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Radiofrequency techniques are minimally invasive procedures used to provide prolonged pain relief compared to local anaesthetic blocks and forms part of a multidisciplinary approach in managing chronic pain. A generator produces a high-frequency current that passes from an electrode to an earthing plate. The electromagnetic field created around the tip of the electrode then has an effect on the surrounding nervous tissue resulting in pain relief.

Local anaesthetics are widely used in the provision of local/regional anaesthesia and the management of acute and chronic pain. Their mechanism of action temporarily inhibits voltage gated sodium channels in neuronal plasma membranes. Local anaesthetic systemic toxicity (LAST) is a serious yet largely preventable complication that can occur by any of the multiple routes of administration. LAST predominantly affects the central nervous and cardiovascular systems. Awareness of LAST and vigilance during administration of local anaesthetics may help in early recognition and successful management of the toxicity. Intralipid emulsion (ILE) infusions have been successfully used in reversing local anaesthetic-induced cardiotoxicity. Since 2007 in the UK, ILE infusion has been incorporated into the safety guidelines for management of LAST.

Many ophthalmic procedures are conducted under a range of local anaesthetic techniques. These range from topical drops through to sharp needle blocks with local anaesthetic. The most commonly used block is the sub-Tenon block; it provides excellent operating conditions while reducing complications and risks.

A patient with an abdominal aortic aneurysm can have surgical management through either an open or endovascular approach. The use of an endovascular approach has benefits for the patient by being a less invasive approach with initially lower mortality and morbidity and lower lengths of hospital stay, although longer term outcomes match open techniques. The endovascular technique requires more specialist equipment, including stents and imaging equipment. In the UK they are usually performed in specialist hospitals with teams of interventional radiologists, vascular surgeons and anaesthetists working together. Patients presenting for endovascular repair of their abdominal aortic aneurysm can present the anaesthetist with range of complex comorbidities which require specific management and optimization pre-operatively. The intraoperative management of the patient can vary, depending on patient, surgical and anaesthetic factors, from local anaesthetic, regional techniques or general anaesthesia. The postoperative complications are generally minimal, but the patients require lifelong follow up, making the procedure more expensive than an open procedure.

The addition of adjuvant agents to intrathecal and epidural anaesthetic techniques is well established, in particular opioids and clonidine. These adjuvants are utilized to improve the quality of anaesthesia and analgesia. Several other adjuvants have been studied but ongoing concerns surrounding safety and efficacy may limit their use in clinical practice. Epinephrine has for many years been administered in combination with local anaesthetic, although more recently a diverse range of adjuvants have been added to peripheral nerve block solutions, again with the aim of prolonging surgical anaesthesia. The evidence to support or refute the benefit of these agents is increasing, as is our understanding of which agents have demonstrable efficacy and safety at clinically appropriate doses. Clinicians must be aware that many adjuvants are not licensed for central neuraxial or perineural use and should be aware of the risks, in particular of neurotoxicity and unwanted side effects.

Local anaesthesia is the technique of choice for a large number of ophthalmic procedures, including cataract surgery. For some procedures topical anaesthesia is sufficient; for more complex procedures a local anaesthetic block will be needed. Sharp needle techniques previously favoured, whilst still useful, have become less common than the cannula-based sub-Tenon's block. This provides favourable operating conditions with a lower risk of complications. Patients should be appropriately counselled regarding local anaesthesia early in their perioperative journey; combined with suitable preoperative assessment this provides high levels of patient satisfaction and limits interruptions to their usual routine.

Adjuvant agents are pharmacological drugs that, when co-administered with local anaesthetic agents, may improve the speed of onset, the quality and/or duration of analgesia. A wide range of drugs have been assessed for both neuraxial and peripheral nerve blocks. Here, we review the adjuvants used in clinical practice in the UK and also briefly mention other drugs that have been used for neuraxial administration and peripheral nerve blockade to provide perioperative analgesia.

Regional anaesthesia has many advantages over systemic analgesia alone for postoperative pain and rehabilitation. Advances in continuous peripheral nerve block techniques enable the benefits of single injection blockade to be extended, providing prolonged, site-specific analgesia. A wide range of equipment, local anaesthetic solutions and adjuvants can be used to provide peripheral nerve blockade. In this article we review equipment, drugs, techniques, indications, benefits and potential complications of peripheral nerve blockade, focussing on continuous perineural catheter techniques.

Ultrasound is a safe, non-invasive imaging modality which is increasingly used in anaesthesia to aid placement of central venous cannulae and local anaesthetic blocks. Transoesophageal echocardiography (TOE) is used to assess myocardial and valvular function during anaesthesia or on the intensive care unit. It is essential to understand the underlying principles of how the ultrasound image is created in order to optimize the image, and recognize and prevent artefacts. This article describes the physics of waves and their interactions, and applies these principles to explain how the ultrasound machine produces an image. The Doppler effect and its application to measurement of blood flow and cardiac output is described.

