Hypoxemia- Pathogenesis and clinical findings interstitial lung disease pulmonary hypertension thickening of interstitium vasculature diffusion across alveolar membrane diffusion limitation exertional desaturation PE AVM pneumonia atelectasis cardiac defects airways disease inefficient blood flow ventilated areas blood bypasses aerated alveolar tissue V:Q mismatch R L shunt negligible significant improvement paO2 response 100% O2 Central drugs coma hypothyroidism peripheral damaged lung structure chest wall disorders minute ventilation alveolar gas exchange altitude barometric pressure driving pressure diffusion across membranes inspired
a-a gradient hypoxemia tissue hypoxia cyanosis anaerobic metabolism organ brain anoxic angina