Good Practice in Postoperative and Procedural Pain Management ...

Section 6.0AnalgesiaContents6.1 Analgesia6.2 Local anesthetics6.2.1 Bupivacaine, levobupivacaine, ropivacaine6.2.2 Lidocaine, Prilocaine and EMLA6.2.3 Tetracaine (amethocaine) and Ametop6.3 Neuraxial analgesics6.3.1 Ketamine and clonidine6.4 Opioids6.4.1 Opioid preparations, dosages and routes6.4.2 Opioid toxicity and side effects6.5 Nonsteroidal anti-inflammatory drugs (NSAIDs)6.5.1 NSAID preparations, dose and routes6.5.2 NSAID toxicity and side effects6.6 Paracetamol6.6.1 Paracetamol preparations, doses and routes6.6.2 Paracetamol toxicity and side effects6.7 Nitrous oxide (N 2 O)6.7.1 Preparations, dosage and administration6.7.2 Side effects and toxicity6.8 Sucrose6.8.1 Sucrose dosage and administration6.8.2 Sucrose side effects and toxicity6.9 Nonpharmacological strategiesmore comprehensive prescribing information, summariesof product characteristics, and license status ofspecific agents for children in the UK, please consultresources such as the British National Formulary forChildren (2012) available at http://bnfc.org/bnfc andthe Electronic Medicines Compendium available athttp://emc.medicines.org.uk/.6.2 Local anestheticsMost widely used local anesthetics are amides with theexception of tetracaine (amethocaine), which is an ester(1–4). They all act by reversibly blocking sodium channelsin nerves. They vary in onset, potency, potential fortoxicity, and duration of effect. Formulations are availablefor topical application to mucosae or intact skin,for local installation or infiltration, for peripheral nerveor plexus blockade, for epidural injection or infusion,and for subarachnoid administration. Vasoconstrictorsmay be added to reduce the systemic absorption of localanesthetic and to prolong the neural blockade. Neuraxialanalgesics such as the a-2-agonist clonidine, the phencyclidinederivative ketamine, or opioids such asfentanyl may be co-administered with the local anestheticto prolong the effect of central nerve blocks.6.1 AnalgesiaThis section describes some of the important properties,dosing regimens, interactions, and adverse effectsof analgesics for acute pain in children.Local anesthetics, opioids, NSAIDs, and paracetamolform the pharmacological basis for the majority of analgesicregimens. Ketamine, a dissociative anesthetic withanalgesic properties and clonidine, an alpha-2-agonist,are used to provide systemic or neuraxial analgesiaalone or as adjuncts to other agents. For painful procedures,inhaled nitrous oxide has an important role, andin neonatology intra-oral sucrose solution is used. Theavailability of specific opioids, NSAIDs, and local anestheticscan vary from country to country.The detailed pharmacology and formulations ofthese drugs are available in standard textbooks. For6.2.1 Bupivacaine, levobupivacaine, and ropivacaine(i) Preparations and routesBupivacaine is an amide LA with a slow onset and along duration of action, which may be prolonged bythe addition of a vasoconstrictor. It is used mainly forinfiltration anesthesia and regional nerve blocks, particularlyepidural block, but is contraindicated forintravenous regional anesthesia (Bier’s block). Bupivacaineis a racemic mixture but the S())-isomerlevobupivacaine is also commonly used. A carbonatedsolution of bupivacaine, with faster onset of action, isalso available for injection in some countries. Bupivacaineis used in solutions containing the equivalent of66 ª 2012 Blackwell Publishing Ltd, Pediatric Anesthesia, 22 (Suppl. 1), 1–79