Labour epidural analgesia underwent marked changes from the mid 1980s to the 1990s. The addition of opioids, such as fentanyl, to local anaesthetic reduced motor block and improved analgesia and maternal satisfaction. The introduction of new techniques such as combined spinal epidural analgesia and patient-controlled epidural analgesia further enhanced regional techniques. Dense motor block, historically associated with labour epidural analgesia, has now been reduced to a level where some mothers can choose to mobilize safely out of bed during their labour. In the past decade, research has focused on finding the ideal technique and combination of drugs to provide reliable analgesia with minimal motor block. No one technique has become universally popular, and the introduction of the new levo or s- enantiomer local anaesthetic has not had a major impact on labour analgesia practice. Currently, women can enjoy safe, reliable epidurals for labour analgesia with reduced or minimal motor blockade. The decisions are based on two decades of published research.

Day surgery is expanding as a specialty, with a drive to perform an increasing number of procedures as day case. Economic benefits, patient preference and modern minimally invasive surgical techniques are responsible for this. Effective, long-lasting postoperative analgesia and stringent discharge criteria are essential in order to run a successful day-surgery facility. A multi-modal approach to analgesia is most effective, incorporating paracetamol, non-steroidal anti-inflammatory drugs, local anaesthesia and opioids if necessary. In patients with opioid-tolerance, gabapentinoids are useful as protective analgesics. Dexamethasone, in addition to anti-emetic properties, has analgesic effects in certain procedures. Spinal anaesthesia may be used in the day-surgery setting, although the dose of local anaesthetic agent should be reduced and the addition of spinal opioids such as fentanyl prolong analgesia and reduce failure rate. Protocols should be in place to manage analgesia in the recovery room. Discharge from day surgery should be done in a safe manner with the emphasis on patient quality of care. Discharge scoring systems are available, which can assist staff to assess whether a patient is fit for discharge. These systems do have limitations and local guidelines are encouraged. Designated lead clinicians incorporating anaesthetists, surgeons and nursing staff should work together in the development of local guidelines and the safe running of a day-surgery facility. Patients and their carers, upon discharge, should be issued with a set of procedure-specific written instructions containing useful information and an emergency helpline. Regular audit is mandatory for the effective running of a day-surgery facility.

Management of acute pain in the neonate is challenging and involves a multimodal approach using non-pharmacological and pharmacological techniques after pain assessment using appropriate tools. Simplicity equates to safety in these vulnerable patients.

Peripheral nerve blocks (PNBs) in paediatric patients are usually used as an adjunct to general anaesthesia, providing intra- and postoperative pain relief. These blocks provide good-quality analgesia and have opioid-sparing effects, preventing morbidity related to pain. PNBs aid early patient recovery and discharge, which is essential in day-case surgery. Like all invasive techniques, PNBs are associated with complications and side-effects. They should therefore be performed only after careful analysis of the risk:benefit ratio for each child. This article discusses a general approach to PNBs in children. It covers a small selection of limb and trunk blocks, and introduces the benefit of ultrasound guidance.

Pain in children can be treated safely and effectively by using combinations of simple analgesics (paracetamol and non-steroidal anti-inflammatory drugs) and opiates, the choice of analgesic being determined by the severity of the child's pain. Safe clinical practice requires an understanding of the age-related changes in the pharmacokinetics and pharmacodynamics of analgesics in neonates, infants and children. Pain should be regularly assessed, and where appropriate local anaesthetic techniques and non-pharmacological techniques should be used in combination with systemic analgesics. Analgesia for children should be administered, assessed and/or supervised only by individuals with adequate training and experience. This article covers a spectrum of systemic analgesics, from simple to complex, used for the treatment of acute pain in children.

Regional anaesthesia forms an important part of anaesthesia and pain management. A wide variety of adjuvant agents are used along with local anaesthetic mixtures to enhance and prolong their actions. In this article we examine the adjuvants used in current clinical practice in the UK: the commonly used opioids as well as non-opioid drugs. Opioids are discussed in greater detail as they are the most researched. The mechanism of action of each drug is discussed and the most popular routes of administration are mentioned. Evidence for clinical effectiveness is also covered. The commonly encountered adverse effects and precautions that should be considered are also cited.

Systemic toxicity from local anaesthetic agent use is a rare but potentially life-threatening complication. It most commonly occurs following inadvertent intravascular injection. High plasma levels of local anaesthetic lead to central nervous system and cardiovascular toxicity. Treatment of toxicity is mainly supportive; however, there is now evidence for the use of lipid emulsions in the management of severe local anaesthetic toxicity.

