动脉血气分析课件.ppt

文档介绍：Arterial Blood Gas Analysis
Paramecium
MIXED VENOUS BLOOD
pH
PCO2 46 mmHg
PO2 40 mmHg
SO2 75%
pH
PCO2 40 mmHg
PO2 95 mmHg
SO2 95%
ARTERIAL BLOOD
External Respiration
Internal Respiration
Obtaining the blood gas specimen
Obtaining the blood gas specimen
Blood collected anaerobically (radial artery)
The specimen adequately anticoagulated (heparin)
Free of air bubbles and clots
A 2 ml sample mended
The specimen analyzed in a few minutes, otherwise stored in ice within 1 hour
Equipment calibration and quality control
The specimen adequately identified
常压环境下,无论患者的吸氧条件如何,只要PaO2>48mmHg,则提示标本多为动脉血
自然状态下吸空气检查:PaO2+PaCO2 <140mmHg
若无原发代谢失衡证据,数小时内HCO3-浓度测量值变化<5mmol/L
What Information Does Arterial Blood Gas provide?
Alveolar ventilation
Arterial oxygenation
Respiratory/metabolic acid-base balance
Alveolar ventilation
肺泡通气(1)
PaCO2是体现病人肺泡通气状态的唯一数值
PaCO2升高即肺泡通气不足,PaCO2降低即肺泡通气过度
PaCO2上升的唯一生理原因是对于产生和运输到肺的CO2量,肺泡通气水平不足
VCO2(ml/min)×
PaCO2=
VA(L/min)
肺泡通气(2)
VCO2: 代谢产生并运输到肺的CO2量
VA: 肺泡分钟通气量
=分钟通气量(VE)-死腔通气量(VD)
=(潮气量-死腔量) ×呼吸频率
Anatomic dead space