2023 American Society of Anesthesiologists Practice Guidelines for Monitoring and Antagonism of Neuromuscular Blockade: A Report by the American Society of Anesthesiologists Task Force on Neuromuscular Blockade.

These practice guidelines provide evidence-based recommendations on the management of neuromuscular monitoring and antagonism of neuromuscular blocking agents during and after general anesthesia. The guidance focuses primarily on the type and site of monitoring and the process of antagonizing neuromuscular blockade to reduce residual neuromuscular blockade.

Perioperative Methadone and Ketamine for Postoperative Pain Control in Spinal Surgical Patients: A Randomized, Double-blind, Placebo-controlled Trial.

BACKGROUND: Despite application of multimodal pain management strategies, patients undergoing spinal fusion surgery frequently report severe postoperative pain. Methadone and ketamine, which are N-methyl-d-aspartate receptor antagonists, have been documented to facilitate postoperative pain control. This study therefore tested the primary hypothesis that patients recovering from spinal fusion surgery who are given ketamine and methadone use less hydromorphone on the first postoperative day than those give methadone alone. METHODS: In this randomized, double-blind, placebo-controlled trial, 130 spinal surgery patients were randomized to receive either methadone at 0.2 mg/kg (ideal body weight) intraoperatively and a 5% dextrose in water infusion for 48 h postoperatively (methadone group) or 0.2 mg/kg methadone intraoperatively and a ketamine infusion (0.3 mg · kg-1 · h-1 infusion [no bolus] intraoperatively and then 0.1 mg · kg-1 · h-1 for next 48 h [both medications dosed at ideal body weight]; methadone/ketamine group). Anesthetic care was standardized in all patients. Intravenous hydromorphone use on postoperative day 1 was the primary outcome. Pain scores, intravenous and oral opioid requirements, and patient satisfaction with pain management were assessed for the first 3 postoperative days. RESULTS: Median (interquartile range) intravenous hydromorphone requirements were lower in the methadone/ketamine group on postoperative day 1 (2.0 [1.0 to 3.0] vs. 4.6 [3.2 to 6.6] mg in the methadone group, median difference [95% CI] 2.5 [1.8 to 3.3] mg; P < 0.0001) and postoperative day 2. In addition, fewer oral opioid tablets were needed in the methadone/ketamine group on postoperative day 1 (2 [0 to 3] vs. 4 [0 to 8] in the methadone group; P = 0.001) and postoperative day 3. Pain scores at rest, with coughing, and with movement were lower in the methadone/ketamine group at 23 of the 24 assessment times. Patient-reported satisfaction scores were high in both study groups. CONCLUSIONS: Postoperative analgesia was enhanced by the combination of methadone and ketamine, which act on both N-methyl-d-aspartate and µ-opioid receptors. The combination could be considered in patients having spine surgery.

Neuromuscular and Clinical Recovery in Thoracic Surgical Patients Reversed With Neostigmine or Sugammadex.

