Utility of high-performance liquid chromatography in the characterization of iatrogenic sodium diatrizoate-induced seizures in a horse.

This research article examines a case where a horse was given sodium diatrizoate, a highly ionic contrast agent, resulting in severe seizures and the subsequent death of the animal. The substance was identified through high-performance liquid chromatography and mass spectrometric analysis of the horse’s cerebrospinal fluid.

Background

• The subject of this research was a young Quarterhorse gelding for which a diagnostic evaluation, including a contrast myelogram, was being conducted due to mild ataxia.
• Sodium diatrizoate, a highly ionic and osmotic contrast agent, was mistakenly administered into the horse, by intrathecal (spinal) injection. This resulted in unrelenting severe seizure activity, leading to the euthanasia of the animal.

Methods and Results

• To ascertain the cause of reaction, the cerebrospinal fluid from the horse was analyzed via high-performance liquid chromatography (HPLC).
• The results from HPLC pointed towards interference by an injected substance. This was confirmed by further probe mass spectrometric analysis. Both tests established the presence of sodium diatrizoate, confirming that it was indeed the agent responsible for the seizures.

Discussion

• Sodium diatrizoate was identified as the agent causing the seizures. It is a highly ionic contrast agent with high osmolarity.
• Furthermore, sodium diatrizoate also interferes with neurotransmission at specific receptors, attributed as another reason for the severe adverse reaction in the horse.
• Given the established properties of this substance and the resultant severe side effect, the study notes that sodium diatrizoate is contraindicated for use in myelography (imaging the spinal cord).

Conclusion

• This report is unique as it is the first documented case of intrathecal administration of sodium diatrizoate in a horse.
• However, the harmful effects of direct spinal injection of this contrast agent are not limited to horses; similar reactions have been reported in dogs, and numerous human instances have also been documented.
• The study thus conveys the significant potential hazards of erroneous administration of contrast agents like sodium diatrizoate, underscoring the need for careful handling and usage of such substances in medical procedures.