NUR 4227 Lecture Notes - Lecture 3: Blood Gas Tension, Hypoxemia, Oxygen Saturation
Document Summary
Increased co2: decreased o2, decreased cardiac output. Impaired diffusion: fibrotic membrane, right to left shunt, oxygen moves right to left side of heart and is not oxygenated, anatomical defect (atrial/ventricle septal defect, vq mismatch (physiological shunt, alveoli filled with puss, water, fluid, etc. Hypoxemic respiratory failure: physiologic mechanisms imbalance: ventilation/perfusion mismatch (v/q)**, shunting*, diffusion limitation, alveolar hypoventilation. Review: etiology and pathophysiology: hypoxemic respiratory failure: v/q mismatch, matched perfusion and ventilation ratio: 1:1 (vq=1, regional mismatch lung apex ((cid:313) ventilation than perfusion, lung base v/q <1, mismatch is not 1:1 but not all pathologic. Hypoxemic respiratory failure: mismatch causes: copd/chronic bronchitis (increased secretions, pneumonia (alveoli, asthma (bronchospasm, atelectasis (alveolar collapse, pain (chest/abd wall movement(cid:314)ventilation; vasoconstriction, pulmonary embolus ((cid:315)perfusion, toxic inhalation, pulmonary artery hemorrhage, first line tx. Review: etiology and pathophysiology: hypoxemic respiratory failure: severe v/q mismatch/shunt, blood exits the heart without gas exchange, anatomic shunt, pulmonic stenosis; transposition great vessels; significant.
