Anaphylactoid response to optison(R) and its effects on pulmonary function in two dogs

Two of 26 anesthetized dogs given the cardiac echo-enhancing agent Optison(R) showed anaphylactoid responses (AR) related to the human albumin component of this agent. The episodes of AR were self-limited, and could be reproduced by human albumin injec-tion alone. Gas exchange was maintained by mechanical ventilation and 5 cm H2O PEEP, and dispersion of ventilation remained normal during AR despite severe hypotension. We suggest that: (1) pre-screening by measuring blood pressure response to intravenous injection of small doses of Optison(R). and (2) availability of access to the airway in addition to emergency agents may be prudent preventive mea-sures when Optison(R) is used in animals to enhance echocardiographic imaging.