Lidocaine's Ineffectiveness in Mitigating Lipopolysaccharide-Induced Pain and Peristaltic Effects in Horses.
Authors: Sousa Lara Nunes, Winter Isabella Caixeta, Varela Diego Duarte, Luvison Eduarda Zancanaro, Guzmán Juan Felipe Colmenares, Machado Ana Moutinho Vilella, Figueiredo Renata Diniz Vilela, Pena Gabriel Tavares, Dos Santos Ana Clara Silva, Faleiros Rafael Resende, Carvalho Armando de Mattos
Journal: Animals : an open access journal from MDPI
Summary
# Editorial Summary Researchers conducted a randomised crossover trial in seven horses to investigate whether intravenous lidocaine could reduce the gastrointestinal and pain responses triggered by endotoxaemia, administering either lidocaine (1.5 mg/kg bolus followed by 0.05 mg/kg/min infusion) or placebo one hour before lipopolysaccharide (LPS) challenge. Using a comprehensive assessment protocol that included clinical examination, haematological analysis, abdominal auscultation, ultrasonography, and pain scoring, the team monitored each horse's response across both treatment phases. Lidocaine provided no measurable protection against LPS-induced changes: there were no significant differences between treatment groups in peristaltic activity, abdominal pain severity, or any other clinical or laboratory parameters before or after endotoxin administration. For practitioners managing colicky horses with suspected or confirmed endotoxaemia, these results suggest that intravenous lidocaine—whilst commonly used for its anti-inflammatory and analgesic properties—cannot be relied upon to prevent or ameliorate the intestinal dysfunction and visceral pain that characterises endotoxic colic, potentially shifting clinical focus towards alternative therapeutic strategies with proven efficacy in this setting.
Read the full abstract on PubMed
Practical Takeaways
- •Do not rely on IV lidocaine to manage abdominal pain or restore gut motility in horses with endotoxemia—alternative analgesic and prokinetic strategies should be prioritized
- •While lidocaine is commonly used in colic cases, this evidence suggests it is ineffective specifically for LPS-induced endotoxic pain and peristaltic dysfunction
- •Consider other pain management approaches (NSAIDs, other analgesics) and motility support when treating endotoxemic horses with gastrointestinal complications
Key Findings
- •Lidocaine (1.5 mg/kg bolus + 0.05 mg/kg/min infusion) provided no clinically relevant benefit over placebo in mitigating LPS-induced endotoxemia signs in horses
- •No significant differences were observed between lidocaine and placebo groups for peristalsis, abdominal pain, or other clinical and hematologic parameters before or after LPS administration
- •Study findings do not support clinical use of lidocaine to treat abdominal pain and intestinal hypomotility secondary to endotoxemia in horses