Comparison of onset of neuromuscular blockade with electromyographic and acceleromyographic monitoring: a prospective clinical trial

Abstract Background Reliable devices that quantitatively monitor the level of neuromuscular blockade after neuromuscular blocking agents' administration are crucial. Electromyography and acceleromyography are two monitoring modalities commonly used in clinical practice. The primary outcome of this study is to compare the onset of neuromuscular blockade, defined as a Train-Of-Four Count (TOFC) equal to 0, as measured by an electromyography-based device (TetraGraph) and an acceleromyography-based device (TOFscan). The secondary outcome was to compare intubating conditions when one of these two devices reached a TOFC equal to 0. Methods One hundred adult patients scheduled for elective surgery requiring neuromuscular blockade were enrolled. Prior to induction of anesthesia, TetraGraph electrodes were placed over the forearm of patients' dominant/non-dominant hand based on randomization and TOFscan electrodes placed on the contralateral forearm. Intraoperative neuromuscular blocking agent dose was standardized to 0.5 mg.kg−1 of rocuronium. After baseline values were obtained, objective measurements were recorded every 20 seconds and intubation was performed using video laryngoscopy once either device displayed a TOFC = 0. The anesthesia provider was then surveyed about intubating conditions. Results Baseline TetraGraph train-of-four ratios were higher than those obtained with TOFscan (Median: 1.02 [0.88, 1.20] vs. 1.00 [0.64, 1.01], respectively, p < 0.001). The time to reach a TOFC = 0 was significantly longer when measured with TetraGraph compared to TOFscan (Median: 160 [40, 900] vs. 120 [60, 300] seconds, respectively, p < 0.001). There was no significant difference in intubating conditions when either device was used to determine the timing of endotracheal intubation. Conclusions The onset of neuromuscular blockade was longer when measured with TetraGraph than TOFscan, and a train-of-four count of zero in either device was a useful indicator for adequate intubating conditions. Clinical trial number and registry URL NCT05120999, https://clinicaltrials.gov/ct2/show/NCT05120999.

Voiding Chain Cystourethography: Assessing A Historical Test's Role in Selection for Urethrolysis

Objective To analyze the benefit of voiding chain cystourethrography (VCC) [placing a radiographic opaque chain into the urethra and bladder and asking the patient to void under fluoroscopy] in the urodynamic evaluation of female bladder outlet obstruction (BOO). Materials and Methods Females with post anti-incontinence operation voiding dysfunction who underwent urodynamic evaluation augmented with VCC and later had urethrolysis were identified. Six diagnostic criteria for obstruction were applied to each patient: (1) VCC ( obstructed: chain was angulated and could not be voiding out) (2) Video urodynamic study (VUDS) (detrusor contraction combined with radiographic obstruction) (3) maximum flow (Qmax) ≤ 15 cc/sec, detrusor pressure (pDet)@ Qmax ≥ 20 cm H20 (4) Qmax ≤ 11 cc/sec, pDet@ Qmax ≥ 25 cm H20 (5) Qmax ≤ 12 cc/sec, pDet@ Qmax ≥ 25 cm H20 (6) Blaivas-Groutz (B-G) nomogram. Urethrolysis results were reviewed. Agreement in assessment of BOO criteria was assessed by estimating the proportion of pair-wise agreements along with an exact binomial 95% confidence interval (CI) and by estimating kappa along with a 95% CI. Results Twenty-one patients were identified. Twenty of the 22 urethrolyses (91%) were clinically successful. Diagnosis of BOO was most common for VCC (86%) and then B-G Nomogram (67%). Agreement with the VCC was relatively poor for each of the five other methods (14%-62%) with the video urodynamic study (VUDS) being the best. Three patients with successful urethrolysis were diagnosed only by the VCC. All of kappa values regarding agreement with the VCC were low; the highest value of 0.15 was observed for VUDS. Conclusion VCC may augment selection criteria for urethrolysis. .