Continuous interscalene infusion and single injection using levobupivacaine for analgesia after surgery of the shoulder. A double-blind, randomised controlled trial.

We performed a double-blind, randomised controlled trial to assess the effectiveness of a continuous-infusion brachial plexus block with levobupivacaine compared with that of a standard single injection for the management of post-operative pain after surgery on the shoulder. Eight patients were randomised to receive a pre-operative brachial plexus block using 30 ml of levobupivacaine 0.5% with adrenaline 1:200 000 followed by insertion of a 20-gauge polyamide catheter. This was connected to a disposable elastometric pump, set immediately after surgery to administer a continuous flow of levobupivacaine 0.25% at a rate of 5 ml per hour. The other eight patients were randomised to receive only the initial injection of 30 ml. The study was double-blinded with the aid of sham catheters and clamped pumps. All patients were given regular paracetamol and were prescribed morphine through a patient-controlled analgesia pump. Motor and sensory block assessments, visual analogue scale pain scores and consumption of morphine were recorded after the operation and then at 6, 12 and 24 hours after administration of the block. Satisfactory motor and sensory block was achieved in all patients. The mean visual analogue scale pain score at 12 hours and consumption of morphine at 24 hours after injection were significantly lower (p < 0.05) in the continuous-infusion group. This group also took longer to request their first additional analgesia and reported a significantly higher overall level of satisfaction. Our study has shown that continuous interscalene infusion of levobupivacaine is an effective method of post-operative analgesia after major surgery of the shoulder.

Double-blind comparison of ropivacaine 7.5 mg ml(-1) with bupivacaine 5 mg ml(-1) for sciatic nerve block.

Two groups of 12 patients had a sciatic nerve block performed with 20 ml of either ropivacaine 7.5 mg ml(-1) or bupivacaine 5 mg ml(-1). There was no statistically significant difference in the mean time to onset of complete anaesthesia of the foot or to first request for post-operative analgesia. The quality of the block was the same in each group. Although there was no statistically significant difference in the mean time to peak plasma concentrations the mean peak concentration of ropivacaine was significantly higher than that of bupivacaine. There were no signs of systemic local anaesthetic toxicity in any patient in either group.

Comparison of two neurostimulation techniques for axillary brachial plexus blockade.

This prospective, randomized, double-blind study compared two techniques of axillary brachial plexus block using a peripheral nerve stimulator. Both groups received initial musculocutaneous nerve block followed by either a single injection on median nerve stimulation (group 1) or a double injection divided between median and radial nerves (group 2). All 60 patients received a total of 30 ml of lidocaine 15 mg/ml with epinephrine 5 microg/ml. Complete sensory blockade of all six peripheral nerves occurred in 53% and 97% of patients in groups 1 and 2, respectively (P<0.001), with a more rapid onset of blockade occurring in group 2 patients (P<0.001). Complete motor blockade was evident in 30% and 83% of patients in groups 1 and 2, respectively (P<0.001).

Anaesthetic experience with laparoscopic cryotherapy. A new technique for treating liver metastases.

BACKGROUND: Laparoscopic cryotherapy is a new technique for treating hepatic tumors that obviates the need for a laparotomy and may reduce the amount of surgical trauma and heat loss associated with the open technique. Liquid nitrogen is applied to the tumor via a cryoneedle probe introduced through a laparoscopic port. The aim of this study was to assess the effect on body temperature and the hematological and biochemical changes associated with this technique. METHODS: Five patients who underwent this procedure were studied prospectively under a standardized general anaesthetic. Core and peripheral temperature were measured during the procedure, and blood samples were taken for hematological and biochemical analysis. RESULTS: Freezing time ranged 19-57 min and measured blood loss 0-1000 ml. In one case, bleeding resulted from hepatic surface cracking. Three patients required a blood transfusion. The mean fall in both nasopharyngeal and right atrial temperature was 0.4 degree C. Postoperatively, all patients showed a large rise in alanine aminotransferase (ALT) and a fall in platelet count. A systemic inflammatory response syndrome was seen in some cases, but all patients survived to hospital discharge. CONCLUSIONS: Laparoscopic hepatic cryotherapy can be performed without significant temperature changes, but it entails significant morbidity.

A comparison of epidural infusions of fentanyl or pethidine with bupivacaine in the management of postoperative pain.

