Investigation of Leukocyte Trafficking Into Skin Blisters During Cardiopulmonary Bypass

The purpose of this study was to see if the heart-lung machine involved in cardiac surgery increases the movement of activated white blood cells from the bloodstream into the patient's tissues and also to see if aprotinin usage during surgery reduces this effect.

It has long been known that exposure of blood to the heart-lung bypass machine can trigger a whole-body inflammatory response in cardiac surgery patients that is linked to activation of circulating white blood cells. The investigators propose to use a technique to track the movement of white blood cells into the skin of patients during bypass surgery. The skin blisters will be elicited by application of the blistering agent cantharidin to the forearm of volunteer patients. This will allow the investigators to study the activation state of white blood cells that enter tissues during bypass surgery and to determine whether aprotinin has any beneficial effect with regards to inflammatory status of these cells. The investigators propose that white blood cell trafficking into the blisters will increase following the use of the heart-lung machine and that the effect of aprotinin will be to ablate this.

Comparison of the number of extravasated leukocytes in the skin blisters pre- and post-operatively, in both the placebo and aprotinin treatment groups

The activation status of the blister leukocytes and the level of soluble inflammatory mediators within the blister

Inclusion Criteria: Primary elective coronary artery bypass surgery Exclusion Criteria: Emergent, urgent or re-do surgery Patients on oral corticosteroid medication Patients on aspirin therapy < 7 days prior to operation

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