微量泵不同泵入速度堵管率的比较分析

目的探讨微量泵入药物时合适的维管速度。方法选取海南省某医院收治的经留置针持续泵入硝酸甘油治疗的住院患者40例,行自身对照试验,抽签决定试验顺序,分别给予药物泵入速度和维管速度共为7、8、9、15 ml/h,每个速度纳为一组,且每个速度持续泵入8 h,分析比较各个速度的堵管率、药物渗出率及给药时患者的心功能分级（New York Heart Association,NYHA）。结果 8 ml/h组堵管率低于7 ml/h组（χ2=4.02,P=0.045）,9 ml/h组堵管率低于8 ml/h组（χ~2=4.21,P=0.040）,差异均具有统计学意义（P〈0.05）;9 ml/h组堵管率与15 ml/h组比较,无统计学差异（χ2=1.01,P=0.314）;各组药物渗出率（χ~2=3.02,P=0.389）、患者的心功能分级（F=0.63,P=0.600）结果比较,无统计学差异。结论微量泵入药物过程中,当速度〈9 ml/h时,泵入适量的维管液可减少堵管发生;当速度〉9 ml/h时,堵管率不会随泵入速度的增大而降低。

Numerical Modeling of the Solidification Phase Change in a Pipe and Evaluation of the Effect of Boundary Conditions

A numerical solution to a two-dimensional model of flow and transient heat transfer involving solidification in a pipe has been established.Where the temperature of pipe wall is below the freezing point of fluid,phase change of flowing fluid and the influence of different boundary condition,such as pipe wall temperature,initial temperature and inlet velocity has been taken into account.Also it has been investigated to elicit proper non-dimensional numbers to show the solidification proceeding results.Additionally comparing the two acceptable inlet conditions,show distinctions between velocity inlet and pressure inlet boundary condition in such problems,which affect the whole freezing process.