The Use of Muscle Relaxants and Reversal Agents in a Setting Without Cost Restrictions: Experience from a Tertiary Academic Hospital in the Netherlands.

Introduction: Muscle relaxants are often given during general anesthesia to facilitate endotracheal intubation. However lingering effects after anesthesia-end may lead to respiratory compromise in the PACU. Strategies to reduce these adverse events include monitoring neuromuscular block, the use of short-acting agents and active pharmacological reversal before extubation. At Leiden University Medical Center (LUMC), a tertiary care academic hospital in the Netherlands, various muscle relaxants and reversal agents are freely available to all clinicians without restrictions. In this setting, we intended to evaluate how patient and surgical characteristics impacted the use of these agents for a variety of non-cardiac surgeries. Material and Methods: This is a retrospective database study of adult patients that had received elective, non-cardiac surgery and general anesthesia with endotracheal intubation between 2016 and 2020 at LUMC in the Netherlands. Exclusion criteria consisted of patients pharmacologically reversed with both sugammadex and neostigmine during the same procedure, diagnosed with myasthenia gravis, receiving pyridostigmine therapy, or with renal failure (eGFR <30 mL.min.1.73m2). Results: We retrieved 23,373 patient records of which 9742 were excluded because one or more exclusion criteria were met. The final cohort consisted of 13,631 cases. Rocuronium was the most commonly used muscle relaxant (88.5%); sugammadex was the most commonly used reversal agent (99.9% of those pharmacologically reversed). Of all cases that received rocuronium as muscle relaxant, 76.9% of patients were not reversed, while 23.1% were reversed with sugammadex. The odds of reversal increased with age, BMI, ASA class (1-3) and shorter duration of surgery. Conclusion: In an unrestricted clinical environment, rocuronium and sugammadex are the preferred agents for muscle relaxation and reversal. Pharmacologic reversal of neuromuscular block was uncommon overall, but more likely in older and obese patients, higher ASA classification and shorter lasting procedures. Sugammadex has largely replaced neostigmine for this purpose.

Intraoperative use of the machine learning-derived nociception level monitor results in less pain in the first 90†min after surgery.

In this pooled analysis of two randomized clinical trials, intraoperative opioid dosing based on the nociception level-index produced less pain compared to standard care with a difference in pain scores in the post-anesthesia care unit of 1.5 (95% CI 0.8-2.2) points on an 11-point scale. The proportion of patients with severe pain was lower by 70%. Severe postoperative pain remains a significant problem and associates with several adverse outcomes. Here, we determined whether the application of a monitor that detects intraoperative nociceptive events, based on machine learning technology, and treatment of such events reduces pain scores in the post-anesthesia care unit (PACU). To that end, we performed a pooled analysis of two trials in adult patients, undergoing elective major abdominal surgery, on the effect of intraoperative nociception level monitor (NOL)-guided fentanyl dosing on PACU pain was performed. Patients received NOL-guided fentanyl dosing or standard care (fentanyl dosing based on hemodynamic parameters). Goal of the intervention was to keep NOL at values that indicated absence of nociception. The primary endpoint of the study was the median pain score obtained in the first 90 min in the PACU. Pain scores were collected at 15 min intervals on an 11-point Likert scale. Data from 125 patients (55 men, 70 women, age range 21-86 years) were analyzed. Sixty-one patients received NOL-guided fentanyl dosing and 64 standard care. Median PACU pain score was 1.5 points (0.8-2.2) lower in the NOL group compared to the standard care; the proportion of patients with severe pain was 70% lower in the NOL group (p = 0.045). The only significant factor associated with increased odds for severe pain was the standard of care compared to NOL treatment (OR 6.0, 95% CI 1.4 -25.9, p = 0.017). The use of a machine learning-based technology to guide opioid dosing during major abdominal surgery resulted in reduced PACU pain scores with less patients in severe pain.

The impact of deep versus standard neuromuscular block on intraoperative safety during laparoscopic surgery: an international multicenter randomized controlled double-blind strategy trial - EURO-RELAX TRIAL.

