[abstract] ACCURACY OF INFUSION PUMP DURING HYPERBARIC OXYGEN THERAPY

Abstract

INTRODUCTION: Some infusion pumps may be unreliable under hyperbaric oxygen therapy (HBO) conditions. We evaluated the influence of different ambient pressures and compression times on two different examples of one type of syringe infusion pump (Top Inst., Tokyo). METHODS: Two pumps and glass measuring devices were set in a multiplace HBO chamber. Compression time was 10 or 15 min, duration of the hyperbaric (2.0 or 2.5 ATA) plateau 30 min, and decompression time 15 min. After HBO, we continued observations for another 30 min. We also checked flow rate at 1 ATA (with a 10- or 15-min "pseudocompression" phase). Nominal flow rate was 10 ml/h. Each measurement duration was 15 min (10 min when compression time was 10 min). Actual flow rate was expressed as a percentage [mean (SD)] of the nominal flow rate during each phase (P-1 through P-7). Statistically [repeated-measures ANOVA followed by multiple analysis (Bonferroni/Dunn method)], P less than 0.05 indicated significance. RESULTS: Fourteen trials were conducted for each HBO pattern. In the 1.0 ATA groups, there were no significant differences in mean flow rate with time [range, 99.3 (2.3)percent to 107 (3.3)percent]. In the 2.0 ATA and 2.5 ATA groups, significant differences were seen with time (repeated-measures ANOVA). Flow rates were significantly decreased during the 10-min compression phase [versus the precompression period (multiple comparison)] in the 2.0 ATA and 2.5 ATA groups, the rates being 93.9 (4.5)percent, and 92.6 (5.1)percent, respectively. Similarly, significant decreases were seen during the 15-min compression phase, the corresponding values being 96.0 (4.8)percent and 94.2 (2.5)percent, respectively. In the plateau and post-plateau phases, significant changes in flow rates (versus the precompression period) were not observed. CONCLUSIONS: Under the present HBO conditions, the output of this syringe pump was reduced during the compression phase, although the decrease was within 10percent. Accuracy, Infusion pump, Hyperbaric oxygen therapy