Lidocaine anaesthesia

Infiltration anaesthesia is applied fan-shaped, with as few needle punctures as possible, in close proximity of the wound or the skin area to be treated. An aspiration should always take place to avoid intravascular injection. Suitable alternatives are lidocaine (lignocaine) or prilocaine for injection 5-10 mg/ml, with or without adrenaline. When making an incision of an abscess it is sometimes difficult to use a local anaesthetic if there is a pronounced inflammatory reaction, since the effect of the anaesthetic is reduced due to an increased acidity level. While adrenaline reduces bleeding and delays dispersion of the anaesthetic, local anaesthetic/adrenaline combinations are contraindicated for local anaesthesia of digits, on the face or where the skin survival is at risk. 

Nerve block anaesthesia in general practice mostly concerns finger or toe blocks. Lidocaine or prilocaine, 10 mg/ml without adrenaline (norepinephrine), is used and is injected on each side of the finger or toe, in two portions by the four nerve branches. Injection of larger volumes than 1-2 ml/side carries a risk of ischaemia because of the firm tissue. The transport through the nerve sheath takes a few minutes, and for a satisfactory result one should wait 5-10 minutes before the planned intervention starts. 

III.b.8.1. Skin. Surface anaesthesia of the skin can be produced with help of a cream containing a eutectic mixture of local anaesthetics (EMLA), which is a water/oil emulsion of equal parts of prilocaine and lidocaine with particularly good penetration capacity. EMLA is applied under occlusion, around 40-60 minutes before the planned intervention. This is an effective way of producing anaesthesia before needle punctures and minor, painful, procedures. The method is excellent, particularly in paediatrics, to reduce fear and pain. 

III.b.8.3. Eye. When removing foreign bodies from the eye a short acting surface anaesthesia can be produced by lidocaine 40 mg/ml, oxybuprocaine 4 mg/ml or tetracaine (amethocaine) 5 mg/ml. Welding flash burns or corneal injuries can be treated with cinchocaine cream. 

Intra-arterial injection of thiopentone is a serious complication as crystals of the thiobarbiturate can form in the arterioles and capillaries, causing intense pain, vasoconstriction, thrombosis, and even tissue necrosis. Accidental intra-arterial injections should be treated promptly with intra-arterial administration of a vasodilator (papaverine 20 mg) and lignocaine (lidocaine) Note leave the needle/cannula in the artery), as well as a regional anaesthesia-induced sympathectomy (stellate ganglion block, brachial plexus block) and anticoagulation with intravenous heparin. The risk of ischaemic damage is much higher with a 5% solution and the use of this concentration is not recommended. 

Lidocaine is used for all forms of infiltration anaesthesia, in addition to peripheral, regional, spinal and epidural block. Unlike bupivacaine, it is suitable for use in intravenous regional anaesthesia. Duration of anaesthesia is about 1 hour but this can be prolonged to 2 hours by the addition of adrenaline. The maximum doses are shown in Table 5.2. 

Intravenous. A double cuff is applied to the arm, inflated above arterial pressure after elevating the limb to drain the venous system, and the veins filled with local anaesthetic, e.g. 0.5-1% lidocaine without adrenaline (epinephrine). The arm is anaesthetised in 6-8 min, and the effect lasts for up to 40 min if the cuff remains inflated. The cuff must not be deflated for at least 20 minutes. The technique is useful in providing anaesthesia for the treatment of injuries speedily and conveniently, and many patients can leave hospital soon after the procedure. The technique must be meticulously conducted, for if the full dose of local anaesthetic is accidentally suddenly released into the general circulation severe toxicity and even cardiac arrest may result. Bupivacaine is no longer used for intravenous regional anaesthesia as cardiac arrest caused by it is particularly resistant to treatment. Patients should be fasted and someone skilled in resuscitation must be present. 

Prilocaine is used similarly to lidocaine (t,i 1.5 h), but it is slightly less toxic. It used to be the preferred drug for intravenous regional anaesthesia but it is... 

Bupivacaine is long-acting 3 h) (see Table 18.1) and is used for peripheral nerve blocks, and epidural and spinal anaesthesia. Whilst onset of effect is comparable to lidocaine, peak effect occurs later (30 min). 

Local anaesthesia is effected as intracutaneous skin wheal using a thin needle, whereas for bathyanaesthesia a long injection needle is applied. Lidocaine is recommended as an anaesthetic (0.5% or 1.0%). With the continuous injection of anaesthetic, a sharp pain is reached in the peritoneum, where a preperitoneal depot is then placed. 

Similar to Voltaren Emulgel, oily droplets of an eutectic mixture of lidocaine and prilocaine are dispersed in a hydrogel to provide local anaesthesia of the skin for injections and surgical treatment (Emla cream). A further possibility is the dermal administration of a liposome dispersion as a spray (Heparin PUR ratiopharm Spriihgel). After administration, water and isopropyl alcohol evaporate partially to result in an increase of concentration and thereby in a transition from the initial liposome dispersion to a lamellar liquid crystal. The therapeutic effect thus appears to be influenced favorably by the presence of lecithins alone, rather than by the degree of dispersion of liposomes. 

Kaukinen S, Eerola R, Eerola M, Kaukinen L. A comparison of carticaine and lidocaine in spinal anaesthesia. Ann Clin Res 1978 10(4) 191-4. 

Keld DB, Hein L, Dalgaard M, Krogh L, Rodt SA. The incidence of transient neurologic symptoms (TNS) after spinal anaesthesia in patients undergoing surgery in the supine position. Hyperbaric lidocaine 5% versus hyperbaric bupivacaine 0.5%. Acta Anaesthesiol Scand 2000 44(3) 285-90. 

