Hypoxia Definiens】 One measure of the position of the curve is the PO 2 at the 50%S2 Percent Norma|vaue】 INCREASED AFFINITY Acute alkalosis(+ pH Decreased Pco 347~3.6kPa 100 Decreased temperature Low levels of 2, 3 DPG 90-Carboxyhemoglobin (26~27mmHg)。 80 Abnormal hemog DECREASED AFFINITY Significance) Acute acidosis(+ pH) High Pco, Increased temperature The Pso indicates affinity P High levels of 2, 3 DPG of hemoglobin for oxygen Influence】 10 H、CO2、温度、2、3DPG 01o2030405060708090100 PO, (mm Hg
P50 ■P50 【Definiens】 One measure of the position of the curve is the PO2 at the 50% SO2 . 【Significance】 The P50 indicates affinity of hemoglobin for oxygen. 【Normal value】 3.47～3.6 kPa (26～27mmHg)。 【Influence】 H+ 、CO2 、温度、2、3-DPG Hypoxia
Classification of hypoxia 呼吸与氧利用 Air Ventilation Pharynx EXternal respiration Alveoli mary Gas exchange Alveolar capillary Bronchioles Gas transport Tissue Bound to haemoglobin cells Internal respiration
呼吸与氧利用 Air Alveoli Alveolar capillary Gas transport Tissue cells Ventilation Gas exchange External respiration Internal respiration Bound to haemoglobin Classification of hypoxia
Classification of hypoxia Classification and Etiology Hypotonic Hypoxia(Hypoxic Hypoxia) Hemic Hypoxia( Isotonic Hypoxia) Circulatory Hypoxia(Hypokinetic Hypoxia) Histogenous Hypoxia(Histotoxic Hypoxia)
Hypotonic Hypoxia (Hypoxic Hypoxia) Classification and Etiology Classification of hypoxia Hemic Hypoxia (Isotonic Hypoxia) Circulatory Hypoxia(Hypokinetic Hypoxia) Histogenous Hypoxia(Histotoxic Hypoxia)
Classification of hypoxia (一)低张性缺氧( Hypotonic Hypoxia) 1.特征( Feature) 以动脉血氧分压(PaO2)明显降低并导致对组织供氧不足 为主要特点的缺氧症。 The main feature of this type of hypoxia is that oxygen tension in arterial blood is lower than normal, which resulted in lack of oxygen from blood to tissues PaO2<8kPa(60mmHg)→SO2和CO2↓一恤液携带O2↓一供氧↓ 2.原因( Causes) 吸入气体PO2过低 ■外呼吸功能障碍 ■静脉血分流入动脉 低张性缺氧血气的特征性变化:PaO2
Classification of hypoxia （一）低张性缺氧（Hypotonic Hypoxia ） 1．特征（Feature） 以动脉血氧分压（PaO2）明显降低并导致对组织供氧不足 为主要特点的缺氧症。 The main feature of this type of hypoxia is that oxygen tension in arterial blood is lower than normal, which resulted in lack of oxygen from blood to tissues. PaO2＜8kPa(60mmHg) SO2和CO2↓ 血液携带O2↓ 供氧↓ 2．原因（Causes） 吸入气体PO2过低 外呼吸功能障碍 静脉血分流入动脉 低张性缺氧血气的特征性变化：PaO2↓
Classification of hypoxia (二)血液性缺氧( Hemic hypoxia) 1.特征( Feature) 由于Hb数量减少或性质改变,使血液携氧能力降低,以致血 氧含量减少;或者同时伴有氧离曲线左移,引起组织氧供应不足, 称为血液性缺氧。 Hemic Hypoxia is caused by a reduction in the amount of available hemoglobin(concentration or/and) 2.原因( Causes) (1)贫血( Anemia) (2)氧离曲线左移( Higher affinity of Hb to oxygen) ■输入大量库存血液;■输入过量硷性液;■某些血红蛋白病。 (3)一氧化碳中毒( Carbon monoxide poisoning) (4)高铁血红蛋白血症( Methemoglobinemia,MHb)
（二）血液性缺氧（Hemic hypoxia） 1. 特征（Feature） 由于Hb数量减少或性质改变，使血液携氧能力降低，以致血 氧含量减少；或者同时伴有氧离曲线左移，引起组织氧供应不足， 称为血液性缺氧。 Hemic Hypoxia is caused by a reduction in the amount of available hemoglobin(concentration or/and ). 2. 原因（Causes） （1）贫血（Anemia） （2）氧离曲线左移（Higher affinity of Hb to oxygen） 输入大量库存血液；输入过量硷性液；某些血红蛋白病。 （3）一氧化碳中毒（Carbon monoxide poisoning） （4）高铁血红蛋白血症（Methemoglobinemia, MHb） Classification of hypoxia