anaesthesia, local

anaesthesia, local Early attempts to relieve the pain of operations were by the application of cold, notably during the retreat of Napoleon's army from Moscow in 1812, and by pressure on main nerves. Not until cocaine was isolated from the South American coca leaf, by Albert Niemann at Gottingen University in 1860, did a drug become available that would effectively block impulses travelling along nerves — though even then its anaesthetic application was not immediately appreciated. The numbing effect on the mouth of chewing coca leaves was well known, and this action of the pure drug on the tongue was soon confirmed. It was known to Sigmund Freud (1856–1939), who thought cocaine might be the antidote to morphine addiction. The potential of cocaine as a local anaesthetic was eventually realized in 1884, when Carl Koller, a young Viennese doctor who was looking for a means of preventing the pain of eye operations without general anaesthesia and its after-effects, applied it to his own tongue. His report of successful trials on animals and people created a sensation, and the use of cocaine spread rapidly, from surface application to injection under the skin and around main nerves.

The method was taken up enthusiastically on the continent of Europe and in the US, but not in the UK, where general anaesthesia reigned supreme. In America, by the end of the 1880s, the leading exponent, the surgeon W. S. Halstead, had become a cocaine addict as the result of self-experimentation, and although eventually cured, he suffered a sad change of personality.

Injection of cocaine solution in the region of the spinal cord by the New York neurologist Leonard Corning in 1885 opened the way for spinal anaesthesia. The deliberate introduction of a needle through the dura, the thick membrane which surrounds the spinal cord, and the injection of cocaine solution into the cerebrospinal fluid which bathes it, was first performed by the German surgeon August Bier in 1898. The patient was judged unfit for a general anaesthetic, and the profound anaesthesia of the legs which ensued allowed Bier to remove several segments of infected bone. Spinal anaesthesia was taken up, again enthusiastically, in the US, and its application gradually spread to abdominal operations. But cocaine is a very toxic drug, and there were a number of deaths from overdose. The search for less dangerous substitutes was soon on, culminating in the synthesis of amylocaine (stovaine), used specifically for spinal anaesthesia, in 1904, and novocaine (procaine), with more general applications, in 1905.

Spinal anaesthesia was a boon for the surgeon. Since he could make the injection himself it freed him from reliance on another practitioner to administer a general anaesthetic. It allowed him to operate on patients who were unfit for general anaesthesia, and since it relaxed the muscles it provided better operating conditions, a more level playing field, so to speak, than he could expect from the often inexpertly administered ether or chloroform. Fall of blood pressure was an undesirable side-effect — very unpleasant for the patient, and treated by tilting the operating table head-down, but not unwelcome to the surgeon, because it reduced bleeding.

As the patients were conscious during the operation, American surgeons in the 1920s attempted to distract their attention by encouraging them to listen to the radio or a Victrola through earphones, to converse, to sing, or, if it did not interfere with the operation, to smoke. The distraction most effectively employed by the surgeon G. P. Pitkin of New Jersey was what he called his psychoanaesthetist, described by him as an auburn-haired vamp who made the patient wish the operation would go on for ever, as long as she would only stay with him.

Spinal anaesthesia was often followed by headache, due to leakage of fluid through the needle puncture, and it was found that this could be avoided if the solution was injected outside the dural membrane — extradural, or epidural anaesthesia. The injection could be made either through an opening in the sacrum at the base of the spine (a ‘caudal block’, very useful for operations such as haemorrhoids, or for relieving the pain of childbirth), or higher up the spine, depending on the operation. The discovery that a low epidural could relieve labour pains without affecting the strength of uterine contractions led to the popularization of the method during childbirth. Inserting a fine catheter through a needle, so that repeated doses could be given, brought the added advantage that if operative intervention such as forceps or Caesarean section became necessary the means of anaesthesia was already installed.

Extradural methods received a boost, and spinals a severe blow, with the publication of a paper by the American neurologist Foster Kennedy and his colleagues in 1950, in which it was claimed that every spinal injection left some pathological changes around the cord. This was augmented by a case which hit the headlines in 1947: two successive patients on an operating list had suffered permanent paralysis of the lower limbs after spinal anaesthesia. Although the anaesthetist was exonerated when the case came to court, and Kennedy's allegations of spinal damage in all cases was resoundingly refuted, the worry remained, and spinal anaesthesia was not practised again to any great extent in the UK until the 1980s. By then the availability of sterile disposable equipment, and a new generation of drugs, allowed a new generation of anaesthetists to restore this valuable technique to its rightful place. Local anaesthesia, either by widespread infiltration or aimed to block particular nerves, is now widely used for day surgery, and also to provide postoperative pain relief.

David Zuck

Bibliography

Rushman, G. B.,, Davies, N. J. H.,, and and Atkinson, R. S. (1996). A short history of anaesthesia. Butterworth-Heinemann, London.
Thorwald, J. (1960). The triumph of surgery. Thames and Hudson, London.