BACKGROUND: Patients undergoing thoracoscopic procedures may be at high-risk for incomplete neuromuscular recovery and associated complications. The aim of this clinical investigation was to assess the incidence of postoperative residual neuromuscular blockade in adult thoracic surgical patients administered neostigmine or sugammadex when optimal dosing and reversal strategies for these agents were used. The effect of choice of reversal agent on hypoxemic events and signs and symptoms of muscle weakness were also determined. Additionally, operative conditions in each group were graded by surgeons performing the procedures. METHODS: Two hundred patients undergoing thoracoscopic surgical procedures were enrolled in this nonrandomized controlled trial. One hundred consecutive patients maintained at moderate levels of neuromuscular blockade were reversed with neostigmine (neostigmine group) followed by 100 consecutive patients given sugammadex to antagonize deeper levels of neuromuscular blockade (sugammadex group). Anesthetic and neuromuscular management were standardized. Surgeons rated operative conditions at the conclusion of the procedure on a 4-point scale (grade 1 = excellent to grade 4 = poor). Train-of-four ratios were measured immediately before extubation and at PACU admission (primary outcomes). Postoperatively, patients were assessed for adverse respiratory events and 11 signs and 16 symptoms of muscle weakness. RESULTS: The 2 groups were similar in intraoperative management characteristics. The percentage of patients with residual neuromuscular blockade, defined as a normalized train-of-four ratio <0.9, was significantly greater in the neostigmine group than the sugammadex group at both tracheal extubation (80% vs 6%, respectively, P < .0001) and PACU admission (61% vs 1%, respectively, P < .0001). Patients in the neostigmine group had less optimal operative conditions (median score 2 [good] versus 1 [excellent] in the sugammadex group; P < .0001), and more symptoms of muscle weakness were present in these subjects (median number [interquartile range] 4 [1-8] vs 1 [0-2] in the sugammadex group, P < .0001). No differences between groups in adverse airway events were observed. CONCLUSIONS: Despite the application of strategies documented to reduce the risk of residual neuromuscular blockade, a high percentage of thoracoscopic patients whose neuromuscular blockade was reversed with neostigmine were admitted to the PACU with clinical evidence of residual paralysis. In contrast, muscle weakness was rarely observed in patients whose neuromuscular blockade was antagonized with sugammadex.

Postoperative Pain and Analgesic Requirements in the First Year after Intraoperative Methadone for Complex Spine and Cardiac Surgery.

BACKGROUND: Methadone is a long-acting opioid that has been reported to reduce postoperative pain scores and analgesic requirements and may attenuate development of chronic postsurgical pain. The aim of this secondary analysis of two previous trials was to follow up with patients who had received a single intraoperative dose of either methadone or traditional opioids for complex spine or cardiac surgical procedures. METHODS: Preplanned analyses of long-term outcomes were conducted for spinal surgery patients randomized to receive 0.2 mg/kg methadone at the start of surgery or 2 mg hydromorphone at surgical closure, and for cardiac surgery patients randomized to receive 0.3 mg/kg methadone or 12 µg/kg fentanyl intraoperatively. A pain questionnaire assessing the weekly frequency (the primary outcome) and intensity of pain was mailed to subjects 1, 3, 6, and 12 months after surgery. Ordinal data were compared with the Mann-Whitney U test, and nominal data were compared using the chi-square test or Fisher exact probability test. The criterion for rejection of the null hypothesis was P < 0.01. RESULTS: Three months after surgery, patients randomized to receive methadone for spine procedures reported the weekly frequency of chronic pain was less (median score 0 on a 0 to 4 scale [less than once a week] vs. 3 [daily] in the hydromorphone group, P = 0.004). Patients randomized to receive methadone for cardiac surgery reported the frequency of postsurgical pain was less at 1 month (median score 0) than it was in patients randomized to receive fentanyl (median score 2 [twice per week], P = 0.004). CONCLUSIONS: Analgesic benefits of a single dose of intraoperative methadone were observed during the first 3 months after spinal surgery (but not at 6 and 12 months), and during the first month after cardiac surgery, when the intensity and frequency of pain were the greatest.

Safety of Beach Chair Position Shoulder Surgery: A Review of the Current Literature.

Although uncommon, severe neurological events have been reported in patients undergoing shoulder surgery in the beach chair position. The presumed etiology of central nervous system injury is hypotension and subsequent cerebral hypoperfusion that occurs after alterations in positioning under general anesthesia. Most clinical trials have demonstrated that beach chair positioning results in reductions in regional brain oxygenation, cerebral blood flow, and jugular bulb oxygenation, as well as impairment in cerebral autoregulation and electroencephalographic/processed electroencephalographic variables. Further studies are needed to define the incidence of adverse neurological adverse events in the beach chair position, identify the best intraoperative neurological monitors that are predictive of neurocognitive outcomes, the lowest "safe" acceptable blood pressure during surgery for individual patients, and the optimal interventions to treat intraoperative hypotension.

Neostigmine Administration after Spontaneous Recovery to a Train-of-Four Ratio of 0.9 to 1.0: A Randomized Controlled Trial of the Effect on Neuromuscular and Clinical Recovery.

