title: Propofol concentrations in whole blood: influence of anticoagulants and storage time.
abstract: Blood samples for propofol determination are collected with oxalate, heparin and EDTA, but we have not found any study comparing the influence of those anticoagulants on propofol concentrations. This study was carried out on 50 samples from patients taking propofol for anesthesia or cerebral protection. First, 26 samples were simultaneously collected into tubes containing lithium heparin or sodium fluoride potassium oxalate as anticoagulant. In a second investigation, 24 samples were simultaneously collected into tubes containing heparin or EDTA. Propofol was assayed by HPLC 2 days after sampling and 2 weeks later. In the first assay, propofol concentration in samples collected with heparin were similar to those collected with oxalate (3.65 +/- 3.50 vs. 3.62 +/- 3.49 mg/l, ns) or EDTA (3.89 +/- 2.58 vs. 3.84 +/- 2.67 mg/L, ns). After storing for 2 weeks at 4 degrees C, propofol concentrations were slightly but insignificantly higher than in the first assay in samples collected with heparin (3.58 +/- 3.24 vs. 3.40 +/- 2.92 mg/l, ns), slightly higher in samples with oxalate (3.86 +/- 3.49 vs. 3.62 +/- 3.49 mg/l, p = 0.06), and slightly but significantly lower in samples with EDTA (3.63 +/- 2.67 vs. 3.84 +/- 2.67 mg/l, p < 0.05). It is concluded that the three anticoagulants used in this study seem to be suitable for determination of propofol concentration in whole blood, and that the stability of propofol concentration when samples are stored at 4 degrees C for up 2 weeks is acceptable.
authors.affiliation: Clinical Pharmacology Service, University of Cantabria School of Medicine, Santander, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Cuadrado
authors.forename: G
authors.initials: G
authors.lastname: Solares
authors.forename: S
authors.initials: S
authors.lastname: González
authors.forename: B
authors.initials: B
authors.lastname: Sánchez
authors.forename: J A
authors.initials: JA
authors.lastname: Armijo
mesh_terms: D000925:Anticoagulants; D001793:Blood Preservation / Q000379:methods*; D004492:Edetic Acid; D006493:Heparin; D006801:Humans; D010070:Oxalates; D015742:Propofol / Q000097:blood*; D013997:Time Factors
chemical_list: D000925:Anticoagulants; D010070:Oxalates; D006493:Heparin; D004492:Edetic Acid; D015742:Propofol