Haematological, serum electrolyte and blood gas effects of small volume hypertonic saline in experimentally induced haemorrhagic shock.

This study investigated how small amounts of hypertonic and isotonic saline solutions impact the blood composition and blood gases in horses experiencing induced hemorrhagic shock. The results revealed that hypertonic saline treatment caused some changes in the blood but did not lead to extreme alterations, suggesting its safe use in horses under such conditions.

Objective and Methodology

• The goal of this research was to evaluate the effects of small-volume hypertonic (Highly concentrated) and isotonic (Normal concentration) saline treatments on horses in a state of induced haemorrhagic shock. The investigators used a sample of 12 horses and examined changes in blood composition and gas concentrations.
• Before proceeding with the test regime, the researchers ensured surgical placement of intravascular catheters for secure sample collection. The haemorrhagic shock in the horses was induced and maintained until the mean systemic pressure reached 50 to 60 mmHg.
• After inducing hemorrhagic shock, the isotonic or hypertonic saline solution was administered intravenously, and data was recorded for two hours.

Findings

• Following induced hemorrhage, there was an increase in packed cell volume (PCV), haemoglobin, blood glucose concentrations, and the number of red blood cells (erythrocytes). Simultaneously, there was a decrease in plasma total protein and albumin concentrations.
• The administration of hypertonic saline led to an additional decrease in the concentrations of total protein and albumin. No significant changes were observed in glucose concentrations and other haematological variables. Also, administration of isotonic saline did not bring about any changes in electrolyte, total protein, or albumin concentrations.
• Induced hypotension did not cause any alterations in sodium and chloride levels. However, these electrolyte levels significantly increased following hypertonic saline treatment, even exceeding normal values during the immediate treatment period. Along with this, serum osmolality (the concentration of all chemical particles found in the plasma) also increased.
• Neither induced haemorrhage nor isotonic saline treatment led to any significant shifts in arterial and venous blood gas values. Hypertonic saline administration led to a transient decrease in arterial and venous blood pH levels, alongside a sustained decrease in venous bicarbonate and base excess concentrations.
• The research findings indicated no significant increases in any serum biochemical concentrations during the period of induced hypotension or after the administration of either isotonic or hypertonic saline.

Conclusion

• The findings of this study showed that small volumes of hypertonic saline could be administered safely to horses without triggering extreme changes in blood composition, gas levels, or haematological parameters. This result provides insight into potential treatment methods for horses under conditions of haemorrhagic shock.