氧供需平衡麻醉
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(P50>27mmHg)
✓Increased hydrogen ions
✓Increased CO2 ✓Increased temperature
✓Increased 2,3-diphosphoglycerate (DPG)
氧供 Oxygen delivery DO2
DO2 是每分钟供给机体的氧量。 DO2=(0.0031×PaO2+1.34×Hb×SaO2)×CO DO2=1.34×Hb×SaO2×CO 如果CO=5L,Hb=15g，
氧-血红蛋白解离曲线
Effects on Oxygen-Hemoglobin Dissociation Curve
PaO2 700 90-100 60
40
26.7
SaO2 100 95-98 90
75
50
The causes of a left-shifted oxy-Hb curve (P50<27mmHg)
Pathological supply dependency
Relationship between DO2 and VO2 seen in critically ill patients, when increases in CO or increases in oxygen delivery, result in parallel increases in VO2.
空气 上呼吸道
饱和蒸汽压=47mmHg PiO2=(760-47)0.2094=149mmHg
肺泡
❖ 二氧化碳 - PACO2, 约等于 PaCO2. ❖PAO2 = PIO2 – PaCO2/R.
- R 为呼吸商. - R＝ 0.8. - PAO2 = 149 – (40/0.8) = 100mmHg
DO2=1.34×150×1×5=1005ml/L
氧耗 . Oxygen consumption (VO2)
Oxygen consumption is the actual amount of oxygen consumed per minute. VO2=CO×(CaO2-CvO2)(ml/min)
Cardiac output Blood oxygen content (CaO2) The affinity of hemoglobin for oxygen
外呼吸
组织
血液 循环
血红蛋白与氧的结合量
1g 血红蛋白最多可结合1.34ml的氧气。 (1.39ml when the hemoglobin is chemically pure)
如果 Hb=15g/100ml, 最大结合的氧量 =15*1.34=20.1ml/100ml
在组织内释放的氧量
动脉血: SaO2=97%, CaO2=19.4ml/100ml
混合静脉血: PvO2=40mmHg, SvO2=75%
CvO2=14.4ml/100ml C(a-v)O2=19.4-14.4=5ml/100ml
正常情况下， 200~250ml/min.
氧需 Oxygen demand
Oxygen demand is the actual amount of oxygen needed per minute.
-is closely related to the oxygen consumption; -Under some conditions, demand may exceed
氧输送 oxygen transport (O2T)
肺通气 肺换气 氧在血液中的运输 氧在组织中释放
外呼吸
组织
血液 循环
氧瀑布 O2 Cascade
氧从空气进入细胞的线粒体内要经历一系 列过程，包括：肺通气、肺换气、氧在血液中 的运输及氧在组织的释放四个步骤。也有学者 把氧运输过程中，从空气中氧分压159mmHg 至细胞内的3~4mmHg的巨大落差形象地称为 氧瀑布。
consumption.
氧供需失衡时机体的代偿机制
CO↑. 血流再分布. 细胞摄氧率↑.
Monitoring?
理想部位：线粒体 难点：细胞内的氧合状况无法直接监测 思路：对氧输送过程进行监测
测定Hct及Hb的方法
全血细胞分析仪-- Hct、Hb 血气分析仪– Hct、Hb 血红蛋白分光光度仪-- Hb 离心机—Hct
Physiological supply dependency
The normal relationship is for a 4:1 ratio between DO2 and VO2. ↑ or ↓ in CO and DO2 do not affect oxygen consumption.
动脉血
氧从肺泡进入肺静脉氧分压通常下降 5 –10 mmHg. PAO2=95mmHg
毛细血管 静脉血
毛细血管和组织间液间的较大的氧分压差 （ 30 mmHg）使得氧气迅速由血液向组织 弥散。
Summary
The factors influence transport of oxygen
✓Alkalosis –the Bohr effect ✓Hypothermia ✓Abnormal and fetal Hb ✓Carboxyhemoglobin, Methemoglobin ✓Decreased 2,3-diphosphoglycerate
The causes of a right-shifted oxy-Hb curve
The esophageal probe (ESOX, ARISTO Medical, Chicago, IL)
Blood gas tension measurement
Oxygen pressure (PO2)
PO2 is to measure directly from a blood sample, usually by using a Clark electrode. Carbon dioxide pressure (PCO2) PCO2 electrodes work by measuring the change in pH induced when blood equilibrates with a potassium chloride/sodium bicarbonate solution.
