Abstract

Objective: To evaluate the correlation between end-tidal carbon dioxide (ETCO2) and arterial carbon dioxide (PaCO2) in ventilated neonates at NICU.
Methodology: This prospective observational study included 111 neonates receiving mechanical ventilation at the NICU, Children Hospital, Multan, from March to August 2025. Neonates aged ≤28 days, of either gender or any gestational age, were enrolled after informed consent. Consecutive sampling was used. Simultaneous capnography (ETCO₂) and PaCO₂ were recorded at 1- and 12-hours post-ventilation (mean values considered). Data were analyzed using IBM SPSS 26.0; normality was tested, quantitative data summarized appropriately, and correlation/agreement between ETCO₂ and PaCO₂ assessed using Pearson’s r and Bland-Altman plots.
Results: Out of 111 neonates, 64 (57.7%) were male, while the median age was 6.0 days, and the mean birth weight was 2.4±0.5 kg. Preterm infants were 78 (70.3%) cases. Mean PaCO₂ was 43.7±7.3 mmHg, and mean ETCO₂ was 40.8±9.2 mmHg. Mean arterial pH, HCO₃⁻, base excess, and lactate were 7.3±0.1, 20.8±3.1 mmol/L, –4.2±2.7 mmol/L, and 2.8±1.1 mmol/L, respectively. A strong correlation was found (r=0.750, p

Key words: Capnography, ETCO₂, neoante, NICU, PaCO₂, preterm.