AIMS: The nature and incidence of errors in prescribing and giving medicines have previously been estimated by trained observers, or by retrospective analysis of incidents in which patients have come to harm. We have examined prospectively in routine clinical practice the concentrations of intravenous infusions of a drug (acetylcysteine) which is given according to a complicated dosing schedule. METHODS: We prospectively collected samples before and, where possible, after the infusion of acetylcysteine in 66 anonymous patients requiring treatment for acetaminophen (paracetamol) overdose in four centres in the United Kingdom. We measured the concentration in each infusion bag, and deduced from the weight of the patient the percentage of the anticipated dose that had actually been given. RESULTS: The experimentally determined dose was within 10% of the anticipated dose in 68 of 184 individual bags (37%), and within 20% of the anticipated dose in 112 bags (61%). Doses in 17 bags were more than 50% from the anticipated doses. In three patients, values in all three bags appeared to be systematically wrong by 50% or more; in a further seven cases, individual bags differed by 50% or more from the anticipated value. The median difference between pre- and post-infusion samples was 0% [interquartile range -5.2% to +14.6%], but 9% showed a disparity of greater than +/- 50%. CONCLUSIONS: Our data suggest that there is large random variation in administered dosage of intravenous infusions. Systematic calculation errors occur in about 5% [95% confidence interval 2, 8%] of cases, and major errors in drawing up in a further 3% [1, 7%], with inadequate mixing in 9% [4, 14%]. While we have no evidence that patients were adversely affected, and while the regime of administration of the drug studied (acetylcysteine) is complicated, these data suggest that the delivered dose often deviates from the intended dose, and that methods of quality control are needed.
AIMS: The nature and incidence of errors in prescribing and giving medicines have previously been estimated by trained observers, or by retrospective analysis of incidents in which patients have come to harm. We have examined prospectively in routine clinical practice the concentrations of intravenous infusions of a drug (acetylcysteine) which is given according to a complicated dosing schedule. METHODS: We prospectively collected samples before and, where possible, after the infusion of acetylcysteine in 66 anonymous patients requiring treatment for acetaminophen (paracetamol) overdose in four centres in the United Kingdom. We measured the concentration in each infusion bag, and deduced from the weight of the patient the percentage of the anticipated dose that had actually been given. RESULTS: The experimentally determined dose was within 10% of the anticipated dose in 68 of 184 individual bags (37%), and within 20% of the anticipated dose in 112 bags (61%). Doses in 17 bags were more than 50% from the anticipated doses. In three patients, values in all three bags appeared to be systematically wrong by 50% or more; in a further seven cases, individual bags differed by 50% or more from the anticipated value. The median difference between pre- and post-infusion samples was 0% [interquartile range -5.2% to +14.6%], but 9% showed a disparity of greater than +/- 50%. CONCLUSIONS: Our data suggest that there is large random variation in administered dosage of intravenous infusions. Systematic calculation errors occur in about 5% [95% confidence interval 2, 8%] of cases, and major errors in drawing up in a further 3% [1, 7%], with inadequate mixing in 9% [4, 14%]. While we have no evidence that patients were adversely affected, and while the regime of administration of the drug studied (acetylcysteine) is complicated, these data suggest that the delivered dose often deviates from the intended dose, and that methods of quality control are needed.
Authors: D W Bates; L L Leape; D J Cullen; N Laird; L A Petersen; J M Teich; E Burdick; M Hickey; S Kleefield; B Shea; M Vander Vliet; D L Seger Journal: JAMA Date: 1998-10-21 Impact factor: 56.272
Authors: W B Runciman; A Sellen; R K Webb; J A Williamson; M Currie; C Morgan; W J Russell Journal: Anaesth Intensive Care Date: 1993-10 Impact factor: 1.669
Authors: L L Leape; D W Bates; D J Cullen; J Cooper; H J Demonaco; T Gallivan; R Hallisey; J Ives; N Laird; G Laffel Journal: JAMA Date: 1995-07-05 Impact factor: 56.272
Authors: Carola Dehmel; Stephan A Braune; Georg Kreymann; Michael Baehr; Claudia Langebrake; Heike Hilgarth; Axel Nierhaus; Dorothee C Dartsch; Stefan Kluge Journal: Intensive Care Med Date: 2011-04-30 Impact factor: 17.440
Authors: Kerry Layne; Louise Hope; Edmund Rab; John Archer; David M Wood; Paul I Dargan Journal: Br J Clin Pharmacol Date: 2018-11-08 Impact factor: 4.335