[Determination of the spread of epidural anesthesia. A comparison between pin-prick and a new method using a metallic roller].

A new method (metal roller) for testing the spread of analgesia in regional anesthesia is introduced. The possible advantages of testing with a metal roller (cold sensation) in comparison to the pinprick method are investigated and discussed to determine whether loss of cold-sensation is comparable to loss of pinprick-sensation and thus reliable in clinical practice. METHOD AND MATERIAL. Spread of analgesia was tested with both the metallic roller and the conventional pinprick method in 40 patients (20 epidural and 20 spinal blocks), and pain perception or cold perception were compared. RESULTS. In epidural as well as in spinal anesthesia, similar levels of loss of pain perception and cold perception were found. DISCUSSION. Testing the spread of analgesia after nerve bock by the pinprick method is sometimes unpleasant for the patient. The metal roller is not unpleasant, and the possible danger of contamination or pinprick pain is virtually impossible because physical integrity is preserved and the feeling of "cold" is not harmful.