[Transcutaneous PCO2 determination in neonatology]

Abstract

Transcutaneous PCO2 studies were performed in 21 healthy preterm infants and in 12 preterm infants with respiratory problems, in order: I. to evaluate the feasibility of transcutaneous PCO2 measurements in the clinical situation; 2. to collect normal values for preterm infants, and 3. to compare transcutaneous tcPCO2 values with PCO2 measured in capillary or arterial blood samples. Normal tcPCO2, measured in 21 healthy preterm infants, mean gestational age 32.5 +/- 2.3 weeks (range 26 6/7-36 1/7, mean birth weight 1547 +/- 498 gram (range 820-2840), postnatal age 2.2 +/- 2.1 days (range 0-6) was 41.2 +/- 5.5 mm Hg. The relation between transcutaneous PCO2 and PCO2 in arterial or capillary blood samples was studied in 12 patients with respiratory problems, 7 boys and 5 girls, mean gestational age 31 4/7, birth weight 1600 gram (range 885-3050). We found a good linear relation between tcPCO2 and arterial PaCO2 (regression coëfficient between 0.66 and 0.96) and a bad correlation between tcPCO2 and capillary PCO2 (regression coefficient 0.14-0.89). We conclude that tcPCO2 measurement is reliable and feasible for clinical use and is more reliable than PCO2 measurement in capillary blood.