The technique of dorsalis pedis cannulation. An overlooked option when the radial artery cannot be used.

When arterial cannulation is required, but the radial artery cannot be used, five alternatives can be considered: the ulnar, brachial, axillary, femoral, and dorsalis pedis arteries. Of these, the dorsalis pedis may be the next best choice: Collateral flow is excellent, and cannulation here is easy to perform, presents minimal patient inconvenience, and has a very low incidence of complications. Systolic pressure readings obtained at the dorsalis pedis artery are 5 to 20 mm Hg higher than measurements obtained at the radial artery; however, by comparing the dorsalis pedis reading with a cuff pressure, you can quickly determine the extent of overshoot and correct the invasive measurement.