• Norma A Metheny, Emily M Gunn, Cynthia S Rubbelke, Terrilynn Fox Quillen, Uthayashanker R Ezekiel, and Kathleen L Meert.
• Norma A. Metheny is a professor at St Louis University School of Nursing, St Louis, Missouri. She has conducted tube feeding research over the past 25 years. methenna@slu.edu.
• Crit Care Nurse. 2017 Jun 1; 37 (3): 50-58.

BackgroundLittle is known about characteristics of colorimetric pH test strips that are most likely to be associated with accurate interpretations in clinical situations.ObjectivesTo compare the accuracy of 4 pH test strips with varying characteristics (ie, multiple vs single colorimetric squares per calibration, and differing calibration units [1.0 vs 0.5]).MethodsA convenience sample of 100 upper-level nursing students with normal color vision was recruited to evaluate the accuracy of the test strips. Six buffer solutions (pH range, 3.0 to 6.0) were used during the testing procedure. Each of the 100 participants performed 20 pH tests in random order, providing a total of 2000 readings. The sensitivity and specificity of each test strip was computed. In addition, the degree to which the test strips under- or overestimated the pH values was analyzed using descriptive statistics.ResultsOur criterion for correct readings was an exact match with the pH buffer solution being evaluated. Although none of the test strips evaluated in our study was 100% accurate at all of the measured pH values, those with multiple squares per pH calibration were clearly superior overall to those with a single test square.ConclusionsTest strips with multiple squares per calibration were associated with greater overall accuracy than test strips with a single square per calibration. However, because variable degrees of error were observed in all of the test strips, use of a pH meter is recommended when precise readings are crucial.©2017 American Association of Critical-Care Nurses.

15 keywords...

hide…