Measuring blood lactate levels in dogs with Gastric Dilatation Volvulus (GDV) can guide you on your resuscitation efforts and help you better understand the prognosis as you communicate with dog owners.
Below are tips on measuring blood lactates that may help you in your practice.
Lactic acid is a weak acid and dissociates into lactate (-) and H+. Normally glucose is converted into pyruvate via glycolysis in the cytosol and then can go through 4 different pathways.
These pathways include:
The conversion of pyruvate to lactate is favored by:
Lactate levels represent the balance between production and clearance. Lactate clearance is done mainly in the liver and about 40% via the kidney.
The normal lactate blood level ranges include:
There are 2 types of lactate – referred to as Lactate L and Lactate D. The “L” Lactate is the kind that matters in most of our emergency patients but “D” lactate can be produced in bacterial fermentation of carbohydrates (SIBO).
Hyperlactatemia is broken into 4 categories – Type A, Type B1, B2, and B3. Type A and B1 are the most clinically relevant.
Lactate has been looked at as a biomarker in GDV as a prognostic indicator. The first papers looked at a single lactate measure. What we have found over time is that it is really the clearance of lactate (the change of lactate over time from therapy, also known as delta lactate) is a better indicator of prognosis.
A landmark human paper looking at lactate clearance in sepsis found that a delta lactate of > 10% is a good indicator.
Below is a summary of lactate variables looked at in various publications:
What you can see is that there isn’t a great consensus and that some of the papers contradict themselves. We utilize lactate solely as interpreted as delta lactate and even with that with a grain of salt.
This means I will do a lactate on presentation and after fluid resuscitation before surgery if the initial is high. If the second value remains high and if the initial value is very high I will have a more serious conversation that we may find gastric necrosis in surgery and may need to do a gastric resection. We also may have a sicker dog that needs more intensive care post-operatively.
A single high lactate or even failure to clearance doesn’t mean the dog will die or even need a gastric resection. It may be telling you that you are not fluid resuscitated yet, there is some other failure of clearance.
I try to discourage euthanasia based solely on a lactate value as the post-operative management with critical care has evolved greatly over the years. There are many of these dogs that survive hospitalization even with numbers that say they wouldn’t.