Despite general anaesthesia being a common procedure that is performed in veterinary practices every day it is not without risks. At Karingal Veterinary Hospital and Ballam Park Veterinary Clinic we endeavour to make every anaesthetic event as safe as possible. For this reason we recommend that all pets that are to undergo general anaesthesia are given intravenous fluids.
Why are Intravenous Fluids Necessary?
There are a number of important reasons why we recommend intravenous fluids during general anaesthesia.
When intravenous fluids are given to your pet they are done so through a catheter placed in one of your pet’s veins in its leg. Having this catheter in place means our veterinary team has immediate access to your pet’s circulatory system. In the event of a problem emergency medications can be given immediately into the bloodstream and therefore act quickly to alleviate the problem.
Animals under general anaesthesia will, in most cases, suffer from low blood pressure. This is due the anaesthetic drugs they have received and in some cases the position they are placed in for the surgery to be performed e.g. on their back as is the case for spays and castrations. Low blood pressure results in decreased circulation to vital organs such as the liver, kidneys and brain. Obviously this is something that should be avoided. The provision of intravenous fluids reduces the effects of low blood pressure and many cases prevents it from occurring altogether.
When under general anaesthesia animals will lose fluid from a number of places. They continue to produce urine, there is water in the breath they expire and there is evaporation of fluid from exposed tissues during surgery. There is also the additional fluid that is lost through the loss of blood during surgery. All these fluid losses will contribute to the development of dehydration. In an awake animal these fluid losses are replaced by the animal drinking but obviously this is not possible when it is under anaesthesia. This dehydration ultimately results in a reduction in blood pressure and the effects that this causes.
Upon completion of the procedure, intravenous fluid therapy speeds the recovery process by diluting the anaesthetic agents circulating in the blood stream and by enhancing their metabolism and elimination through the liver and kidneys. Patients that receive intravenous fluid therapy generally wake up faster than those that do not.
Studies have shown that 0.9 – 2% of all patients that receive general anaesthesia will develop kidney dysfunction or failure 7-14 days after anaesthesia. This risk is almost completely eliminated in patients that receive intravenous fluid therapy. Sure, 98% of all pets will have no problem, but our veterinarian’s goal is to eliminate that unknown 2%. For these reasons, all surgery patients should receive intravenous catheterisation and fluid therapy.
How are Intravenous Fluids Administered?
All intravenous fluids are delivered using modern and accurate electronic fluid pumps. These machines mean we can delivered the appropriate amounts of fluids at the correct rates. If too much fluid is given or it is given to fast it can cause serious problems. In very small patients such as birds, rabbits and reptiles we have special intravenous syringe pumps that can accurately deliver small volumes of fluids.
Are Intravenous Fluids Optional?
We believe so strongly in the benefits of intravenous fluids for our anaesthetised patients that they are compulsory for everything but de-sexing procedures. In castrations and spays we allow owners the option. Intravenous fluids for de-sexing attract an additional charge but we strongly recommend them.