Assessing residual neuromuscular blockade using acceleromyography can be deceptive in postoperative awake patients

Neuromuscular block monitoring by smartphone application (i-TOF© system): an observational pilot study

Neuromuscular block monitoring is recommended by international guidelines to improve myorelaxation during surgery and reduce the risk of postoperative residual curarization. We conducted a pilot study to verify the efficacy of i-TOF, a wireless neuromuscular monitoring device connectable to a smartphone, comparing it with TOF WATCH SX. We enrolled 53 patients who underwent general anesthesia. For each patient, we recorded by both devices, in different time intervals, train-of-four (TOF) count/ratio after induction to general anesthesia (TI0-TI3) and during recovery (TR0-TR3). Moreover, post-tetanic count (PTC) was evaluated during deep neuromuscular block (TP0-TP2). We noticed no significant differences between the devices in recorded mean values of TOF ratio, TOF count, and PTC analyzed at time intervals for every phase of general anesthesia, although the i-TOF tends to an underestimation compared to TOF WATCH SX. For each patient, data sessions were successfully recorded by a smartphone. This aspect could be relevant for clinicians in order to have a stored proof of good clinical practice to be added on anesthesiologist records. By our results, i-TOF demonstrates a comparable efficacy to TOF WATCH SX, suggesting that it could be a proven alternative to standard devices for neuromuscular block monitoring. Further studies are needed to confirm our findings.

A randomized-controlled trial of sugammadex versus neostigmine: impact on early postoperative strength

BACKGROUND

Residual neuromuscular blockade after surgery is associated with airway obstruction, hypoxia, and respiratory complications. Compared with neostigmine, sugammadex reverses neuromuscular blockade to a train-of-four ratio > 0.9 more rapidly. It is unknown, however, whether the superior reversal profile of sugammadex improves clinically relevant measures of strength in the early postoperative period.

METHODS

Patients undergoing general, gynecological, or urologic surgery were randomized to receive either neostigmine (70 µg·kg^-1, maximum 5 mg) or sugammadex (2 or 4 mg·kg^-1) to reverse neuromuscular blockade. The primary outcome was the ability to breathe deeply measured by incentive spirometry at 30, 60, and 120 min after reversal.

RESULTS

We randomized 62 patients to either a neostigmine (n = 31) or sugammadex (n = 31) group. The incentive spirometry volume recovery trajectory was not different between the two groups (P = 0.35). Median spirometry volumes at baseline, 30, 60, and 120 min postoperatively were 2650 vs 2500 mL, 1775 vs 1750 mL, 1375 vs 2000 mL, and 1800 vs 1950 mL for the sugammadex and neostigmine groups, respectively. Postoperative incentive spirometry decrease from baseline was not different between the two groups. Hand grip strength, the ability to sit unaided, train-of-four ratio on postanesthesia care unit (PACU) admission, time to extubation, time to PACU discharge readiness, and Quality of Recovery-15 scores were also not different between the groups.

CONCLUSIONS

Measures of postoperative strength, such as incentive spirometry, hand group strength, and the ability to sit up in the early postoperative period were not different in patients who received neostigmine or sugammadex for the reversal of neuromuscular blockade.

TRIAL REGISTRATION

www.clinicaltrials.gov (NCT02909439); registered: 21 September, 2016.

Usefulness of intra-operative neuromuscular blockade monitoring and reversal agents for postoperative residual neuromuscular blockade: a retrospective observational study

BACKGROUND

Complete avoidance of residual neuromuscular blockade (RNMB) during the postoperative period has not yet been achieved in current anesthesia practice. Evidently, compliance with NMB monitoring is persistently low, and the risk of RNMB during the perioperative period remains underestimated. To our knowledge, no publications have reported the incidence of RNMB in a university hospital where access to quantitative NMB monitoring and sugammadex is unlimited and where NMB management is not protocolised. The primary aim of this study was to estimate the incidence of RNMB in patients managed with or without sugammadex or neostigmine as antagonists and quantitative NMB monitoring in the operating room. The secondary aim was to explore the associations between RNMB and potentially related variables.

METHODS

This retrospective observational cohort study was conducted at a tertiary referral university hospital in Buenos Aires, Argentina. Records created between June 2015 and December 2015 were reviewed. In total, 240 consecutive patients who had undergone elective surgical procedures requiring NMB were included. All patients were monitored via acceleromyography at the adductor pollicis muscle within 5 min of arrival in the postanaesthesia care unit (PACU). Scheduled recovery in the intensive care unit was the only exclusion criterion.

