Protamine sulphate is routinely used after cardiopulmonary bypass (CPB) to restore the patient's baseline coagulatory state. However, adverse reactions are encountered, and alternative means to neutralize heparin are, therefore, necessary. The Heparin Removal Device (HRD) constitutes an extracorporeal circuit that allows ex vivo deheparinization by mean of a polycationic ligand that binds heparin molecules. This paper presents the setup of the HRD circuit. It is illustrated by the report of a 68-year-old man with a known severe crustacean allergy. The patient (78 kg, 170 cm) was admitted for elective coronary artery bypass graft surgery. It was decided that the HRD would be used as a precaution in order to avoid the risks of using protamine sulphate. The CPB time and aortic crossclamp time were 70 and 40 min, respectively. At the end of CPB, the device was inserted and processing started. Activated coagulation time values were monitored over a 130 min period and diminished from 480 to 300 s after 45 min, 220 s after 90 min, and settled at 150 s. Haemostasis was acceptable and processing stopped. The operation was terminated and the patient transferred to the intensive care unit. Clinical evolution was excellent, with minimal postoperative bleeding. The HRD presents an alternative to protamine sulphate when this drug is contraindicated for a certain patient population who might have a suspected, known or emergency adverse reaction.