Enlund M, Mentell O, Krekmanov L. Unintentional hypotension from lidocaine infiltration during orthognathic surgery and general anaesthesia. Acta Anaesthesiol Scand 2001 45(3) 294-7. 

Beydon L, Lorino AM, Verra F, Labroue M, Catoire P, Lofaso F, Bonnet F. Topical upper airway anaesthesia with lidocaine increases airway resistance by impairing glottic function. Intensive Care Med 1995 21(ll) 920-6. 

Gisvold SE. Lidocaine may still be an excellent drug for spinal anaesthesia. Acta Anaesthesiol Scand 1999 43(4) 369-70. 

Salazar F, Bogdanovich A, Adalia R, Chabas E, Gomar C. Transient neurologic symptoms after spinal anaesthesia using isobaric 2% mepivacaine and isobaric 2% lidocaine. Acta Anaesthesiol Scand 2001 45(2) 240-5. 

Panadero A, Monedero P, Fernandez-Liesa JI, Percaz J, Olavide I, Iribarren MJ. Repeated transient neurological symptoms after spinal anaesthesia with hyperbaric 5% lidocaine. Br J Anaesth 1998 81(3) 471-2. 

Ostgaard G, Hallaraker O, Ulveseth OK, Flaatten H. A randomised study of lidocaine and prilocaine for spinal anaesthesia. Acta Anaesthesiol Scand 2000 44(4) 436-40. 

Lindh A, Andersson AS, Westman L. Is transient lumbar pain after spinal anaesthesia with lidocaine influenced by early mobilisation Acta Anaesthesiol Scand 2001 45(3) 290-3. 

Kireker HD, Aynacioglu AS, Goksu S. Determination of 0.5% lidocaine serum concentrations and evaluation for toxicity in intravenous regional anaesthesia. Turk Anesteziyol Reanim 2000 28 211-16. 

Local anaesthetics Lidocaine hydrochloride Minims Lignocaine and Fluorescein Local anaesthesia POM medicine for administration (not for sale or supply)... 

It is a local anaesthetic of the amide type which is employed for surface, infiltration and nerve block anaesthesia. Its duration of action is in between the shorter-acting lidocaine and longer-acting mepivacaine. It possesses less vaso-dilator activity than lidocaine and hence may be used without adrenaline. Therefore, solutions of prilocaine hydrochloride are specifically beneficial for such patients who cannot tolerate vasopressor agents patients having cardiovascular disorders, diabetes, hypertension and thyrotoxicosis. 

It is a local anaesthetic used for infiltration, peridural, nerve block, and caudal anaesthesia. It is found to be twiee as potent as procaine. It has been reported that its duration of action is significantly longer than that of lidocaine, even without adrenaline. Henee, it is of particular importance in subjects showing contraindication to adrenaline. 

It is used in dentistry for infiltration and block anaesthesia. Its duration of action as well as potency is almost similar to that of lidocaine. 

The local anaesthetics mentioned in this section are listed in Table 5.1 , (p.91). The interactions discussed in this section mainly involve the interaction of drugs with local anaesthetics used for epidural or spinal anaesthesia. The interactions of lidocaine used asanantiarrhythmicisdealtwith in Antiarrhythmics , (p.243). 

A randomised, double-blind, placebo-controlled study involving 44 patients found that lidocaine epidural anaesthesia (15 mL of 2% plain lidocaine) reduced the MAC of sevoflurane required for general anaesthesia by approximately 50% (from 1.18 to 0.52%). This implies that a lower dose of inhalational anaesthetic provides adequate anaesthesia during combined epidural-general anaesthesia than for general anaesthesia alone. ... 

A study on the use of chloroprocaine 3%, bupivacaine 0.5% or a mixture of chloroprocaine 1.5% with bupivacaine 0.375% in obstetric epidural anaesthesia found that time to onset of analgesia, time to maximum analgesia, and effectiveness of analgesia were similar irrespective of the treatment regimen. Bupivacaine 0.5% alone had a longer duration of action than chloroprocaine or the mixture of anaesthetics. Another study found that lidocaine did not affect the pharmacokinetics of bupivacaine. ... 

Severe hypotension and bradycardia have been seen in patients taking captopril or verapamii when they were given epidurai anaesthesia with bupivacaine. Acute hypotension aiso occurred in a man taking prazosin when he was given epidurai anaesthesia with bupivacaine. Cionidine may increase the duration of caudal block with bupivacaine, aithough there are reports of reduced plasma levels of lidocaine with concurrent cionidine. Verapamil does not appear to interact with epidural lidocaine. 

Twenty patients undergoing surgery were given repeated 1-mg intravenous doses of midazolam as induction anaesthesia every 30 seconds until they failed to respond to three repeated commands to squeeze the anaesthetist s hand. This was considered as the induction end-point titrated dose. It was found that the 10 who had been given prior spinal anaesthesia with tetracaine 12 mg needed only half the dose of midazolam (7.6 mg) than the 10 other patients who had not received tetracaine (14.7 mg). The reasons are not known. The authors of this report simply advise care in this situation. In another study in which patients were given intravenous midazolam following an intramuscular injection of either bupivacaine, lidocaine or saline, it was found that both anaesthetics enhanced the effect of midazolam. This effect was dose-dependent and it was concluded that the use of lidocaine or bupivacaine for regional blocks or local infiltration could alter the effect of midazolam from sedative to hypnotic. ... 

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