brain barrier. We tested the hypothesis that premedication with oral nimodipine in healthy patients would reduce the induction dose of propofol, independently of its effects on the cerebral circulation. Sixty ASA physical status I or II patients (18-60 yr), undergoing knee arthroscopy or minor urological surgery, were randomized to receive either nimodipine 60 mg or placebo, orally 1-2 h before induction. Noninvasive mean blood pressure, heart rate, and time-averaged mean velocity in the middle cerebral artery by using transcranial Doppler ultrasonography were obtained before and 5 min after the induction of anesthesia. Propofol 1% was administered by an infusion pump at a rate of 10 mL/min. Both groups of patients had a reduction in mean blood pressure after the induction (P < 0.01), but there were no significant differences between the groups. The induction dose of propofol was 2.19 mg/kg (95% confidence interval [CI]: 1.97-2.42) in the nimodipine group, compared with 2.16 mg/kg (95% CI 1.98-2.34) in the control group, P = 0.8. Time-averaged mean velocity remained unchanged after the induction of anesthesia in both patients receiving nimodipine premedication (51% CI 43-59 cm/s to 52% CI 46-58 cm/s, P = 0.6) and those receiving placebo (50% CI 43-58 cm/s to 53% CI 45-59 cm/s, P = 0.3). Premedication with oral nimodipine 60 mg does not reduce the induction dose of propofol compared with placebo, casting doubt on the hypothesis that propofol has an anesthetic action at L-VSCC. IMPLICATIONS: Premedication with oral nimodipine 60 mg does not reduce the induction dose of propofol compared with placebo, casting doubt on the hypothesis that propofol has an anesthetic action at L-type voltage sensitive calcium channels.

Adolescent↗
PubMed2000

Ondansetron given before induction of anesthesia reduces shivering after general anesthesia.

UNLABELLED: The neurotransmitter pathways involved in the mechanism of postanesthetic shivering (PAS) are poorly understood. Meperidine, clonidine, and physostigmine are all effective treatments, indicating that opioid, alpha(2)-adrenergic, and anticholinergic systems are probably involved. We investigated the effect of ondansetron, a 5-HT(3) antagonist used to treat postoperative nausea and vomiting, on intraoperative core and peripheral temperatures and PAS. Eighty-two patients (age, 18-60 yr) undergoing orthopedic, general, or urological surgery were randomized into three groups in this double-blinded, placebo-controlled, study: Group O4 (n = 27) received ondansetron 4 mg IV, Group O8 (n = 27) received ondansetron 8 mg IV, and Group C (n = 28) received saline IV immediately before the anesthetic induction. Core (tympanic) and fingertip temperature (dorsum of middle finger) were recorded. Anesthesia was induced with IV fentanyl 1 microg/kg and propofol 2.0-2.5 mg/kg and maintained with 1 minimum alveolar anesthetic concentration isoflurane in 70% nitrous oxide/oxygen. The occurrence of shivering was documented clinically during recovery by nursing staff, who were unaware of the group assignment. PAS occurred in 16 of 28 (57%) patients in Group C, compared with 9 of 27 (33%) in Group O4 (P = 0.13) and 4 of 27 (15%) patients in Group O8 (P = 0.003). Within each group, core temperature decreased and peripheral temperature increased significantly, but there were no significant differences among the groups at any time interval. We conclude that ondansetron 8 mg IV given during the induction of anesthesia prevents PAS without affecting the core-to-peripheral redistribution of heat during general anesthesia. This suggests that serotonergic pathways have a role in the regulation of PAS. IMPLICATIONS: In a randomized, double-blinded, placebo-controlled, clinical study, ondansetron 8 mg IV, given just before the induction, reduced the incidence of postanesthetic shivering compared with saline. The anticipated core-to-peripheral redistribution of body temperature during general anesthesia was not affected. This implies that ondansetron probably acts by a central inhibitory mechanism, and that 5-hydroxytryptaminergic pathways have a role in regulating postanesthetic shivering.

Adult↗
PubMed2000

Effects of intravenous anesthetic agents on glutamate release: a role for GABAA receptor-mediated inhibition.

