Revisiting the Classification of Neuromuscular Blockade, Aligning Clinical Practice and Research

A Practical Dosing Algorithm for Deep Neuromuscular Blockade during Total Intravenous Anesthesia: ROCURITHM

BACKGROUND

The number of trials investigating the effects of deep neuromuscular blockade (NMB) on surgical conditions and patient outcomes is steadily increasing. Consensus on which surgical procedures benefit from deep NMB (a posttetanic count [PTC] of 1 to 2) and how to implement it has not been reached. The European Society of Anaesthesiology and Intensive Care does not advise routine application but recommends use of deep NMB to improve surgical conditions on indication. This study investigates the optimal dosing strategy to reach and maintain adequate deep NMB during total intravenous anesthesia.

METHODS

Data from three trials investigating deep NMB during laparoscopic surgery with total intravenous anesthesia (n = 424) were pooled to analyze the required rocuronium dose, when to start continuous infusion, and how to adjust. The resulting algorithm was validated (n = 32) and compared to the success rate in ongoing studies in which the algorithm was not used (n = 180).

RESULTS

The mean rocuronium dose based on actual bodyweight for PTC 1 to 2 was (mean ± SD) 1.0 ± 0.27 mg · kg-1 ·h-1 in the trials, in which mean duration of surgery was 116 min. An induction dose of 0.6 mg ·kg-1 led to a PTC of 1 to 5 in a quarter of patients after a mean of 11 min. The remaining patients were equally divided over too shallow (additional bolus and direct start of continuous infusion) or too deep; a 15-min wait after PTC of 0 for return of PTC to 1 or higher. Using the proposed algorithm, a mean 76% of all 5-min measurements throughout surgery were on target PTC 1 to 2 in the validation cohort. The algorithm performed significantly better than anesthesiology residents without the algorithm, even after a learning curve from 0 to 20 patients (42% on target, P ≤ 0.001, Cohen's d = 1.4 [95% CI, 0.9 to 1.8]) to 81 to 100 patients (61% on target, P ≤ 0.05, Cohen's d = 0.7 [95% CI, 0.1 to 1.2]).

CONCLUSIONS

This study proposes a dosing algorithm for deep NMB with rocuronium in patients receiving total intravenous anesthesia.

EDITOR’S PERSPECTIVE

Deep neuromuscular blockade in adults undergoing an abdominal laparoscopic procedure

BACKGROUND

Laparoscopic surgery is the preferred option for many procedures. To properly perform laparoscopic surgery, it is essential that sudden movements and abdominal contractions in patients are prevented, as it limits the surgeon's view. There has been a growing interest in the potential beneficial effect of deep neuromuscular blockade (NMB) in laparoscopic surgery. Deep NMB improves the surgical field by preventing abdominal contractions, and it is thought to decrease postoperative pain. However, it is uncertain if deep NMB improves intraoperative safety and thereby improves clinical outcomes.

OBJECTIVES

To evaluate the benefits and harms of deep neuromuscular blockade versus no, shallow, or moderate neuromuscular blockade during laparoscopic intra- or transperitoneal procedures in adults.

SEARCH METHODS

We used standard, extensive Cochrane search methods. The latest search date was 31 July 2023.

SELECTION CRITERIA

We included randomised clinical trials (irrespective of language, blinding, or publication status) in adults undergoing laparoscopic intra- or transperitoneal procedures comparing deep NMB to moderate, shallow, or no NMB. We excluded trials that did not report any of the primary or secondary outcomes of our review.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Our primary outcomes were 1. all-cause mortality, 2. health-related quality of life, and 3. proportion of participants with serious adverse events. Our secondary outcomes were 4. proportion of participants with non-serious adverse events, 5. readmissions within three months, 6. short-term pain scores, 7. measurements of postoperative recovery, and 8. operating time. We used GRADE to assess the certainty of evidence for each outcome.

MAIN RESULTS

We included 42 randomised clinical trials with 3898 participants. Most trials included participants undergoing intraperitoneal oncological resection surgery. We present the Peto fixed-effect model for most dichotomous outcomes as only sparse events were reported. Comparison 1: deep versus moderate NMB Thirty-eight trials compared deep versus moderate NMB. Deep NMB may have no effect on mortality, but the evidence is very uncertain (Peto odds ratio (OR) 7.22, 95% confidence interval (CI) 0.45 to 115.43; 12 trials, 1390 participants; very low-certainty evidence). Deep NMB likely results in little to no difference in health-related quality of life up to four days postoperative (mean difference (MD) 4.53 favouring deep NMB on the Quality of Recovery-40 score, 95% CI 0.96 to 8.09; 5 trials, 440 participants; moderate-certainty evidence; mean difference lower than the mean clinically important difference of 10 points). The evidence is very uncertain about the effect of deep NMB on intraoperatively serious adverse events (deep NMB 38/1150 versus moderate NMB 38/1076; Peto OR 0.95, 95% CI 0.59 to 1.52; 21 trials, 2231 participants; very low-certainty evidence), short-term serious adverse events (up to 60 days) (deep NMB 37/912 versus moderate NMB 42/852; Peto OR 0.90, 95% CI 0.56 to 1.42; 16 trials, 1764 participants; very low-certainty evidence), and short-term non-serious adverse events (Peto OR 0.94, 95% CI 0.65 to 1.35; 11 trials, 1232 participants; very low-certainty evidence). Deep NMB likely does not alter the duration of surgery (MD -0.51 minutes, 95% CI -3.35 to 2.32; 34 trials, 3143 participants; moderate-certainty evidence). The evidence is uncertain if deep NMB alters the length of hospital stay (MD -0.22 days, 95% CI -0.49 to 0.06; 19 trials, 2084 participants; low-certainty evidence) or pain scores one hour after surgery (MD -0.31 points on the numeric rating scale, 95% CI -0.59 to -0.03; 22 trials, 1823 participants; very low-certainty evidence; mean clinically important difference 1 point) and 24 hours after surgery (MD -0.60 points on the numeric rating scale, 95% CI -1.05 to -0.15; 16 trials, 1404 participants; very low-certainty evidence; mean clinically important difference 1 point). Comparison 2: deep versus shallow NMB Three trials compared deep versus shallow NMB. The trials did not report on mortality and health-related quality of life. The evidence is very uncertain about the effect of deep NMB compared to shallow NMB on the proportion of serious adverse events (RR 1.66, 95% CI 0.50 to 5.57; 2 trials, 158 participants; very low-certainty evidence). Comparison 3: deep versus no NMB One trial compared deep versus no NMB. There was no mortality in this trial, and health-related quality of life was not reported. The proportion of serious adverse events was 0/25 in the deep NMB group and 1/25 in the no NMB group.

