Assessment of the New Acceleromyograph TOF 3D Compared with the Established TOF Watch SX: Bland-Altman Analysis of the Precision and Limits of Agreement between Both Devices-A Randomized Clinical Comparison.

The new acceleromyograph TOF 3D was compared with the established TOF Watch SX in patients undergoing elective laparoscopic gynecological surgery. Neuromuscular transmission was assessed by simultaneous recording with both devices. Measurements were performed simultaneously at the left and the right M. adductor pollicis (Group A, 25 patients), or the M. corrugator supercilii (Group CS, 25 patients). The repeatability, time course, and limits of agreement (Bland-Altman) were compared. The primary endpoint was the 90% train-of-four recovery time (TOFR 0.9). Other endpoints included onset time of block, maximum T1 depression, time to 25% T1 recovery, the recovery time course of T1 response, and TOF ratio, respectively. In group CS, the repeatability coefficient of the TOF 3D was lower (4.66 (1.6)) than of the TOF Watch SX (6.02 (1.9); p = 0.026). In group A, the onset of the block was faster when measured by the TOF 3D (98.7 (30) s vs. 112.2 (36) s (mean (SD)); p = 0.032). In group A, time to recovery to a TOFR of 90% was measured earlier by the TOF 3D (bias -0.71 min, limits of agreement from -8.94 to +7.51 min). The TOF 3D provides adequate information with high precision and sensitivity. It is suitable even for measurement sites with small muscle contractions such as the M. corrugator supercilii.