1、新生儿肺功能监测新生儿肺功能监测 气血交换气血交换:肺通气肺通气,肺换气肺换气 呼吸力学，肺泡上皮细胞生物学呼吸力学，肺泡上皮细胞生物学 呼吸肌，能量代谢呼吸肌，能量代谢 呼吸中枢与化学感受器反馈性调节呼吸中枢与化学感受器反馈性调节 液体吸收平衡液体吸收平衡胚胎期胚胎期Embryonic period假腺样期假腺样期Pseudoglandular stage导管期导管期Canalicular stage囊泡期囊泡期Saccular肺泡期肺泡期Alveolar102030369weeksBirthmonthsA C:4 weeks D E:5 weeksF:6 weeks G:8 weeks胎儿
2、肺泡面胎儿肺泡面积增加与肺积增加与肺容量增加成容量增加成正比正比Lung Development新生儿肺功能监测新生儿肺功能监测 气血交换气血交换:肺通气肺通气,肺换气肺换气 呼吸力学，肺泡上皮细胞生物学呼吸力学，肺泡上皮细胞生物学 呼吸肌，能量代谢呼吸肌，能量代谢 呼吸中枢与化学感受器反馈性调节呼吸中枢与化学感受器反馈性调节 液体吸收平衡液体吸收平衡新生儿肺功能监测新生儿肺功能监测 Gas Exchange Volume The portion of each breath that is available for gas exchange.Optimizing Alveolar Minu
3、te Ventilation provides the most effective CO2 removal.Alveolar VentilationFetal Circulation and PlacentaUpper bodyPulmonary arteryForamenovaleDuctusvenosusLiverUmbilicalcordLower bodyPlacentaApplication of Lung Function ParametersDetection of Lung Overdistention V-PNormalOverdistendedP value C(ml/c
4、mH2O)0.51?0.370.75?0.50-C20(ml/cmH2O)1.08?1.130.46?0.32-C20/C1.93?0.910.63?0.11 95%5%再生能力再生能力差差可转变为可转变为I型型功能功能气体交换气体交换,液体吸收液体吸收 合成、分泌合成、分泌PS、细胞因子细胞因子Hypoxia-pO2 Compensatory mechanismsCentralization of blood flow to the brain and heart Vasodilation in brain and heartIncreased extraction of oxygen Hy
5、poxia leads toOrgan failure Multiple organ failureBrain damage The natural compensatory mechanisms may be reduced in the premature newbornCerebral blood flow velocity(cm/s)NormaloxygenationHyperoxiaNormaloxygenationHypocapnia-pCO2 pCO2 leads toReduction of blood flow to the brainReduction of oxygen
6、supply to the brainIncreased risk of brain damage Lung Function MonitoringC20/C Ratio Overdistention can lead to volutrauma and increased pulmonary vascular resistance To decrease overdistention,decrease PIP in PLV*or Vt in VLV*Optimize PEEP level:excessive level of PEEP might lead to overdistention
7、PV-LoopVolumePressureOverdistentionbeginsC20Clinical SignificanceVolume Overdistention*PLV=Pressure Limited Ventilation*VLV=Volume Limited VentilationCPeepApplication of Lung Function Monitoring Detection of Lung OverdistentionIdentifying Lung Overdistention During MechanicalVentilation by Using Vol
8、ume-Pressure LoopsFisher/Mammel/Coleman/Bing/Boros:Ped Pulmonol:5:10-14(1988).In conclusion,V-P loops can provide useful information regarding the interaction of lungs and mechanical ventilator.Lung overdistention may be identified before lung rupture occurs.The C20/C ratio quantifies such V-P loop evidence of lung overdisten-tion during neonatal mechanical ventilation.N=23 neonatesLung Function MonitoringDisplaying Values and TrendsLFM values Compliance Resistance C20/C Time Constant Correlation coefficient rTrends of LFM parameters Compliance Resistance
