Comparison of sampler filling times among selected arterial blood samplers.

BACKGROUND True arterial blood samples are essential in making clinical decisions for respiratory patients. Previous studies using only the Portex Pro-Vent arterial sampler have shown a significant difference between arterial and venous filling times. The goal of this study was to determine whether there is a statistically significant difference between sampler filling times measured at a normal mean arterial pressure among multiple arterial samplers with plungers and to determine whether there is a statistically significant difference in filling times between venous and normal mean arterial pressures for a sampler without a plunger. METHODS We assembled an extracorporeal laboratory model to circulate a synthetic compound composed of 0.9% sodium chloride solution and Life/form artificial blood, and we used hemostats to create pressures within the circuit. We randomly selected samplers and measured the filling times of 4 arterial samplers with plungers at a normal mean arterial pressure (93 ± 1 mm Hg). We also measured the filling time of one arterial sampler without a plunger at a normal mean arterial pressure and at a simulated venous pressure (9 ± 2 mm Hg). We used the Kruskal-Wallis one-way analysis of variance to compare arterial filling times in samplers, and we used a t test for independent samples to compare venous and arterial filling times in the sampler without a plunger. RESULTS There was a statistically significant difference between sampler filling times among the 4 arterial samplers with a plunger (P < .001). There was a statistically significant difference between arterial and venous pressure filling times for the sampler without a plunger (P < .001). CONCLUSIONS Although there was a statistically significant difference between arterial filling times among various samplers with plungers, the difference was < 1 s and was not deemed clinically important. Regardless of the sampler brand being used, respiratory therapists and other clinicians performing arterial punctures can use sampler filling time to identify a successful arterial puncture while drawing blood.