PubMed Health⌕ Search

Biomedical subjects

B A Loughnan

Publications and source records attributed to B A Loughnan.

15 recordsLinked to original sources
PubMed2002

Epidural analgesia and backache: a randomized controlled comparison with intramuscular meperidine for analgesia during labour.

BACKGROUND: Concern has been expressed that epidural analgesia for labour may be associated with a higher incidence of backache. METHODS: A prospective randomized trial investigating the effect of epidural analgesia on the outcome of labour in nulliparae, mothers were randomized to receive either epidural analgesia or meperidine. A questionnaire on postnatal symptoms was sent to them 6 months after delivery. RESULTS: In all, 611 mothers were studied; 310 were randomly allocated to receive i.m. meperidine up to 300 mg and 301 to receive epidural bupivacaine. The response rate to our questionnaire was 83%. Intention-to-treat analysis showed similar prevalence rates of postpartum backache in the epidural (48%) and meperidine groups (50%), with an observed difference (epidural-meperidine) of -2% (95% CI, -11 to +6%). After excluding mothers with backache before delivery, there were also similar incidence rates of postpartum backache in the epidural (29%) and meperidine groups (28%), observed difference 1% (95% CI, -8 to +10%). CONCLUSIONS: Epidural analgesia in labour was not associated with an increase in the prevalence or incidence of backache.

Analgesia, Epidural↗
PubMed2000

Randomized controlled comparison of epidural bupivacaine versus pethidine for analgesia in labour.

We compared the incidence of Caesarean delivery in nulliparous women randomized to receive epidural analgesia with those randomized to intramuscular (i.m.) pethidine. On admission to the delivery suite in established labour, 802 nulliparae had already agreed to be randomized with respect to their first analgesia. One hundred and eighty-eight women required either no analgesia or 50% nitrous oxide in oxygen (Entonox) only. Of the remaining 614 women, 310 were randomly allocated to receive i.m. pethidine up to 300 mg and 304 to receive epidural bupivacaine. Labour management was standardized according to the criteria for active management of labour. The intention-to-treat analysis showed similar Caesarean section rates in those randomized to epidural (12%) or pethidine analgesia (13%). The difference in Caesarean rate was -1.1% with 95% confidence intervals from -6.3% to +4.1%. The normal vaginal delivery rates were similar (epidural, 59%; pethidine, 61%).

Adolescent↗
PubMed1998

Pituitary-adrenal, hormonal changes during induced hypotension with labetol or isoflurane for middle-ear surgery.

BACKGROUND: Pituitary-adrenal secretion during induced hypotension for middle-ear surgery has received little attention. Previous work failed to differentiate the effects of induced hypotension from surgical stimulation. We have undertaken a preliminary study examining the effects of hypotension, achieved with labetalol or isoflurane, on pituitary-adrenal secretion before, during and after middle-ear surgery. METHODS: Twenty-four patients were allocated randomly to 3 groups. The control group were anaesthetised with isoflurane, and normotension maintained for 30 min before hypotension was induced with isoflurane and surgery started. In the labetalol group, this drug was given i.v. to obtain a mean arterial pressure (MAP) of 60 mm Hg for 30 min before surgery and hypotension maintained with labetalol during the operation. In the isoflurane group, hypotension was induced to a MAP of 60 mm Hg for 30 min before surgery and continued throughout the procedure. All 3 groups received metoprolol i.v. before hypotension was established. Blood samples were collected before induction of anaesthesia, during anaesthesia alone (normotensive or hypotensive), surgery with hypotension, and recovery. They were analysed for adrenocorticotropic hormone (ACTH), arginine vasopressin (AVP), cortisol and aldosterone. RESULTS: Induced hypotension before surgery failed to stimulate release of ACTH, AVP and cortisol. No significant increase in these hormones occurred until the postoperative period. Aldosterone concentrations increased significantly during anaesthesia and hypotension in the labetalol and isoflurane groups (P<0.05) and continued to rise significantly in all 3 groups during surgery. However, there was no significant difference in aldosterone concentration before surgery between the control and the 2 hypotensive groups. CONCLUSION: ACTH, AVP and cortisol secretion were not stimulated by induced hypotension to MAP of 60 mm Hg before surgery. Increased aldosterone secretion occurred and a further study with a larger sample size is needed.

Adrenal Cortex Hormones↗
PubMed1994

Etidocaine and extradural somatosensory evoked potentials after posterior tibial nerve stimulation.

We have examined the effects of lumbar extradural administration of 1% etidocaine 10 ml on somatosensory evoked potentials to posterior tibial nerve stimulation measured in the cervical extradural space. Eight patients, anaesthetized with propofol and nitrous oxide, were studied before hysterectomy and a control group received a similar anaesthetic and 0.9% sodium chloride solution 10 ml in the lumbar extradural space. Etidocaine decreased significantly overall amplitude of the evoked potentials and the amplitudes of all peaks, between 30 and 50 min after extradural injection. The effects of etidocaine on spinal cord conduction were greater than those found previously for lignocaine and bupivacaine, suggesting that it is the local analgesic of choice for inhibiting afferent conduction.

Adult↗
PubMed1991

Effects of epidural diamorphine on the somatosensory evoked potential to posterior tibial nerve stimulation.

