Content continues after advertisement

Clinical Implications of Delayed Lactate Analysis

Søren R. Boysen, DVM, DACVECC, University of Calgary

Emergency Medicine & Critical Care

|November/December 2021

Sign in to Print/View PDF

In the Literature

Rizzo KN, Rozanski EA, DeLaforcade AM. Effect of time until sample analysis on lactate in dogs with shock. Vet Clin Pathol. 2020;49(4):614-617.


Lactate concentration is widely used as a point-of-care diagnostic indicator to rapidly assess the severity of shock and response to treatment in patients with clinical signs of hypoperfusion. Confounding factors (eg, prolonged vessel occlusion, certain medications, patient stress, time delays between blood collection and analysis) can falsely increase lactate concentrations and complicate interpretation of baseline and serial lactate values in critically ill patients.1,2

This study used a handheld point-of-care lactate meter to assess the impact of time between whole blood collection and lactate analysis in clinically ill dogs at an emergency clinic. In prior studies of healthy dogs, lactate concentrations increased up to 34% from baseline within 15 to 25 minutes when blood was stored at room temperature.3 The current study reported significantly increased lactate concentrations when whole blood samples from ill dogs were stored at room temperature, with increases observed in as few as 7.5 minutes. The greatest increases occurred in dogs with lower presenting lactate concentrations. 

Within 7.5 minutes of sampling, average increase above baseline was 11% in dogs with initial lactate values <4 mmol/L and 4% in dogs with initial lactate values >4 mmol/L. Although a 4% increase is unlikely to influence clinical decision-making when baseline lactate is already ≥4 mmol/L, after 30 minutes of sampling, the percentage increase above baseline grew to 39% and 15% in dogs with initial lactate concentrations <4 mmol/L and ≥4 mmol/L, respectively, which could influence clinical management.

This study emphasized the importance of standardizing blood collection and analysis for lactate concentration in small animal patients and suggested that caution should be used when interpreting blood lactate results from room temperature samples analyzed >7.5 minutes after collection.


Key pearls to put into practice:


There are multiple causes of increased lactate in dogs and cats, with hypoperfusion being the most common. Serial lactate measurement is often recommended to guide treatment for patients in shock.


Confounding factors—such as those that result in type B lactic acidosis (eg, strenuous exercise, prednisone administration, seizures, decreased clearance) and sampling errors (eg, prolonged vessel occlusion, delayed analysis of whole blood samples)—should be considered when interpreting baseline and serial lactate concentrations.


When using point-of-care handheld lactate meters, whole blood samples should be analyzed within 7.5 minutes of collection to avoid misinterpretation of lactate concentration.


For global readers, a calculator to convert laboratory values, dosages, and other measurements to SI units can be found here.

All Clinician's Brief content is reviewed for accuracy at the time of publication. Previously published content may not reflect recent developments in research and practice.

Material from Clinician's Brief may not be reproduced, distributed, or used in whole or in part without prior permission of Educational Concepts, LLC. For questions or inquiries please contact us.


Clinician's Brief:
The Podcast

Listen as host Alyssa Watson, DVM, talks with the authors of your favorite Clinician’s Brief articles. Dig deeper and explore the conversations behind the content here.
Clinician's Brief provides relevant diagnostic and treatment information for small animal practitioners. It has been ranked the #1 most essential publication by small animal veterinarians for 9 years.*

*2007-2017 PERQ and Essential Media Studies

© Educational Concepts, L.L.C. dba Brief Media ™ All Rights Reserved. Privacy Policy (Updated 05/08/2018) Acceptable Use Policy (Updated 11/22/2021)