Background: During hospitalization, horses typically undergo frequent blood sampling for diagnostic testing and monitoring. The need for numerous samples in hospitalized horses makes acquisition from an intravenous catheter (IVC) both convenient and less stressful to the patient.
Hypothesis: We hypothesized that there would be no significant difference in the plasma chemistry and CBC variables from blood samples obtained from a jugular catheter as compared with direct jugular venipuncture.
Animals: Fifty adult hospitalized horses; 25 receiving constant rate crystalloid therapy, and 25 receiving low volume IV medication.
Methods: This study was conducted using a prospective, blinded, cross-over design. Samples were obtained sequentially by direct venipuncture of the jugular vein and aspiration from an IVC in the contralateral vein after an appropriate presample of blood was obtained and discarded. Samples were submitted for blinded analysis including CBC, plasma chemistry analysis, stall side plasma glucose concentration, PCV, and total protein concentration. Data obtained were analyzed using a Student's t-test with compensation for unequal variances between the 2 groups. Analyses were Bonferroni corrected for a 5% 2-tailed hypothesis test.
Results: There were no statistically significant or clinically relevant differences associated with sampling method (venipuncture versus catheter) regardless of fluid administration status in any of the 24 analytes measured.
Conclusions and Clinical Importance: Blood samples obtained by IVC have clinically equivalent values to those taken by direct venipuncture in commonly performed analyses. Additional investigation is warranted to establish if this technique is associated with increased complications such as phlebitis or bacteremia.