BACKGROUND: Muscle relaxants are routinely used during anesthesia to facilitate endotracheal intubation and to optimize surgical conditions. However, controversy remains about the required depth of neuromuscular block (NMB) needed for optimal surgical working conditions and how this relates to other outcomes. For instance, a deep neuromuscular block yields superior surgical working conditions compared to a standard NMB in laparoscopic surgery, however, a robust association to other (safety) outcomes has not yet been established. METHODS: Trial design: an international multicenter randomized controlled double-blind strategy trial. Trial population: 922 patients planned for elective, laparoscopic or robotic, abdominal surgery. INTERVENTION: Patients will be randomized to a deep NMB (post-tetanic count 1-2 twitches) or standard care (single-dose muscle relaxant administration at induction and repeated only if warranted by surgical team). Main trial endpoints: Primary endpoint is the difference in incidence of intraoperative adverse events during laparoscopic surgery graded according to ClassIntra® classification (i.e., ClassIntra® grade ≥ 2) between both groups. Secondary endpoints include the surgical working conditions, 30-day postoperative complications, and patients' quality of recovery. DISCUSSION: This trial was designed to analyze the effect of deep neuromuscular block compared to standard neuromuscular block on intra- and postoperative adverse events in patients undergoing laparoscopic surgery. TRIAL REGISTRATION: ClinicalTrials.gov NCT04124757 (EURO-RELAX); registration URL: https://clinicaltrials.gov/ct2/show/NCT04124757 , registered on October 11th, 2019.

Deep neuromuscular block does not improve surgical conditions in patients receiving sevoflurane anaesthesia for laparoscopic renal surgery.

BACKGROUND: Deep neuromuscular block is associated with improved working conditions during laparoscopic surgery when propofol is used as a general anaesthetic. However, whether deep neuromuscular block yields similar beneficial effects when anaesthesia is maintained using volatile inhalation anaesthesia has not been systematically investigated. Volatile anaesthetics, as opposed to intravenous agents, potentiate muscle relaxation, which potentially reduces the need for deep neuromuscular block to obtain optimal surgical conditions. We examined whether deep neuromuscular block improves surgical conditions over moderate neuromuscular block during sevoflurane anaesthesia. METHODS: In this single-centre, prospective, randomised, double-blind study, 98 patients scheduled for elective renal surgery were randomised to receive deep (post-tetanic count 1-2 twitches) or a moderate neuromuscular block (train-of-four 1-2 twitches). Anaesthesia was maintained with sevoflurane and titrated to bispectral index values between 40 and 50. Pneumoperitoneum pressure was maintained at 12 mm Hg. The primary outcome was the difference in surgical conditions, scored at 15 min intervals by one of eight blinded surgeons using a 5-point Leiden-Surgical Rating Scale (L-SRS) that scores the quality of the surgical field from extremely poor1 to optimal5. RESULTS: Deep neuromuscular block did not improve surgical conditions compared with moderate neuromuscular block: mean (standard deviation) L-SRS 4.8 (0.3) vs 4.8 (0.4), respectively (P=0.94). Secondary outcomes, including unplanned postoperative readmissions and prolonged hospital admission, were not significantly different. CONCLUSIONS: During sevoflurane anaesthesia, deep neuromuscular block did not improve surgical conditions over moderate neuromuscular block in normal-pressure laparoscopic renal surgery. CLINICAL TRIAL REGISTRATION: NL7844 (www.trialregister.nl).

Reduced postoperative pain using Nociception Level-guided fentanyl dosing during sevoflurane anaesthesia: a randomised controlled trial.

BACKGROUND: The majority of postoperative patients report moderate to severe pain, possibly related to opioid underdosing or overdosing during surgery. Objective guidance of opioid dosing using the Nociception Level (NOL) index, a multiparameter artificial intelligence-driven index designed to monitor nociception during surgery, may lead to a more appropriate analgesic regimen, with effects beyond surgery. We tested whether NOL-guided opioid dosing during general anaesthesia results in less postoperative pain. METHODS: In this two-centre RCT, 50 patients undergoing abdominal surgery under fentanyl/sevoflurane anaesthesia were randomised to NOL-guided fentanyl dosing or standard care in which fentanyl dosing was based on haemodynamics. The primary endpoint of the study was postoperative pain assessed in the PACU. RESULTS: Median postoperative pain scores were 3.2 (inter-quartile range 1.3-4.3) and 4.8 (3.0-5.3) in NOL-guided and standard care groups, respectively (P=0.006). Postoperative morphine consumption (standard deviation) was 0.06 (0.07) mg kg-1 (NOL-guided group) and 0.09 (0.09) mg kg-1 (control group; P=0.204). During surgery, fentanyl dosing was not different between groups (NOL-guided group: 6.4 [4.2] µg kg-1vs standard care: 6.0 [2.2] µg kg-1, P=0.749), although the variation between patients was greater in the NOL-guided group (% coefficient of variation 66% in the NOL-guided group vs 37% in the standard care group). CONCLUSIONS: Despite absence of differences in fentanyl and morphine consumption during and after surgery, a 1.6-point improvement in postoperative pain scores was observed in the NOL-guided group. We attribute this to NOL-driven rather than BP- and HR-driven fentanyl dosing during anaesthesia. CLINICAL TRIAL REGISTRATION: www.trialregister.nl under identifier NL7845.

