[Cannulation of the radial artery. Risks, effective examination methods and monitoring of the circulation in the hand during the procedure].

Cannulization of the radial artery with the object of continuous measurement of the blood pressure or repeated analyses of the arterial blood gases is an easy and relatively safe procedure. Thrombosis is observed in 25-40% of the cases. The frequency depends upon the condition of the patient, the cannula and technique of cannulization and duration of this. Permanent ischaemic damage resulting from thrombosis is, however, rare. Other complications of clinical significance are infections and vascular lesions which are, similarly, rare. Allen's test for assessing the collateral circulation of the hand has a high negative predictive value while the positive predictive value is so low that a positive test result does not exclude cannulization. In these cases, better assessment of the perfusion of the hand may be obtained by combining the test with pletysmography. After cannulization, it should be possible to monitor perfusion distal to the site of cannulization employing more recent pulse oximeters with the aid of the pletysmographic curve.