Comparative biochemical analyses of venous blood and peritoneal fluid from horses with colic using a portable analyser and an in-house analyser.
Authors: Saulez M N, Cebra C K, Dailey M
Journal: The Veterinary record
Summary
# Editorial Summary When managing acute colic cases, rapid biochemical assessment of blood and peritoneal fluid can inform treatment decisions and prognosis; however, portable analysers offer convenience at the potential cost of accuracy. This study compared measurements of glucose, lactate, pH, and electrolytes (sodium, potassium, chloride) from 56 colic cases using a portable point-of-care device against standard laboratory analysis, evaluating their clinical concordance across the physiological ranges encountered in equine emergency medicine. The portable analyser demonstrated concerning limitations: it systematically underestimated lactate and glucose concentrations in peritoneal fluid—particularly problematic since elevated peritoneal lactate suggests septic peritonitis and guides decisions regarding surgical intervention—whilst pH readings showed greater variability, especially at alkaline values. Electrolyte measurements proved less reliable in peritoneal fluid than venous blood, with notably higher bias in sodium and chloride readings. Clinicians using portable analysers for colic assessment should recognise that results, particularly peritoneal fluid lactate and glucose values below reference thresholds, may underestimate metabolic derangement and should be interpreted cautiously or confirmed with laboratory analysis when diagnostic uncertainty exists or when results will substantially alter treatment strategy.
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Practical Takeaways
- •Portable analysers may not be interchangeable with in-house laboratory analysers for colic cases; results in critical ranges (acidic pH, low lactate, low glucose) should be verified with laboratory confirmation
- •When using portable analysers for colic evaluation, be aware of systematic underestimation of lactate and glucose, particularly in peritoneal fluid assessment
- •Portable analyser measurements of electrolytes in peritoneal fluid are less reliable than in blood; prioritise laboratory analysis for peritoneal fluid if making treatment decisions based on sodium and chloride concentrations
Key Findings
- •Portable analyser gave higher pH values for blood and peritoneal fluid in alkaline range but lower pH values in acidic range compared to in-house analyser
- •Portable analyser underestimated lactate concentrations in venous blood (<5 mmol/l) and peritoneal fluid (<2 mmol/l)
- •Portable analyser underestimated glucose concentrations in blood below 8.3 mmol/l
- •Portable analyser showed higher bias and greater variability for sodium and chloride in peritoneal fluid but lower bias and less variability for potassium measurements