Successful blood transfusion in a Holstein cow experiencing hemorrhagic shock under general anesthesia

A 2-year-old Holstein cow weighing 530 kg at 2 mo gestation was scheduled for a paracostal laparotomy and abomasotomy following diagnosis of a reticular foreign body causing obstruction and abomasal impaction. Hemorrhagic shock occurred during surgery, with a rapid, approximately 60% decrease in arterial blood pressure, and reflex tachycardia with a 2-fold increase in heart rate. Following identification of hemorrhagic shock, arterial blood pressure was supported by reducing the inhalant anesthetic requirement, positive inotropic support (IV dobutamine infusion), and IV fluid therapy. Hypertonic saline was administered IV for initial resuscitation of arterial blood pressure, followed by a whole blood transfusion to replenish red blood cells, support oxygencarrying capacity, and provide intravascular volume to maintain cardiac output and tissue perfusion. A gradual increase in arterial blood pressure and a decrease in heart rate were observed in response to treatment. This case report demonstrates the physiologic compensatory response to hemorrhagic shock and the treatment to stabilize cardiovascular parameters in an anesthetized cow. Key clinical message: This case illustrates the physiological reponses to acute hemorrhage under general anesthesia and the effects of various treatment interventions.