Evaluation of Gastric pH and Gastrin Concentrations in Horses Subjected to General Inhalation Anesthesia in Dorsal Recumbency.
Authors: Guerrero Jesus Leonardo Suarez, Brito Pedro Henrique Salles, Ferreira Marília Alves, Arantes Julia de Assis, Rusch Elidiane, Oliveira Brenda Valéria Dos Santos, Velasco-Bolaños Juan, Carregaro Adriano Bonfim, Dória Renata Gebara Sampaio
Journal: Animals : an open access journal from MDPI
Summary
# Editorial Summary Given that gastric ulceration affects 50–90% of performance horses with significant consequences for soundness and athletic function, understanding how routine procedures might exacerbate gastric pathology is clinically important. Researchers monitored gastric pH continuously during 90 minutes of general inhalation anaesthesia in dorsal recumbency across 22 mares, then tracked pH changes hourly for 24 hours post-recovery whilst comparing gastrin concentrations at baseline, during recovery, and four months later; control groups of fasted and non-fasted horses provided comparison data. During anaesthesia, gastric pH remained appropriately acidic (mean 4.52 ± 1.69), with no significant variation across the procedure, whereas post-recovery pH shifted alkaline (ranging 6.74–7.43 between hours 5 and 17), and serum gastrin increased significantly from 15.15 ± 3.82 pg/mL at baseline to 20.15 ± 7.65 pg/mL during recovery—a response unrelated to feeding status. The findings suggest that general anaesthesia and dorsal recumbency do not compromise gastric acidification or create an environment conducive to ulcer formation, contradicting assumptions that might otherwise prompt pre-anaesthetic gastroprotective medication. For equine professionals managing surgical candidates, this research supports proceeding with routine anaesthesia without additional pharmaceutical gastric protection solely on the grounds of acid exposure risk, though individual case assessment remains warranted.
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Practical Takeaways
- •Anesthesia in dorsal recumbency does not cause excessive gastric acidification—normal physiological pH is maintained during the procedure, reducing concern for perioperative gastric ulcer risk from this position alone
- •Post-operative gastric pH becomes alkaline rather than acidic, which is unexpected and suggests anesthesia may alter normal gastric acid secretion; monitor post-operative feed intake as normal acid environment needed for digestion may be transiently disrupted
- •Routine gastric protectant medications are not indicated based on gastric pH changes alone during routine inhalation anesthesia, though clinical decision-making should consider individual risk factors and concurrent medications
Key Findings
- •Gastric pH remained acidic and within physiological range (4.52 ± 1.69) during 90 min of general inhalation anesthesia in dorsal recumbency
- •Post-anesthesia gastric pH increased to weakly alkaline range (6.74–7.43) and remained elevated for 24 hours
- •Serum gastrin concentrations increased significantly post-anesthesia (20.15 ± 7.65 pg/mL) compared to baseline fasted state (15.15 ± 3.82 pg/mL; p < 0.05)
- •General inhalation anesthesia and dorsal recumbency do not require preventive pharmacological measures to protect against gastric pH changes in horses