Syringe pumps take too long to give occlusion alarm.
The aim of this study was to assess the time needed to trigger an occlusion alarm, and the influence of the type of infusion pump, type and size of the syringe, and the set infusion rate. Forty syringe pumps (20 JMS SP-100 and 20 JMS SP-500 machines) were tested using two types (JMS and Hayat) and two sizes (20 and 50 ml) of syringes at four infusion rates (0.5, 1, 2 and 5 ml x h(-1)). Syringes filled with saline were occluded with a stopcock, and times to activation of the occlusion alarm were recorded. Statistical analysis was performed with Wilcoxon and Mann-Whitney U-tests, P < 0.05 was considered significant. The mean time to alarm activation was longer with lower infusion rates and larger syringes (P < 0.05). We recorded delays up to 117.3 +/- 9.4 min with 50 ml syringe at 0.5 ml x h(-1) and 15.0 +/- 7.1 min at 5 ml x h(-1). Syringe type had no effect on time to alarm activation (P > 0.05). The alarm on the JMS SP-500 pump was activated faster than the JMS SP-100 pump (P < 0.05). Our results showed that activation of occlusion alarms on both pumps takes a considerable time, and that the mean time to alarm activation was longer with low infusion rates and larger syringes. To reduce occlusion alarm delays smaller sized syringes with low compliance should be used and staff be alerted when using low flow rates with highly concentrated potent drugs.