BACKGROUND: Many anesthetic agents are known to enhance the alpha1beta2gamma2S gamma-aminobutyric acid type A (GABAA) chloride current; however, they also depress excitatory neurotransmission. The authors evaluated two hypotheses: intravenous anesthetic agents inhibit glutamate release and any observed inhibition may be secondary to GABAA receptor activation. METHODS: Cerebrocortical slices were prepared from Wistar rats. After perfusion in oxygenated Krebs buffer for 60 min at 37 degrees C, samples for glutamate assay were obtained at 2-nmin intervals. After 6 min, a 2-min pulse of 46 mM K+ was applied to the slices (S1); this was repeated after 30 min (S2). Bicuculline (1-100 microM) was applied when the S1 response returned to basal level, and 10 min later, thiopental (1-300 micro/M), propofol (10 microM), or ketamine (30 microM) were also applied until the end of S2. Perfusate glutamate concentrations were measured fluorometrically, and the area under the glutamate release curves was expressed as a ratio (S2/S1). RESULTS: Potassium (46 mM) evoked a monophasic release of glutamate during S1 and S2, with a mean control S2/S1 ratio of 1.07 +/- 0.33 (mean +/- SD, n = 96). Ketamine and thiopental produced a concentration-dependent inhibition of K+-evoked glutamate release with half-maximum inhibition of release values of 18.2 and 10.9 /microM, respectively. Release was also inhibited by propofol. Bicuculline produced a concentration dependent reversal of thiopental inhibition of glutamate release with a half-maximum reversal of the agonist effect of 10.3 microM. Bicuculline also reversed the effects of propofol but not those of ketamine. CONCLUSIONS: The authors' data indicate that thiopental, propofol, and ketamine inhibit K+-evoked glutamate release from rat cerebrocortical slices. The inhibition produced by thiopental and propofol is mediated by activation of GABAA receptors, revealing a subtle interplay between GABA-releasing (GABAergic) and glutamatergic transmission in anesthetic action.

Anesthetics, Intravenous↗
PubMed1999

Propofol or sevoflurane for laryngeal mask airway insertion.

PURPOSE: Sevoflurane is a volatile anesthetic agent, which combines rapid, smooth inhalational induction of anesthesia with rapid recovery, making it particularly suitable for day case anesthesia. The laryngeal mask airway is often also used in ambulatory anesthesia, with intravenous propofol being the agent of choice for its insertion. Our objective was to compare the conditions for laryngeal mask airway (LMA) insertion obtained by modified vital capacity breath sevoflurane inhalational induction of anesthesia with propofol intravenous induction. METHODS: Eighty-eight patients, aged 18-65 yr, ASA I-II, undergoing general anesthesia for elective surgery were randomized into two groups in a prospective, single-blind study. Patients in Group P (n=44) received 2.5 mg x kg(-1) propofol i.v. and in Group S (n=44) received sevoflurane 8% in nitrous oxide 50% and oxygen. Ventilation was not assisted. Laryngeal mask airway insertion was attempted at one minute intervals from loss of both verbal response and eyelash reflex, by an anesthesiologist unaware of the induction technique. Complications, such as coughing and head movement, were also noted at each attempt. RESULTS: Mean time to successful LMA insertion was 1.3 (1-3) min in P and 2.2 (1-3) min in S, P < 0.05. Eleven patients in Group P, (25%) required additional propofol compared with four (9%) in S, P < 0.05. Incidence of complications was similar in both groups and by 3 min, LMA was successfully inserted in all patients. CONCLUSION: Modified vital capacity breath inhalational induction with sevoflurane 8% is efficient for LMA insertion in most cases, but takes slightly longer than propofol.

Adolescent↗
PubMed1999

Central neuraxial opioid analgesia after caesarean section: comparison of epidural diamorphine and intrathecal morphine.

In a prospective, randomized, double-blind study in 55 women undergoing elective caesarean section under spinal anaesthesia, we compared epidural diamorphine 3 mg (2 distinct boluses, group ED) with single-dose intrathecal morphine 0.2 mg (group SM), in terms of analgesic efficacy, patient satisfaction and side-effects at 2, 3, 4, 8, 12, 16, 24 and 28 h postoperatively. There were no significant differences between groups in pain (assessed by 100 mm visual analogue scale), incidence of pruritus, sedation or respiratory depression measured by continuous pulse oximetry. However, time to first request for supplementary oral analgesia was longer in SM than in ED (mean +/- SD: 22.3+/-12.0 h vs. 13.8+/-6.5 h, P=0.04). The incidence of nausea or vomiting was significantly higher in SM than ED (73% vs. 41%, P=0.01). In ED, the mean +/- SD time to requirement of the second bolus was 6.7+/-3.2 h. There was a high level of satisfaction in both groups. We conclude that two boluses of epidural diamorphine 3 mg and single-dose intrathecal morphine 0.2 mg provide satisfactory analgesia after caesarean section, but spinal morphine was associated with both delayed requirement for supplementary analgesia and a higher incidence of nausea and vomiting.