BACKGROUND: When a muscle relaxant is administered to facilitate intubation, the benefits of anticholinesterase reversal must be balanced with potential risks. The aim of this double-blinded, randomized noninferiority trial was to evaluate the effect of neostigmine administration on neuromuscular function when given to patients after spontaneous recovery to a train-of-four ratio of 0.9 or greater. METHODS: A total of 120 patients presenting for surgery requiring intubation were given a small dose of rocuronium. At the conclusion of surgery, 90 patients achieving a train-of-four ratio of 0.9 or greater were randomized to receive either neostigmine 40 µg/kg or saline (control). Train-of-four ratios were measured from the time of reversal until postanesthesia care unit admission. Patients were monitored for postextubation adverse respiratory events and assessed for muscle strength. RESULTS: Ninety patients achieved a train-of-four ratio of 0.9 or greater at the time of reversal. Mean train-of-four ratios in the control and neostigmine groups before reversal (1.02 vs. 1.03), 5 min postreversal (1.05 vs. 1.07), and at postanesthesia care unit admission (1.06 vs. 1.08) did not differ. The mean difference and corresponding 95% CI of the latter were -0.018 and -0.046 to 0.010. The incidences of postoperative hypoxemic events and episodes of airway obstruction were similar for the groups. The number of patients with postoperative signs and symptoms of muscle weakness did not differ between groups (except for double vision: 13 in the control group and 2 in the neostigmine group; P = 0.001). CONCLUSIONS: Administration of neostigmine at neuromuscular recovery was not associated with clinical evidence of anticholinesterase-induced muscle weakness. VISUAL ABSTRACT: An online visual overview is available for this article.(Figure is included in full-text article.).

Comparison of the TOFscan and the TOF-Watch SX during Recovery of Neuromuscular Function.

WHAT WE ALREADY KNOW ABOUT THIS TOPIC: WHAT THIS ARTICLE TELLS US THAT IS NEW: BACKGROUND:: Quantitative neuromuscular monitoring is required to ensure neuromuscular function has recovered completely at the time of tracheal extubation. The TOFscan (Drager Technologies, Canada) is a new three-dimensional acceleromyography device that measures movement of the thumb in multiple planes. The aim of this observational investigation was to assess the agreement between nonnormalized and normalized train-of-four values obtained with the TOF-Watch SX (Organon, Ireland) and those obtained with the TOFscan during recovery from neuromuscular blockade. METHODS: Twenty-five patients were administered rocuronium, and spontaneous recovery of neuromuscular blockade was allowed to occur. The TOFscan and TOF-Watch SX devices were applied to opposite arms. A preload was applied to the TOF-Watch SX, and calibration was performed before rocuronium administration. Both devices were activated, and train-of-four values were obtained every 15 s. Modified Bland-Altman analyses were conducted to compare train-of-four ratios measured with the TOFscan to those measured with the TOF-Watch SX (when train-of-four thresholds of 0.2 to 1.0 were achieved). RESULTS: Bias and 95% limits of agreement between the TOF-Watch SX and the TOFscan at nonnormalized train-of-four ratios between 0.2 and 1.0 were 0.021 and -0.100 to 0.141, respectively. When train-of-four measures with the TOF-Watch SX were normalized, bias and 95% limits of agreement between the TOF-Watch SX and the TOFscan at ratios between 0.2 and 1.0 were 0.015 and -0.097 to 0.126, respectively. CONCLUSIONS: Good agreement between the TOF-Watch SX with calibration and preload application and the uncalibrated TOFscan was observed throughout all stages of neuromuscular recovery.

Clinical Effectiveness and Safety of Intraoperative Methadone in Patients Undergoing Posterior Spinal Fusion Surgery: A Randomized, Double-blinded, Controlled Trial.

