BNF for Children 2011-2012

650 15.2 Local anaesthesia BNFC 2011–201215 AnaesthesiaContra-indications of local anaesthetics Localanaesthetics should not be injected into inflamed orinfected tissues nor should they be applied to damagedskin. In such circumstances, increased absorption intothe blood increases the possibility of systemic sideeffects,and the local anaesthetic effect may also bereduced by altered local pH. See also Use of Vasoconstrictors,p. 649.Local anaesthetic preparations containing preservativesshould not be used for caudal, epidural, or spinal block,or for intravenous regional anaesthesia (Bier’s block).Local anaesthetics can cause ototoxicity and should notbe applied to the middle ear. They are also contraindicatedin children with complete heart block.Toxicity and side-effects A single application of atopical lidocaine preparation does not generally causesystemic side-effects. Toxic effects after administrationof local anaesthetics are a result of excessively highplasma concentrations; severe toxicity usually resultsfrom inadvertent intravascular injection or too rapidinjection.The systemic toxicity of local anaesthetics mainlyinvolves the central nervous and cardiovascular systems.CNS effects include a feeling of inebriation andlightheadedness followed by drowsiness, numbness ofthe tongue and perioral region, restlessness, paraesthesia(including sensations of hot and cold), dizziness,blurred vision, nausea and vomiting, muscle twitching,tremors, and convulsions. Transient excitation may alsooccur, followed by depression with drowsiness, respiratoryfailure, unconsciousness, and coma. Effects on thecardiovascular system include myocardial depressionand peripheral vasodilatation resulting in hypotensionand bradycardia; arrhythmias and cardiac arrest canoccur.Hypersensitivity reactions occur mainly with the estertypelocal anaesthetics, such as tetracaine; reactions areless frequent with the amide types, such as articaine,bupivacaine, levobupivacaine, lidocaine, mepivacaine,prilocaine, and ropivacaine. Cross-sensitivity reactionsmay be avoided by using the alternative chemical type.ArticaineArticaine is an amide-type local anaesthetic used fordental anaesthesia (see Dental Anaesthesia, p. 649). It isavailable in a preparation that also contains adrenaline(see Use of Vasoconstrictors, p. 649).ARTICAINE HYDROCHLORIDE WITHADRENALINE(Carticaine hydrochloride with adrenaline)Cautions see Cautions of Local Anaesthetics, p. 649and Adrenaline, section 2.7.2Contra-indications see Contra-indications of LocalAnaesthetics, p. 650 and Adrenaline, section 2.7.2Hepatic impairment use with caution; increased riskof side-effects in severe impairmentRenal impairment see Adrenaline, section 2.7.2Pregnancy use only if potential benefit outweighsrisk—no information availableBreast-feeding avoid breast-feeding for 48 hours afteradministrationSide-effects see Toxicity and Side-effects, above andAdrenaline, section 2.7.2; also methaemoglobinaemia(see Prilocaine (p. 653) for treatment)Indication and doseTo avoid excessive dosage in obese children, doseshould be calculated on the basis of ideal weight forheightInfiltration anaesthesia in dentistryChild 4–18 years consult expert dental sources;important: see also Administration, p. 649Septanest c (Septodont) AInjection, articaine hydrochloride 40 mg/mL, adrenaline1 in 200 000 (5 micrograms/mL), net price2.2-mL cartridge = 41pExcipients include sulphitesInjection, articaine hydrochloride 40 mg/mL, adrenaline1 in 100 000 (10 micrograms/mL), net price2.2-mL cartridge = 41pExcipients include sulphitesBupivacaineBupivacaine has a longer duration of action than otherlocal anaesthetics. It has a slow onset of action, takingup to 30 minutes for full effect. It is often used in lumbarepidural blockade and is particularly suitable for continuousepidural analgesia in labour, or for postoperativepain relief. It is the principal drug used for spinal anaesthesia.Hyperbaric solutions containing glucose may beused for spinal block.BUPIVACAINE HYDROCHLORIDECautions see Cautions of Local Anaesthetics, p. 649;myocardial depression may be more severe and moreresistant to treatment; cardiovascular disease; hypertension;hypotension; cerebral atheroma; interactions:Appendix 1 (bupivacaine)Contra-indications see Contra-indications of LocalAnaesthetics, aboveHepatic impairment use with caution in severeimpairmentRenal impairment use with caution in severe impairmentPregnancy large doses during delivery can causeneonatal respiratory depression, hypotonia, andbradycardia after paracervical or epidural block; uselower doses for intrathecal use during late pregnancyBreast-feeding amount too small to be harmfulSide-effects see Toxicity and Side-effects, aboveIndication and doseTo avoid excessive dosage in obese children, doseshould be calculated on the basis of ideal weight forheightAdjusted according to child’s physical status andnature of procedure, seek expert advice—important:see also under Administration, p. 649Bupivacaine (Non-proprietary) AInjection, anhydrous bupivacaine hydrochloride2.5 mg/mL (0.25%), net price 10 mL = 82p; 5 mg/mL(0.5%), 10 mL = 94p