1. Deidra Huckabee MSN, RN, CCRN

2. Research Question Medical ICU staff inquired about the accuracy of utilizing the bedside Point of Care Testing (POCT) analyzer and standard laboratory analysis of samples transported via Pneumatic tube system

3. Rationale POCT assessment of arterial blood gases is an increasingly common method of measurement for guiding ventilator management in ICU’s.

4. Rationale The team observed discrepancies in PaO2 values between our POCT analyzer (the i- Stat) and blood gas specimens transported to our laboratory via the pneumatic tube system (PTS).

5. Rationale The purpose of this study was to determine accuracy of PaO2 values obtained via: POCT analyzer PTS system Hand delivery to the laboratory

6. Methods The project took place in the Medical ICU in 2 stages Stage 1 12 patient blood gases were analyzed per bedside i-Stat and by a blood specimen to be tested in the lab.

7. Methods Stage 1 12 patient blood gases were analyzed per bedside i- Stat and by a blood specimen to be tested in the lab. After evaluation 8 of the 12 specimens has PaO2 difference great than 10mmHg This was considered clinically significant and moved the analysis into the next stage

8. Method Stage 2 18 samples were drawn from different patients with three different types of testing: Bedside i-Stat Sending blood gas to the lab Walking blood gas to the lab

9. Results The results were obtained via a two-sided, dependent paired t-test The largest variation in PaO2 results was found between samples sent via PTS versus POCT and specimens walked to the laboratory.

10. Results The mean difference between POCT analysis and samples sent via PTS was 18.4 mm Hg (95% Cl 9.4-27.4mmHg) The mean difference between walked samples and PTS samples was 9.7 mmHg ( 95% Cl 5.9-13.5 mmHg)

11. Results The results were obtained via a two-sided, dependent paired t-test The specimens that were tested at the bedside using an i-Stat monitor and the specimen walked to the lab had similar PaO2 results. The specimen sent through PTS has consistent higher PaO2 results than the other 2 methods

12. Conclusion Arterial blood gas samples sent via PTS have more PaO2 variability in PaO2 results than samples tested using POCT or walked to the lab.

13. Why? May be due to air bubbles which are mixed in the sample when transported via PTS This theory is also supported by the observation of consistently lower PaO2 values obtained via POCT which might avoid the introduction of microscopic air resulting from transport

14. Change in Practice MUHA now has a policy in place for all ICU’s to tube blood gas testing via POCT or walk them to the lab to obtain the most accurate results.