Abstract
BACKGROUND: High-frequency oscillatory ventilation (HFOV) presents challenges for noninvasive CO(2) monitoring due to its rapid oscillations. This study examines the feasibility of instantaneous CO(2) partial pressure (INST CO(2)) monitoring during HFOV with a capnometer equipped with a mainstream CO(2) sensor. METHODS: This study included seven neonates receiving HFOV in the neonatal intensive care unit (NICU) at Shizuoka Children's Hospital. INST CO(2) values were recorded over 3- and 5-min intervals surrounding each blood gas sampling to determine the maximum INST CO(2) value (INST CO(2) MX). The primary outcome was the correlation between INST CO(2) MX and arterial partial pressure of carbon dioxide (PCO(2)). RESULTS: A total of 216 paired INST CO(2) MX and PCO(2) values were analyzed. The coefficient of determination (R(2)) was 0.571 for INST CO(2) MX (3 min) and 0.579 for INST CO(2) MX (5 min). Univariable and multivariable analyses revealed that a lower fraction of inspired oxygen (FiO(2)), reduced minute ventilation, and increased postnatal age were associated with improved concordance between INST CO(2) MX and PCO(2). CONCLUSION: INST CO(2) MX demonstrated a strong correlation with PCO(2) in neonates undergoing HFOV. This novel, noninvasive monitoring approach may serve as a valuable tool for neonatal respiratory management. Future research is needed to validate these findings in broader patient populations and across various ventilatory settings.