Regional hip blockade in osteoarthrosis

Eighteen patients with unilateral osteoarthrosis of the hip were investigated in a trial which involved the injection of nine with bupivacaine and nine with normal saline. All the patients completed daily pain analogue charts. Their pain, mobility and functional activity were assessed and gait characteristics analysed, once before the injection and then at three monthly intervals. All the patients recorded a decrease in pain level within two weeks of injection, but it subsequently rose to pre-injection levels. There were no other significant general improvements after the injection. A significant increase in the maximum force at toe-off for the good leg was recorded one month after the injection. However, no further significant differences were found in the gait performance of either group of patients throughout the study. It is concluded that the hip nerve regional blockade offers no useful relief to the pain of osteoarthrosis of the hip joint.     

Exaggerated epidural blockade resulting from unusual spread of bupivacaine in a patient with low back pain

A 75-year-old woman with chronic low back pain was given bupivacaine and methylprednisolone epidurally through a catheter in the L1-L2 interspace. An unusual spread of bupivacaine resulted in a block from the C4 to the L1 dermatome with no relief of back pain. Injection of a radiopaque dye and subsequent X rays showed a similar spread. The possible causes are discussed.     

Intravenous regional analgesia. The danger of the congested arm and the value of occlusion pressure

Two cases are described in which congestion of the arm occurred during intravenous regional analgesia. One case exhibited signs of serious local anaesthetic toxicity, while a significant plasma bupivacaine level was demonstrated in the other. In a study in a volunteer, leakage of contrast medium past the cuff was demonstrated radiologically only when congestion of the arm was produced. The Hoyle double cuff apparatus has narrow cuffs producing less tissue compression than a standard blood pressure cuff inflated to the same pressure. It may sometimes not occlude the brachial artery when inflated to a pressure based on the systolic arterial pressure measured with a standard cuff and congestion of the arm may then result. Increases in arterial blood pressure occurring during the procedure can also lead to congestion of the arm. Congestion may increase the risk of local anaesthetic agent leaking past the tourniquet into the systemic circulation. Recommendations are made about the choice of cuff gauge pressure and the prevention of arm congestion occurring during intravenous regional analgesia.     

The effect of a priming epidural injection of adrenaline on epidural blockade with bupivacaine

Twenty-four patients receiving epidural anaesthesia were studied to test the hypothesis that 1:200,000 adrenaline administered into the epidural space 5 minutes before 20 ml bupivacaine 0.5% would improve nerve block and delay systemic absorption of the local anaesthetic. Group A/B received 20 ml adrenaline 1:200,000 5 minutes before 20 ml bupivacaine 0.5%, group S/BA 20 ml saline followed by 20 ml bupivacaine 0.5% with 100 micrograms adrenaline, and group S/B saline 20 ml followed by 20 ml plain bupivacaine 0.5%. Mean maximum plasma concentrations of bupivacaine tended to be lower in the adrenaline groups. A delay in the time to peak plasma concentration of bupivacaine was noted in the A/B group; this indicated that priming with adrenaline may be effective at delaying early systemic uptake of the local anaesthetic. In both adrenaline groups a more prolonged epidural block and increased efficacy were noted, although this was only significant for the duration of block at T6 (p = 0.023) and duration of motor block at Bromage level 1 (p = 0.016) in group A/B. There seems little clinical advantage in administering adrenaline 5 minutes before bupivacaine.     

Upper limb sympathetic blockade following intercostal nerve blocks

A case of transient sympathetic block of the arm following percutaneous intercostal nerve injections is described and the possible aetiology discussed.     

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.     

Accidental spinal anaesthesia following intrathoracic intercostal nerve blockade

A case of high spinal anaesthesia following intrathoracic intercostal nerve blockade is described and the possible causative mechanisms are discussed.     

Possible inadvertent subdural block following attempted stellate ganglion blockade

A case is reported of suspected inadvertent subdural block following attempted stellate ganglion blockade for relief of cervicobrachial pain in a patient suffering from reflex sympathetic dystrophy. Possible complications due to neuraxial spread of local anaesthetics while performing a cervicothoracic ganglion blockade are considered.     

The alkalinisation of bupivacaine for intercostal nerve blockade

A double-blind randomised study was performed to investigate the effect of pH adjustment of bupivacaine, with adrenaline 1:200,000, on the duration of block and pain relief after intercostal nerve blockade following thoracotomy. One group (n = 10) received bupivacaine with adrenaline 1:200,000 (pH = 4.1) and the other (n = 10) received alkalinised bupivacaine with adrenaline 1:200,000 (pH = 6.9). There was no significant difference in block duration (mean 23.9 and 26.4 hours respectively) visual analogue pain scores or morphine usage. Patients were more likely to have a block during the first 12 hours if they received alkalinised bupivacaine (p less than 0.01, Chi-squared test). A progressive regression of block, not previously described, was observed, explicable by means of spread of local anaesthesia to adjacent intercostal nerves. Alkalinisation of bupivacaine with adrenaline for intercostal nerve blockade has little clinical benefit.     

Sciatic nerve palsy following uneventful sciatic nerve block

We describe the loss of function in the sciatic nerve after an uneventful sciatic nerve block using 25 ml of lignocaine 1% with adrenaline 1 in 200 000 in a patient receiving β blocker drugs. Lack of pain on injection and complete regeneration of the nerve after 12 months in a patient with severe peripheral vascular disease led us to postulate ischaemic nerve damage as a mechanism of injury. Adrenaline-induced unopposed α-mediated vasoconstriction in a β-blocked patient is suggested as a possible mechanism of peripheral nerve injury worthy of further investigation.     

Repeated unilateral epidural blockade

Unilateral epidural analgesia occurring in a parturient three times in successive pregnancies is reported. Possible causes are reviewed, and clinical and radiological evidence in support of the most likely explanation are presented.     

Convulsions following axillary brachial plexus blockade with levobupivacaine

Neurotoxicity manifesting as convulsions is a recognised complication of the administration of local anaesthetic drugs as part of a regional anaesthetic technique. We describe a case of self-limiting convulsions following the institution of an axillary brachial plexus block with levobupivacaine. Although the occurrence of convulsions following the administration of racemic bupivacaine is a well-recognised complication, there have been no clinical case reports published describing convulsions following the use of levobupivacaine in regional anaesthesia.     

Plasma concentrations of bupivacaine after supraclavicular brachial plexus blockade in patients with chronic renal failure

The plasma concentrations of bupivacaine and the latency and duration of anaesthesia after supraclavicular block with 30 ml of 0.5% bupivacaine were measured in 10 patients with chronic renal failure and in 10 patients with normal renal function. No significant difference was found between the two groups in respect of pharmacokinetic parameters, or in block latency or duration.