Fluid therapy is important for many medical conditions in veterinary patients. It is dictated by many factors and is highly patient variable. Fluid selection for a given patient may change during therapy, depending on patient needs. The goal of these guidelines is to assist the clinician in prioritizing goals, selecting appropriate fluids and rates of administration, and assessing patient response to therapy.
The reader must recognize the highly individual patient variables and dynamic nature of fluid therapy. Because fluid therapy can be highly individualized in complex cases, having a relationship with a referral facility for consultation can be helpful.
Ongoing research is challenging current dogma regarding fluid administration rates, particularly rates for administration during anesthesia (Table 6). There are few evidencebased recommendations, and limited research has been performed related to fluid administration in veterinary patients. The reader is encouraged to be alert to future data as it becomes available and incorporate that information in practice protocols.
Relearning what you thought you knew*
- Current recommendations for routine anesthetic fluid rates are for 10 mL/kg/hr to avoid adverse effects6,7
- The use of a K-containing balanced electrolyte solution does not increase blood K in cats with urethral obstruction51
- LRS will not exacerbate lactic acidosis52
- Patients with subclinical hypertrophic cardiomyopathy may be able to tolerate cautious fluid boluses for hypotension if their volume status is questionable, but they should be closely monitored for fluid overload and congestive heart failure53
- LRS or acetated Ringer’s solution may be used in liver disease. LRS contains both D- and L-lactate and is unlikely to increase blood lactate levels52
- When flushing an IV catheter, normal saline is as effective as heparin solution48,54
- In general, the choice of fluid is less important than the fact that it is isotonic. Volume benefits the patient much more than exact fluid composition. Isotonic fluids won’t have a severe negative impact on most electrolyte imbalances, and their use will begin to bring the body’s fluid composition closer toward normal pending laboratory results that will inform the clinician of more specific fluid therapy36
LRS, lactated Ringer’s solution.