Katz L, Johnson D L, Neufeld P D, Gupta K G
Can Med Assoc J. 1975 Aug 9;113(3):208-13.
Five cases of nosocomial infection caused by Serratia marcescens were traced to backflow of blood from nonsterile evacuated blood-collection tubes. The mechanism of backflow was investigated theoretically and the conditions were determined under which backflow can occur. The theory was confirmed by experiments conducted on a simulated venous system and by measurements of the venous pressure in the brachial vein of a patient during application and removal of a tourniquet. Various possible solutions to the backflow hazard include strict adherence to correct venipuncture technique, sterilization of all blood-collection tubes, improvement of the vacuum in the tubes and incorporation of a check valve into the system.
五例由粘质沙雷氏菌引起的医院感染被追溯到来自未消毒的真空采血管的血液回流。从理论上研究了血液回流的机制，并确定了可能发生回流的条件。通过在模拟静脉系统上进行的实验以及在给患者上臂静脉扎上和松开止血带期间对静脉压力的测量，证实了该理论。针对回流风险的各种可能解决方案包括严格遵守正确的静脉穿刺技术、对所有采血管进行消毒、提高采血管的真空度以及在系统中加入止回阀。
