Comfortably numb: The history of local and regional anaesthesia | Association of Anaesthetists

Comfortably numb: The history of local and regional anaesthesia


Comfortably numb: The history of local and regional anaesthesia

The Anaesthesia Museum’s temporary exhibition for 2020 focuses on local and regional anaesthesia. As the museum is currently closed due to COVID-19, we have made it accessible online. Do come and visit us when we re-open to explore the objects on display which tell the story of this aspect of anaesthesia.

Local and regional anaesthesia These terms are often used interchangeably, but they are not the same. Local anaesthesia is administered in a very limited area to block nerve endings and pain conduction. Regional anaesthesia, by contrast, makes it possible to block pain in a larger area of the body depending on the type of procedure. Getty Images: Nerve trunks and endings of the brachial plexus Local anaesthesia is produced by placing local anaesthetic on the surface of the body, or by injecting it just below the surface. This results in a very limited area of numbness, which means minor procedures can be performed with minimal side effects. Getty Images: Local anaesthesia in dentistry Regional anaesthesia involves injecting the drug solution around nerve trunks, which run between the spinal cord in the vertebral canal and the periphery. Injections within the canal are often referred to as central nerve blocks (spinal and epidural blocks), those outside are known as peripheral nerve blocks. The closer to the spine the injection is made, the wider the area of numbness, allowing more major operations to be performed. Regional anaesthesia is less stressful to the body than general anaesthesia and offers significant advantages. Patients recover quicker and experience less pain, sickness and breathing issues after surgery. Nerve blocks can be used to prolong pain relief even after major surgery or during labour, especially with the insertion of a catheter, which provides repeated or continuous administration. Getty Images: Epidural anaesthesia with a catheter

History and development Attempts to numb parts of the body date back to antiquity, when methods such as nerve compression or the application of cold were used. The concept of local anaesthesia was identified by James Young Simpson in the 1840s, but it was another twenty years before Benjamin Ward Richardson developed his ether spray, the first practical method of local anaesthesia. Getty Images: Nerve compression using a tourniquet Wellcome Collection: Benjamin Ward Richardson’s ether spray Explorers in South America brought back samples of cocaine in the 1500s, noting that tasting it produced numbness of the lips and tongue. However, it was not until 1884 that aspiring Viennese ophthalmologist, Carl Koller, recognised the clinical significance of cocaine. The news spread rapidly, and nerve block techniques using cocaine were practised soon after. Cocaine, however, caused side effects and was difficult to sterilise. While effective for use on the eye, lips and tongue, its use by injection was restricted as only limited amounts could be used. A more effective, though still problematic, alternative was found in 1904 with the introduction of procaine. It was only in the 1930s, with the development of other drugs, that regional techniques were used more widely. With the introduction of the easy to sterilise and reliable drug lidocaine in 1943, the effectiveness of these methods improved further. Getty Images: Map of South America Getty Images: Coca plant As doctors began to specialise in anaesthesia, they acquired the anatomical knowledge and clinical skills to ensure correct placement of local anaesthetic near the relevant nerve. After the Second World War, advances in plastics and other technologies led to the introduction of a range of high quality disposable equipment, helping to improve drug administration, safety and effectiveness.

Possibilities The popularity of local and regional methods has fluctuated over the decades. As drugs, equipment, and expertise have improved, so have the techniques for operations. Today, regional anaesthetics are used for a wide range of procedures and treatments. Spinal anaesthesia is now widely used for surgery on the lower half of the body, for continuous epidural analgesia in labour, and after very major surgery. Use of regional anaesthesia leaves the patient conscious, something which makes many patients anxious, but careful use of sedative drugs means they will have no awareness or memory of the surgery. Some breast surgeries are performed whilst the patient is ‘awake’. The patient receives regional anaesthesia in the form of nerve blocks, but is usually given a sedative. This is becoming an increasingly popular alternative to mastectomy under general anaesthesia for many reasons. Anna Garvey: Tattoo artist Anna Garvey working on a post-mastectomy cover up

Tel Aviv Sourasky Medical Centre: Violinist Naomi Elishuv playing the violin during her brain surgery in 2014 It has, for instance, been shown that patients who undergo a mastectomy using regional anaesthesia need less pain relief than those who had the same operation with general anaesthetic. Developments in surgery mean that having a conscious patient may actually be a positive benefit, the extreme example being certain types of brain surgery. ‘Awake’ brain surgery is mainly used to treat conditions such as tumours or epileptic seizures. If a tumour or seizure occurs in the parts of the brain that control vision, movement or speech, a patient’s brain activity is monitored through prompts during the operation. This helps the surgeon avoid damaging functional brain tissue.

A selection of objects on display

Nerve stimulator

Nerve stimulator

To confirm the correct placement of the needle tip, nerve stimulators were introduced. A low electrical current is passed down the needle to stimulate the target nerves and cause a ‘twitch’ in the muscles it supplies. To ‘see’ where the nerve is, an ultra-sound device can be used.

Novocaine

Novocaine bottle in display case

Novocaine bottle

Novocaine decays when in solution so clinicians used the tablets to make up a fresh solution just before use. 

Courtesy of Thackray Medical Museum.

Glass hypodermic syringe

Glass Hypodermic Syringe

Early syringes were ill-suited for the administration of regional anaesthesia. The Record Syringe, introduced in 1906, was one of the first glass and metal syringes that was highly dependable and easy to take apart for sterilisation.

Labat spinal set and Labat syringe

Labat spinal set

Labat syringe

Introduced by Gaston Labat in 1922, one of the pioneers of regional methods, this spinal set contained a syringe and a needle that were specifically developed for the administration of regional anaesthesia.

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