《内科学呼吸衰竭课件》由会员分享，可在线阅读，更多相关《内科学呼吸衰竭课件（67页珍藏版）》请在金锄头文库上搜索。
1、1,Respiratory failure,2,Male, 32 Fever, cough with sputum for 3 days No finding on physical examinationDiagnosis: pneumonia Xray: shadow in left lower lobe,August 16, 2003,August 20, 2003,Acute shortness of breath Anxiety RR 40/min, CyanosisABG: PaO2 61mm Hg(FiO2 1.0)PaCO2 35 mmHg, pH 7.20X-ray: clo
2、uded glassDiagnosis：ARDSAcidosis,3,Intubation via mouth tracheotomy,Monitoring and ventilation,4,Contents 0f outline,Definition Etiology & Pathogenesis Classification Clinical manifestations Diagnosis Treatment,5,Introduction,Be a frequently encountered medical problem A major cause of death in Chin
3、a Mortality from COPD, which ends in death from respiratory failure, continues to increase More than 70% of patients with pneumonia are attributed to respiratory failure About 1/3 patients in ICU in the United States, about 500 000 persons, receive mechanical ventilation each year,6,Introduction (co
4、nt.),Short-term survival is more than 80% for acute respiratory failure not preceded by additional lung disease or systemic illness Multi-system organ failure or pre-existing renal, liver, or chronic gastrointestinal disease with malnutrition substantially worsens outlook About 17% of patients place
5、d on mechanical ventilation require assistance for more than 14 days Among those requiring this amount of mechanical ventilation, elderly patients have a 9% survival and younger patients a 36% survival,7,Definition,Be a clinical syndrome of respiratory and metabolism dysfunction caused by any condit
6、ion that severely affects the lungs ability to maintain arterial oxygenation or carbon dioxide elimination. Both acute or chronic respiratory failure may be divided into two main categories. A failure of gas exchange hypoxemia A failure of ventilation hypercapnia,8,Classification,According to pathop
7、hysiology and arterial blood gas analysis:Type I: A failure of gas exchange Hypoxemia, PaO2 50 mmHgPaO2 60 mmHg, PaCO2 50 mmHg Iatrogenic,9,Classification,According to the involved site Central respiratory failure Change of respiratory rhythm and frequency Peripheral respiratory failure Dyspnea Acco
8、rding to onset of respiratory failure Acute, develops in seconds or hours Chronic, develops in days or longer, elevated HCO3- Acute onset of Chronic respiratory failure Have no definitive borderline According to mechanisms Pump failure Lung failure,10,Etiology,Airway obstruction Airway inflammation,
9、 tumor, foreign bodies, fibrosis scar COPD and asthma Alveolar or interstitial lung diseases pneumonia, emphysema, pulmonary tuberculosis, diffuse interstitial pulmonary fibrosis, pulmonary edema Pulmonary vascular diseases Pulmonary embolism, pulmonary vasculitis Chest wall or pleural diseases Flai
10、l chest caused by trauma, pneumothorax, severe spinal deformity, massive pleural effusion Neuromuscular diseases Cerebrovascular diseases, craniocerebral trauma, cerebritis and sedative-hypnotic, poliomyelitis, polyneuritis, myasthenia gravis,11,Respiratory Pump Failure（泵衰竭）,Pump failure is caused b
11、y dysfunction of respiratory pump Low respiratory drive due to central or peripheral nervous system diseases, neuromuscular junction problem or fatigue of respiratory muscleshypoventilation manifested as type respiratory failure,12,Lung Failure（肺衰竭）,Lung failure is caused by disorder of lung parench
12、yma, pulmonary vascular or airway obstruction Airway obstruction hypoventilation，manifested as type respiratory failure Disorder of lung parenchyma dysfunction of oxygenation, manifested as hypoxemia Disorder of pulmonary vascular system ventilation/perfusion mismatch, manifested as hypoxemia,13,Mec
13、hanisms & Pathophysiology,Hypoxemia Alveolar ventilation FiO2 Diffusion abnormality V/Q mismatch A-V shunt,Hypercapnia(CO2 retention) CO2 production Alveolar ventilation ,14,15,Mechanisms of hypoxemia,FiO2 Altiplano or under a deep well PAO2 & PaO2 Hypoventilation VA = VE VD The diffusion capacity o
14、f CO2 is 20 times of that of O2,25 20 15 10 5 肺泡分压(kPa),0 2 4 6 8 10肺泡通气量(l/min),PACO2,PAO2,PACO2 =0.863*VCO2/VA,16,Mechanisms of hypoxemia Diffusion abnormality (弥散障碍),The factors that influence rate of gas diffusion across the respiratory membrane include: the partial pressure difference of the ga
15、s between the two sides of the membrane, the surface area of membrane the time of contact between blood and alveoli the permeability of the membraneDiffusion abnormality manifested as hypoxemia,100806040,动脉氧分压,0.25 0.5 0.75血液通过肺泡毛细血管时间,17,Mechanisms of hypoxemia,Ventilation/perfusion mismatch（通气/灌流失衡） Shunt（肺动-静脉分流）,V/Q=0.8,V/Q0.8,V/Q V (A-V shunt),Normal,V Q (dead space effect),18,(二)通气/血流比例 V/Q,肺泡死腔通气V/Q0.8,静-动脉分流V/Q0.8,正常通气/血流V/Q 0.8,VD PaCO2PeCO2 VT PaCO2,Qs CcO2 CaO2 QT CcO2 CvO2,VA 4.2L(R2.1, L2.1) Q 5.0L(R2.5, L2.5),见于肺不张，ARDS,见于COPD,正常,Mechanisms of hypoxemia,
