When blood gas changes occur when pulmonary diffusion disorders cause respiratory failure

Hypoxia, hypoxia caused by decreased partial pressure of oxygen causing hypoxemia, carbon dioxide retention, and increased partial pressure of carbon dioxide causing hypercapnia.

Blood in contact with the alveoli is too short for a short time to diffuse Under normal rest, blood flows through the alveolar capillaries for about seconds, and during strenuous exercise, about seconds. The time to complete the gas exchange is only seconds for O2 and even shorter for CO2. Therefore, even if the alveolar membrane area decreases or the thickness of the alveolar membrane increases at rest, gas exchange can still be completed within a second without abnormality of blood gas, and only when the cardiac output increases and the pulmonary blood flow accelerates due to increased physical load and emotional agitation, the contact time between blood and alveolar air is significantly shortened, and the blood gas changes will occur.

Difference in O2 and CO2 dissociation curves: ?When the blood in the lungs changes from venous blood to arterial blood, about 8ml of CO2 is released per 100ml of blood, and when the blood in the lungs changes from venous blood to arterial blood, the O2 that can be bound by Hb per 100ml of blood is only about 3 5ml, and it can no longer be increased due to the influence of blood oxygen saturation. Based on the resistance, the following equation is derived:

1 = 1 + 1 .DLCO DM VC 1 DLCO = 1 DM + 1 VC * is the binding force of the gas to hemoglobin, the uptake rate per milliliter of blood CO, DM (membrane diffusion volume), VC pulmonary capillary blood volume * the area of effective alveoli and effective pulmonary capillaries matching, disruption of normal alveolar structures (emphysema, pulmonary cyst), reduction of functional capillary beds (pulmonary embolism, emphysema), effective reduction of surface area. The diffusion path is only, but very long in the disease state,1

The alveolar wall can be thickened2The capillary endothelium can be thickened,3The cell layers can be separated by interstitial edema fluid, and the exudate can be replaced by fibrous tissue; 4.

There may be exudate and edema in the alveoli,5telangiectasia and clumping of cells, prolonged diffusion distance within capillaries; Anything that prolongs the CO dispersion distance will result in a reduction in the amount and rate of diffusion. Under certain conditions, increasing temperature The measurement of diffusion requires the use of a gas that can reversibly bind hemoglobin, and the comparison of these three gases In lung parenchymal or peripheral airway disease, there is often a decrease in total diffusion volume and unit diffusion volume at the same time, and a more severe decrease in diffusion per unit of parenchymal disease.

In isolated extrapulmonary disease such as lung resection, DLCO decreases markedly due to the normal structure of the ventilated tissue and the diffusion volume per unit.

Under normal alveolar ventilation conditions, the characteristic nucleus of blood gas changes in pulmonary diffusion disorders is () increased blood gas mixture.

Lower. Heighten.

Lower. Normal.

Correct answer: PAO2 is lowered.

Answer]: e diffusion disorder refers to o <>

co<>

The physical diffusion process of the alveolar membrane through the alveolar membrane is impeded, and the diffusion energy of the O <> is only the <> of CO

1 of 20, so in diffusion disorders, hypoxemia is usually predominant.

Answer]: When the ventilation function of the lung is impaired, the obstruction of carbon dioxide excretion leads to an increase in PaCO2, and the obstruction of oxygen exchange leads to a decrease in PaO2. The diffusion function of the lungs affects the exchange of qi in the lungs, it mainly affects the oxygen exchange in the fingers of the lungs, and the diffusion capacity of carbon dioxide is 21 times stronger than that of oxygen, so it has little impact, and the lack of oxygen will cause the frequency of poor breathing to increase, so that the emission of carbon dioxide increases, so that its partial pressure decreases, so E is selected.

Answer]: E Analysis: When pulmonary ventilation dysfunction is obstructed, the emission of carbon dioxide is blocked, and the PaCO2 rises due to the obstruction of oxygen exchange.

The diffusion function of the lungs affects the gas exchange of the lungs, it mainly affects the oxygen exchange of the lungs, the diffusion capacity of carbon dioxide is 21 times stronger than that of oxygen, so the impact is not large, and the lack of oxygen will cause the respiratory rate to increase, so that the emission of carbon dioxide increases, so that its partial pressure decreases, so choose E. Master the knowledge points of "overview, classification, and pathogenesis of respiratory failure".

Pulmonary diffusion disorder, Qin Zhan Li has nothing to do with the delay ().

a.Interstitial pneumonia.

b.Alveolar hyaline membrane formation.

c.Obstruction of the airway.

d.Severe atelectasis.

e.Extensive consolidation of the lungs.

Correct answer: c

Which of the following mechanisms can be used to cause respiratory failure in diffuse pulmonary fibrosis (a).Restrictive ventilation disorders.

b.Obstructive ventilation disorder.

c.Diffusion disorder.

d.Ventilation and blood flow are out of proportion.

e.Blood slag burns, such as contact with the alveoli for too short a short time.

Correct answer: ACD

Answer]: The respiratory part of the lungs is made up of respiratory bronchioles, alveolar tubes, alveolar sacs, and alveoli. The qi-blood barrier is a structure through which the alveoli and the blood must be exchanged for clearing the shed.

It includes type I epithelial cells and their basement membranes, thin layers of connective tissue, capillary basement membranes and endothelial cells.