atheter introducer sets are useful for rapid venoclysis in hypovolemic patients. The introducers with cal-ibre of 8.5 F are superior to those with standard calibre. Our experience showed that both the time for imtro-ducing catheter and fluid flow rate were significntly different between larg-bore catheter and 14-gauge cannula (P<0. 01 ). Catheterization was successful in 20 critical patients