Lab values

[EDnurse1228]

Can someone explain lactic acid in a nutshell?

[canned_bread]

It's produced by our bodies during metabolism and exercise. The concentration in our body is usually 1-2 nmol/L but can rise after exercise (sometimes up to 20... when it goes above 20 you start to wonder what's happening). It's added to IV fluids like Hartmann's to be isotonic for our blood.

If you want to know the chemical processes, that gets more confusing. But basically during exercise when you need energy, glucose is broken down and turned into pyruvate and lactic acid comes from pyruvate. When it's time to reverse it turns back into pyruvate (remember Krebs cycle?), or converts to glucose in the liver and goes back into circulation.

Tissue death = raised lactic acid.

Mitochondrial disorders = raised lactic acid.

[CABG patch kid, BSN, RN]

I just wanted to add that lactic acid is increased during times of anaerobic metabolism, when there isn't enough oxygen getting to the tissues. That's why it's increased during sepsis.

[Vespertinas]

My $0.02

You can find lactic acidosis in individuals with both acute and chronic liver disease simply because the liver is what clears lactic acid.

You may often hear that metformin can lead to lactic acidosis. That's because metformin causes a slight elevation in lactate already by its MOA but that is easily cleared by the kidneys. You probably noticed we we are careful to hold metformin for any reason that could lead to renal insufficiency such as dehydration, contrast dye, or sepsis. That could tip the scales toward lactic acidosis.

[turnforthenurse, MSN, NP]

You may often hear that metformin can lead to lactic acidosis. That's because metformin causes a slight elevation in lactate already by its MOA but that is easily cleared by the kidneys. You probably noticed we we are careful to hold metformin for any reason that could lead to renal insufficiency such as dehydration, contrast dye, or sepsis. That could tip the scales toward lactic acidosis.

Where I work, if a patient is on metformin at home, the MD immediately suspends it and puts the patient on insulin for those exact reasons.

You can find lactic acidosis in individuals with both acute and chronic liver disease simply because the liver is what clears lactic acid.

This is exactly why you never give a liver patient LR, too.