of 60
Respiratory pathophysiologyDepartment of Pathology Shanghai University of TCM
External RespirationGas TransportInternal Respiration
Pulmonary ventilation (total lung capacityTLC)(forced vital capacityFVC)(alveolar ventilation, VA)(residual volumeRV)(dead space volume, VD)(compliance) Gas exchange(diffusing capacity)[P(A-a)O2]
(total lung capacityTLC): 5000ml3500ml(forced vital capacity, FVC)3500ml2500ml
(residual volumeRV)1000 1500ml(functional residual capacity, FRC)2500ml
(alveolar ventilation, VA)(dead space volume, VD)(compliance)
(diffusing capacity)1mmHg [P(A-a)O2]
(respiratory failure)PaO60mmHg/PaCO250mmHg(respiratory insufficiency)
I II
(restrictive hypoventilation)obstructive hypoventilation)
1.
1. alveolar surfactant
LaplaceP=2T/r
Neonatal respiratory distress syndrome (NRDS): lack of surfactantretraction of soft tissue on inspiration
2. obstructive hypoventilation)airway resistanceR 1/r4
2. :22mm COPD
extrathoracic obstruction Inspiratory dyspnea intrathoracic obstrucdtion Expiratory dyspnia
ExpiratoryInspiratory
ExpiratoryInspiratory
isobaric point, IP
* PaO250 mmHg PAO2PACO2 PaO2PaCO2PaCO2CO2/PaCO2 PaCO2 PACO20.86Vco2/VA
diffusion impairment ventilation-perfusion imbalanceincrease of anatomical shunt
diffusion impairment
PO2KPa13.310.78.005.332.67 00 0.25 0.50 0.75Hb1 212S
* IPaO2 PaCO2 O2CO2O2CO2
O2CO2
*CO2O2PaCO2
(Ventilation/perfusion ratio, VA/Q) = 4.2 / 5 = 0.840.6~3.0
ventilation-perfusion imbalanceVA/Q : Venous Admixture VA/Q : Alveolar Dead Space
1. VA/Q VA/Q(venous admixtrue)(functional shunt)
1. VA/Q 3% 30%-50% (-)
2. VA/Q VA/Q(dead space like ventilation)30% 60%-70%
VA/QIPaO2 PaCO2 O2CO2O2CO2
VAVA / QPaO2 CaO2PaCO2CO2 CaCO2 NN NN
QVA / QPaO2 CaO2PaCO2CO2 CaCO2 NN NN
3. (anatomic shunt)-2~3%ture venous admixture
1. CO2K+
1.
2. PaO2 < 60mmHg PaO2 < 30mmHg PaCO2 > 50mmHg PaCO2 > 80mmHg PaO2
2. II(30%)(12L/min)PaO2 5060mmHg
3.
3. A
3. A
4. PaO260mmHg PaO240~50mmHg PaO220mmHg PaCO280mmHg CO2
(pulmonary encephalopathy) ATP Na+-K+ -
5. GFR
PaO2PaCO2
(acute respiratory distress syndromeARDS)(acute lung injuryALI)
() (40%)
ALI-TNFIL-1[5-5-HTA2TXA2LTSFDP]
ALI
Chronic obstructive pulmonary diseaseCOPD2mm
COPD:
(respiratory failure)PaO60mmHg/PaCO250mmHgPaO2PaO2PaO2=1000.325mmHgPaCO2400.5mmHg (respiratory insufficiency)(respiratory failure) 1. PaOPaCO2PaCO2I IIPaOPaOPaCO22. PaO2PaCO2PaO2PaCO2 3. 4. ARDS26.0L/min4.2L/min30%
/chronic obstructive pulmonary diseaseCOPD COPD2mm-LaplacePTrP=2T/ralveolar surfactant3 -LaplacePTrP=2T/ralveolar surfactant
2 2mm 2()isobaric point, IPisobaric point, IP
3 PaO250 mmHgPAO2PACO2PaO2PaCO2PACO2VAVco2, PACO20.86Vco2/VAVco2PACO2PACO2PaCO2
180m23540m22 1m
30.750.34O20.25CO20.130.75IPaO2 PaCO2 IO2CO2100mlHb8ml CO2100mlHbO235ml O2CO2 CO2O224CO2O221CO2O2CO2O2PaCO2 O2CO2100mlHb8ml CO2100mlHbO235ml
O2CO2 CO2O224CO2O221CO2O2CO2O2PaCO2
VA4.2L/minQ5L/minVA/Q0.84VA/Q3.00.6VA/Q0.8 ventilation-perfusion imbalance 3%30%~50%VA/Q(dead space like ventilation)30%60%~70% IPaO2PaCO2 VA / QCO2CO2CO2CO2 CO2CO2CO2CO2
CO2CO2CO2(anatomic shunt)-2~3%ture venous admixture-PaO2PaCO2PaO2PaO2 1 NH3 1 NH3 2 3 4 PaO2AA PaO260mmHgPaO230mmHg PaCO2PaCO2 80mmHg PaO2 PaCO2CO2 AcapA PaO2