Relationship between Arterial and End-Tidal Carbon Dioxide Pressure during Controlled Ventilation in Porcine Neonates

摘要

To investigate the validity of ETCO_2 in porcine neonates, which have been frequently used as an experimental model for human neonates, the relationship between arterial (PaCO_2) and end-tidal PCO_2 (ETCO_2) in porcine neonates was examined under different respiratory conditions by regulating both inspiratory flow and positive end expiratory pressure (PEEP). The difference between PaCO_2 and ETCO_2 widened significantly, according to the significant decrease in tidal volume/body weight ratio (TV/BW) caused by the increase of PEEP. A lower correlation between PaCO_2 and ETCO_2 was observed in < 6 ml/kg than in ≥ 6 ml/kg TV/BW. It therefore seems reasonable to conclude that, in porcine neonates, the valid ETCO_2 measurements corresponding to PaCO_2 would be obtained at ≥ 6 ml/kg TV/BW.