In probes we trust? Saturation accuracy between two oximeter probes and arterial blood gas in a pediatric intensive care unit

Abstract

Background: Transcutaneous oxygen saturation (SpO2) is used daily clinically to measure/monitor blood oxygen levels. Recent research indicates oximeter probe readings poorly correlate with arterial blood gas (ABG) values. The aim of this study was to assess the accuracy of Masimo (M) and Nellcor (N) probes compared to ABGs in the pediatric intensive care unit (PICU). Methods: SpO2 values were prospectively collected/validated along with ABGs in children 0-16 years old with an arterial line at the Lady Cilento Children's Hospital PICU. M and N oximeter probes were placed on the same limb as the arterial line, and values were compared with ABGs. ANZPIC diagnosis codes, inotropes, respiratory disease/support, cardiovascular disease severity/support, volume status, and perfusion status were collected. Results: A total of 3,802 events of matched M and N SpO2 and ABGs were documented in 333 patients. Eighty-five patients had principal postoperative cardiac surgery diagnoses, 29 had cardiac diagnoses, and 219 had noncardiac diagnoses. Bland-Altman plot statistics showed the mean percentage differences between the M and N probes and ABG were 1.50-4.50 (range,-36-50, 95% confidence interval [CI] 1.45-1.55) and 0.57-4.97 (range,-77-47, 95% CI 0.53-0.61), respectively. Overall, 12% M and 15% N SpO2 values lay outside a clinically acceptable-5% ABG, with approximately 10% of those >5%. In cardiac surgery patients, 11% M and 12% N values were outside-5% of ABG (9% of both probes >5%). In cardiac patients, 12% M and 14% N values were outside-5% of ABG (10% and 9% >5%, respectively). In noncardiac patients, 14% M and 17% N values were outside-5% ABG (12% of values >5%). Conclusion: Despite overall good statistical agreement between SpO2 and ABG, the results indicated an unacceptable 10% of SpO2s overestimated ABG by >5%. Important clinical decisions for short-and long-term management are based on SpO2 measurement. Hence, an urgent improvement of the technology is needed.L6213533222018-03-27 <br />