BNF for Children 2011-2012

BNFC 2011–2012 15.1.1 Intravenous anaesthetics 629tous fall in blood pressure unless corticosteroid cover isprovided during anaesthesia and in the immediate postoperativeperiod. Anaesthetists must therefore knowwhether a child is, or has been, receiving corticosteroids(including high-dose inhaled corticosteroids).Other drugs that should normally not be stopped beforesurgery include drugs for epilepsy, asthma, immunosuppression,and metabolic, endocrine and cardiovasculardisorders (but see potassium sparing diuretics, below).Expert advice is required for children receiving antiviralsfor HIV infection. For general advice on surgery inchildren with diabetes, see section 6.1.1.Children taking antiplatelet medication or an oral anticoagulantpresent an increased risk for surgery. In thesecircumstances, the anaesthetist and surgeon shouldassess the relative risks and decide jointly whether theantiplatelet or the anticoagulant drug should be stoppedor replaced with unfractionated or low molecular weightheparin therapy.Drugs that should be stopped before surgery includecombined oral contraceptives (see Surgery, section 7.3.1for details). If antidepressants need to be stopped, theyshould be withdrawn gradually to avoid withdrawalsymptoms. Tricyclic antidepressants need not bestopped, but there may be an increased risk of arrhythmiasand hypotension (and dangerous interactions withvasopressor drugs); therefore, the anaesthetist should beinformed if they are not stopped. Lithium should bestopped 24 hours before major surgery but the normaldose can be continued for minor surgery (with carefulmonitoring of fluids and electrolytes). Potassium-sparingdiuretics may need to be withheld on the morning ofsurgery because hyperkalaemia may develop if renalperfusion is impaired or if there is tissue damage.Anaesthesia and skilled tasks Children and theircarers should be very carefully warned about the risk ofundertaking skilled tasks after the use of sedatives andanalgesics during minor outpatient procedures. Forintravenous benzodiazepines and for a short generalanaesthetic the risk extends to at least 24 hours afteradministration. Responsible persons should be availableto take children home. The dangers of taking alcoholshould also be emphasised.Prophylaxis of acid aspiration Regurgitation andaspiration of gastric contents (Mendelson’s syndrome)can be a complication of general anaesthesia, particularlyin obstetrics and in gastro-oesophageal reflux disease;prophylaxis against acid aspiration is not routinelyused in children but may be required in high-risk cases.An H 2 -receptor antagonist (section 1.3.1) or a protonpump inhibitor (section 1.3.5), such as omeprazole, canbe used before surgery to increase the pH and reducethe volume of gastric fluid. They do not affect the pH offluid already in the stomach and this limits their value inemergency procedures; oral H 2 -receptor antagonistscan be given 1–2 hours before the procedure, but omeprazolemust be given at least 12 hours earlier.Anaesthesia, sedation, andresuscitation in dental practiceFor details see A Conscious Decision: A review ofthe use of general anaesthesia and conscious sedationin primary dental care; report by a groupchaired by the Chief Medical Officer and ChiefDental Officer, July 2000 and associated documents.Further details can also be found in Conscious Sedationin the Provision of Dental Care; report of anExpert Group on Sedation for Dentistry (commissionedby the Department of Health), 2003. Bothdocuments are available at www.dh.gov.uk.Guidance is also included in Standards for DentalProfessionals, London, General Dental Council, May2005 (and as amended subsequently) and ConsciousSedation in Dentistry: Dental Clinical Guidance,Scottish Dental Clinical Effectiveness Programme,May 2006.15.1.1 Intravenous anaestheticsImportantThe drugs in this section should be used by experiencedpersonnel only and when resuscitation equipmentis available.Intravenous anaesthetics may be used either to induceanaesthesia or for maintenance of anaesthesia throughoutsurgery. Intravenous anaesthetics nearly all producetheir effect in one arm-brain circulation time and cancause apnoea and hypotension, and so adequate resuscitativefacilities must be available. They are contraindicatedif the anaesthetist is not confident of beingable to maintain the airway. Extreme care is required insurgery of the mouth, pharynx, or larynx and in childrenwith acute circulatory failure (shock) or fixed cardiacoutput.To facilitate tracheal intubation, induction is usuallyfollowed by a neuromuscular blocking drug (section15.1.5) or a short-acting opioid (section 15.1.4.3).The doses of all intravenous anaesthetic drugs shouldbe titrated according to response (except when using‘rapid sequence induction’). The doses and rates ofadministration should be reduced in those with hypovolaemiaor cardiovascular disease; reduced doses mayalso be required in premedicated children.Total intravenous anaesthesia This is a techniquein which surgery is carried out with all drugs givenintravenously. Respiration can be spontaneous, or controlledwith oxygen-enriched air. Neuromuscular blockingdrugs can be used to provide relaxation and preventreflex muscle movements. The main problem to beovercome is the assessment of depth of anaesthesia.Target Controlled Infusion (TCI) systems can be used totitrate intravenous anaesthetic infusions to predictedplasma-drug concentrations; specific models with paediatricpharmacokinetic data should be used for children.Anaesthesia and skilled tasks See section 15.1.15 Anaesthesia