Does nociception monitor-guided anesthesia affect opioid consumption? A systematic review of randomized controlled trials.

Monitors that estimate nociception during anesthesia may be used to guide opioid and other analgesics administration to optimize anesthesia care and possibly outcome. We reviewed the literature to evaluate current evidence of the effect of nociception-guided management over standard anesthesia practice during surgery. A systematic review of the literature on the effect of nociception monitoring on anesthesia practice was conducted. Reports were eligible if they compared nociception-guided anesthesia to standard practice during surgery. Primary endpoint of this review is intraoperative opioid consumption. Secondary endpoints included hemodynamic control, postoperative pain and pain treatment. We identified 12 randomized controlled trials that compared one of five different nociception monitoring techniques to standard anesthesia care. Most studies were single center studies of small sample size. Six studies reported intraoperative opioid consumption as primary outcome. There was considerable variability with respect to surgical procedure and anesthesia technique. For nociception monitors that were investigated by more than one study, analysis of the pooled data was performed. The surgical plethysmographic index was the only monitor for which an intra operative opioid sparing effect was found. For the other monitors, either no effect was detected, or pooled analysis could not be performed due to paucity of study data. On secondary outcomes, no consistent effect of nociception-guided anesthesia could be established. Although some nociception monitors show promising results, no definitive conclusions regarding the effect of nociception monitoring on intraoperative opioid consumption or other anesthesia related outcome can be drawn.Clinical trial number PROSPERO ID 102913.

Nociception-guided versus Standard Care during Remifentanil-Propofol Anesthesia: A Randomized Controlled Trial.

BACKGROUND: The multidimensional index of nociception, the nociception level, outperforms blood pressure and heart rate in detection of nociceptive events during anesthesia. We hypothesized that nociception level-guided analgesia reduces opioid consumption and suboptimal anesthesia events such as low blood pressure and use of vasoactive medication. METHODS: In this single-blinded randomized study, 80 American Society of Anesthesiologists class I-III adult patients of either sex, scheduled for major abdominal procedures under remifentanil/propofol anesthesia by target-controlled infusion, were included. During the procedure nociception level, noninvasive blood pressure, and heart rate were monitored. Patients were randomized to receive standard clinical care or nociception level-guided analgesia. In the nociception level-guided group, remifentanil concentration was reduced when index values were less than 10 or increased when values were above 25 for at least 1 min, in steps of 0.5 to 1.0 ng/ml. Propofol was titrated to bispectral index values between 45 and 55. The primary outcomes of the study were remifentanil and propofol consumption and inadequate anesthesia events. RESULTS: Compared with standard care, remifentanil administration was reduced in nociception level-guided patients from (mean ± SD) 0.119 ± 0.033 to 0.086 ± 0.032 µg · kg · min (mean difference, 0.039 µg · kg · min; 95% CI, 0.025-0.052 µg · kg · min; P < 0.001). Among nociception level-guided patients, 2 of 40 (5%) experienced a hypotensive event (mean arterial pressure values less than 55 mm Hg) versus 11 of 40 (28%) patients in the control group (relative risk, 0.271; 95% CI, 0.08-0.77; P = 0.006). In the nociception level-guided group, 16 of 40 (40%) patients received vasoactive medication versus 25 of 40 (63%) patients in the standard care group (relative risk, 0.64; 95% CI, 0.40-0.99; P = 0.044). CONCLUSIONS: Nociception level-guided analgesia during major abdominal surgery resulted in 30% less remifentanil consumption.

