Mortality and Response to Fluid Resuscitation After Acute Blood Loss
Presenting Author: Maria Lichtenberger, DVM, Dipl ACVECC
The Animal Emergency Center, Glendale, WI
Interpretive Review and comments by Dr. Nemetz:
Often birds are presented to a veterinarian undergoing acute blood loss from ruptured blood feathers, animal attacks, traumas, internal hemorrhage from ulcerated neoplasms, proventricular/ventricular ulcers, or improper grooming procedures. How should these cases best be handled? Dr. Lichtenberger presented an excellent medical protocol to give these patients the best chance of survival.
Acute hemmorhagic shock is a syndrome resulting in many physiological changes, but the primary concern is the actual reduction in the circulating blood volume. At some point this reaches a state of irreversible circulatory failure. The LD50 (the Lethal (L) Dose (D) or event when 50% of the patients will die) in mammals from acute blood loss is 40-50%. The LD50 in ducks has been shown to be 60%. This indicates birds can tolerate a greater blood loss compared to mammals without as severe clinical signs; however this does not mitigate the internal physiological changes.
The most obvious changes seen clinically in acute blood loss cases are an elevated heart rate and a decrease in blood pressure. These can be used as simple indicators for monitoring response to therapy. Dr. Lichtenberger used isotonic crystalloids (Lactated Ringers) alone or in combination with large molecular weight colloids (Hetastarch) or stroma-free hemoglobin (Oxyglobin) given intravenously or intraosseously to measure the best therapeutic effects for survival of patients with acute blood loss.
Her findings indicate that a combination 10 mg/kg of a crystalloid COMBINED with 5 mg/kg of stroma-free hemoglobin given over a 5-minute period intravascularly under anesthesia had the most therapeutic effect in the survival of the avian patient.