Anaphylactoid shock in a patient following 5% human serum albumin infusion during off-pump coronary artery bypass grafting

Abstract

A 59-year-old diabetic male patient undergoing off-pump coronary artery bypass grafting developed anaphylactoid shock after 5% human serum albumin (HSA) infusion started. During the first anastomosis, blood loss was more than 600 ml, with slightly decreased blood pressure. Therefore, 5% HSA, 250 ml, was infused against hypovolemia. However, as his blood pressure was decreasing continuously during the second anastomosis, another 250 ml of 5% HSA was added. The blood pressure rapidly dropped to 50/30 mmHg after the second 5% HSA administration started. As i.v. phenylephrine and ephedrine were not effective, norepinephrine was infused. Then we found a high cardiac output (10 l·min⁻¹) and peak airway pressure (32 cmH₂O), with a decrease of oxygenation (P/F ratio, 82), and we suspected 5% HSA-caused anaphylactic shock. Therefore, aminophylline was infused to treat bronchoconstriction. These treatments were effective, and the operation was successfully completed. Postoperatively, we noticed that these reactions may have been anaphylaxis, because the patient had a higher serum tryptase level (16.2 ng·ml⁻¹) than the reported nonanaphylaxis serum tryptase level (8.23 ng·ml⁻¹). HSA is a relatively safe colloid for use as a volume expander, because it has been reported that the risk of anaphylactoid reactions with HSA was much less than that with gelatins and dextrans, and similar to that with starches. However, the present case suggests that severe allergic reactions should be kept in mind with the use of any colloids.