Monitoring of pH and PCO2 in children using the Paratrend 7 in a peripheral vein

Abstract

Purpose: To determine the accuracy of the Paratrend 7 monitor inserted into a peripheral vein in providing continuous measurements of PCO2 and pH in children with respiratory failure. Methods: In a prospective, case series at a University based PICU in a tertiary referral hospital and following informed consent, the Paratrend 7 intra-arterial blood gas monitoring system was inserted through a peripheral intravenous cannula. When clinically indicated, an arterial blood gas (ABG) was obtained. The values of pH and PCO2 from the Paratrend 7 and the ABG were compared using linear regression analysis and Bland-Altman analysis. Results: Seventeen ABGs were obtained in the 4 patients. Pa(CO2) ranged from 29 to 51 mmHg and the pH values from 7.16 to 7.50. Linear regression analysis for the:Paratrend 7 pH vs the ABG pH resulted in an r = 0.9678 and an r2 = 0.9367 (P < 0.0001). Linear regression analysis for the Paratrend 7 CO2 vs ABG CO2 resulted in an r = 0.8273 and an r2 = 0.6845 (P = 0.01). Using a Bland and Altman analysis, the bias ± precision of the PCO2 values was 3 ± 1.4 and 0.036 ± 0.02 for the pH values. Conclusion: The pH and PCO2 values obtained from the Paratrend 7 monitor provide a clinically acceptable correlation with arterial values.