Bier's Block Revisited: Intercuff Block

Bier introduced his intravenous technique of local anaesthesia to facilitate palliative surgery on the elbow or knee. He cannulated a suitably large vein in the vicinity of the joint to inject procaine after first isolating the operating site with a proximal and a distal tourniquet. This extra containment of the local anaesthetic solution made it feasible to flush out any unfixed drug with saline before release of the main tourniquet, an advantage which has been lost in the currently fashionable technique of intravenous regional anaesthesia (IVRA) involving a single tourniquet above the elbow or knee and a fine butterfly needle in a vein on the dorsum of the hand or foot. A modern version of Bier's original method is described, conveniently called an intercuff block (ICB), which reintroduces the possibility of effective flushing, offers better operating conditions and engenders new ideas for further study.

Topical guanethidine relieves dentinal hypersensitivity and pain

The topical application of guanethidine solution to the affected teeth has been successful in relieving natural and clinically induced dentinal pain and hypersensitivity in 13 of 14 dental patients in a pilot study. The mechanism of this analgesia was unclear but probably involved anti-noradrenergic block as there was no evidence of local anaesthesia. Further studies may generate new ideas about the cause of the excruciating pain and hypersensitivity often associated with the acute exposure of tooth dentine and lead to new ways of managing the discomforts of dental conservation and restoration.

Sumatriptan relieves and prevents peri-operative migraine attacks

The novel use of sumatriptan as an adjunct to the management of general anaesthesia in patients with a history of migraine is described. In two unpremedicated patients awaiting day surgery an acute pre-operative attack of migraine was successfully terminated by the injection of sumatriptan, allowing surgery to proceed uneventfully under general anaesthesia without postoperative complications. Two other patients with a history of severe habitual vomiting after general anaesthesia, who also had a history of migraine, were each given a prophylactic injection of sumatriptan after induction of anaesthesia and for the first time emerged from general anaesthesia free of these distressing complications.

Does failed natural opioid modulation in regional sympathetic ganglia cause reflex sympathetic dystrophy?

Early features of reflex sympathetic dystrophy in a limb resemble the general effects of autonomic arousal associated with opioid withdrawal. It is suggested that natural opioid peptide modulation in regional sympathetic ganglia normally rises to prevent excessive autonomic activity in an injured limb. After an injury (especially a trivial one) to a susceptible subject, this localised increase in opioid modulation may fail or may rapidly wane so that autonomic features of opioid withdrawal appear in the affected limb. Florid dystrophic changes may then occur because of passive complications of disuse associated with pain, or as a result of more active processes. Preservation of an appropriate opioid bias in the regional sympathetic ganglia might be an important factor in the successful management and prevention of reflex sympathetic dystrophy.

Faulty Superset plastic catheter mounts. A cautionary tale applicable to other mass-produced disposable products

Nine Superset (Intersurgical Ltd) single-use corrugated plastic catheter mounts were found to be faulty in a boxed batch of 75. The manufacturer's meticulous system of batch coding enabled the source of the problem to be traced quickly. Sporadic faults must be expected to occur in mass-produced disposable equipment and the unusual origin of the defect reported in these catheter mounts is testimony to the way unexpected events can prejudice the most carefully regulated quality control. It is emphasised that the user can help safeguard the community by ensuring that stock is used in strict rotation and that batch numbers are accurately reported when faults arise.

The need for analgesic cover after ENT surgery--comparison of nefopam and papaveretum

Intra-operative intramuscular injections of either papaveretum 0.3 mg/kg or nefopam 0.4 mg/kg were given to alternate patients to promote smooth emergence from ENT anaesthesia in a consecutive series of 40 children. Observations over a period of 30 minutes following completion of surgery showed that emergence was satisfactory in 19 out of 20 children given papaveretum, and in 15 out of 20 children given nefopam. The study confirms that this indication for papaveretum is justifiably popular and that nefopam is a useful alternative mainly because it does not cause respiratory depression. There are no previous reports of the use of nefopam in children.

Ocular interlimbic distance. A new method of monitoring muscle relaxation during anaesthesia

Measurement of the ocular interlimbic distance (OILD) with a vernier caliper has proved a useful method of studying the reduction in muscle tone caused by general anaesthetic agents and non-depolarising muscle relaxants. The depolarising muscle relaxant, suxamethonium, has a special effect on the extraocular muscles which can be exploited to monitor the incremental use of this drug and to assist in the management of suxamethonium-apnoea in patients with atypical pseudocholinesterase.

Relief of Sudeck's atrophy by regional intravenous guanethidine

17 consecutive cases of Sudeck's atrophy were treated with intravenous regional guanethidine. Results were encouraging, especially in the arm.

Measurement of recovery from outpatient general anaesthesia with a simple ocular test

Measurements of extraocular muscle balance with a Maddox wing can be a useful clinical test of the rate of recovery from general anaesthesia. In 65 dental outpatients recovery was found to be most rapid in those patients given only nitrous oxide, oxygen, and halothane, whereas the previous administration of methohexitone, propanidid, or thiopentone for induction was associated with slower recovery. Recovery rates after methohexitone and propanidid were similar and rapid enough to confirm their choice for intravenous induction of anaesthesia in outpatients, but delayed recovery after thiopentone showed that this agent is best avoided in these circumstances.

Timing of atropine and neostigmine in the reversal of muscle relaxants

The antimuscarinic effects of atropine were studied in 46 patients to whom neostigmine had been given after operation to reverse the action of a muscle relaxant. Neostigmine was given to alternate patients three minutes after, or together with, atropine, and the effects of the two procedures were compared by measuring the secretions which collected in the buccal and oropharyngeal cavities and observing the heart rate.It was found that the glands of the oral cavity were stimulated to a greater extent when neostigmine was given with atropine than after atropine. Any dose of atropine sufficient to inhibit peristaltic movements of the bowel is more than enough to block completely secretion by the salivary glands, and the appearance of some secretion in all cases after the administration of neostigmine suggests that the bowel was at liberty to react to the neostigmine in every case, but perhaps particularly so when atropine and neostigmine were given mixed. The integrity of an anastomosis of the bowel could be endangered by vigorous peristalsis in the early postoperative period.Electrocardiograms in about half the patients from each group confirmed earlier work that the muscarinic effects of neostigmine on the heart can be prevented by giving the atropine either before or together with the neostigmine.