Infiltration anaesthesia

The use of local anaesthetics outside specialized surgical or anaesthetical practice is usually limited to infiltration anaesthesia, different surface anaesthetic methods, and (nerve) block of fingers and toes. Lo-... 

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. 

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. 

Prilocaine is suitable for most types of local anaesthetic block but is not suitable for epidural use in obstetrics because of the need for repeat administration. Its main uses are for infiltration anaesthesia and intravenous regional anaesthesia where its low toxicity makes it the drug of choice. Levobupivacaine... 

Infiltration anaesthesia, to paralyse the sensory nerve endings and small cutaneous nerves... 

Krasowski M D, Nishikawa K, Nikolaeva N et al 2001 Methionine 286 in transmembrane domain 3 of the GABAa receptor beta subunit controls a binding cavity for propofol and other alkylphenol general anesthetics. Neuropharmacology 41 952-964 Kristinsson J, Thordarson T H, Johannesson T 1996 Pharmacokinetics of lignocaine in Icelandic horses after infiltration anaesthesia. Veterinary Record 138 111-112... 

Dose For infiltration anaesthesia 1% for nerve block anaesthesia 1 and 2% solution andfor topical application to skin and mucous membranes 1 to 5%. 

Lignocaine injections are indicated for production of local or regional anaesthesia by infiltration techniques such as percutaneous injection, peripheral nerve block, spinal or subarachnoid block. 

It is a potent and long acting local anaesthetic used for spinal, infiltration, epidural anaesthesia and nerve block. 

Adrenaline along with local anaesthetics may be used for infiltration, nerve block and spinal anaesthesia for prolonging the action and to reduce the systemic toxicity of local anaesthetics. 

Local anaesthetics can be applied topically, deposited around peripheral nerves, or infiltrated into tissues. Central neural blockade can be produced by injection into the subarachnoid or epidural spaces. Less common uses are for intravenous regional anaesthesia and attenuation of cardiovascular responses to tracheal intubation. The membrane-stabilising effect of local anaesthetics has been utilised in the treatment of myocardial arrhythmias. 

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. 

It is one of the least toxic and most commonly used local anaesthetics. The salient features for its wide popularity may be attributed due to its lack of local irritation, minimal systemic toxicity, longer duration of action, and low cost. It can be effectively used for causing anaesthesia by infiltration, nerve block, epidural block or spinal anaesthesia. In usual practice it is used in a solution containing adrenaline (1 50,000) which exerts and modifies the local anaesthetic activity through retarded absorption, and the duration of action is considerably prolonged. 

It is an all-purpose local anaesthetic drug used frequently in surface infiltration, block, caudal and spinal anaesthesia. It is reported to be 10 times more toxic and potent than procaine, whereas its duration of action is twice than that of procaine. 

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. 

It is one of the most toxie, most potent and longest aeting of the frequently used loeal anaesthetics. It may be used as infiltration, surfaee, epidural and spinal anaesthesia. It finds its use in dentistry. Its anaesthetie aetivity is similar to those of proeaine or eoeaine when injected. However, it is several times more potent than proeaine when injeeted subeutaneously and about 5 times more toxie than cocaine when injected intravenously. 

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. ... 

Liver biopsies showed moderate to severe fatty infiltration, thereby possibly increasing uptake of methoxyflurane and exposed more methoxyflurane to hepatic microsomal enzymes [208]. Control halothane-nitrous oxide anaesthesia with 12 obese patients led to a peaking in the serum fluoride level after 3 h anaesthesia (10.4 1.5 /tmol dm" ) [208]. 

Fig. 152. Microglial cell infiltration in the granule layer of the cerebellum (block 4766) of a 221 g female rat (N0.668) medicated with 5,000 ppm molsidomine added to the food (powdered Altromin R) from July 17/18, 1978 to November 30, 1978. After discontinuation of the medication for 7 weeks, under pentobarbital anaesthesia (30 mg/kg), the animal was perfused from the abdominal aorta with 2.5 % glutaraldehyde in 0.1 M sodium cacodylate buffer (pH 7.4). Postfixation with 1 % osmium tetroxide in sodium cacodylate buffer. Embedded in Epon 812 and sectioned at 50 nm. Lead citrate and uranyl acetate. Film 182/79...

If an infiltration type of anaesthetic injection is used, a great deal of bloody oozing can be prevented by adrenaline injection, while at the same time an increased duration of anaesthesia is obtained. 

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