Collins J L, Lutz R J
Clinical Center, National Institutes of Health, Bethesda, MD 20892.
Heart Lung. 1991 May;20(3):271-7.
Multilumen catheters are commonly used to simultaneously administer incompatible drugs to critically ill patients. Though there are no known documented reports that this practice has been responsible for harmful events in patients, likewise there are no published data to verify the safety and efficacy of this practice. This study utilized an in vitro model flow system to examine the physicochemical phenomena that occur when two incompatible drugs (phenytoin and total parenteral nutrition) are simultaneously administered through multilumen catheters. Flow conditions and drug infusions in the venous model were designed to mimic the in vivo clinical situation to evaluate two central venous catheter types, a double- and a triple-lumen catheter. Video recordings were made of drug interactions, and assays of phenytoin concentration were performed on samples of the circulating fluid. White clouds of phenytoin precipitation were observed near the tip of the double-lumen catheter but not the triple-lumen catheter. Infusion through the double-lumen catheter resulted in an average of 6% loss of phenytoin to precipitate, which, on microscopic examination, appeared as spindle-shaped crystals 25 to 50 microns in length and 5 to 10 microns wide. In some cases, millimeter-size fragments of phenytoin precipitate were seen to dislodge from the tip of the double-lumen catheter. The adjacent orifices at the tip of the end hole of the double-lumen catheter appeared to permit interaction of the two effusing streams of the incompatible drugs, whereas the staggered orifices of the triple-lumen catheter reduce this interaction.(ABSTRACT TRUNCATED AT 250 WORDS)
多腔导管常用于同时为重症患者输注不相容的药物。尽管尚无已知的文献报道这种做法会导致患者出现有害事件，但同样也没有已发表的数据来证实这种做法的安全性和有效性。本研究利用体外模型流动系统，来研究当两种不相容药物（苯妥英和全胃肠外营养）通过多腔导管同时输注时所发生的物理化学现象。静脉模型中的流动条件和药物输注设计为模拟体内临床情况，以评估两种中心静脉导管类型，即双腔导管和三腔导管。对药物相互作用进行了视频记录，并对循环液样本进行了苯妥英浓度测定。在双腔导管尖端附近观察到了苯妥英沉淀的白色云雾，但在三腔导管中未观察到。通过双腔导管输注导致平均6%的苯妥英沉淀损失，经显微镜检查，沉淀呈现为长度25至50微米、宽度5至10微米的纺锤形晶体。在某些情况下，可见毫米大小的苯妥英沉淀碎片从双腔导管尖端脱落。双腔导管末端孔尖端相邻的孔口似乎允许不相容药物的两股流出液相互作用，而三腔导管交错排列的孔口则减少了这种相互作用。（摘要截取自250字）
