Limited applicability of the DATEX Reloxograph in diabetics with peripheral polyneuropathy

The aim of the study was to investigate whether peripheral nerve dysfunction can influence the applicability of the DATEX Relaxograph in diabetics. Sixty two patients (43 diabetics, 19 non-diabetics) undergoing ophthalmosurgical procedures under general anesthesia were tested. The distal motor latency (DML) of the ulnar nerve served as a graduation tool for peripheral nerve dysfunction. The patients were divided in three groups: non-diabetics (group 1), diabetics with DML < 3.8 msec (group 2), diabetics with DML > 3.8 msec (group 3). Relaxometry was performed by stimulating the right ulnar nerve near the wrist, and the evoked response (EMG) was obtained from the hypothenar muscle. Calibration of the device (i.e. supramaximal stimulation within the given current range of a maximum of 70 mA) was carried out successfully in most patients of group 1 and 2 (94.7% and 85.7% respectively). In contrast to that calibration could be carried out in only 40.9% of the patients of group 3 (P < 0.01 vs. group 1 and 2). Consequently in a high percentage (59.1%) of the patients of group 3 relaxometry had to be performed in an uncalibrated manner. The results substantiate the hypothesis that peripheral nerve dysfunction can restrict the applicability of the Relaxograph in diabetics.