Perioperative dextromethorphan reduces postoperative pain after hysterectomy.

UNLABELLED: We studied the effect of dextromethorphan, an N-methyl-D-aspartate antagonist, on analgesic consumption and pain scoring after abdominal hysterectomy. In this double-blinded study, 50 patients were randomized into two groups. Group DM was given oral dextromethorphan 40 mg with their premedication, then 40 mg three times per day for the next 2 days. Group P received placebo at identical times. Postoperative analgesic requirements were assessed using a patient-controlled analgesia system and subsequent oral analgesic intake using a set protocol. Pain was assessed at rest and on movement using a visual analog scale 4, 24, 48, and 72 h after the operation. Median pain scores at rest were significantly lower at 48 and 72 h and also for the sum of all resting pain scores. Mean morphine consumption was less in Group DM (1.1 vs 1.5 mg/h; P = 0.054). Usage of oral diclofenac, given every 8 h as needed, did not differ between groups, but consumption of codydramol (paracetamol 500 mg and dihydrocodeine 10 mg) was significantly less in Group DM. We conclude that the use of oral dextromethorphan has an analgesia-sparing effect and some beneficial effects on pain scoring at rest after abdominal hysterectomy. IMPLICATIONS: Patients given dextromethorphan before and after surgery had a significant reduction in some pain scores at rest, but not on movement. There was a trend to lower morphine requirements in the first 24 h. Over the next 48 h, oral analgesic usage was significantly reduced.

Comparison of 0.25% S(-)-bupivacaine with 0.25% RS-bupivacaine for epidural analgesia in labour.

We have compared the efficacy of 0.25% S(-)-bupivacaine with 0.25% RS-bupivacaine in providing epidural analgesia for labour in a randomized, multicentre, double-blind study. Analgesia was initiated with 10 ml of the study solution and maintained with 10-ml top-ups. We studied 137 women and treatments were found to be equivalent for onset, duration and quality of block. Median onset of pain relief was 12 min for both drugs and median duration was 49 (range 3-129) min and 51 (7-157) min for S(-)-bupivacaine and RS bupivacaine, respectively. The estimated treatment difference for duration of pain relief was -4 (90% CI -13, 6) min. Thirty patients failed to achieve pain relief after the first injection (20 patients after S(-)-bupivacaine and 10 after RS-bupivacaine; P = 0.039). However, median duration of pain relief from the first top-up was 82 (range 3-164) min for S(-)-bupivacaine and 76 (22-221) min for RS-bupivacaine. There were no significant differences in the quality of analgesia, as assessed by the investigators. There were no significant differences in the extent of sensory block, percentage of patients with motor block or incidence of adverse events.

Extradural S(-)-bupivacaine: comparison with racemic RS-bupivacaine.

Bupivacaine has a chiral centre and is currently available as a racemic mixture of its two enantiomers: R(+)-bupivacaine and S(-)-bupivacaine. Preclinical studies have demonstrated that there is enantiomer selectivity of action with the bulk of central nervous system and cardiovascular toxicity residing with the R(+) isomer. The aim of this study was to compare the clinical efficacy and safety of S(-)-bupivacaine with racemic RS-bupivacaine for extradural anaesthesia. We studied 88 patients undergoing elective lower limb surgery under lumbar extradural anaesthesia who received 15 ml of 0.5% or 0.75% S(-)-bupivacaine, or 0.5% RS-bupivacaine in a randomized, double-blind study. There was no difference in onset time, maximum spread of sensory block or intensity of motor block between the three groups. Duration of sensory block was significantly longer for 0.75% S(-)-bupivacaine. We conclude that S(-)-bupivacaine has similar local anaesthetic characteristics to RS-bupivacaine when used for extradural anaesthesia.

Transient radicular irritation with intrathecal plain lignocaine.

