Chemical stability of heparin, isopropanol, and ethanol line lock solutions

Background: Ethanol line locks are used in the US to prevent catheter associated bloodstream infections. Heparin precipitates in solution with ethanol. However, isopropanol may reduce precipitate formation. We aimed to determine the chemical stability of heparin, isopropanol, and ethanol line lock for a 10 day period at 2–8 °C and 25 °C.<br></br> Methods: Forty samples were prepared for analysis. Each sample was prepared identically using a 5 ml syringe capped with a Combi-stopper: 1 ml 70% isopropanol, 1 ml 70% ethanol, and 1 ml heparin sodium 10 IU/ml. Twenty syringes were stored at 2–8 °C and 20 at 25 °C. Analysis was carried out on days 1, 3, 6, 8, and 10 with a single syringe from each condition being tested in duplicate. Samples were assessed visually. Sub-visible particle count analysis was carried out using a CLIMET particle counting system. Heparin concentration was analysed using an anti-Xa assay. Ethanol and isopropanol concentrations were analysed by gas chromatography.<br></br> Results: Samples remained clear and colourless throughout the study. Sub-visible particle counts remained within limits specified in British Pharmacopoeia 2013 when stored at 2–8 °C and 25 °C, 60% humidity for up to 10 days. There was no significant change in ethanol or isopropanol concentration during the study. However, heparin activity fell by > 10% after 1 day storage and to 65% of original activity after 10 days.<br></br> Conclusions: This study shows that addition of isopropanol to heparin and ethanol prevents precipitation. However, this solution shows a progressive decline in heparin activity over time making it unsuitable for extended shelf life

Distribution of Semen Parameters Among Adolescent Males Undergoing Fertility Preservation in a Multicenter International Cohort

To determine the distribution of semen parameters among adolescent and adult males presenting for fertility preservation. A retrospective, cross-sectional cohort study of adolescent males age 11-19 who underwent semen analysis for fertility preservation at 3 centers in 2 countries with a comparison cohort of adult men presenting for fertility preservation. Prevalence of azoospermia and distribution of semen parameters was compared across groups. A total of 197 adolescents and 95 adults underwent semen analysis for fertility preservation. Azoospermia was present in 17 (8.6%) adolescents and 3 (3.2%) adults. There was decline in the prevalence of azoospermia with increasing age. After exclusion of patients with azoospermia, the adolescent and adult cohorts were comprised of 180 and 92 patients, respectively. Median age at presentation among adolescents vs adults was 16.5years (interquartile range [IQR] 15.2-17.6) and 30.8years (IQR 22.7-43.8), respectively. Median semen volume was 1.0mL (IQR 0.5-2.0) vs 2.5mL (IQR 1.5-3.5), P <.001. Median sperm concentration was 30million/mL (IQR 10-57) vs 39million/mL (IQR 14-57), P = .2. Median sperm motility was 39% (IQR 20-55) vs 45% (IQR 35-55), P = .01. Median total motile sperm count was 11million (IQR 1.4-33) for adolescents vs 29million (IQR 13-69) for adults, P <.001. Young adolescent males had higher prevalence of azoospermia and lower semen parameters compared to adults. In conjunction with physical examination, Tanner stage, and specific clinical context, these data can help to inform patients and their families about potential for fertility preservation, even in very young adolescent patients