Clinical Use of Continuous Arterial Blood Gas Monitoring in the Pediatric Intensive Care Unit

Context. Continuous arterial blood gas monitoring is a new technology based on the combination of opto-chemical and fiber-optic detectors that can measure pH, Pco 2, Po 2, and temperature on a continuous basis via a sensor placed in an artery. Objective. To evaluate this technology in pediatric patients who would normally require frequent arterial blood gas sampling. Design. A criterion standard study in which the results of arterial blood gas samples measured by the laboratory analyzer were compared with the sensor readings. Setting. A pediatric intensive care unit of a tertiary referral center. Patients. Children with severe respiratory failure who required frequent arterial blood gas sampling and who had a 20-gauge arterial line in either a radial or femoral site. Results. Twenty-four patients with a mean age of 6.4 years (range 1-21 years) had a sensor placed. Sensors were in place for a mean of 101 ± 62 hours. Eighteen patients underwent continuous monitoring for at least 24 hours or until no longer clinically necessary. There were 414 pairs of blood gas samples obtained. The bias/precision for pH was 0.005/0.030; for Pco 2, -1.8/6.3 mm Hg; and for Po 2, 1.2/24 mm Hg. The correlation (r value) between the sensor readings and the blood gases were pH 0.960, Pco 2 0.927, Po 2 0.813 (P <.01 for all values). The bias and precision for Po 2 levels < 70 mm Hg were 0.057/9.34 mm Hg. There were no complications from sensor placement. Continuous blood gas monitoring allowed immediate recognition of clinical changes. Conclusion. The continuous arterial blood gas sensor is capable of clinically accurate blood gas measurements. This technology provides the clinician with immediate data that can allow rapid interventions in unstable patients.