• 1. Maddison JE. Hepatic encephalopathy. J Vet Intern Med 1992; 6: 341353.

  • 2. Taboada J, Dimski DS. Hepatic encephalopathy: clinical signs, pathogenesis, and treatment. Vet Clin North Am Small Anim Pract 1995; 25: 337355.

    • Search Google Scholar
    • Export Citation
  • 3. Ong JP, Aggarwal A, Krieger D, et al. Correlation between ammonia levels and the severity of hepatic encephalopathy. Am J Med 2003; 114: 188193.

    • Search Google Scholar
    • Export Citation
  • 4. Kundra A, Jain A, Banga A, et al. Evaluation of plasma ammonia levels in patients with acute liver failure and chronic liver disease and its correlation with the severity of hepatic encephalopathy and clinical features of raised intracranial tension. Clin Biochem 2005; 38: 696699.

    • Search Google Scholar
    • Export Citation
  • 5. Berent AC, Tobias KM. Portosystemic vascular anomalies. Vet Clin North Am Small Anim Pract 2009; 39: 513541.

  • 6. Barsotti RJ. Measurement of ammonia in blood. J Pediatr 2001; 138: S11S19.

  • 7. Green A. When and how should we measure plasma ammonia? Ann Clin Biochem 1988; 25: 199209.

  • 8. Huizenga JR, Tangerman A, Gips CH. Determination of ammonia in biological fluids. Ann Clin Biochem 1994; 31: 529543.

  • 9. Howanitz JH, Howanitz PJ, Skrodzki CA, et al. Influences of specimen processing and storage conditions on results for plasma ammonia. Clin Chem 1984; 30: 906908.

    • Search Google Scholar
    • Export Citation
  • 10. Goggs R, Serrano S, Szladovits B, et al. Clinical investigation of a point-of-care blood ammonia analyzer. Vet Clin Pathol 2008; 37: 198206.

    • Search Google Scholar
    • Export Citation
  • 11. van Straten G, Spee B, Rothuizen J, et al. Diagnostic value of the rectal ammonia tolerance test, fasting plasma ammonia and fasting plasma bile acids for canine portosystemic shunting. Vet J 2015; 204: 282286.

    • Search Google Scholar
    • Export Citation
  • 12. Cheng C-F, Tong TK, Kuo Y-C, et al. Inspiratory muscle warm-up attenuates muscle deoxygenation during cycling exercise in women athletes. Respir Physiol Neurobiol 2013; 186: 296302.

    • Search Google Scholar
    • Export Citation
  • 13. PocketChem BA user manual. Kyoto, Japan: Arkray Group, 2013.

  • 14. PocketChem BA strip [packet insert]. Kyoto, Japan: Arkray Group, 2016.

  • 15. Hitt ME, Jones BD. Effects of storage temperature and time on canine plasma ammonia concentrations. Am J Vet Res 1986; 47: 363364.

    • Search Google Scholar
    • Export Citation
  • 16. Nikolac N, Omazic J, Simundic A-M. The evidence based practice for optimal sample quality for ammonia measurement. Clin Biochem 2014; 47: 991995.

    • Search Google Scholar
    • Export Citation
  • 17. Maranda B, Cousineau J, Allard P, et al. False positives in plasma ammonia measurement and their clinical impact in a pediatric population. Clin Biochem 2007; 40: 531535.

    • Search Google Scholar
    • Export Citation

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Ammonia concentrations in canine whole blood, EDTA-anticoagulated whole blood, and plasma measured by use of a point-of-care ammonia meter

Adesola Odunayo DVM, MS1, Karen M. Tobias DVM, MS2, Chika C. Okafor DVM, Phd3, and Bente Flatland DVM, MS4
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  • 1 Department of Small Animal Clinical Sciences, College of Veterinary Medicine, University of Tennessee, Knoxville, TN 37996.
  • | 2 Department of Small Animal Clinical Sciences, College of Veterinary Medicine, University of Tennessee, Knoxville, TN 37996.
  • | 3 Department of Biomedical and Diagnostic Sciences Sciences, College of Veterinary Medicine, University of Tennessee, Knoxville, TN 37996.
  • | 4 Department of Biomedical and Diagnostic Sciences Sciences, College of Veterinary Medicine, University of Tennessee, Knoxville, TN 37996.

Abstract

OBJECTIVE To investigate the use of canine whole blood (WB) for measurement of ammonia concentration by use of a point-of-care ammonia meter and to compare results of measuring ammonia concentrations in WB, EDTA-anticoagulated WB, and plasma.

ANIMALS 40 client-owned dogs.

PROCEDURES A blood sample (2 mL) was obtained from each dog. One drop of WB was immediately applied to a test strip for evaluation with an ammonia meter. The remainder of the blood sample was placed in an EDTA-containing tube, and 1 drop of EDTA-anticoagulated WB was applied to a test strip. The remaining EDTA-anticoagulated WB sample was centrifuged, and the plasma was harvested and placed on ice. One drop of plasma was applied to a test strip; the remainder of the plasma sample was transported on ice and used for ammonia measurement with a reference laboratory instrument. All samples were tested within 1 hour after sample collection. Results were evaluated to detect significant differences in ammonia concentration.

RESULTS Ammonia concentrations did not differ significantly between WB and EDTA-anticoagulated WB and between plasma samples measured with the meter and reference laboratory instrument. However, median ammonia concentration was significantly higher in plasma than in WB or EDTA-anti-coagulated WB.

CONCLUSIONS AND CLINICAL RELEVANCE Anticoagulant-free WB was a valid sample for measurement by use of the ammonia meter. Plasma samples had higher ammonia concentrations than did WB samples. Results for each sample type should be interpreted by use of specimen- and method-specific reference intervals.

Contributor Notes

Address correspondence to Dr. Odunayo (aodunayo@utk.edu).