Influence of hypertonic saline solution 7.2% on different hematological parameters in awake and anaesthetized ponies.

The research article examines the effects of a 7.2% hypertonic saline solution on various blood parameters in awake and anaesthetized ponies, compared with a 0.9% isotonic saline solution as a control.

Research Methodology

• The study involved five ponies, some of which were standing and awake, while others were anaesthetized with standard halothane anaesthesia.
• The researchers infused a 7.2% hypertonic saline solution into the ponies at a volume of 4 ml/kg of body weight. An isotonic 0.9% saline solution was used as a control in the standing ponies.
• Following the infusion, the researchers measured various hematological parameters including plasma and blood volume, sodium, chloride, and potassium plasma concentrations, osmolality, total protein content, packed cell volume, and red blood cell count.
• In the anaesthetized ponies, the researchers additionally monitored arterial blood gases.

Research Findings

• The isotonic solution caused only minor decreases in potassium, total protein content, packed cell volume, and red blood cell count in the standing ponies.
• Significant increases in sodium, chloride, and osmolality were observed following the 7.2% saline infusions in both the standing and anaesthetized ponies.
• Significant decreases in packed cell volume, red blood cell count, and total protein content were noted after the hypertonic solution administration, indicating occurrence of hemodilution, although no significant increases in plasma and blood volume could be demonstrated.
• Increased urination was observed in the standing ponies and during the recovery period after anaesthesia, suggesting partial compensation for the fluid shift towards the intravascular compartment occurring due to the hypertonic solution.
• The decreases in packed cell volume, red blood cell count, and total protein content were less dramatic in the anaesthetized ponies, which the researchers hypothesized might be due to stress responses during anaesthesia.
• An abnormal increase in potassium was noted at the end of anaesthesia, likely due to minor muscle damage resulting from the dorsal recumbent position.
• The 7.2% saline solution did not change arterial blood gas levels during anaesthesia and no specific clinical side effects related to its use were observed.

Research Conclusion

• The use of hypertonic saline solution led to significant alterations in various hematological parameters and caused a shift in fluids towards the intravascular compartment, which was partly countered by increased urination.
• Although no clinical side effects were observed in this study, further research is recommended to thoroughly evaluate the effects of hypertonic saline solution in horses with disturbed fluid balance, such as hypovolemia.