BACKGROUND: The aetiology of the syndrome known as transient radicular irritation (TRI) has generated much interest. METHOD: A 50-year-old woman had right knee arthroscopy performed under spinal anaesthesia with 1% plain lignocaine. RESULT: At home, on the night of the procedure, she was woken by severe, bilateral cramp-like pain in both buttocks radiating to her thighs. Neurological examination of her lower limbs, the next morning, was entirely normal. The pain lasted for 36 h and a full recovery was made. CONCLUSION: This case of transient radicular irritation occurred in a patient given 40 mg of subarachnoid lignocaine (the lowest dose of isobaric preservative-free lignocaine reported thus far that has been associated with these symptoms). Her operation was performed in the supine position. The lack of confounding factors (hyperbaricity, high concentration solution, preservatives, lithotomy position) suggests lignocaine as a possible cause, yet current theories do not fully explain the aetiology of transient radicular irritation. Results from large-scale epidemiological studies will hopefully provide insight into the cause of this problem.

Anticholinergics improve fibreoptic intubating conditions during general anaesthesia.

PURPOSE: To determine if anticholinergic agents improve fibreoptic intubating conditions and to compare the efficacy and side effects of glycopyrrolate and hyoscine. METHODS: Eighty ASA I adults undergoing elective wisdom tooth extraction were randomly allocated to receive 0.4 mg hyoscine hydrobromide po, 0.4 mg hyoscine hydrobromide im, 0.4 mg glycopyrrolate im or no anticholinergic, one hour pre-operatively. All underwent nasal fibreoptic intubation under general anaesthesia. The time taken to pass the fibreoptic scope was noted and visual analogue scores (VAS) were recorded for clarity of visual field and post-operative sore throat, dry mouth and nausea. RESULTS: The time to intubation was not different among the four groups (Kruschal-Wallis P = 0.07). The clarity of visual field was improved in all three anticholinergic groups (Kruschal-Wallis P = 0.006), but there was no difference among the three groups (median VAS control 6.4, glycopyrrolate 8.0, oral hyoscine 7.9, im hyoscine 7.7). There was no difference in post-operative side effects among any of the groups at both 30 min and four hours. CONCLUSION: The addition of an anticholinergic produced better visual conditions for intubation but had no effect on the incidence of post-operative sore throat, dry mouth and nausea.

An in vitro comparison of fluid leakage after dural puncture with Atraucan, Sprotte, Whitacre, and Quincke needles.

BACKGROUND AND OBJECTIVES: The study was designed to evaluate the influence of needle size and design on the rate of leakage following dural puncture. METHODS: An in vitro model and fresh human lumbar dura were used to examine the rate of fluid leakage after puncture with Sprotte (24-gauge and 26-gauge), Atraucan (24-gauge and 26-gauge), Quincke (26-gauge and 29-gauge), and Whitacre (22-gauge and 25-gauge) needles. RESULTS: The study confirmed that finer-gauge needles tend to produce less leakage and that traditional Quincke pattern bevels result in greater leakage than pencil-point designs of the same diameter. CONCLUSIONS: The comparably low leakage rate produced by the Atraucan, a new needle with a terminal opening, suggests that this needle is worthy of further clinical evaluation.

Does pre-incisional thoracic extradural block combined with diclofenac reduce postoperative pain after abdominal hysterectomy?

In a double-blind, randomized study, we investigated 40 patients undergoing abdominal hysterectomy; patients received 0.5% plain bupivacaine 20 ml via a low thoracic extradural catheter and a diclofenac suppository (100 mg), either 30 min before incision (group 1) or 30 min after incision (group 2). All patients received a standard general anaesthetic and no opioid was used before or during operation. Postoperative analgesic requirements were measured using a patient-controlled analgesia (PCA) system. Pain was assessed using a visual analogue scale (VAS) and a verbal pain score (VPS) on movement up to 48 h after operation. There was no significant difference in the time to first request for morphine but consumption of morphine was significantly greater in group 1 at all times except 24 h. There were no significant differences in VAS and VPS pain scores, although both scores were consistently higher in group 1. Patient satisfaction with the quality of analgesia, at 24 h, demonstrated no significant difference between the two groups. The combination of extradural block and diclofenac suppository given before operation did not appear to produce a clinically effective pre-emptive analgesic effect.

Efficacy and kinetics of extradural ropivacaine: comparison with bupivacaine.