Clinical Trial↗
PubMed1999

Profound motor blockade with epidural ropivacaine following spinal bupivacaine.

Ropivacaine, a relatively new amide local anaesthetic, reputedly produces less motor block than equivalent doses of bupivacaine, potentially combining high-quality analgesia with the ability to ambulate. We report two cases of prolonged, profound motor block with patient-controlled epidural analgesia using 0.1% ropivacaine, following spinal bupivacaine for Caesarean section. As there was no evidence of inadvertent intrathecal ropivacaine administration or of any neurological injury, we hypothesise that epidural ropivacaine may interact with intrathecal bupivacaine to prolong its effect.

Adult↗
PubMed1998

Acute airway obstruction during spinal anaesthesia for caesarean section.

A 30-year-old primiparous Caucasian woman with known placenta praevia required an emergency caesarean section for a mild antepartum haemorrhage at the onset of spontaneous term labour. Following intravenous prehydration with 500 ml gelatin colloid (Haemaccel trade mark ), spinal anaesthesia was induced in the sitting position with 2.6 ml of 0.5% hyperbaric bupivacaine (13 mg). The patient was then placed in the recumbent position with left lateral tilt, whereupon she suddenly became dyspnoeic. A generalized erythematous urticarial rash with associated facial, periorbital, glossal and perioral oedema became evident. Although maternal blood pressure remained within normal limits, emergency conversion to general anaesthesia with tracheal intubation was necessary to secure the airway. Laryngoscopy revealed gross submucosal, epiglottic and pharyngeal oedema, characteristics of the syndrome of angioneurotic oedema, which may complicate an anaphylactoid reaction. After the airway was secured with a cuffed endotracheal tube, caesarean section proceeded uneventfully and a healthy male infant was delivered. Maternal facial and airway oedema subsided and extubation was performed in intensive care 2 h later. Life-threatening airway obstruction often accompanies angioneurotic oedema. Since parturients have a higher incidence of difficult airway management than the general population, anaphylactoid reactions presenting as angioneurotic oedema pose a particular challenge for the anaesthetist. The lower incidence of allergy associated with hydroxyethyl starch (Hetastarch) may make it a more appropriate choice of colloid in this setting. However, the balance of evidence now suggests that vasopressors, particularly ephedrine, are superior to fluids for maintenance of blood pressure during regional anaesthesia for caesarean section.

Journal Article↗
PubMed1998

Prevention of spinal anaesthesia-induced hypotension in the elderly: i.m. methoxamine or combined hetastarch and crystalloid.

We have compared two methods of reducing hypotension during spinal anaesthesia in elderly patients, 6% hetastarch and crystalloid or methoxamine 10 mg i.m., in terms of haemodynamic stability and requirements for additional vasopressors. Sixty-two patients (aged 60-97 yr) undergoing surgical fixation of fractured neck of femur were allocated randomly to receive 6% hetastarch (Hespan) 500 ml followed by Hartmann's solution 500 ml (group HS, n = 32) or a bolus injection of methoxamine 10 mg i.m. (group MX, n = 30), 10 min before induction of spinal anaesthesia with 0.5% hyperbaric bupivacaine 2.25-3.0 ml. Arterial pressure was measured non-invasively by an oscillotonometer at 2-min intervals from 0 to 40 min and at 5-min intervals thereafter. Methoxamine 2 mg i.v. was given if systolic arterial pressure (SAP) decreased to < 100 mm Hg. Hypotension was defined as a 25% decrease from baseline SAP or mean arterial pressure (MAP). Patient data, sensory level and blood loss were similar in the two groups. SAP and MAP increased initially from baseline until induction of spinal anaesthesia and then decreased for 30 min in both groups, but remained higher in group MX (P < 0.05). Heart rate (HR) decreased from baseline in group MX (P < 0.05) and was less than in group HS at all times from 2 to 60 min (P < 0.01). The incidence of SAP hypotension (47% vs 75%; P = 0.03, odds ratio (OR) = 3.43) and MAP hypotension (47% vs 67%; P = 0.09, OR = 2.51) was less in group MX than in group HS. Requirements for rescue methoxamine i.v. (27% vs 53%, P = 0.04, OR = 3.11) was less in group MX than in group HS but the dose of rescue methoxamine given (mean 6.3 (95% confidence intervals 3.0-9.6) vs 8.9 (5.6-12.2) mg) and time to onset of hypotension (20.7 (14.5-26.7) vs 17.3 (11.4-23.1) min) were similar in groups MX and HS, respectively. We conclude that methoxamine 10 mg i.m., given 10 min before induction of spinal anaesthesia in normovolaemic elderly patients, reduced subsequent SAP and MAP hypotension, HR and requirements for rescue vasopressor therapy compared with a combination of 6% hetastarch 500 ml and crystalloid 500 ml. The previously reported benefit of such volume administration may not extend to the elderly.