The use of surgical rating scales for the evaluation of surgical working conditions during laparoscopic surgery: a scoping review.

INTRODUCTION: Surgical rating scales (SRSs) enable the surgeon to uniformly quantify surgical working conditions. They are increasingly used as a primary outcome in studies evaluating the effect of anaesthesia or surgery-related interventions on the quality of the surgical work field. SRSs are especially used in laparoscopic surgery due to a renewed interest in deep neuromuscular block. There are however no guidelines regarding the uniform use of SRS and the uniform reporting of results. METHODS: A systematic search was conducted in the databases of PubMed, Web of Science and Embase for studies that reported the use of an SRS to evaluate surgical conditions in laparoscopic surgery. Only original human research in English language with full text availability through the Leiden university library was considered for this review. The full texts of eligible abstracts were independently reviewed by the first and second author. The quality of SRSs and methodology of rating were systematically reviewed. RESULTS: The search yielded 2830 reports, of which 17 were identified using a surgical rating scale (SRS) in laparoscopic surgery. Ten of these reports used a unique SRS, these were systematically appraised for their quality. The overall quality of the SRSs was low: the majority of the scales were poorly described and lacked assessment of inter- and intra-rater reliability. In addition, considerable differences exist in the methodology of rating and the reporting of results. CONCLUSION: There is substantial inconsistency in SRS quality, methodology, and results reporting. The uniform use of high-quality surgical rating scales is needed to improve the quality and reproducibility of future research.

Impact of high- versus low-dose neuromuscular blocking agent administration on unplanned 30-day readmission rates in retroperitoneal laparoscopic surgery.

Recent data shows that a neuromuscular block (NMB) induced by administration of high doses of rocuronium improves surgical conditions in certain procedures. However, there are limited data on the effect such practices on postoperative outcomes. We performed a retrospective analysis to compare unplanned 30-day readmissions in patients that received high-dose versus low-dose rocuronium administration during general anesthesia for laparoscopic retroperitoneal surgery. This retrospective cohort study was performed in the Netherlands in an academic hospital where routine high-dose rocuronium NMB has been practiced since July 2015. Charts of patients receiving anesthesia between January 2014 and December 2016 were searched for surgical cases receiving high-dose rocuronium and matched with respect to procedure, age, sex and ASA classification to patients receiving low-dose rocuronium. The primary post-operative outcome was unplanned 30-day readmission rate. There were 130 patients in each cohort. Patients in the high- and low-dose rocuronium cohorts received 217 ± 49 versus 37 ± 5 mg rocuronium, respectively. In the high-dose rocuronium group neuromuscular activity was consistently monitored; matched patients were unreliably monitored. All patients receiving high-dose rocuronium were reversed with sugammadex, while just 33% of matched patients were reversed with sugammadex and 20% with neostigmine; the remaining patients were not reversed. Unplanned 30-day readmission rate was significantly lower in the high-dose compared to the low-dose rocuronium cohort (3.8% vs. 12.7%; p = 0.03; odds ratio = 0.33, 95% C.I. 0.12-0.95). This small retrospective study demonstrates a lower incidence of unplanned readmissions within 30-days following laparoscopic retroperitoneal surgery with high-dose relaxant anesthesia and sugammadex reversal in comparison to low-dose relaxant anesthesia. Further prospective studies are needed in larger samples to corroborate our findings and additionally assess the pharmacoeconomics of high-dose relaxant anesthesia taking into account the benefits (reduced readmissions) and harm (cost of relaxants and reversal agents) of such practice.

Recent advances in neuromuscular block during anesthesia.

Muscle relaxation is a routine part of anesthesia and has important advantages. However, the lingering effects of muscle relaxants in the postoperative period have historically been associated with postoperative adverse events. Neuromuscular reversal, together with neuromuscular monitoring, is a recognized strategy to reduce the rate of postoperative residual relaxation but has only marginally improved outcome in the past few decades. Sugammadex, a novel reversal agent with unique encapsulating properties, has changed the landscape of neuromuscular reversal and opened up new opportunities to improve patient care. By quickly and completely reversing any depth of neuromuscular block, it may reduce the rate of residual relaxation and improve respiratory recovery. In addition, sugammadex has made the use of deep neuromuscular block possible during surgery. Deep neuromuscular block may improve surgical working conditions and allow for a reduction in insufflation pressures during selected laparoscopic procedures. However, whether and how this may impact outcomes is not well established.