We have studied the effects of the epidural administration of diamorphine 0.1 mg/kg at the L3-4 interspace on somatosensory evoked potentials in the cervical epidural space before corrective surgery for idiopathic adolescent scoliosis. A further eight patients in whom anaesthesia was maintained with a propofol infusion acted as a control group. Epidural diamorphine had no effect on the latency or amplitude of the evoked potentials. We conclude that epidural diamorphine is a suitable technique to use in scoliosis surgery because of its lack of effect on neurophysiological variables, although the potential respiratory problems need investigation.

Adult↗
PubMed1990

Effects of 2% lignocaine on somatosensory evoked potentials recorded in the extradural space.

We have studied the effects of extradural administration of 2% lignocaine at the L3-4 interspace on somatosensory evoked potentials recorded in the cervical extradural space before corrective surgery for idiopathic adolescent scoliosis. Eight patients in whom the equivalent volume of 0.9% sodium chloride solution was administered into the lumbar extradural space acted as a control group. Lignocaine 2% resulted in a decrease in overall amplitude, but its main effect was a significant decrease in the amplitude of the second and third peaks, suggesting an action on the dorsal columns of the spinal cord. A significant increase in latency was found in both the lignocaine and sodium chloride groups. We conclude that the use of extradural 2% lignocaine in patients undergoing scoliosis surgery may interfere with the intraoperative monitoring of somatosensory evoked potentials.

Adolescent↗
PubMed1990

A technique for monitoring evoked potentials during scoliosis and brachial plexus surgery.

A total of 40 patients undergoing scoliosis or brachial plexus surgery had bipolar electrodes inserted preoperatively in the cervical epidural space located by the 'hanging drop technique'. The angle of approach to the space was different for each spinal interspace used. Good quality recordings were obtained of SSEPs with no long-term complications and we recommend this as a safe technique.

Adult↗
PubMed1989

Effects of halothane on somatosensory evoked potentials recorded in the extradural space.

We studied the effects of supplementing anaesthesia with halothane (up to 1.5%, inspired) on the somatosensory evoked potential recorded in the extradural space of six patients before corrective surgery for idiopathic adolescent scoliosis. A further six patients in whom anaesthesia was supplemented with thiopentone acted as a control group. Halothane 1.5% resulted in a significant decrease in overall amplitude (P less than 0.05) from the left leg only. Halothane had no significant effect on overall amplitude, first peak amplitude, second peak amplitude and first peak latency. We conclude that halothane is unlikely to alter the interpretation of somatosensory evoked potentials recorded extradurally during scoliosis surgery. A possible unilateral effect of halothane on the concave side in idiopathic adolescent scoliosis needs further investigation.

Adolescent↗
PubMed1989

Effects of halothane on motor evoked potential recorded in the extradural space.

We studied the effects of supplementing nitrous oxide-oxygen anaesthesia with halothane (1 MAC end-tidal concentration) on the motor evoked potential recorded in the extradural space of eight patients before corrective surgery for idiopathic adolescent scoliosis. The motor cortex was stimulated electrically through the scalp. An additional eight patients in whom anaesthesia was supplemented with an infusion of propofol acted as a control group. Halothane had no significant effect on the amplitude or latency of the motor evoked potential. We conclude that halothane is unlikely to alter the interpretation of motor evoked potentials recorded extradurally during scoliosis surgery.

Adolescent↗
PubMed1988

Use of i.m. ranitidine for the prophylaxis of aspiration pneumonitis in obstetrics.

Twenty patients who underwent elective Caesarean section received ranitidine 150 mg by mouth 8-14 h, and 50 mg i.m. 90 min, before surgery. Intraoperative gastric aspiration resulted in contents with a pH greater than 2.5 and volume less than 25 ml in all patients (mean pH 6.5 (SD 0.8); mean volume 9.0 (SD 7.2) ml). Sixty patients in labour, who received ranitidine 50 mg i.m. 6-hourly, underwent emergency surgery. Half of this group received, in addition, a single preinduction dose of either 15 or 30 ml of sodium citrate 0.3 mol litre-1. A further 30 patients who remained unmedicated during labour and required emergency surgery received a preinduction dose of 15 or 30 ml of sodium citrate 0.3 mol litre-1 alone. Ranitidine medication resulted in a mean aspirated gastric volume of 31.4 (26.6) ml and pH of 5.3 (2.1); five of 30 patients had a pH less than 2.5. The addition of sodium citrate 0.3 mol litre-1 resulted in gastric pH greater than 2.5 in all patients and a mean gastric volume of 43.2 (38.3) ml. The group who received only sodium citrate 0.3 mol litre-1 had a mean pH of 5.3 (1.1) and a mean volume 122.7 (98.2) ml.

Adult↗
PubMed1986

Alfentanil infusion for abdominal surgery.

Twelve patients undergoing abdominal surgery were studied. Alfentanil was used as the sole anesthetic agent in these patients via a predetermined infusion regime. In 7 cases this was sufficient but in five cases the infusion had to be supplemented. Induction was with alfentanil 100 micrograms/kg over 2 minutes, then 10 micrograms/kg/min for 10 minutes followed by 2 micrograms/kg/min for 50 minutes. After one hour the infusion rate was varied between 1-3 micrograms/kg/min. Vecuronium 0.1 mg/kg with increments of 0.025-0.075 mg/kg was used for neuromuscular blockade in nine patients, the other three patients received identical doses of pancuronium. There was no statistically significant change in blood pressure and heart rate after induction or in response to intubation and both were well maintained throughout surgery.

Abdomen↗