BACKGROUND: Patients undergoing spinal fusion surgery often experience severe pain during the first three postoperative days. The aim of this parallel-group randomized trial was to assess the effect of the long-duration opioid methadone on postoperative analgesic requirements, pain scores, and patient satisfaction after complex spine surgery. METHODS: One hundred twenty patients were randomized to receive either methadone 0.2 mg/kg at the start of surgery or hydromorphone 2 mg at surgical closure. Anesthetic care was standardized, and clinicians were blinded to group assignment. The primary outcome was intravenous hydromorphone consumption on postoperative day 1. Pain scores and satisfaction with pain management were measured at postanesthesia care unit admission, 1 and 2 h postadmission, and on the mornings and afternoons of postoperative days 1 to 3. RESULTS: One hundred fifteen patients were included in the analysis. Median hydromorphone use was reduced in the methadone group not only on postoperative day 1 (4.56 vs. 9.90 mg) but also on postoperative days 2 (0.60 vs. 3.15 mg) and 3 (0 vs. 0.4 mg; all P< 0.001). Pain scores at rest, with movement, and with coughing were less in the methadone group at 21 of 27 assessments (all P = 0.001 to < 0.0001). Overall satisfaction with pain management was higher in the methadone group than in the hydromorphone group until the morning of postoperative day 3 (all P = 0.001 to < 0.0001). CONCLUSIONS: Intraoperative methadone administration reduced postoperative opioid requirements, decreased pain scores, and improved patient satisfaction with pain management.

Consent for Anesthesia Clinical Trials on the Day of Surgery: Patient Attitudes and Perceptions.

BACKGROUND: Opportunities for anesthesia research investigators to obtain consent for clinical trials are often restricted to the day of surgery, which may limit the ability of subjects to freely decide about research participation. The aim of this study was to determine whether subjects providing same-day informed consent for anesthesia research are comfortable doing so. METHODS: A 25-question survey was distributed to 200 subjects providing informed consent for one of two low-risk clinical trials. While consent on the day of surgery was permitted for both studies, a preadmission telephone call was required for one. The questionnaire was provided to each subject at the time of discharge from the hospital. The questions were structured to assess six domains relating to the consent process, and each question was graded on a 5-point Likert scale (1 = strongly disagree to 5 = strongly agree). Overall satisfaction with same-day consent was assessed using an 11-point scale with 0 = extremely dissatisfied and 10 = extremely satisfied. RESULTS: Completed questionnaires were received from 129 subjects. Median scores for satisfaction with the consent process were 9.5 to 10. Most respondents reported that the protocol was well explained and comprehended and that the setting in which consent was obtained was appropriate (median score of 5). Most patients strongly disagreed that they were anxious at the time of consent, felt obligated to participate, or had regrets about participation (median score of 1). Ten percent or less of subjects reported negative responses to any of the questions, and no differences were observed between the study groups. CONCLUSION: More than 96% of subjects who provided same-day informed consent for low-risk research were satisfied with the consent process.

Residual Neuromuscular Block in the Elderly: Incidence and Clinical Implications.

BACKGROUND: Elderly patients are at increased risk for anesthesia-related complications. Postoperative residual neuromuscular block (PRNB) in the elderly, defined as a train-of-four ratio less than 0.9, may exacerbate preexisting muscle weakness and respiratory dysfunction. In this investigation, the incidence of PRNB and associated adverse events were assessed in an elderly (70 to 90 yr) and younger cohort (18 to 50 yr). METHODS: Data were prospectively collected on 150 younger and 150 elderly patients. Train-of-four ratios were measured on arrival to the postanesthesia care unit (PACU). After tracheal extubation, patients were examined for adverse respiratory events during transport to the PACU, for 30 min after PACU admission, and during hospital admission. Postoperative muscle weakness was quantified using a standardized examination, and PACU and hospital lengths of stay were determined. RESULTS: The incidence of PRNB was 57.7% in elderly and 30.0% in younger patients (difference, -27.7%; 99% CI, -41.2 to -13.1%; P < 0.001). Airway obstruction, hypoxemic events, signs and symptoms of muscle weakness, postoperative pulmonary complications, and increased PACU and hospital lengths of stay were observed more frequently in the elderly (all P < 0.01). Within each cohort, most adverse events were observed in patients with PRNB. Younger patients with PRNB received larger total doses of rocuronium than did those without it (60 vs. 50 mg, P < 0.01), but there were no differences in rocuronium dose between elderly patients with PRNB and those without it (both 50 mg). CONCLUSION: The elderly are at increased risk for PRNB and associated adverse outcomes.

