Does the Duration of CRI Matter?

If you work in a 24-hour facility, odds are high that you've employed a constant rate infusion (CRI) to control seizures in dogs with cluster seizures or status epilepticus. A recent article evaluated the duration of a CRI of diazepam and propofol to see if there was a superior choice.

Why could duration matter?

On one side, the longer a pet is on a CRI (12 h or 24 h), the longer they must remain in hospital which incurs more charges. However, most dogs will have a recurrence of seizures within 12 hours of hospitalization according to prior studies, so if you run a CRI longer perhaps the less chance they have to have another one and thus return to hospitalization.

Materials and Methods

Cagnotti et al (Frontiers, 2023) collected 73 dogs and separated them into two experimental groups. The first group received diazepam CRI for 12 hours, the second propofol for 12 hours. No standard dosing was employed for either group, just the duration. These were compared to a prior study of dogs with identical inclusion criterial in which the CRI was continued for 24 hours.

Results

No difference in outcome, or hospital duration was noted between the 12 hour CRI group (both diazepam and propofol) and the 24 hour group. Surprisingly, the dogs receiving the 12 hour CRI still had a 56 hour hospitalization! I cannot locate any data on breakthrough seizures after stopping CRI in either group but one might suspect this occurred to result in a 56 hour hospitalization for the 12-hour group. Either that, or the CRI dose was much higher and therefore had more step down doses compared to the 24 hour CRI? Those are my suppositions, not verified by data in this study.

Take Home Message:
It is well established that a CRI should be employed for dogs having cluster seizures or status epilepticus and that 2 step-down doses are typically recommended to avoid withdrawal seizures when stopping. That said, this paper suggests that a 12 hour CRI is comparable to a 24 hour CRI. Personally, I typically start with 0.25 mg/kg/hr diazepam CRI for 12 hours and then step down in 50% increments until the dose is below 0.1 mg/kg/hr. This data would suggest that this is an appropriate approach but I think it is 'loosely' supportive!

Reference: Cagnotti G, Ferrini S. Duration of constant rate infusion with diazepam or propofol for canine cluster seizures and status epilepticus. Frontiers in Vet Sc Aug 2023.

Thanks for reading! I hope you have a great week and I look forward to working with you next week when we're back stateside again!