The toxicity of local anaesthetic agents occurs as a result of their pharmacological action on nerve and muscle cells that rely on a high degree of electrophysiological activity for their action. The signs and symptoms of systemic toxicity are caused by the local anaesthetic reversibly inactivating the fast sodium channels of these cell membranes.

Local anaesthetic techniques combined with light general anaesthesia are the mainstay for many general, orthopaedic and plastic procedures in children, especially in day-case surgery. They reduce the use of opioids and their associated side-effects. Regional techniques (e.g. femoral or digital nerve blockade or local anaesthetic infiltration) are also used in awake children with trauma or for minor surgery. Other procedures (e.g. division of prepucial adhesions, removal of skin lesions, percutaneous tenotomy) are also possible under topical anaesthesia alone. Recently, blockade of specific peripheral nerves in preference to neuroaxial techniques (e.g. caudal block) has been advocated to reduce the risk of catastrophic complications (e.g. intravascular or subarachnoid injection of local anaesthetic, extensive neurological damage). Catheters can also be inserted for some peripheral techniques (e.g. fascia iliaca or sciatic nerve blockade) to extend the duration of analgesia.

Managing postoperative pain in children usually involves systemic analgesics, often combined with local anaesthetic techniques. Systemic analgesia is commonly administered by the oral, rectal or intravenous routes; less commonly, the buccal or subcutaneous routes are used. Generally, transdermal, intranasal and intramuscular administration are not used postoperatively.

Spinal anaesthesia is the injection of local anaesthetic into the subarachnoid space. It is a simple technique that can be used to provide surgical anaesthesia for procedures involving the abdomen, pelvis and lower limbs. To perform the technique safely it is important to understand the physiology of the block and the pharmacology of the drugs commonly used. Although serious complications are rare, they must be recognized and managed quickly.

Adjuvant drugs are agents that, when co-administered with local anaesthetic agents, may improve the speed of onset, the quality and/or duration of analgesia. A wide range of drugs have been assessed for both neuraxial and peripheral nerve blocks. Here, we review the adjuvants used in clinical practice in the UK and also briefly mention other drugs that have been used for neuraxial administration to provide perioperative analgesia.

In 1898, the first subarachnoid blockade in man was performed by Karl August Bier using a cocaine solution. From 1930 to 1950, spinal techniques were used widely for anaesthesia, but subsequently declined in popularity, partly because of the fear of toxicity and partly owing to the improvements in general anaesthesia that occurred at the time. Epidural anaesthesia was described by Sicard and Cathelin in 1901, but did not become popular until after World War II with the introduction of amide local anaesthetic agents and catheters that allowed replenishment of the block. Since 1960, there has been a resurgence of these regional techniques and subarachnoid and epidural anaesthesia and analgesia are used widely in current clinical practice.

The muscles of the anterior abdominal wall comprise rectus femoris, external and internal oblique and transverse abdominis. They flex the trunk, raise the intra-abdominal pressure (forcible expiration, initiation of micturition, defecation and parturition) and protect the viscera in blunt trauma. The lateral muscles end medially in aponeuroses, which enclose rectus in the rectus sheath; through most of its length this is formed by the split aponeurosis of internal oblique with external in front and transversus aponeurosis behind. However, at its distal extremity, all three aponeuroses pass anteriorly. This forms a gap that enables the inferior epigastric vessels to enter the posterior sheath. The superior epigastric vessels enter the posterior sheath above, and the two sets of vessels form an important anastomosis between the subclavian above and the external iliac vessels inferiorly. The rectus sheath is firmly adherent to the rectus in front but loosely behind. This allows local anaesthetic solution to pass up and down freely in the posterior sheath in an abdominal field block. The anterior abdominal wall and its muscles are supplied by the anterior primary rami of T7 to L1.

Intravenous regional anaesthesia (IVRA) was first described almost a century ago by August Bier and has been used for the past 50 years. It is a safe anaesthetic technique for upper or lower distal limb surgery. It utilizes a tourniquet, ideally a double tourniquet, followed by exsanguination of the appropriate limb after insertion of a cannula, through which local anaesthetic is injected. Anaesthesia and analgesia follow rapidly, the tourniquets preventing systemic local anaesthetic toxicity as well as fixing the local anaesthetic to where it is required. The safest local anaesthetic is prilocaine 0.5%. Lidocaine 0.5% can also be used. Several adjuvants have been described to prolong anaesthesia time and reduce tourniquet pain.

Arthur Barker developed his glass spine (a glass tube bent to represent the space in the spinal column containing the spinal cord and the cerebrospinal fluid) to view the behaviour of different local anaesthetic solutions. He tested three solutions of local anaesthetic each with a different specific gravity. He is thought to have been the first person to use glucose with the local anaesthetic in the injection fluid.