Transcutaneous blood gas monitoring among neonatal intensive care units in Japan

Background: This study aimed to investigate the utility of transcutaneous (tc) measurements of partial pressure of oxygen (tcPO₂) and carbon dioxide (tcPCO₂) monitoring in neonatal intensive care units (NICUs) in Japan. Methods: At the end of 2016,we sent a survey questionnaire on tc monitoring to all 106 NICUs registered with the Japanese Neonatologist Association. The questions included usage, subjects, methods, management, and the practical usefulness of tc monitoring. Results: The questionnaire was returned by 69 NICUs (65.1% of response rate). Seventeen institutions (24.6%) measured both tcPCO₂ and tcPO₂, and 42 (60.9%) measured tcPCO₂ alone. Transcutaneous PCO₂ or tcPO₂ monitoring was applied for “pre-viable” infants born at 22–23 weeks’ gestational age (18.6% vs 23.5%), and infants of <500 g birthweight (30.5% vs 17.6%). The tcPCO₂ and tcPO₂ monitoring was started at birth in 49.2% and 70.6% of the newborn infants, respectively. The temperature of the sensor was set at <38°C for tcPCO₂ in 54.3% and >42°C for tcPO₂ in 58.9% of NICUs. The accuracy for tcPO₂ was rated as good in 35.3% or moderate in 64.7%, of institutions but or for tcPCO₂ as 1.7% or 93.2%of institutions, respectively. Conclusion: Transcutaneous monitoring was widely, but limitedly, used for preterm infants. The lower temperature of the tcPCO₂ sensor compared to that reported in other developed countries might compromise the accuracy but increase the feasibility of tc monitoring in Japan.