vi medicine informatics

Acid Base Review All Systems


Normal Values

Hypoxemia – Low PaO2 in the setting of also low PAO2 –> Normal A-a gradient?

Emphysema: Chronic Respiratory Acidosis w/ Metabolic Compensation

Pulmonary Embolism -> Respiratory Alkalosis

Hypercapnea and Hypoxemia in Obstructive Sleep Apnea

Altitute Sickness

  1. First: PiO2 is reduced (parttial pressure of inspiored oxygen) –> Hypoxemia –> Chemoreceptors trigger change and respond with Hyperventilation –> Excessive C02 removal (Hypocapnea) –> Respiratory Alkalosis
  2. Within ours to several days: Kidneys respond –> Decrease HCO3 reabsorption in PCT & Decrease H+ secretion –> Compensatory Metabolic Acidosis
  3. Chronic Hypoxemia –> Inc EPO –> Inc RBC count
    • Alkalosis causes LEFT SHIFT –> Reduced O2 delivery to tissues –> Eventually RBCs increase 2,3 BPG to increase O2 delivery`

Renal System

Diuretics Overuse –> Increase pH, Increase HCO3 retention –> METABOLIC ALKALOSIS

GastroIntestinal System

Excessive Vomitting –> Loss of HCL –> H+ loss, High pH, High HCO3 –> __Metabolic Alkalosis –> Compensated: Hypoventilation –> pCO2 retention.

Acute Ischemic Colitis


Opioid Overdose: respiratory arrest –> Hypoventilation, Hypoxemia –> retention of CO2 –> Acute Respiratory Acidosis

tags: acid-base - review