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Acidosis: Quick Steps to Evaluate, Protect and Intervene
Barbara McLean, MN, RN, CCRN, CCNS, CRNP, FCCM; bamclean@mindspring.com
Upon completion of this course, the participant will be able to:
1. Identify the complications that occur with metabolic acidosis;
2. Define the indicators of metabolic acidosis; and
3. Relate basic physiology to anion gap and potassium.
Metabolic Acidosis Complications A. When the patient has refractory hypotension 1. Consider the effects of hydrogen 2. Evaluate serum potassium 3. Determine the effects of vasopressor therapies 1. Cellular protection 2. Ion shifts 3. Loss of sympathetic tone 1. Treat the problem not the symptom 2. Neutralize the pH 3. Utilize agents that bypass sympathetic receptors D. Case study—12-year-old diabetic presents with Kussmaul breathing 1. pH: 7.05 2. pCO2: 12 mm Hg 3. pO2: 108 mm Hg 4. HCO3: 5 mEq/L 5. BE: -30 mEQ/L E. Case study—seven year-old post op presenting with chills, fever and hypotension 1. pH: 7.25 2. pCO2: 32 mm Hg 3. pO2: 55 mm Hg 4. HCO3: 10 mEq/L 5. BE: -15 mEQ/L The Indicators of Metabolic Acidosis: Simple to Sublime A. Simple predictors that require further evaluation 1. Persistent rapid respiratory rate 2. Persistent tachycardia 3. Perceived prodrome 4. Urinary output (U/O) less than 1.0 mL/kg 1. Anion gap 2. Ketoacid 3. Lactic acid 4. Central venous oxygen saturation 5. Skeletal muscle tissue oxygenation 6. End tidal carbon dioxide Basic Physiology to Anion Gap and Potassium A. When there is an increase in unmeasured ions, there will be a gap between the positive and negative measure. 1. A gap of greater than 20 implies a metabolic increase in acid production 2. Lactic acid and ketoacid donate H+ 3. Hydrogen binds to HCO3 and/or Chloride (CI) changing the charge; HCO3 and/or CI decreases. 4. The gap between positive and negative gets wide B. Ionic shift: potassium for hydrogen C. Strong ion dissociation D. Components if strong ion dissociation E. Cases
Resources
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