Page 355 - Fluid, Electrolyte, and Acid-Base Disorders in Small Animal Practice

Introduction to Fluid Therapy 345

Figure 14-4 A and B, Fluid infusion pumps. A, Baxter Flo-Gard 6200 Volumetric Infusion Pump (Baxter
Health Care, Deerfield Ill.). B, Medex Medfusion 2010 Syringe Infusion Pump (Medex, Carlsbad Calif.).

experiencing ongoing loss of fluids from the intravascular
compartment or other more complex cardiovascular
derangements, response to fluid resuscitation should be
rapid and complete.
The initial assessment of hydration determines the vol-
ume of fluid needed to replace the hydration deficit
(replacement requirement). 12,20 The hydration deficit
is calculated as the percentage dehydration (estimated
by physical examination) times the patient’s body weight
in kilograms. The resultant value is the fluid deficit in
liters. During the rehydration phase of therapy, this vol-
ume is administered for 24 hours in conjunction with
maintenance fluid requirements and replacement of
ongoing or contemporary losses that are occurring.
Coincident with or after replacement of the animal’s
hydration deficit, the maintenance fluid requirement
must be administered. 12,20 The maintenance fluid
requirement is the volume needed per day to keep the ani-
mal in balance (i.e., no net change in body water). Daily
Figure 14-5 Use of labeled adhesive tape to monitor rate of fluid fluid requirements (milliliters per kilogram per day)
administration. (From Chew DJ. Parenteral fluid therapy. In: parallel energy requirements (kilocalories per kilogram
Sherding RG, editor. The cat: diseases and clinical management. per day). 20,22,23
New York: Churchill Livingstone, 1989: 54.) The basal energy requirement (BER) is that of a rest-
ing animal in a thermoneutral environment 12 to 18
and hypotension should receive a volume of fluid suffi- hours after eating. 24 In dogs, BER is not a linear function
cient to return these cardiovascular parameters to normal, of body weight but rather is related to body surface area
1
and these parameters should not deviate from normal by the following equation :
when the rate of fluid administration is decreased and 0:655
BER ðkcal=dayÞ¼ 97W
rehydration of the patient begun. In patients not