【正文】 ? Depression caused by pulmonary encephalopathy in late stage: apathy, convulsion, a, tendon reflex weakened or disappear Circulatory system: ? Peripheral vesodilation, skin congestion, warm and sweaty extremities, BP↑, CO↑, pulsus magnus, HR↑, pulsatile headache 36 Diagnostic criteria ? History of respiratory dysfunction that severely affects the lung’s ability to maintain arterial oxygenation or carbon dioxide elimination ? Clinical manifestation of dyspnea and cyanosis ? Blood gas analysis ? PaO2 60 mmHg, or plus ? PaCO2 50 mmHg ? Breathing air on sea level and standard atmosphere pressure at rest ? Exclude intracardiac shunt and decreased cardiac output, such as ventricular septal defect ? In fact it is a pathophysiology amp。故影響糾正低氧血癥并防止高碳酸血癥的發(fā)生的治療觀察。 ? severe hypoxemia。 ? upper airway obstruction。 FiO2 (%)=21+4 oxygen flow rate (L/min) ? Flow rates should be limited to less than 7L/min. ② Mask: ? Simple oxygen mask, nonrebreathing mask with reservoir bag, Venturi mask. ? Advantage: FiO2 delivered is paratively stable and is adjustable。 O2 Delivery capacity ? ? blood viscosity ?， blood stream resistance? → cardiac load amp。1 Respiratory failure Guo Yubiao, amp。 CO? ? hypoxemia and blood viscosity ? → the risk of DIC? 25 Influence of hypoxemia Renal amp。 less irritative to nasopharyngeal mucosa ? Disadvantage: inconvenient for patients to expectorate, eat and drink Treatment Oxygen therapy 58 Nasal cannula/prongs 鼻導(dǎo)管吸氧 ? 鼻導(dǎo)管給氧的上限量為 6L/min，大于這一流量時，由于管道和鼻咽內(nèi)產(chǎn)生渦流，吸氧濃度不再增加。 impaired airway protection。 ? acute hypercapnia that is not quickly reversed by appropriate specific therapy。因為隨呼吸頻率、每分鐘通氣量、室內(nèi)空氣的流動、輸氧裝置的放置等因素的不同而改變。 excitability ? ? Consciousness: dizziness, asterixis, somnolence, a, convulsion ? Peripheral nerves: sympathetic nerve, adrenal gland, distal nerves， catecholamine(CA)? 27 Influence of hypercapnia Cardiovascular system ? HR?, CO ?, BP? ? With stimulation of sympathetic nerve, the skin and abdominal vessels contract while coronary vessels dilate ? Severe hypoxia and hypercapnia → directly inhibit cardiovascular center → depressed cardiac function, dilated vessels → BP↓, arrhythmia ? Acute severe hypercapnia → ventricular fibrillation or cardiac arrest especially during intubation procedure ? PaCO2 enhance cardiac inhibition by vagus 28 Influence of hypercapnia Respiratory system ? Stimulate respiratory center → strengthen respiratory movement, Ventilation ? ? (PaCO2 ? kPa， Ventilation volume? 2 L/min) ? Slight contraction of small pulmonary arteries ? Directly relax the bronchial smooth muscle ? PAO2? ? PaCO2? → rightward shift of the oxyhaemoglobin dissociation curve (ODC) 29 pH? pH ? 30 Influence of hypercapnia urinary system ? Mild CO2 retention →dilation of renal blood vessels → renal blood flow? → urine ? ? PaCO2 8 kPa, pH ? ? →renal blood vessels spasm → renal blood flow ? ? HCO3 and Na+ reabsorption? → urine ? 31 Influence of hypoxemia amp。 Critical Care Medicine The first Affiliated Hospital of SunYat Set University 2 Male, 32 Fever, cough with sputum for 3 days No finding on physical examination Diagnosis: pneumonia X－ ray: shadow in left lower lobe August 16, 2022 August 20, 2022 Acute shortness of breath Anxiety ? RR 40/min, Cyanosis ? ABG: PaO2 61mm Hg(FiO2 ) PaCO2 35 mmHg, pH ? Xray: clouded glass ? Diagnosis： ARDS Acidosis 3 Intubation via mouth tracheotomy Monitoring and ventilation 4 Contents 0f outline ? Definition ? Etiology amp。 PaO2 ↓ ? Hypoventilation ? VA = VE – VD ? The diffusion capacity of CO2 is 20 times of that of O2 25 20 15 10 5 肺泡分壓(kPa) 0 2 4 6 8 10 肺泡通氣量 (l/min) PACO2 PAO2 PACO2 =*VCO2/VA 16 Mechanisms of hypoxemia –– Diffusion abnormality (彌散障礙 ) ? The factors that influence rate of gas diffusion across the respiratory membrane include: ? the partial pressure difference of the