Comparison of STA-NeoPTimal (Stago) and STA-Neoplastine CI Plus (Stago) thromboplastin reagents using a STA Satellite Max analyzer to measure prothrombin times in dogs.

BACKGROUND: Different thromboplastins are available to measure prothrombin time (PT). Stago coagulation analyzers and reagents are currently used in veterinary laboratories and enable PT measurements to explore the coagulation cascade (extrinsic pathway). OBJECTIVES: The main objective was to compare PT measurements obtained with the STA-NeoPTimal reagent with the commonly used STA-Neoplastine CI Plus reagent. The secondary objective was to compare the PT ratio with the international normalized ratio (INR) calculated from our derived clotting times. METHODS: Analytical performance was evaluated with intra-assay and inter-assay precision. Seventy-two individual canine plasma samples were collected. Each sample was tested with both thromboplastins, using an STA Satellite Max analyzer. The PT, PT ratio, and INR values obtained with the two reagents were compared using Passing-Bablok regression for correlations and Bland-Altman plots for method agreements. RESULTS: The analytical performance of STA-NeoPTimal reagent was acceptable. Compared with the STA-Neoplastine CI Plus reagent, the STA-NeoPTimal reagent showed a positive proportional bias for PT values. Narrow range analyses showed good agreement for normal PT values (less than 9.5 seconds, internal reference cutoff with STA-Neoplastine CI Plus), and clinical concordance was achieved. When PT was prolonged (more than 9.5 seconds), PT increases were more marked with the STA-NeoPTimal reagent. Agreement was good for INR values across the whole range of PT results. CONCLUSION: STA-NeoPTimal can be reliably implemented in veterinary laboratories for canine PT measurements, as agreement between the PT results measured with the two reagents was clinically acceptable.

Controversies in the use of fresh frozen plasma in critically ill small animal patients.

OBJECTIVE: To review the literature supporting or discouraging the use of fresh frozen plasma (FFP) transfusion in critically ill patients. DATA SOURCES: Human and animal publications were searched using PubMed without time limits and the following keywords were used: "fresh frozen plasma," "coagulopathy," "hypocoagulable state," "hypercoagulable states," and "critical illness." HUMAN DATA SYNTHESIS: The commonly used tests of coagulation (eg, prothrombin time, activated partial thromboplastin time, international normalized ratio) are poorly predictive of clinical bleeding. FFP use in critically ill patients is unlikely to result in improved outcomes and may be associated with increased risks. VETERINARY DATA SYNTHESIS: There is insufficient evidence to make definitive conclusions regarding the use of FFP in critically ill animals, but clinical studies are underway that may provide further data that clarify the optimal use of FFP in animals. CONCLUSIONS: The use of FFP in critically ill patients remains controversial. In the absence of clinical bleeding or a risk for clinical bleeding associated with a planned procedure, treatment use of FFP is not recommended in human patients. There are insufficient data in critically ill animals to enable formulation of recommendations. Further research is warranted in dogs and cats to establish evidence-based guidelines.

Assessment of a portable prothrombin time analyzer (CoaguChek-XS) in dogs.

OBJECTIVES: To assess the performance of a portable prothrombin time (PT) analyzer (CoaguChek-XS) in dogs. ANIMALS: Ninety-seven dogs composed of 20 healthy dogs, 45 ill dogs, and 32 ill dogs with altered coagulation. PROCEDURES: Samples were concurrently obtained and PT was measured using the CoaguChek-XS and an automated coagulation analyzer. Agreement between methods was assessed using Spearman's correlation and Bland-Altman analysis. RESULTS: The reference interval for PT using the CoaguChek-XS was 9.6-11.5 s. The CoaguChek-XS was easy to use, required a small volume of whole blood, and gave results within 1 min. The mean difference in PT between the 2 methods was 2.58 s (SD 3.10), and 94% of the samples fell within limits of agreement. The correlation was moderate, but significant (r = 0.35, P < 0.001). Sensitivity and specificity of the CoaguCheck-XS PT compared to analyzer PT were 92% and 56%, respectively, and increased to 95% and 77% on intent to treat basis. The coefficient of variance was 0.72%. The CoaguChek-XS identified all 8 dogs with anticoagulant rodenticide intoxication, although a discrepancy was noted from the analyzer results. In anemic dogs (PCV≤25%), the CoaguChek-XS did not display accurate results. CONCLUSIONS: The CoaguChek-XS is a simple, user-friendly, highly precise PT analyzer. Results had moderate correlation and good agreement with a standard method. It can be used reliably for screening dogs when the PT is normal. However, when the CoaguChek-XS PT is prolonged or when the PCV is ≤25%, results should be confirmed using a standard method.