Ninety-one patients were allocated randomly to three groups to receive 1% ropivacaine 10 ml, 0.5% ropivacaine 20 ml or 0.5% bupivacaine 20 ml extradurally. Intermittent sensory (pinprick) and motor (Bromage scale) assessments of the block produced were recorded, with an assessment of the quality of the block and the requirement for supplementary analgesia. There was little difference between the groups in frequency, onset, duration or spread of sensory block. However, the motor block produced by 0.5% ropivacaine was less intense and of shorter duration than that with bupivacaine. The block produced by the smaller volume of ropivacaine was less reliable clinically than the larger, more dilute, solution and more anaesthetic supplements were required in that group. Cardiovascular changes were similar in all three groups. The peak plasma concentration of ropivacaine was significantly greater and T1/2 significantly shorter than those of bupivacaine, although no patient showed any features of systemic toxicity. The systemic kinetics of ropivacaine were not influenced significantly by varying the concentration or volume administered.

Atraucan: a new needle for spinal anesthesia.

BACKGROUND AND OBJECTIVES: Atraucan 26-gauge spinal needles have a tip designed to make a small linear cut (as opposed to a V-shaped cut) in the dura mater. The cut is shorter than the outside diameter of the needle and is dilated as the needle passes through the dura. The needle is used with a 20-gauge introducer. In vitro, it causes less leakage of cerebrospinal fluid than Quincke 26-gauge or Sprotte 24-gauge needles. This study was designed to test the ease of use and any damage caused to the needle tip during lumbar dural puncture. METHODS: This was a multicenter trial (six centers in five countries) involving 362 patients undergoing spinal anesthesia. A detailed questionnaire was filled in for every patient by the anesthesiologist. All the needles were returned to the factory and examined microscopically for damage. RESULTS: Lumbar dural puncture was successful in all but one patient. Spinal anesthesia was satisfactory for the planned surgery in 97%. Microscopy of the needle tips showed only a minor degree (0.01-0.19 mm) of bending in 14%, and none of the tips had a "hook." Postdural puncture headache (PDPH) occurred in nine patients (2.5%), all but one of whom (a 15-year-old male) were females under 55 years of age. CONCLUSIONS: The Atraucan needle is easy to use and has a high success rate in identifying the subarachnoid space. Lumbar dural puncture causes minimal damage to the tip. The incidence of PDPH is low, but a larger comparative study needs to be performed.

The open access Continence Resource Centre for Greater Glasgow Health Board.

The development of an open access Continence Resource Centre is described. The role of the Centre in helping the sufferers and carers is highlighted. The educational role exceeded expectations. The benefits of the centre in education, research and potential cost saving are discussed. The aims and achievements are in accord with the Department of Health document "An Agenda for Action on Continence". From its opening in August 1989 to the end of February 1992 the centre has served 8070 incontinent individuals and 4736 carers. At a cost of 44,000 pounds per annum this represents good value for money.

Effects of nitrous oxide on psychological performance.

Thirty healthy volunteers took part in this double-blind crossover study comparing 15 percent nitrous oxide in oxygen with 100 percent oxygen. They received each treatment for 45 minutes, in counter-balanced order, with no break between treatments. Central nervous system (CNS) effects of nitrous oxide were assessed by a battery of performance tests and by the Visual Analog Scales. The Digit-symbol Substitution Test showed significant slowing with nitrous oxide as did Symbol-digit Substitution and Sentence Verification. Subjects rated themselves as more drowsy, dizzy, abnormal, drunk, and muzzy on nitrous oxide than on oxygen. Significant carryover effects were seen only for the Alert-Drowsy scale at 2.5 minutes after the start of treatment, and not at any later time point. These results show that the onset and offset of the CNS effects of 15 percent nitrous oxide are sufficiently rapid to permit the study of two treatment periods within a single experimental session.

Effects of i.v. lignocaine on psychological performance and subjective state in healthy volunteers.

