Home

helps physicians and healthcare professionals

Erectile Dysfunction

helps physicians and healthcare professionals

Doctor123.org

helps physicians and healthcare professionals

Bicarbonate (HCO3−), Blood


Definition


  • Bicarbonate is an indicator of the buffering capacity of the blood. Low bicarbonate indicates that a larger pH change will occur for a given amount of acid or base produced.
  • Bicarbonate in the blood is calculated from the pH and PCO2 using the Henderson-Hasselbalch equation.
  • Normal range:
    • Arterial: 21 " �28 mEq/L
    • Venous: 22 " �29 mEq/L

Use


  • Significant indicator of electrolyte dispersion and anion deficit.
  • Together with pH determination, bicarbonate measurements are used in the diagnosis and treatment of numerous potentially serious disorders associated with acid " �base imbalance in the respiratory and metabolic systems. Some of these conditions are diarrhea, renal tubular acidosis, carbonic anhydrase inhibitors, hyperkalemic acidosis, renal failure, and ketoacidosis.

Interpretation


Increased In


  • Primary metabolic alkalosis
  • Primary respiratory acidosis
  • Severe vomiting
  • Lung disease (COPD)
  • Cushing syndrome
  • Diuretics
  • Primary hyperaldosteronism
  • Laxative abuse

Decreased In


  • Primary metabolic acidosis
  • Primary respiratory alkalosis
  • Addison disease
  • Ethylene glycol or methanol poisoning
  • Chronic diarrhea
  • Salicylate overdose

Limitations


  • Bicarbonate can be determined by titration, but this is rarely done.
  • HCO3 � � � is the largest fraction contributing to the total CO2. Therefore, both parameters usually change in the same direction.
  • The standard HCO3 � � � is the concentration of HCO3 � � � in whole blood at 38 � �C equilibrated at a PCO2 of 40 mm Hg with the blood Hb fully oxygenated.
Copyright © 2016 - 2017
Doctor123.org | Disclaimer