Intraoperative Methadone for the Prevention of Postoperative Pain: A Randomized, Double-blinded Clinical Trial in Cardiac Surgical Patients.

BACKGROUND: The intensity of pain after cardiac surgery is often underestimated, and inadequate pain control may be associated with poorer quality of recovery. The aim of this investigation was to examine the effect of intraoperative methadone on postoperative analgesic requirements, pain scores, patient satisfaction, and clinical recovery. METHODS: Patients undergoing cardiac surgery with cardiopulmonary bypass (n = 156) were randomized to receive methadone (0.3 mg/kg) or fentanyl (12 µg/kg) intraoperatively. Postoperative analgesic requirements were recorded. Patients were assessed for pain at rest and with coughing 15 min and 2, 4, 8, 12, 24, 48, and 72 h after tracheal extubation. Patients were also evaluated for level of sedation, nausea, vomiting, itching, hypoventilation, and hypoxia at these times. RESULTS: Postoperative morphine requirements during the first 24 h were reduced from a median of 10 mg in the fentanyl group to 6 mg in the methadone group (median difference [99% CI], -4 [-8 to -2] mg; P < 0.001). Reductions in pain scores with coughing were observed during the first 24 h after extubation; the level of pain with coughing at 12 h was reduced from a median of 6 in the fentanyl group to 4 in the methadone group (-2 [-3 to -1]; P < 0.001). Improvements in patient-perceived quality of pain management were described in the methadone group. The incidence of opioid-related adverse events was not increased in patients administered methadone. CONCLUSIONS: Intraoperative methadone administration resulted in reduced postoperative morphine requirements, improved pain scores, and enhanced patient-perceived quality of pain management.

The effect of single low-dose dexamethasone on blood glucose concentrations in the perioperative period: a randomized, placebo-controlled investigation in gynecologic surgical patients.

BACKGROUND: The effect of single low-dose dexamethasone therapy on perioperative blood glucose concentrations has not been well characterized. In this investigation, we examined the effect of 2 commonly used doses of dexamethasone (4 and 8 mg at induction of anesthesia) on blood glucose concentrations during the first 24 hours after administration. METHODS: Two hundred women patients were randomized to 1 of 6 groups: Early-control (saline); Early-4 mg (4 mg dexamethasone); Early-8 mg (8 mg dexamethasone); Late-control (saline); Late-4 mg (4 mg dexamethasone); and Late-8 mg (8 mg dexamethasone). Blood glucose concentrations were measured at baseline and 1, 2, 3, and 4 hours after administration in the early groups and at baseline and 8 and 24 hours after administration in the late groups. The incidence of hyperglycemic events (the number of patients with at least 1 blood glucose concentration >180 mg/dL) was determined. RESULTS: Blood glucose concentrations increased significantly over time in all control and dexamethasone groups (from median baselines of 94 to 102 mg/dL to maximum medians ranging from 141 to 161.5 mg/dL, all P < 0.001). Blood glucose concentrations did not differ significantly between the groups receiving dexamethasone (either 4 or 8 mg) and those receiving saline at any measurement time. The incidence of hyperglycemic events did not differ in any of the early (21%-28%, P = 0.807) or late (13%-24%, P = 0.552) groups. CONCLUSIONS: Because blood glucose concentrations during the first 24 hours after administration of single low-dose dexamethasone did not differ from those observed after saline administrations, these results suggest clinicians need not avoid using dexamethasone for nausea and vomiting prophylaxis out of concerns related to hyperglycemia.

The changing anesthesia economic landscape: emergence of large multispecialty practices and Accountable Care Organizations.

