Blood flow monitoring by pulse oximetry during a forearm flap elevation

The Allen's test for blood flow is performed before a forearm flap is elevated to examine vascularization through the ulnar artery. In this study, to ensure the survival of the donor site when a forearm flap was elevated, we monitored patients using a pulse oximeter. From oral cancer patients who were undergoing reconstructive surgery using the forearm flap, twenty patients were randomly selected to be served as subjects. A pulse oximeter probe was attached to the thumb on the side from which a skin flap was to be elevated. Oxygen saturation was measured when the tourniquet was released, and the radial artery was clamped and severed. The results showed that oxygen saturation temporarily decreased when the radial artery was ligated, but it recovered in one to two minutes.