title: Sources and magnitude of error in preparing morphine infusions for nurse-patient controlled analgesia in a UK paediatric hospital.
abstract: Background Administering nurse/patient controlled analgesia (N/PCA) to children requires complex dose calculations and multiple manipulations to prepare morphine solutions in 50 mL syringes for administration by continuous infusion with additional boluses. Objective To investigate current practice and accuracy during preparation of morphine N/PCA infusions in hospital theatres and wards at a UK children's hospital. Methods Direct observation of infusion preparation methods and morphine concentration quantification using UV-Vis spectrophotometry. The British Pharmacopoeia specification for morphine sulphate injection drug content (±7.5 %) was used as a reference limit. Results Preparation of 153 morphine infusions for 128 paediatric patients was observed. Differences in preparation method were identified, with selection of inappropriate syringe size noted. Lack of appreciation of the existence of a volume overage (i.e. volume in excess of the nominal volume) in morphine ampoules was identified. Final volume of the infusion was greater than the target (50 mL) in 33.3 % of preparations. Of 78 infusions analysed, 61.5 % had a morphine concentration outside 92.5-107.5 % of label strength. Ten infusions deviated by more than 20 %, with one by 100 %. Conclusions Variation in morphine infusion preparation method was identified. Lack of appreciation of the volume overage in ampoules, volumetric accuracy of different syringe sizes and ability to perform large dilutions of small volumes were sources of inaccuracy in infusion concentration, resulting in patients receiving morphine doses higher or lower than prescribed.
authors: Institute of Pharmaceutical Science, King's College London, 150 Stamford Street, London, SE1 9NH, UK. asia.rashed@kcl.ac.uk.|Pharmacy Department, Evelina London Children's Hospital, Guy's & St. Thomas' NHS Foundation Trust, Westminster Bridge Road, London, SE1 7EH, UK. asia.rashed@kcl.ac.uk.
authors: Asia N
authors: AN
authors: Rashed
authors: Institute of Pharmaceutical Science, King's College London, 150 Stamford Street, London, SE1 9NH, UK. Stephen.Tomlin@gstt.nhs.uk.|Pharmacy Department, Evelina London Children's Hospital, Guy's & St. Thomas' NHS Foundation Trust, Westminster Bridge Road, London, SE1 7EH, UK. Stephen.Tomlin@gstt.nhs.uk.
authors: Stephen
authors: S
authors: Tomlin
authors: Pharmacy Department, Evelina London Children's Hospital, Guy's & St. Thomas' NHS Foundation Trust, Westminster Bridge Road, London, SE1 7EH, UK.
authors: Virginia
authors: V
authors: Aguado
authors: Institute of Pharmaceutical Science, King's College London, 150 Stamford Street, London, SE1 9NH, UK.
authors: Ben
authors: B
authors: Forbes
authors: School of Medicine, Pharmacy and Health, Durham University, Durham, UK.
authors: Cate
authors: C
authors: Whittlesea
mesh_terms: D016058:Analgesia, Patient-Controlled / Q000009:adverse effects* / Q000639:trends; D000701:Analgesics, Opioid / Q000008:administration & dosage / Q000009:adverse effects*; D002648:Child; D002675:Child, Preschool; D004305:Dose-Response Relationship, Drug; D005260:Female; D006776:Hospitals, Pediatric / Q000639:trends; D006801:Humans; D007262:Infusions, Intravenous; D008297:Male; D008508:Medication Errors / Q000517:prevention & control*; D009020:Morphine / Q000008:administration & dosage / Q000009:adverse effects*; D024802:Nurse's Role; D006113:United Kingdom / Q000453:epidemiology
chemical_list: D000701:Analgesics, Opioid; D009020:Morphine
keywords: Analgesia; Children; Medication Error; Morphine; Nurse; Opioid intravenous infusions; Paediatrics; Preparation; United Kingdom