PURPOSE OF REVIEW: In this review, we evaluate the current US employment models for healthcare in general and anesthesiologists in particular and the emergence of large, multispecialty physician groups and the forces behind this change to the current anesthesia practice model. We will also examine the present payment method for anesthesiologists and determine how Accountable Care Organizations will affect the future payment models. RECENT FINDINGS: Very few anesthesiologists are aware of the changing economic landscape in the specialty, and this review will provide an up-to-date examination of the changes that anesthesiologists may face in the ensuing years. Accountable Care Organizations will have a drastic impact on the ways in which anesthesiologists are reimbursed and will require anesthesiologists to become more involved in perioperative patient care and outcomes. SUMMARY: This is the most critical time in the specialty of anesthesiology from an economic viewpoint, and significant threats and opportunities will arise for anesthesiologists in how they are reimbursed, and how they demonstrate the delivery of quality care to patients.

Postoperative residual neuromuscular blockade is associated with impaired clinical recovery.

BACKGROUND: In this investigation, we sought to determine the association between objective evidence of residual neuromuscular blockade (train-of-four [TOF] ratio <0.9) and the type, incidence, and severity of subjective symptoms of muscle weakness in the postanesthesia care unit (PACU). METHODS: TOF ratios of 149 patients were quantified with acceleromyography on arrival to the PACU. Patients were stratified into 2 cohorts: a TOF <0.9 group (n = 48) or a TOF ≥0.9 (control) group (n = 101). A standardized examination determined the presence or absence of 16 symptoms and 11 signs of muscle weakness on arrival to the PACU and 20, 40, and 60 minutes after admission. RESULTS: The incidence of symptoms of muscle weakness was significantly higher in the TOF <0.9 group at all times (P < 0.001), as was the median (range) number of symptoms from PACU arrival (7 [3-6] TOF <0.9 group vs 2 [0-11] control group; difference 5, 99% confidence interval of the difference 4-6) until 60 minutes after admission (2 [0-12] TOF <0.9 group vs 0 [0-11] control group; difference 2, 99% confidence interval of the difference 1-2) (all P < 0.0001). CONCLUSION: The incidence and severity of symptoms of muscle weakness were increased in the PACU in patients with a TOF <0.9.

Multiorganizational consensus to define guiding principles for perioperative pain management in patients with chronic pain, preoperative opioid tolerance, or substance use disorder.

Significant knowledge gaps exist in the perioperative pain management of patients with a history of chronic pain, substance use disorder, and/or opioid tolerance as highlighted in the US Health and Human Services Pain Management Best Practices Inter-Agency Task Force 2019 report. The report emphasized the challenges of caring for these populations and the need for multidisciplinary care and a comprehensive approach. Such care requires stakeholder alignment across multiple specialties and care settings. With the intention of codifying this alignment into a reliable and efficient processes, a consortium of 15 professional healthcare societies was convened in a year-long modified Delphi consensus process and summit. This process produced seven guiding principles for the perioperative care of patients with chronic pain, substance use disorder, and/or preoperative opioid tolerance. These principles provide a framework and direction for future improvement in the optimization and care of 'complex' patients as they undergo surgical procedures.

A multisociety organizational consensus process to define guiding principles for acute perioperative pain management.

The US Health and Human Services Pain Management Best Practices Inter-Agency Task Force initiated a public-private partnership which led to the publication of its report in 2019. The report emphasized the need for individualized, multimodal, and multidisciplinary approaches to pain management that decrease the over-reliance on opioids, increase access to care, and promote widespread education on pain and substance use disorders. The Task Force specifically called on specialty organizations to work together to develop evidence-based guidelines. In response to this report's recommendations, a consortium of 14 professional healthcare societies committed to a 2-year project to advance pain management for the surgical patient and improve opioid safety. The modified Delphi process included two rounds of electronic voting and culminated in a live virtual event in February 2021, during which seven common guiding principles were established for acute perioperative pain management. These principles should help to inform local action and future development of clinical practice recommendations.