In order to assess the effects of different doses of lignocaine on performance, nine healthy volunteers aged 21-34 yr received i.v. infusions of saline, low and high dose lignocaine (mean plasma concentrations 0.92 and 1.78 micrograms ml-1, respectively) in a double-blind randomized order. The Digit-Symbol Substitution Test (DSST) and Visual Analogue Scales (VAS) were performed repeatedly and a battery of performance tests once. The median (lower, upper quartile) number of correct responses for the DSST during the infusion period was: placebo 69 (67, 77); low 74 (71, 80); high 66 (61, 75) (P less than 0.001, General Linear Models; all pairwise comparisons P less than 0.05). None of the measures in the full battery showed any significant changes. VAS showed that subjects felt more interested (P less than 0.05), drowsy (P less than 0.01), dizzy, tense, abnormal, drunk and muzzy (P less than 0.001) with lignocaine than with placebo. These results confirm that lignocaine can produce acute performance effects (both improvements and impairments). Subjects were clearly aware of the presence of lignocaine, suggesting that subjective reports may be a useful indicator of its CNS effects.

Clinical evaluation of a spinal catheter technique in femoro-popliteal graft surgery.

The use of a 24-gauge catheter for continuous spinal anaesthesia was evaluated in 20 patients undergoing femoro-popliteal graft surgery for occlusive disease. The catheter was inserted through either a Tuohy or Quincke-tip needle and isobaric amethocaine used for the initial injection. In five patients identification of the subarachnoid space was not straightforward, but clear difficulty with catheter insertion was encountered in only one. The range of blocks seen was wider than expected, but it was adequate for surgery 15 minutes after injection in 16 of the 20 patients. In another three the injection of a small dose of hyperbaric bupivacaine produced the necessary extension of block. Two patients (10%) required a general anaesthetic, one because of grossly inadequate spread of solution, the other because the catheter kinked and prevented injection of a second dose after the start of surgery.

Adrenaline, fentanyl or adrenaline and fentanyl as adjuncts to bupivacaine for extradural anaesthesia in elective caesarean section.

We have compared the effects of extradural fentanyl and fentanyl plus adrenaline with adrenaline alone as adjuncts to extradural bupivacaine in patients undergoing elective Caesarean section. Forty-five patients were allocated randomly to receive 0.45% bupivacaine 20 ml with adrenaline 4.5 micrograms ml-1, fentanyl 4.5 micrograms ml-1 or adrenaline plus fentanyl (4.5 micrograms ml-1 of each) as supplements. The main outcome measures were time to bilateral analgesia of T6 or higher, need for intraoperative analgesic supplements, observer rating of intraoperative analgesia and patient assessment of analgesia using a 10-cm visual analogue scale. The time to onset of analgesia to T6 was reduced insignificantly by the fentanyl solutions compared with adrenaline only. The quality of analgesia as assessed by the need for analgesic supplements was superior for the patients given fentanyl. An observer rating of pain and visual analogue pain scoring by the patient also indicated superior analgesia with fentanyl supplementation. Two patients experienced respiratory depression after extradural fentanyl and were given naloxone. Two neonates were also given naloxone. Close supervision is therefore recommended in the early postoperative period when this technique is used.

Comparison of speed of onset of analgesic effect of diamorphine and morphine.

In a random, double-blind crossover trial using an ischaemic limb pain model we have assessed the speed of onset of analgesia after an i.v. bolus of equipotent doses of diamorphine and morphine in 12 healthy male volunteers. Pain and its subsequent relief were assessed by means of a visual analogue scale. Two of the subjects found diamorphine acted quicker than morphine, one found no difference and nine found that morphine was quicker than diamorphine. The mean time to diamorphine effect was 53% greater than for morphine (P less than 0.005, Wilcoxon rank sum test). These findings suggest that, for rapid relief of pain, morphine is more suitable than diamorphine.

Computer applications in a urology department.

An integrated approach to computerising the urology department has been implemented, using a XENIX multi-user system, with 6 terminals. Standard discharge letters, patient databases and urodynamic reporting programs are the main features. In addition, there are programs for patient history-taking and urodynamics on personal computers not linked at present to the main system.

Comparison of complications associated with single-holed and multi-holed extradural catheters.

Adverse events associated with single-holed and multi-holed extradural catheters were compared in obstetric practice. Two hundred and forty-five patients were given an extradural block using a single-holed catheter and 229 received a block via a multi-holed catheter. There was no difference in the incidence of major side effects. Flow of fluid under gravity in the catheter was restricted significantly more often in the single-holed catheters. Blood was found significantly more often in the multi-holed catheters.