A double-blind randomised clinical trial was undertaken in 40 patients undergoing major abdominal surgery. Postoperative pain relief was provided using epidural infusions of 0.06% bupivacaine with fentanyl 4 micrograms.ml-1 (n = 20) (group F) or with pethidine 1.5 mg.ml-1 (n = 20) (group P). Postoperative pain scores using a visual analogue scale (0-100 mm) were not significantly different between the two groups. Median pain scores were 0-19 mm at all times of assessment indicating that good analgesia was provided by both regimens. There was no significant difference between the epidural infusion rates in the two groups. The side effects and effect on pulmonary function were similar in each group. Nine patients were withdrawn from the study (four from group F, five from group P) due to failure of the epidural technique or other complications. Fourteen patients, equally distributed, required a total of 24 epidural 'top-ups' by an anaesthetist because of inadequate analgesia. We demonstrated no advantage with epidural pethidine over fentanyl when used by infusion in combination with bupivacaine in the management of postoperative pain.

Anaesthesia for laparoscopic surgery.

Laparoscopic surgery offers patients a significant number of advantages, including a reduction in pain and cosmetic injury that facilitates early ambulation and a rapid return to normal activities. Although the surgery is of a minimally invasive nature, there are a number of specific physiological alterations occurring as a result of creating the pneumoperitoneum and the postural changes involved in optimizing patient position. These may be particularly in patients with pre-existing respiratory and cardiovascular disease. In addition, there may be surgical hazards related to trocar insertion or other instrumental injuries leading to haemorrhage, peritonitis or gas embolism. It is important for all clinicians involved with these cases to be familiar with the physiological alterations and potential hazards and for the anaesthetist to employ appropriate techniques and monitoring to allow early detection of problems and to minimize perioperative morbidity.

A comparison of two approaches to sciatic nerve block.

This study compared the posterior and popliteal fossa approaches for sciatic nerve block. Patients scheduled to undergo foot surgery were allocated randomly into one of two groups: group A (n = 20) received sciatic nerve block via the posterior approach and group B (n = 20) received a block using the popliteal fossa approach. All blocks were performed with the aid of a peripheral nerve stimulator and alkalinised 0.5% bupivacaine with 1 in 200,000 adrenaline was injected in a dose of 2 mg.kg-1. Nineteen of 20 blocks in group A were successful compared with nine of 20 in group B (p less than 0.01). There was no significant difference between the groups in respect of time to onset or duration of block. Patients in group B reported less discomfort during performance of the sciatic nerve block but required supplementary nerve blocks more frequently. We recommend the use of the posterior approach for sciatic nerve block.

Sedation for paediatric computerized tomography--a double-blind assessment of rectal midazolam.

This double-blind study investigated the rectal administration of midazolam as an alternative to general anaesthesia for elective computerized tomography (CT) of the brain. Thirty children were randomly allocated to receive either midazolam 0.3 mg kg-1 (Group 1) or midazolam 0.6 mg kg-1 (Group 2) by the rectal route. Sedation was obtained in 13 children in Group 1 and 12 in Group 2 but this was only satisfactory for scanning in seven children in Group 1 and eight in Group 2. We concluded that although the technique produced sedation, it did not reliably produce satisfactory conditions for CT scanning.

Alkalinisation of bupivacaine for sciatic nerve blockade.

This double-blind study investigates the effect of pH adjustment of bupivacaine 0.5% with adrenaline 1:200,000 on block latency, duration of analgesia and systemic absorption of local anaesthetic after sciatic nerve blockade. Twenty-four adult patients were randomly allocated into one of two groups: Group A (n = 12) received bupivacaine with adrenaline 1:200,000 (pH 3.9) 2 mg/kg, while Group B (n = 12) received alkalinised bupivacaine with adrenaline 1:200,000 (pH 6.4) 2 mg/kg. Increasing the pH of the local anaesthetic solution significantly reduced block latency from 25 minutes in Group A to 12.5 minutes in Group B (p less than 0.001) and prolonged the duration of useful analgesia from 14.1 hours to 18.3 hours (p less than 0.001). There was no significant difference in plasma bupivacaine levels between the two groups. The results indicate that alkalinisation of bupivacaine reduces time to onset and prolongs the duration of useful analgesia when used for sciatic nerve blockade, without significantly increasing systemic absorption.

Bradycardia during intra-abdominal surgery. Modification by pre-operative anticholinergic agents.

The aim of the present study was to examine, in a double-blind, randomised manner, the effects of glycopyrronium 0.005 mg/kg, atropine 0.01 mg/kg or a placebo (normal saline) on the frequency of bradycardia in 92 patients scheduled for major abdominal or gynaecological surgery. All patients received fentanyl, halothane and vecuronium. The frequency of bradycardia in the group that received saline was 18%. No cases occurred in either anticholinergic group. Mean heart rates intra-operatively were not significantly different between the atropine and glycopyrronium groups. It is suggested that the routine use of pre-operative anticholinergic agents should be considered when a similar anaesthetic technique is employed.