文本框: Measurement of Tidal Volume, Functional Residual Capacity and Noninvasive Monitoring of O2 and CO2 in Ventilated Newborn Infants Bo Sun, Lab of Pediatric Respiratory and Intensive Care Medicine, Children's Hospital of Fudan University, Shanghai 200032, P.R. China Overventilation for immature and mature lungs of newborns may potentiate inflammatory injury and develop bronchopulmonary dysplasia (BPD). New types of infant ventilators with inspired and expired tidal volume (VT) indicators, or build-in screen for lung mechanics, should help to avoid overventilation, especially good for extremely low birth weight infants. Careful adjustment of pressure and volume during ventilation should be mainly based on the expired VT to a level of 6-8 ml/kg body weight. Expired minute volume should also be maintained by adjusting sensitivity of trigger level and adequate ventilator frequency. The bedside lung mechanic monitor, such as Bicore, Navigator and Datex with an infant compatible probe, are recommended. Recruitment of lung volume during respiration should improve both residual volume and compliance. An ultrasonic flow meter (Spiroson, ECO Medics) is introduced into neonatal clinics recently (Pediatric Research 2001; 49: 581-588) for measurement of functional residual capacity (FRC).. This device uses SF6 washout and mass spectrometer technics, and is suitable for infants with tidal breathing while effects of positive end-expiratory pressure (PEEP) and/or exogenous surfactant can be determined. A transcutaneous pO2 and pCO2 monitor (TCM3, Radiometer) is used bedside for low birth weight infants, and this technique facilitates realtime monitoring of O2 and CO2 metablism without repeated blood gas measurement. This device enables stabilization of low birth weight infant with respiratory disorders without potentiate adverse effects on infant skin condition, and is easy for nursing care. Application of these techniques in our neonatal clinics in recent years has significantly improved conditions of neonates with spontaneous breath or mechanical ventilation.