Since colloids remain within the vascular compartment for comparatively long periods, their combination with hypertonic solutions
should produce a sustained hemodynamic effect (Table 4).
Table 4: Volume expansion
The most significant advance in fluid therapy has been the development and clinical approval of an oxygen-carrying blood substitute.
Oxyglobin is a solution of approximately 13 g/dl of purified, polymerized bovine hemoglobin diluted in a modified lactated
Ringer's solution and has an osmolality of approximately 300 mOsm/kg and a colloid osmotic pressure of approximately 40 mm
Hg. The average molecular weight of this solution is 200 kD and its oxygen affinity is regulated by physiologic chloride concentrations,
This solution increases the oxygen-carrying capability of blood while reducing blood viscosity. What all this means is that
Oxyglobin can be administered at any time to dogs or cats in need of a blood transfusion or during acute and critical situations
in which an acute increase in blood volume and oxygen-carrying capacity are needed. It is an excellent fluid to use in animals
suffering from acute blood loss secondary to trauma or surgical mishap. It should be administered to patients that have become
hemodiluted (PCV less than 15 percent to 18 percent) from crystalloids. The product can be administered to patients suffering
from chronic anemia with PCV values less than 10 percent. Importantly, Oxyglobin has a two-year shelf life and requires no
cross matching because it contains no red-cell membranes.
Fluid-therapy guidelines for patients in shock should include frequent physical examination, hemodynamic monitoring and blood-chemical
monitoring (Table 5).
Table 5: Algorithm of fluid therapy for shock patients
Finally, remember that fluid-therapy protocols are guides only and must be modified to meet the changing needs (volume, electrolyte,
acid-base, oxygen) of the patient for fluid therapy to be successful without producing side effects.
Dr. Hoskins is owner of Docu-Tech Services. He is a diplomate of the American College of Veterinary Internal Medicine with
specialities in small animal pediatrics. He can be reached at (225) 955-3252, fax: (214) 242-2200 or e-mail: firstname.lastname@example.org