Retrospective study on the use of lidocaine constant rate infusions for the treatment of ileus in ruminants and camelids

23 August 2023 -

Although ileus is a poorly documented condition in ruminants, most of the cases happen after surgery and there are very few studies that mention drugs that can affect intestinal motility in these species.
Lidocaine is frequently used in veterinary medicine, not just as a local anaesthetic but also as an anti-arrhythmic, anti-inflammatory and prokinetic agent. In equids, for example, it is regularly used to treat post-operative ileus (POI).

The goal of this retrospective analysis was to determine the outcome and possible adverse effects of the administration of a constant rate infusion (CRI) of lidocaine in ruminants and camelids. The dose and rate were extrapolated from those used in equids.

This study included 11 cases, from which 8 where cattle, 1 an alpaca and 1 a goat. Presenting complaints were all related to intestinal disease and 8 of the cases were submitted to an exploratory surgery prior to lidocaine administration. The drug was initially given as a bolus of 1.3mg/kg, followed by a CRI of 0.05mg/kg/minute. The median duration of treatment was 2.5 days.

Success of treatment was based on several factors including positive changes in mental state, increase in appetite, normal faeces, minimal abdominal distension, and positive intestinal motility detected via ultrasound. Considering these factors, 9 cases had a positive outcome. One of the 2 remaining cases didn’t respond favourably initially but ended up with a positive outcome and was eventually discharged.

As mentioned, the authors goal with this study was to determine the possibility of adverse effects and none were detected. Some of those that were considered where seizure activity, muscular fasciculations, tachycardia and arrythmias.

In conclusion, administration of a lidocaine CRI in ruminants and camelids appear to be safe when using doses extrapolated from equids. This study also suggests that it is beneficial in cases of ileus in these species.

Due to the retrospective and uncontrolled nature of this study, these results could be coincidental or even be biased from the attending clinician’s interpretation. Another important fact is that the study group is very limited.