? Help understanding blood ketone readings

I have a Ketomojo Blood Ketone Test Kit. I also have some Ketodiastik urine test strips. I primarily use the blood meter since it's more immediate, however it only gives a number so I refer to the urine strips for the descriptive value (trace, small, medium, large). The blood meter is in mmol/L, the urine strips in mg/L, and the conversion from mmol/L to mg/L is x18. So I would take my meter reading, x18, and then read on the test strip to see where we were at.

Yesterday, Sebastian threw a 2.2 on the meter which, based on the conversion factor, would be 40 on the urine strips or "moderate". Obviously concerned, I added that info to yesterday's thread and went into crisis management mode. Then, people started saying "ketones start to show up in cat's blood at about 2.4 - 2.5 on a human ketone/BG meter", referencing this post and the attached research studies.

This made no sense to me. I've gotten a wide range of readings on the meter, 0.2, 0.5, 1.1, etc etc etc, so if "ketones don't show until 2.4", what was my ketone meter reading at those <2.4 values?

I re-read the insert from the ketone meter. I also skimmed over the research papers. So far I've only come up with one explanation to reconcile the disconnect:

The ketone meter says it measures "Beta-Hydroxybutyrate". So the explanation I came up with is that the presence of that in the blood means different things for cats than it does for humans and it's not until that gets to 2.4 that we starting seeing "ketones" in the cat.

So, if that's the case, how do interpret the blood meter readings to know how Sebastian's ketones are? How do I know when he's at trace, small, medium, or large levels?

Tagging a couple people who were supplying info in yesterday's thread (@Bobbie And Bubba @Crista & Ming @Christie & Maverick) as well as @Jill & Alex (GA) as the original source of the info.

 

Actually, the source of the info was Kirsten Roomp from tillydiabetes.com / Tight Regulation with Lantus or Levemir for Diabetic Cats. The two studies done in 2012 conclude a blood ketone concentration as in DKA is more likely to be present at 2.4 / 2.55 mmol/L.
References:

• The blood Measurement of β-hydroxybutyrate in cats with nonketotic diabetes mellitus, diabetic ketosis, and diabetic ketoacidosis. - published March 2012
  
• Point-of-care β-hydroxybutyrate measurement for the diagnosis of feline diabetic ketoacidaemia. - published in June 2012

You don't. You're trying to compare apples & oranges.

• Urine dipsticks measure acetoacetate.
• The blood ketone meter measures β-hydroxybutyrate in diabetic cats.

"The objectives of the current study were to assess the diagnostic utility of β-HB to diagnose diabetic ketosis (DK) and DKA in cats and to establish a cut-off value for the diagnosis of DKA." The studies concluded that cut-off is 2.4 / 2.5 mmol/L.

"A β-hydroxybutyrate concentration of >2·55 mmol/L had a sensitivity of 94% and a specificity of 68% for diagnosing ketoacidaemia."


ketoacidaemia: the presence of ketones in the blood
ketoaciduria: the presence of ketones in the urine




Clear as mud?

 

I think the terminology being used is what's confusing me, like "ketones" and "DKA" are being used interchangeably. Before, I was thinking that DKA was a tipping point where the ketones had reached a certain concentration. But now it's sounding like they're one in the same, any amount of ketones means DKA is going on? But then that still leaves me with the question of, when the reading is <2.4, what does that mean? And what are the equivalent trace, small, moderate, large thresholds for the blood meter?

 

A 2.4 would make me nervous. If it were my cat I'd give the vet a call. If you have sub q's at home you could try that and retest later.

 

This probably isn't what you want to hear, but my interpretation is if I were to get a blood ketone reading of 2.4 or greater, my cat would have lab work done immediately.

There aren't any. You're looking for something that isn't there. If you want to know the results of those measurements, use the dipsticks (apples & oranges).

 

And that's what I did yesterday when we hit 2.2. I don't see the vets helping much, at least not mine. At best they'll give sub-q and a fast acting insulin, both of which I have and can do. At worst they're going to pump him full of antibiotics and screw up his system even more. But we got it under control at home, 2.2 yesterday morning, 1.2 yesterday evening, 0.8 this morning.

Okay. I'm still curious about what's going on when we're below 2.4 but I guess I can work with this. I was hoping to hold off on getting his lab done for another couple weeks because I wanted to tie in the results of his fecal transplant but if the ketones start jumping up again I'll get it now so we can see what's going on.

 

I'm glad Jill weighed in about the difference with the measurements from the urine dip stick and the blood ketone meter. It is all very confusing adapting a piece of equipment designed for human blood to cat blood.

 

Awesome! The sub q really helped. Great that you are on top of it