Deep Neuromuscular Block Improves Surgical Conditions during Bariatric Surgery and Reduces Postoperative Pain: A Randomized Double Blind Controlled Trial.

BACKGROUND: It remains unknown whether the administration of a deep neuromuscular block (NMB) during bariatric surgery improves surgical conditions and patient outcome. The authors studied the effect of deep versus moderate NMB in laparoscopic bariatric surgery on surgical conditions and postoperative pain. METHODS AND RESULTS: One hundred patients scheduled to undergo elective bariatric surgery were randomized to a deep NMB (post-tetanic-count 2-3) or a moderate NMB (train-of-four 1-2). The quality of the surgical field was scored using the Leiden-Surgical Rating Scale (L-SRS), a 5-point scale ranging from 1 (extremely poor conditions) to 5 (optimal conditions). Three surgeons scored the L-SRS at 10-min intervals during surgery; postoperative pain scores were obtained in the postanesthesia-care-unit (PACU) and on the ward. Mean (95% confidence interval) L-SRS scores in moderate NMB 4.2 (4.0-4.4) versus 4.8 (4.7-4.9) in deep NMB (p < 0.001). Moderate NMB resulted in 17% of scores at L-SRS scores of 1-3, while deep NMB resulted in 100% scores at the high end of the L-SRS (4-5). Deep NMB led to improved pain scores in the PACU (4.6 (4.2-4.9) versus 3.9 (3.6-4.4), p = 0.03) and reduced shoulder pain on the ward (1.8 (1.5-2.1) versus 1.3 (1.1-1.5), p = 0.03). A composite score of pain and opioid use in the PACU favoured deep NMB (p = 0.001). CONCLUSIONS: In bariatric surgery, deep relaxation has advantages for surgeon and patient. Compared to moderate NMB, deep NMB produced stable and improved surgical conditions with less postoperative pain.

Effect of variations in depth of neuromuscular blockade on rating of surgical conditions by surgeon and anesthesiologist in patients undergoing laparoscopic renal or prostatic surgery (BLISS trial): study protocol for a randomized controlled trial.

BACKGROUND: Surgical conditions in laparoscopic surgery are largely determined by the depth of neuromuscular relaxation. Especially in procedures that are confined to a narrow working field, such as retroperitoneal laparoscopic surgery, deep neuromuscular relaxation may be beneficial. Until recently, though, deep neuromuscular block (NMB) came at the expense of a variety of issues that conflicted with its use. However, with the introduction of sugammadex, rapid reversal of a deep NMB is feasible. In the current protocol, the association between the depth of NMB and rating of surgical conditions by the surgeon and anesthesiologist is studied. METHODS/DESIGN: This is a single-center, prospective, randomized, blinded, parallel group and controlled trial. Eligible patients are randomly assigned to one of two groups: (1) deep NMB (post-tetanic count, one or two twitches; n = 12) and (2) moderate NMB (train-of-four, 1 to 2 twitches, n = 12) by administration of high-dose rocuronium in Group 1 and a combination of atracurium and mivacurium in Group 2. The NMB in Group 1 is reversed by 4 mg/kg sugammadex; the NMB in Group 2 by 1 mg neostigmine and 0.5 mg atropine. Patients are eligible if they are over 18 years, willing to sign the informed consent form, and are scheduled to undergo an elective laparoscopic renal procedure or laparoscopic prostatectomy. A single surgeon performs the surgeries and rates the surgical conditions on a five-point surgical rating scale (SRS) ranging from 1 (poor surgical conditions) to 5 (excellent surgical conditions). The intra-abdominal part of the surgeries is captured on video and a group of five anesthesiologists and ten surgical experts will rate the videos using the same SRS. The primary analysis will be an intention-to-treat analysis. Evaluation will include the association between the level of NMB and SRS, as obtained by the surgeon performing the procedure and the agreement between the scoring of the images by anesthesiologists and surgeons. DISCUSSION: We aim to show that under the right conditions the perceived opposing goals of surgeons and anesthesiologists (optimal surgical conditions vs. optimal postoperative conditions) may be met without compromise to either. TRIAL REGISTRATION: ClinicalTrials.gov identifier NCT01631149.