Effects of collecting serial tracheal aspirate and bronchoalveolar lavage samples on the cytological findings of subsequent fluid samples in healthy Standardbred horses.

The study investigates how repeatedly collecting tracheal aspirate (TA) and bronchoalveolar lavage (BAL) fluid samples affect the cytological properties of these samples in healthy Standardbred horses. The research finds that these samples can be taken at 24-hour intervals without significantly altering subsequent cytological results, enabling frequent testing without skewing results.

Methodology

• Researchers performed an experimental study on six healthy Standardbred horses, focusing on collecting TA and BAL samples at specified intervals.
• All these samples were obtained using Endoscopically-guided and blind field techniques on days 1, 2, 3, 4, 5, 12, and 17. On the 17th day, the procedure was conducted three times at different intervals – baseline, 2.5 hours, and 4 hours apart.
• The differential cytology of the collected fluid samples was analyzed and expressed in percentages for statistical comparison.

Findings

• The study notes a significant increase in the neutrophil percentage in the TA samples at the 2.5 hours interval on day 17, whereas no such significant change was witnessed at a 4-hour interval on the same day.
• In cases where repeated TA samples were collected with a time difference of at least 24 hours, there were no significant alterations in neutrophil percentages.
• Regarding the neutrophil percentages in the BAL fluid, no significant change was observed at any particular collection point.
• The researchers did notice inconsistent shifts in the percentages of lymphocytes and macrophages in the BAL fluid over time. However, these changes were within the normal reference ranges and hence were considered clinically insignificant.

Conclusion

• Their research concludes that serial TA and BAL samples can be procured at 24 hours intervals without influencing subsequent sample’s cytological findings. This ensures the genuineness of the results even with frequent sampling and testing.