The impact of needle size and angle on rubber coring after multiple puncturing of multi-dose propofol vial rubber stoppers

BACKGROUND: Multiple puncturing of the rubber stoppers of multi-doses vials can produce a rubber core. Propofol is one of the multi-dose anesthesia frequently used for sedation and induction of general anesthesia, and a previous study reported a high incidence of rubber coring in propofol vials but no study has yet reported the factors that affect rubber coring. OBJECTIVE: To investigate the variables which have an impact on rubber core contamination after the puncturing of rubber stoppers of multi-dose propofol vials using various sizes of needles and different angles of piercing. MATERIALS AND METHODS: An experimental study which involved puncturing the rubber stoppers of 50 ml propofol vials with needles of various sizes (18G, 20G, 21G) and at different angles of puncture (45 and 90°). The particles occurred in the vials in each situation were evaluated under the microscope, including the number, width and length. Sizes of the needle and degrees of puncture were evaluated to determine the cause of coring. RESULTS: Rubber coring occurred in 26 out of a total of 150 samples (17.33%). Comparing the incidence of coring by needle size, the 18G needle produced the highest number (38%, P-value < 0.01). Especially, puncturing with 18 gauge needle at 45° (56%, P-value 0.01). CONCLUSION: Large-bore needle was the factor that impacted rubber coring after puncturing through the rubber stopper of the multi-dose vial, regardless of the angle of puncture.