AUTHORS' CONCLUSIONS

There was insufficient evidence to draw conclusions about the effects of deep NMB compared to moderate NMB on all-cause mortality and serious adverse events. Deep NMB likely results in little to no difference in health-related quality of life and duration of surgery compared to moderate NMB, and it may have no effect on the length of hospital stay. Due to the very low-certainty evidence, we do not know what the effect is of deep NMB on non-serious adverse events, pain scores, or readmission rates. Randomised clinical trials with adequate reporting of all adverse events would reduce the current uncertainties. Due to the low number of identified trials and the very low certainty of evidence, we do not know what the effect of deep NMB on serious adverse events is compared to shallow NMB and no NMB. We found no trials evaluating mortality and health-related quality of life.

Deep neuromuscular block reduces the incidence of intra-operative complications during laparoscopic donor nephrectomy: a pooled analysis of randomized controlled trials

Study objective

To assess whether different intensities of intra-abdominal pressure and deep neuromuscular blockade influence the risk of intra-operative surgical complications during laparoscopic donor nephrectomy.

Design

A pooled analysis of ten previously performed prospective randomized controlled trials.

Setting

Laparoscopic donor nephrectomy performed in four academic hospitals in the Netherlands: Radboudumc, Leiden UMC, Erasmus MC Rotterdam, and Amsterdam UMC.

Patients

Five hundred fifty-six patients undergoing a transperitoneal, fully laparoscopic donor nephrectomy enrolled in ten prospective, randomized controlled trials conducted in the Netherlands from 2001 to 2017.

Interventions

Moderate (tetanic count of four > 1) versus deep (post-tetanic count 1–5) neuromuscular blockade and standard (≥10 mmHg) versus low (<10 mmHg) intra-abdominal pressure.

Measurements

The primary endpoint is the number of intra-operative surgical complications defined as any deviation from the ideal intra-operative course occurring between skin incision and closure with five severity grades, according to ClassIntra. Multiple logistic regression analyses were used to identify predictors of intra- and postoperative complications.

Main results

In 53/556 (9.5%) patients, an intra-operative complication with ClassIntra grade ≥ 2 occurred. Multiple logistic regression analyses showed standard intra-abdominal pressure (OR 0.318, 95% CI 0.118–0.862; p = 0.024) as a predictor of less intra-operative complications and moderate neuromuscular blockade (OR 3.518, 95% CI 1.244–9.948; p = 0.018) as a predictor of more intra-operative complications. Postoperative complications occurred in 31/556 (6.8%), without significant predictors in multiple logistic regression analyses.

Conclusions

Our data indicate that the use of deep neuromuscular blockade could increase safety during laparoscopic donor nephrectomy. Future randomized clinical trials should be performed to confirm this and to pursue whether it also applies to other types of laparoscopic surgery.

Trial registration

Clinicaltrials.gov LEOPARD-2 (NCT02146417), LEOPARD-3 trial (NCT02602964), and RELAX-1 study (NCT02838134), Klop et al. (NTR 3096), Dols et al. 2014 (NTR1433).

REsidual Neuromuscular Block Prediction Score Versus Train-of-Four Ratio and Respiratory Outcomes: A Retrospective Cohort Study

BACKGROUND

Residual neuromuscular blockade is associated with an increased incidence of postoperative respiratory complications. The REsidual neuromuscular block Prediction Score (REPS) identifies patients at high risk for residual neuromuscular blockade after surgery.

METHODS

A total of 101,510 adults undergoing noncardiac surgery under general anesthesia from October 2005 to December 2018 at a tertiary care center in Massachusetts were analyzed for the primary outcome of postoperative respiratory complications (invasive mechanical ventilation requirement within 7 postoperative days or immediate postextubation desaturation [oxygen saturation {Spo2} <90%] within 10 minutes). The primary objective was to assess the association between the REPS and respiratory complications. The secondary objective was to compare REPS and train-of-four (TOF) ratio <0.90 on the strength of their association with respiratory complications.

RESULTS

A high REPS (≥4) was associated with an increase in odds of respiratory complications (adjusted odds ratio [OR], 1.13 [95% confidence interval {CI}, 1.06-1.21]; P < .001). In 6224 cases with available TOF ratio measurements, a low TOF ratio (<0.9) was associated with respiratory complications (adjusted OR, 1.43 [95% CI, 1.11-1.85]; P = .006), whereas a high REPS was not (adjusted OR, 0.96 [95% CI, 0.74-1.23]; P = .73) (P = .018 for comparison between ORs).

CONCLUSIONS

The REPS may be implemented as a screening tool to encourage clinicians to use quantitative neuromuscular monitoring in patients at risk of residual neuromuscular blockade. A positive REPS should be followed by a quantitative assessment of the TOF ratio.