Categories: Endocrinology

WHAT IS THE ANION GAP?

Anion gap = Difference between the unmeasured cations and unmeasured  anions in the serum [artificial]

It will done with serum (has clotting factor removed) or with plasma [MOST OFTEN DONE WITH SERUM]

= ([Na+]) − ([Cl] + [HCO3]) = 10 , if greater than 12, IAGMA (when K+ is added, it is ~16)

*You can remove potassium due to its low concentration often having little or no effect on the gap

NORMALLY, there are cations > anions, so the gap is + [BUT plasma is overall electrically neutral]

Increase in this gap will result in increased ion gap acidosis [AKA a drop in the Cl- or Bicarbonate] which will result in more unmeasured anions needed to counter balance the sodium/ unmeasured cations.

WHAT DROPS THE HC03 or Cl-???

There will be an increase in unmeasured acids, that will dissociate into their weak conjugate base (unmeasured anion) AND Hydrogen; the hydrogen will bind with HC03 and shift the equilibrium LEFT [reducing bicarbonate].

WHAT CAUSES THE INCREASED ION GAP ACIDOSIS?

  • G — glycols ( ethylene glycol &  propylene glycol )
  • O — oxoproline, a metabolite of  acetaminophen 
  • L — L-lactate, the chemical responsible for  lactic acidosis 
  • D — D-lactate [REMEMBER: D/L are chiral enantiomers [optical isomers or non-superposable mirror image]
  • M —  methanol / metformin
  • A —  aspirin / salicylic acids
  • R —  renal failure 
  • K —  ketoacidosis , ketones generated from starvation, alcohol, and  diabetic ketoacidosis

 *There is also MUDPILES

REFERENCES

1. Chapter 17. Pancreatic Hormones and Diabetes Mellitus. Greenspan’s Basic & Clinical Endocrinology, 9e  

Get Medical Pearls directly to your inbox every week!
Weekly posts with high yield medical knowledge, directly to your mailbox!
Dr. C Humphreys

Internal Medicine

Recent Posts

Mechanism of a Mixed Apnea

Mixed apneas are characterized by absent respiratory effort and airflow in the first section of…

12 months ago

How Does Hypothyroidism Cause Hypoventilation?

Although rare, the differential diagnosis of hypoventilation and hypercapnia respiratory failure includes hypothyroidism. It is…

12 months ago

Why is Pro-BNP/ BNP lower in Obesity?

B-type natriuretic peptide (BNP) is a hormone created in response to cardiac wall stretch due…

1 year ago

What is Peribronchovascular Distribution on CT imaging?

A common finding described on computed tomography (CT) imaging. A disease with a peribronchovascular distribution…

2 years ago

Trapped Lung vs. Lung Entrapment

Though often used synonymously; Trapped Lung and Lung Entrapment technically describe separate entities along the…

3 years ago

Cause of Pericardial Effusion in Pulmonary Hypertension: Pathogenesis

It is not clearly understood why patients with pulmonary hypertension (PH) develop pericardial effusions. However,…

3 years ago

This website uses cookies.