Aged↗
PubMed1996

Extradural analgesia with clonidine and fentanyl compared with 0.25% bupivacaine in the first stage of labour.

Conventional extradural analgesia during labour with 0.25-0.375% bupivacaine may induce motor weakness and subjective sensory deficit, reducing maternal satisfaction. Even in a regimen for ambulatory extradural analgesia (0.1% bupivacaine-fentanyl 2 micrograms ml-1), a potential for proprioreception impairment exists, which may impair safe ambulation. We have combined fentanyl with clonidine for extradural analgesia in labour, and compared its effects with 0.25% bupivacaine, in a randomized, double-blind study. We studied 28 women requesting extradural analgesia for labour; they were allocated randomly to either group 1, who received clonidine 120 micrograms with fentanyl 50 micrograms, or group 2, who received bupivacaine 25 mg. Detailed clinical neurological examination was undertaken 30 min later. Pain was assessed subjectively using a 10-cm visual analogue scale (VAS). There were no significant differences in VAS between the groups at any time. Median onset of analgesia was longer in group 1 (24.3 (interquartile range 20-35) compared with 17.5 (15-25) min) (P < 0.05) and 79% of group 1 vs 86% of group 2 patients reported a high degree of satisfaction with extradural analgesia. Patients in group 2 had a much higher incidence of motor weakness (P < 0.01), impaired perception of pinprick (P < 0.01) and impaired distal joint proprioception (P < 0.05) than group 1. We conclude that clonidine 120 micrograms-fentanyl 50 micrograms provided comparable extradural analgesic efficacy as 0.25% bupivacaine for the first stage of labour. Furthermore, unwanted neurological effects were significantly less.

Adolescent↗
PubMed1994

Preoperative or postoperative diclofenac for laparoscopic tubal ligation.

We have compared the analgesic effects of diclofenac given before operation or immediately after operation in a randomized, double-blind, double-dummy study of 40 healthy female patients undergoing laparoscopic tubal ligation. Group 1 patients received diclofenac 75 mg as a 3-ml i.m. injection 1-2 h before operation and normal saline 3 ml i.m. immediately after surgery. Group 2 patients received normal saline 3 ml i.m. before operation and diclofenac 75 mg i.m. immediately after surgery. Outcome measures were patients' perception of pain on a visual analogue scale (VAS), verbal response scale (VRS), the number of patients who required postoperative morphine, time to first postoperative morphine injection and total dose of morphine given. VAS at 30 min and at 1, 3 and 6 h after operation were, respectively (median, interquartile range) 4.5 (2.3-6.0) vs 5.3 (2.8-7.8); 3.3 (2.3-5.0) vs 4.4 (3.0-5.8); 1.4 (0-2.3) vs 1.9 (0.8-3.0); 0.5 (0-1) vs 0.7 (0-1.3), (ns). VRS at 1 and 3 h after operation were, respectively, (median, interquartile range) 2.2 (1.5-3.0) vs 2.7 (2.0-4.0) and 0.8 (0-1.3) vs 0.9 (0-1.5) (ns). Sixteen patients in group 1 compared with 17 in group 2 required postoperative morphine. Time to first morphine administration and dose given were, respectively, (median, interquartile range) 50.6 (39-60) min vs 35.7 (20-49) min (P = 0.1) and 9.0 (5-10) mg vs 9.5 (7.5-10) (P = 0.9).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