Fra Baidu bibliotek
SpO2 monitored by Pulse oximetry since 1980 SO2=O2Hb/(O2Hb+HHb)(%)
If R940/R660=1, SO2=85%
Transcutaneous SpO2 monitoring
Two types oximetry:
反射式脉搏氧饱和度探头
✓Increased hydrogen ions
✓Increased CO2 ✓Increased temperature
✓Increased 2,3-diphosphoglycerate (DPG)
氧供 Oxygen delivery DO2
DO2 是每分钟供给机体的氧量。 DO2=(0.0031×PaO2+1.34×Hb×SaO2)×CO DO2=1.34×Hb×SaO2×CO 如果CO=5L,Hb=15g，
氧-血红蛋白解离曲线
Effects on Oxygen-Hemoglobin Dissociation Curve
PaO2 700 90-100 60
40
26.7
SaO2 100 95-98 90
75
50
The causes of a left-shifted oxy-Hb curve (P50<27mmHg)
Pathological supply dependency
Relationship between DO2 and VO2 seen in critically ill patients, when increases in CO or increases in oxygen delivery, result in parallel increases in VO2.
空气 上呼吸道
饱和蒸汽压=47mmHg PiO2=(760-47)0.2094=149mmHg
肺泡
❖ 二氧化碳 - PACO2, 约等于 PaCO2. ❖PAO2 = PIO2 – PaCO2/R.
- R 为呼吸商. - R＝ 0.8. - PAO2 = 149 – (40/0.8) = 100mmHg
DO2=1.34×150×1×5=1005ml/L
氧耗 . Oxygen consumption (VO2)
Oxygen consumption is the actual amount of oxygen consumed per minute. VO2=CO×(CaO2-CvO2)(ml/min)
Cardiac output Blood oxygen content (CaO2) The affinity of hemoglobin for oxygen
外呼吸
组织
血液 循环
血红蛋白与氧的结合量
1g 血红蛋白最多可结合1.34ml的氧气。 (1.39ml when the hemoglobin is chemically pure)
如果 Hb=15g/100ml, 最大结合的氧量 =15*1.34=20.1ml/100ml
在组织内释放的氧量
动脉血: SaO2=97%, CaO2=19.4ml/100ml
混合静脉血: PvO2=40mmHg, SvO2=75%
CvO2=14.4ml/100ml C(a-v)O2=19.4-14.4=5ml/100ml
正常情况下， 200~250ml/min.
氧需 Oxygen demand
Oxygen demand is the actual amount of oxygen needed per minute.
-is closely related to the oxygen consumption; -Under some conditions, demand may exceed
氧输送 oxygen transport (O2T)
肺通气 肺换气 氧在血液中的运输 氧在组织中释放
外呼吸
组织
血液 循环
氧瀑布 O2 Cascade
氧从空气进入细胞的线粒体内要经历一系 列过程，包括：肺通气、肺换气、氧在血液中 的运输及氧在组织的释放四个步骤。也有学者 把氧运输过程中，从空气中氧分压159mmHg 至细胞内的3~4mmHg的巨大落差形象地称为 氧瀑布。
consumption.
氧供需失衡时机体的代偿机制
CO↑. 血流再分布. 细胞摄氧率↑.
Monitoring?
理想部位：线粒体 难点：细胞内的氧合状况无法直接监测 思路：对氧输送过程进行监测
测定Hct及Hb的方法
全血细胞分析仪-- Hct、Hb 血气分析仪– Hct、Hb 血红蛋白分光光度仪-- Hb 离心机—Hct
Physiological supply dependency
The normal relationship is for a 4:1 ratio between DO2 and VO2. ↑ or ↓ in CO and DO2 do not affect oxygen consumption.
动脉血
氧从肺泡进入肺静脉氧分压通常下降 5 –10 mmHg. PAO2=95mmHg
毛细血管 静脉血
毛细血管和组织间液间的较大的氧分压差 （ 30 mmHg）使得氧气迅速由血液向组织 弥散。
Summary
The factors influence transport of oxygen
✓Alkalosis –the Bohr effect ✓Hypothermia ✓Abnormal and fetal Hb ✓Carboxyhemoglobin, Methemoglobin ✓Decreased 2,3-diphosphoglycerate
The causes of a right-shifted oxy-Hb curve
The esophageal probe (ESOX, ARISTO Medical, Chicago, IL)
Blood gas tension measurement
Oxygen pressure (PO2)
PO2 is to measure directly from a blood sample, usually by using a Clark electrode. Carbon dioxide pressure (PCO2) PCO2 electrodes work by measuring the change in pH induced when blood equilibrates with a potassium chloride/sodium bicarbonate solution.
Fra Baidu bibliotek
SpO2 monitored by Pulse oximetry since 1980 SO2=O2Hb/(O2Hb+HHb)(%)
If R940/R660=1, SO2=85%
Transcutaneous SpO2 monitoring
Two types oximetry:
反射式脉搏氧饱和度探头