RESULTS

RNMB was present in 1.6% patients who received intra-operative quantitative NMB monitoring and 32% patients whose NMB was not monitored (P <  0.01). Multivariable analysis revealed that the use of intra-operative quantitative NMB monitoring and sugammadex were associated with a lower incidence of RNMB, with calculated odds ratios of 0.04 (95% confidence interval [CI]: 0.005 to 0.401) and 0.18 (95% CI: 0.046 to 0.727), respectively.

CONCLUSIONS

The results of the present study suggest that intra-operative quantitative NMB monitoring and use of sugammadex are associated with a decreased incidence of RNMB in the PACU, reinforcing the contention that the optimal strategy for RNMB avoidance is the use of quantitative NMB monitoring and eventual use of reversal agents, if needed, prior to emergence from anaesthesia.

Development of an algorithm using clinical tests to avoid post-operative residual neuromuscular block

BACKGROUND

Quantitative neuromuscular monitoring is the gold standard to detect postoperative residual curarization (PORC). Many anesthesiologists, however, use insensitive, qualitative neuromuscular monitoring or unreliable, clinical tests. Goal of this multicentre, prospective, double-blinded, assessor controlled study was to develop an algorithm of muscle function tests to identify PORC.

METHODS

After extubation a blinded anesthetist performed eight clinical tests in 165 patients. Test results were correlated to calibrated electromyography train-of-four (TOF) ratio and to a postoperatively applied uncalibrated acceleromyography. A classification and regression tree (CART) was calculated developing the algorithm to identify PORC. This was validated against uncalibrated acceleromyography and tactile judgement of TOF fading in separate 100 patients.

RESULTS

After eliminating three tests with poor correlation, a model with four tests (r = 0.844) and uncalibrated acceleromyography (r = 0.873) were correlated to electromyographical TOF-values without losing quality of prediction. CART analysis showed that three consecutively performed tests (arm lift, head lift and swallowing or eye opening) can predict electromyographical TOF. Prediction coefficients reveal an advantage of the uncalibrated acceleromyography in terms of specificity to identify the EMG measured train-of-four ratio < 0.7 (100% vs. 42.9%) and <0.9 (89.7% vs. 34.5%) compared to the algorithm. However, due to the high sensitivity of the algorithm (100% vs. 94.4%), the risk to overlook an awake patient with a train-of-four ratio < 0.7 was minimal. Tactile judgement of TOF fading showed poorest sensitivity and specifity at train of four ratio < 0.9 (33.7%, 0%) and <0.7 (18.8%, 16.7%).

CONCLUSIONS

Residual neuromuscular blockade can be detected by uncalibrated acceleromyography and if not available by a pathway of four clinical muscle function tests in awake patients. The algorithm has a discriminative power comparable to uncalibrated AMG within TOF-values >0.7 and <0.3.

TRIAL REGISTRATION

Clinical Trials.gov (principal investigator's name: CU, and identifier: NCT03219138) on July 8, 2017.

The use of sugammadex for bariatric surgery: analysis of recovery time from neuromuscular blockade and possible economic impact

BACKGROUND

Neuromuscular block (NMB) monitoring and use of reversal agents accelerate the recovery time and improve the workflow in the operating room. We aimed to compare recovery times after sugammadex or neostigmine administration, and estimate the time spent in operating theater and the possible economic impact of a faster recovery, in morbidly obese patients undergoing bariatric surgery.

METHODS

We conducted a retrospective study that analyzed data from records of morbidly obese patients (body mass index >40 kg/m(2)) undergoing elective laparoscopic bariatric surgery in which sugammadex or neostigmine were used to reverse NMB. Patients were divided in two groups: group 1 (sugammadex group [SUG]) received rocuronium and sugammadex for reversal and group 2 (neostigmine group [NEO]) received either rocuronium or cisatracurium and neostigmine. Data are presented as mean (standard deviation).

