Mayo Block


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An extremely effective field block technique used to provide local anaesthesia to the forefoot for surgical correction of hallux deformity, bunionectomy, and first metatarsal surgery. It anaesthetises the specific nerves of the forefoot that innervate the surgical field, requires less anaesthesia than that of direct local infiltration and does not distort surgical tissue planes

anaesthesia

general or local loss of sensation, due to pharmacological or pathological suppression of nerve function; the syringe should be aspirated prior to the deposition of injectable anaesthetic
  • ankle block anaesthesia the introduction of local anaesthetic (ILA) to nerve trunks supplying the foot as they cross the ankle joint (deep injections to reach the tibial and deep peroneal nerves, and superficial/subcuticular injections to reach the superficial peroneal, sural and saphenous nerves) to achieve whole-foot anaesthesia (see named sites below)

  • Bier's block anaesthesia ILA into the venous circulation of a limb after the application of pressure cuffs inflated to above systolic pressure to prevent venous drainage of the limb, to achieve whole-limb anaesthesia

  • common peroneal block anaesthesia ILA to subcuticular tissue at neck of fibula, to achieve dorsal foot anaesthesia; this injection also causes footdrop that persists for the duration of anaesthesia

  • deep peroneal block anaesthesia ILA to the deep peroneal nerve where it crosses the anterior ankle joint, deep to the extensor retinaculum, to anaesthetize the dorsal area of the first interdigital cleft; the needle is introduced either between tibialis anterior and extensor hallucis longus tendons, passing through the extensor retinaculum to the anterior tibia; or adjacent to dorsalis pedis pulse where the nerve becomes superficial (injection into the adjacent artery is avoided by aspirating the syringe prior to deposition of LA solution)

  • digital block anaesthesia ILA to digital nerves (dorsal/medial; dorsal/lateral; plantar/medial; plantar/lateral) at the base of the toe, to achieve whole-digit anaesthesia

  • epidural anaesthesia ILA into cerebrospinal fluid to anaesthetize all tissues distal to the injection site

  • field block anaesthesia; regional anaesthesia ILA about all nerves subserving part or all of a limb/body region, to achieve anaesthesia of all tissues distal to the injection sites, e.g. ankle block, digital block, popliteal block, epidural anaesthesia

  • first-ray block anaesthesia; Mayo block anaesthesia ILA to branches of the medial plantar, superficial and deep peroneal nerves at the base of the first metatarsal, to achieve anaesthesia of the distal first ray

  • general anaesthesia; GA central suppression of conscious awareness of pain and other sensations, induced by an intravenous anaesthetic agent, and maintained by inhaled agents, often supplemented with muscle relaxants

  • high saphenous nerve anaesthesia ILA to the saphenous nerve at the medial side of the knee joint to achieve anaesthesia of the medial aspect of the lower leg and the medial longitudinal arch

  • infiltration anaesthesia; local infiltration anaesthesia the introduction of a small volume (e.g. 1 mL) of local anaesthetic solution into the subcuticular tissues underlying a skin lesion, to permit painless treatment of the lesion (see bleb)

  • intermetatarsal anaesthesia ILA to branches of the medial and/or lateral plantar, superficial and deep peroneal nerves at the bases of adjacent lesser metatarsals, to achieve anaesthesia of adjacent rays, interposed soft tissues and distal structures

  • local anaesthesia; LA loss of tissue sensation and pain by the injection or topical application (e.g. Emla) of local anaesthetic agents; LAs cause reversible conduction block of sensory, motor and autonomic nerve fibres

  • local infiltration anaesthesia see infiltration anaesthesia

  • Mayo block anaesthesia see first-ray block anaesthesia

  • medial dorsal cutaneous nerve anaesthesia see superficial peroneal block anaesthesia

  • peroneal block anaesthesia see common peroneal block anaesthesia

  • popliteal block injection ILA to the tibial nerve at the superior lateral area of the popliteal fossa, at a point approximately 5 cm proximal to a line joining the medial and lateral condyles and 1 cm lateral to the vertical bisection of the knee joint, i.e. before the nerve trunk divides to form the sural communicating and tibial nerves, in order to achieve anaesthesia of all parts of the lower leg and foot except the medial longitudinal arch; the deep location of the popliteal nerve is identified by a nerve stimulator

  • proximal digital block ILA just proximal to the medial and lateral aspects of the metatarsophalangeal joint to achieve anaesthesia of dorsal and plantar digital nerves just before they divide to form the proper plantar and dorsal digital nerves; the needle is introduced at right angles to dorsal skin to one side of the metatarsal neck and a bolus of LA solution deposited, the needle is advanced through the intermetatarsal soft tissues towards the plantar aspect of the foot and a further bolus of LA solution deposited just deep to the dermoepidermal junction; the plantar tissues will blanch on delivery of the plantar LA bolus

  • ray block ILA to the medial and lateral aspects of a metatarsal, as in intermetatarsal anaesthesia, in order to achieve ray anaesthesia

  • regional anaesthesia see field block anaesthesia

  • ring block anaesthesia see digital block anaesthesia

  • saphenous block injection ILA to saphenous nerve as it crosses the medial/ anterior ankle joint, superficial to the extensor retinaculum, in order to achieve anaesthesia of the medial/plantar longitudinal; the needle is introduced subdermally, medial to tibialis anterior tendon and directed towards the medial border of the ankle, parallel to the skin surface; LA is deposited as a 'sausage' in the subcuticular tissue between the anterior ankle and the medial malleolus

  • spinal anaesthesia reversible block of nerve transmission from all distal tissues by the introduction of local anaesthetic solution into the spinal cord subarachnoid space

  • superficial peroneal anaesthesia; medial dorsal cutaneous nerve anaesthesia ILA to the superficial peroneal nerve (medial dorsal cutaneous nerve) as it crosses the anterior ankle joint, superficial to the extensor retinaculum, to achieve anaesthesia of the majority dorsum of the foot (except the dorsal area of the first interdigital cleft); the needle is introduced subdermally adjacent to the extensor digitorum longus tendons, and directed towards the lateral border of the ankle, parallel to the skin surface; LA is deposited as a 'sausage' within the subcuticular tissue along the anterior ankle

  • sural nerve block anaesthesia ILA to the sural nerve as it crosses the lateral/ posterior ankle joint, superficial to the extensor retinaculum, to achieve anaesthesia of the lateral border of the foot and fifth toe; the needle is introduced subdermally behind the lateral malleolus and the tip of the needle aimed in the direction of the hallux

  • tibial block anaesthesia ILA to the tibial nerve in order to achieve anaesthesia of the plantar surface; anaesthetic solution is deposited around the tibial nerve posterior to the medial malleolus; the needle should pass through the retinaculum to the posterior, directing the tip of the needle toward the little toe; injection into the adjacent tibial artery is avoided by aspirating the syringe before depositing LA solution

  • toe block anaesthesia see digital block anaesthesia