Why is it inappropriate to estimate GFR in AKI with CG or MDRD?

The eGFR estimation formulas [(such as Cockcroft-Gault or MDRD)] were derived using patients at steady states, whose renal function was stable; can only be used in patients with stable creatinines.

EXAMPLE: A patient goes for surgery and has a baseline creatinine of 125. They sustain a very severe renal injury => their GFR will fall suddenly (let’s just say to near zero) but their creatinine will lag behind (remain @125) initially when you run bloodwork post surgery. The following day their creatinine will begin rising to ~200, yet their GFR would still be near zero. This lag demonstrates why you can’t use this estimation in the setting of AKI.

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

Published by
Dr. C Humphreys

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.