Effects of preoperative administration of hypertonic saline or pentastarch solution on hematologic variables and long-term survival of surgically managed horses with colic.

This research investigates how the administration of hypertonic saline or pentastarch solution prior to surgery impacts the hematologic parameters and long-term survival of horses with colic. The study found that while the hypertonic saline resulted in a more significant reduction in hemoconcentration than the pentastarch solution, there was no observed difference in the long-term survival of the horses in either group.

Objective and Research Design

• The research article aimed to compare the effects of the preoperative administration of two different solutions: hypertonic saline (a solution with 7.2% salt concentration) and pentastarch (a 10% solution in isotonic saline which is equivalent to 0.9% of normal salt concentration). Specifically, the research observed their impacts on certain hematologic parameters — packed cell volume (PCV) and total protein (TP) concentration — in horses with colic that were undergoing emergency exploratory laparotomy.
• The researchers used a prospective, randomized study method to carry out this experiment. They gathered a sample size of 100 horses showing signs of abdominal pain and with a PCV of more than or equal to 0.46 L/L. Each horse was randomly assigned to receive the hypertonic saline or the pentastarch solution before the induction of anesthesia.

Methods and Assessment

• For the comparison, a 4 mL/kg dose of the assigned solution was administered to each horse within a 10 to 20-minute period prior to anesthetic induction. Blood samples were collected at the time of evaluation and not more than 5 minutes after fluid resuscitation. Changes in PCV and TP concentration were then compared.
• The survival rates of the horses were assessed using Kaplan-Meier survival analysis and Cox proportional hazards analysis.

Results

• The initial examination showed that the age, weight, sex, PCV, and heart rate were similar in both groups, indicating that the random allocation was successful in creating comparable treatment groups.
• The treatment using hypertonic saline solution resulted in a significantly greater reduction in PCV and TP concentration than did the treatment using pentastarch solution. The median change in PCV for the hypertonic saline group was -0.14 L/L, while it was -0.07 L/L for the pentastarch group. For TP concentration, the median change in the hypertonic saline group was -16 g/L, while it was -2 g/L in the pentastarch group.
• Contrary to expectations given the differences in hematologic parameters, long-term survival was found to be not significantly different between both groups.

Conclusions

• Despite the more substantial reduction in preanesthetic hemoconcentration following the administration of hypertonic saline solution, there was no substantial difference in long-term survival between the horses that were treated with this solution and those that were treated with an equal volume of pentastarch solution.
• Based on these findings, the research suggests that, in a clinical setting, either of these fluids could be used appropriately for preoperative fluid resuscitation in horses suffering from colic.