Veterinarians are occasionally faced with challenges in providing supportive intravenous fluid therapy care, such as they experienced with a supply shortage in the past few years. Horses with gastrointestinal disease or other syndromes that lead to dehydration are just some examples where intravenous fluid therapy is critical. Without availability of sterile IV fluid formulations due to manufacturer backorder, it became necessary for equine hospitals to prepare custom formulations of non-sterile solutions. In addition, while short-term use of 3- or 5-liter bags of commercially available IV replacement solutions is useful for hydration and correction of electrolyte imbalances, long-term, high-volume IV fluid treatment can cause problems. This is due primarily to excessive concentrations of sodium and chloride in many commercial fluids. For those cases, it might be necessary to prepare customized IV solutions by adding bulk electrolyte products to distilled or reverse osmosis water.
A retrospective study from 2014-2017 included 186 horses receiving sterile IV fluids and 37 horses receiving non-sterile IV fluids to determine what complications might arise [Kopper, J.J.; Bolger, M.E.; Kogan, C.J.; Schott, H.C. Outcome and complications in horses administered sterile or non-sterile fluids intravenously. Journal of Veterinary Internal Medicine 2019, DOI: 10.1111/jvim.15631].
The parameters evaluated included time to discharge, fever, jugular vein phlebitis/thrombosis, heart auscultation for arrhythmia every six hours, signs of laminitis, blood pH and plasma electrolyte concentrations. In this study, there was insufficient information regarding presence or magnitude of bacterial contamination in the non-sterile solutions.
The time to discharge did not differ between horses receiving either sterile or non-sterile IV fluids. There was no increased risk of death, fever, arrhythmia or laminitis when using non-sterile fluids. Despite previous reports of a 17-times greater likelihood of jugular vein phlebitis/thrombosis from non-sterile IV fluids, only 3 out of 37 horses developed jugular vein complications with 14-gauge x 9 cm polyurethane catheter placement. These cases resolved after discharge.
Based on human studies, another potential complication when using non-sterile solutions for a longer term is a tendency to create additional electrolyte abnormalities, in particular hyperchloremic metabolic acidosis. Armed with this knowledge, custom-made intravenous fluid can be adjusted to better balance chloride concentrations in the solutions relative to an individual horse’s needs.
The authors recommend that for events that necessitate using non-sterile IV solutions, practitioners should obtain informed client consent of possible jugular vein complications and electrolyte derangements.