• Open Access

Use of Pericardial Fluid pH to Distinguish between Idiopathic and Neoplastic Effusions

Authors

  • Deborah M. Fine,

    1. Department of Small Animal Clinical Sciences, College of Veterinary Medicine, University of Minnesota, St Paul, MN
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  • Anthony H. Tobias,

    1. Department of Small Animal Clinical Sciences, College of Veterinary Medicine, University of Minnesota, St Paul, MN
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    • 2

      BVSc, PhD, DiplACVIM, Department of Small Animal Clinical Sciences, University ofMinnesota, 1352 Boyd Avenue, Saint Paul, MN 55108; E-mail: tobia004@umn edu

  • Kristin A. Jacob

    1. Department of Small Animal Clinical Sciences, College of Veterinary Medicine, University of Minnesota, St Paul, MN
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Abstract

Pericardial effusion (PE) resulting from neoplasia usually is associated with a poor prognosis, whereas idiopathic PE frequently has a good prognosis. This study examined the utility of pH measurement to distinguish between these 2 etiologies. Dogs were classified as having idiopathic PE (n = 12) if pericarditis was diagnosed on histopathology (n = 4) or if no historical, physical, or echocardiographic evidence of recurrent PE was present for at least 6 months after pericardiocentesis (n = 8). Dogs were classified as having neoplastic PE (n = 25) if pericardial or myocardial neoplasia was detected on histopathology (n = 11) or a discrete mass associated with the right atrium, right ventricle, or the aorta was visualized on echocardiography (n = 14). Samples of PE were centrifuged and the supernatant pH was measured with a portable pH meter. The lowest pH (6.40) was found in a dog with idiopathic PE and the highest pH (7.85) was found in a dog with neoplastic PE. However, data from the 2 groups overlapped in 33 out of 37 (89%) instances, and median pH from the idiopathic and neoplastic groups was not significantly different (7.40 and 7.47, respectively; P= 0.28; difference in medians =–0.07; 95% CI, –0.26-0.06). Because of the degree of overlap, our data provide little justification for the use of pH measurement as a diagnostic test in cases of PE. Key words: Canine; Cardiac tumor; Pericardial effusion; Pericarditis.

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