به نام خدا

1. به نام خدا

2. Respiratory Failure Dr.FarzinGhiasi Pulmunologist

3. Hypoxemic RF PaO2 < 60 mmHg ( SaO2 < 90% ) And/or HypercarbicRF PaCO2 > 50 mmHg

4. Acute RF Chronic • Acute hypercapnic failure : PH drops 0.08 for every 10 mmHg rise in PaCO2 • Chronic hypercapnic failure : PH drops 0.03 for every 10 mm Hg rise in PaCO2

5. type I ( acute hypoxemic RF ) RF type II ( hypercapnicRF )

6. Hypoxemic RF primary causes : • Decreased inspired O2 • Alveolar hypoventilation • (V/Q )mismatch • Shunt • Diffusion impairment • Perfusion / diffusion impairment • Venous admixture

7. Type I ( Hypoxemic ) • ARDS • Pulmonary embolism • Pulmonary edema • Septic shock • Pulmonary infection • Inhalation • Pleural effusion • ILD • COPD • Aspiration • PH

8. Differentiating the Causes of Acute Hypoxemic RF PAO2 = FIO2 ( PB – PH2O ) – PaCO2 / R R = respiratory exchange ratio = 0.8 P( A – a ) O2 ranges from 10 to 25 mmHg Mean age – specific P( A – a ) O2 = ( age / 4 ) + 4 For example : 76 – year – old person living at sea level : P(A – a ) O2 = ( 76/4 ) + 4 = 19 + 4 = 23

9. Differentiating the Causes of Hypoxemia

22. Hypercapnic Respiratory Failure VT= VD + VA D + = E A A = E – • D A = E ( 1 – VD / VT ) PaCO2 = (0.863 CO2 )/ A

23. Type II ( Hypercapnic ) • Decreased ventilatiry drive • Neurologic disease • Increased work of breathing

24. Decreased Ventilatory Drive • Drug overdose • CSA • Brain stem lesions • Metabolic alkalosis • PAH • CNH • Carotid body resection • Obesity - hypoventilation

25. Neurologic Disease • Spinal cord trauma • Motor neuron Polio ALS • Motor nerve Phrenic nerve Guillain – Barre Charco – Marie – Tooth • Neuromuscular junction Myasthenia gravis Botulism • Muscular Dysrophy Myositis Myopathy Acid maltase Metabolic

26. Increased WOB • Resistance Bronchospasm Asthma COPD • Lung Compliance Alveolar edema Atelectasis Auto PEEP • CW compliance Pneumothorax PE Abdominal distention • VE requirements PTE Sepsis