Metabolic Alkalosis Lecture Notes

Introduction

• Presenter: Sarah from Registered Nurse Orion
• Series on acid and base imbalances
• Focus of this video: Metabolic Alkalosis
  • Upcoming video on Metabolic Acidosis
• Encourage viewers to take a quiz available on the website

General Concepts

• Metabolic problems involve bicarbonate (HCO3) regulated by the kidneys
• Metabolic Alkalosis involves:
  • Excessive loss of hydrogen ions or acids
  • Increase in bicarbonate levels
• Body compensates through respiratory system:
  • Causes hypoventilation to retain CO2 (acid) to balance the alkalotic state

Laboratory Findings

• pH > 7.45 (normal: 7.35 - 7.45)
• Bicarbonate (HCO3) > 26 (normal: 22 - 26)
• PaCO2 levels can be elevated or normal (normal: 35 - 45)

Causes of Metabolic Alkalosis

• Remember the mnemonic ALKALI:
  • A: Aldosterone production (Hyperaldosteronism)
    • Renin-angiotensin-aldosterone system activation
    • Loss of hydrogen ions and potassium
  • L: Loop diuretics (e.g., Lasix, thiazides)
    • Loss of hydrogen ions through urination
  • K: Alkali ingestion
    • Consumption of antacids or alkaline substances
  • A: Anticoagulant use (citrate in blood transfusions or renal replacement therapy)
    • Citrate metabolized as bicarbonate
  • L: Loss of fluids (vomiting, NG suction)
    • Loss of hydrogen ions from GI tract
  • I: Increased sodium bicarbonate administration
    • Overcorrection during metabolic acidosis treatment

Signs and Symptoms

• Bradypnea due to compensation (respiration < 12 breath/min)
• Symptoms of hypokalemia:
  • Tetany, tremors, muscle weakness
  • Fatigue
  • EKG changes: depressed ST segments, flat/inverted T waves, prominent U waves

Nursing Interventions

• Treat the underlying cause:
  • Administer antiemetics for vomiting
  • Monitor and control NG suctioning
  • Discontinue diuretics if necessary
  • Monitor potassium and chloride levels
• Watch arterial blood gases for changes in PaCO2
• Possible administration of Diamox (monitor for hypokalemia)

Arterial Blood Gas (ABG) Problem Solving

• Example Problem:
  • HCO3: 42
  • pH: 7.6
  • PaCO2: 53
• Analysis using Tic-tac-toe method:
  • HCO3 is basic: Metabolic Alkalosis
  • pH is basic
  • PaCO2 is elevated, indicating partial compensation
  • Conclusion: Metabolic Alkalosis, Partially Compensated

Conclusion

• Watch related videos on Metabolic Acidosis and fluid/electrolyte imbalances
• Take the quiz to test knowledge
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