Preliminary evaluation of a point-of-care blood gas-electrolyte analyzer potentially robust in cold during emergencies and disasters: Evidence from evaluation of reagents in stress testing chambers

OBJECTIVE: Our purpose was to evaluate the effects of a dynamic cold profile on the performance of epoc (Alere, Waltham, Mass) test cards for blood gas and electrolyte measurements using quality control (QC) reagents. METHODS: Test cards for the epoc system were stressed under a profile modeling the conditions experienced during the rescue and recovery phase following the 2011 earthquake and tsunami off the Pacific coast of Tōhoku, Japan. Thermally stressed test cards and control test cards stored at room temperature were evaluated in pairs using 3 levels of aqueous QC material (levels 1, 2, and 3). Paired measurements were taken at stress durations of 24, 72, 168 (1 week), 336 (2 weeks), and 672 hours (4 weeks) to determine differences between control and stressed. RESULTS: Wilcoxon signed rank test results identified no difference between stressed and control pairs for each analyte at each QC Level. The Kruskal-Wallis test distinguished 3 analyte groups affected by the duration of stress at QC level 3 (PO2 [P < 0.01], Na [P < 0.01], and K [P < 0.05]). Post hoc analysis of PO2 (P < 0.01), Na (P < 0.01), and K (P < 0.05) time points using the Mann-Whitney U test evaluated with a stricter P value generated by the Holm-Bonferroni method recognized no statistically significant differences between analyte time points. CONCLUSIONS: The epoc test cards do not appear to be affected significantly by the dynamic cold conditions observed during the 2011 Great East Japan Earthquake. Therefore, use of epoc blood gas systems may be feasible and should be explored with field trials.