RESULTS

Compared with NEO, SUG group showed shorter times to achieve train-of-four ratio of 0.9 (P<0.05) and an Aldrete score of 10 (P<0.05), a higher cost (€146.7 vs €3.6 [P<0.05]), plus a remarkable less duration of operating theater occupancy (P<0.05). Sugammadex cost accounted for 2.58% of the total cost per surgery, while neostigmine cost accounted for 0.06%. Total time saved in SUG group was 19.4 hours, which could be used to perform 12 extra laparoscopic sleeve gastrectomies.

CONCLUSION

Reversal from NMB was significantly faster with sugammadex than with neostigmine. Although sugammadex was substantially more expensive, duration of operating theater occupancy was reduced with potentially workflow increase or personnel reduced cost.

Feasibility of full and rapid neuromuscular blockade recovery with sugammadex in myasthenia gravis patients undergoing surgery - a series of 117 cases

Purpose

Myasthenia gravis (MG) is an autoimmune disease interfering with neuromuscular transmission. Patients are at risk of postoperative residual curarization (PORC) if nondepolarizing muscle relaxants are used. Clinically inapparent insufficient muscle strength may result in hypoventilation and postoperative bronchopneumonia. We describe a cohort of 117 cases in which sugammadex was used in MG patients undergoing surgery with muscle relaxation with rocuronium.

Methods and patients

We anesthetized 117 patients with MG using rocuronium and sugammadex as neuromuscular blockade reversal agent. One hundred five patients underwent surgical thymectomy and 12 underwent cholecystectomy (five laparotomic and seven laparoscopic). We measured time from sugammadex administration to recovery and to extubation, using the TOF-Watch^® (series of four consecutive electrical impulses [the train-of-four] >0.9). We tracked peripheral capillary oxygen saturation (SpO₂) <95%, elevation of partial pressure of carbon dioxide (pCO₂) >10% above baseline, number of reintubations within the first 48 hours, and number of pneumonias within 120 hours, postoperatively. Results were processed as average, minimum, and maximum values.

Results

The period needed to reach train-of-four of 0.9 following sugammadex administration was on average 117 seconds (minimum of 105 seconds/maximum of 127 seconds) and differed within deviation <10%. The time to extubation following sugammadex administration was on average 276 seconds (minimum of 251 seconds/maximum of 305 seconds) and differed minimally among patients as well. We observed no SpO₂ <95%, no pCO₂ elevation >10% above a baseline, no emergent reintubation within the first 48 hours, and no pneumonia diagnosed on clinical basis within 120 hours, postoperatively in all 117 patients.

Conclusion

In this cohort of MG patients undergoing surgery using rocuronium and sugammadex, we did not observe any signs of postoperative residual curarization and respiratory depression. The neuromuscular blockade recovery was reliable, predictable, and rapid.

Comparison between the Effects of Rocuronium, Vecuronium, and Cisatracurium Using Train-of-Four and Clinical Tests in Elderly Patients

Background

Postoperative residual blockade, longer duration of action for neuromuscular blockade, and slower recovery were relatively common in elderly patients.

Objectives

We aimed to investigate the safety of train-of-four ratio and clinical tests in the assessment of patient recovery, and to determine the effects of the rocuronium, vecuronium, and cisatracurium on intubation, extubation and recovery times in elderly patients undergoing abdominal surgery.

Patients and Methods

After obtaining institutional approval and informed consent, 60 patients over 60 years old and undergoing elective abdominal operations were included in this double-blind, randomized clinical trial. Following a standard anesthesia induction, 0.6mg kg-1 rocuronium, 0.1mg kg-1 vecuronium, and 0.1mg kg-1 cisatracurium were administered to the patients in Group R, Group V, and Group C, respectively. Train-of-four (TOF) ratios were recorded at 10-minute intervals during and after the operation. Modified Aldrete Score (MAS) and clinical tests were recorded in the recovery room at 10-minute intervals. In addition, intubation and extubation times, duration of recovery room stay, and any complications were recorded.

Results

Intubation time was found to be shorter in Group R than that in Groups V and C (P ˂ 0.001). Times to positive visual disturbances and grip strength tests were shorter in Group C than that in Group V (P = 0.016 and P = 0.011, respectively). In Group R and group C, time to TOF ≥ 0.9 was significantly longer than all positive clinical test times except grip strength (P < 0.05).

Conclusions

We hold the opinion that cisatracurium is safer in elderly patients compared to other drugs. We also concluded that the usage of TOF ratio together with clinical tests is suitable for assessment of neuromuscular recovery in these patients.