Acid-Base Balance Ahmed Abughaban 2021040088 Acid-Base abnormalities Metabolic Acidosis Metabolic Alkalosis Respiratory Acidosis Respiratory Alkalosis Mechanisms of acid-base balance Respiratory system Kidneys Buffers HCO3 reabsorption Excretion of organic acids Titrable acids (HPO4) Ammonium (NH4) Ca, Hb, PP bones Metabolic Acidosis Definition: Primary decrease in serum HCO3 Decreased pH Accumulation of acids Anion Gap Represents the unmeasured anions in plasma. AG=Na - (Cl + HCO3) Normal AG= 10-12 mEq/L Causes of ↑AG metabolic acidosis: “Accumulation of acids” 1. lactic acidosis 2. Ketoacidosis - diabetic, alcoholic, starvation 3. Toxins - ethylene glycol, methanol, salicylates 4. RF - acute & chronic Causes of normal AG metabolic acidosis: 1- Renal • RTA • Fanconi’s synd 2- GIT • Severe diarrhea • GIT fistula 3- Drugs (+ renal insuff.) • K sparing diuretics • Heavy metals • ACEIs • NSAIDs “Loss of alkali” POG unmeasured NON-IONIZED AG unmeasured IONIZED Plasma Osmolal Gap POG= measured - calculated plasma osm Steps in Acid-Base Diagnosis Obtain ABG & electrolytes Check pH & compare HCO3 on ABG & measured for accuracy Calculate AG Try to identify the cause according to the AG Estimate compensatory response (PaCo2 ↓ 1.25 mmHg per mmol/L ↓ in HCO3) . Acid-Base Balance Ahmed Abughaban 2021040088 Acid-Base abnormalities Metabolic Acidosis Metabolic. Alkalosis Respiratory Acidosis Respiratory Alkalosis Mechanisms of acid-base balance Respiratory system Kidneys Buffers HCO3 reabsorption Excretion