The impact of intraoperative N-acetylcysteine on opioid consumption following spine surgery: a randomized pilot trial.

Aim: N-acetylcysteine (NAC) decreases inflammation and could augment perioperative analgesia. Materials & methods: This prospective pilot trial examined postoperative opioid consumption at 12 h following intraoperative NAC. In phase I, 20 adults scheduled for posterior spine surgery were randomized to NAC (0, 50, 100 and 150 mg/kg) to determine the optimal dose. In phase II, 30 patients were randomized to placebo or NAC (150 mg/kg). Opioid consumption, pain ratings and time to opioid rescue were recorded. Results: Postoperative opioid consumption was reduced in the NAC group 19.3% at 12 h and 20% at 18 and 36 h. Opioid consumption was reduced 22-24% in the NAC group at all times after adjusting for intraoperative opioid administration. NAC subjects reported lower pain scores relative to placebo. Conclusion: Subjects randomized to NAC consumed less postoperative opioids and reported less pain versus placebo. Larger randomized controlled trials are needed to further evaluate NAC for analgesia. Clinical Trial Registration: NCT04562597 (ClinicalTrials.gov).

N-acetylcysteine (NAC) is a powerful anti-inflammatory drug used to treat some types of poisoning. It could help pain for patients after surgery. This study looked at how much pain medicine patients needed after back surgery when they received NAC or no drug (placebo). In the first 20 patients, people randomly received placebo or a small, medium or large dose of NAC (0, 50, 100, and 150 mg/kg) with five patients in each group. Since there were only a small number of patients, it was difficult to see any definite differences, and the next 30 patient patients randomly received placebo or the large dose of NAC (150 mg/kg). Patients that were given NAC received 16­22% less opioids in the first 2 days after surgery compared with those that were given placebo. NAC patients also took longer to request pain medications after surgery and reported lower pain scores in the first 2 days after surgery relative to placebo.

Particulate Gastric Contents in Patients Prescribed Glucagon-Like Peptide 1 Receptor Agonists After Appropriate Perioperative Fasting: A Report of 2 Cases.

Glucagon-like peptide 1 (GLP-1) receptor agonists have surged in popularity for the treatment of both diabetes mellitus and obesity. While GLP-1 reduces proximal gastrointestinal motility and delays gastric emptying, the impact of these medications on adequate fasting before surgery is not clear. We present 2 cases of particulate gastric contents after following appropriate presurgical fasting in diabetic patients taking GLP-1 receptor agonists and review current literature regarding perioperative implications of these drugs.

Parasternal intercostal plane block catheters for cardiac surgery: a retrospective, propensity weighted, cohort study.

Aim: Anesthesia for cardiac surgery has evolved toward fast-track recovery strategies incorporating non opioid analgesics and regional anesthesia. Materials & methods: This retrospective cohort study compared opioid consumption, pain scores and length of stay in patients who underwent cardiac surgery via median sternotomy and did or did not receive preoperative parasternal intercostal plane block catheters with postoperative ropivacaine infusions. Results: Postoperative opioid consumption and postoperative pain scores did not differ. Blocks were associated with decreased intraoperative opioids and reduced length of stay in the intensive care unit and hospital. Conclusion: Parasternal intercostal plane block catheters were not associated with decreased postoperative opioid consumption or pain scores, but were associated with reduced intraoperative opioids and length of stay.

Stellate ganglion block catheters for refractory electrical storm: a retrospective cohort and care pathway.

BACKGROUND: Electrical storm can be challenging to treat, requiring a multidisciplinary team to coordinate medical management and invasive procedures. As the stellate ganglion provides efferent sympathetic outflow to the myocardium, stellate ganglion blocks (SGB) can be used to combat ventricular arrhythmias that arise from sympathetic overactivity. Data are scarce regarding SGB catheters as a treatment for electrical storm. We reviewed our use of SGB catheters for refractory electrical storm using our pathway collaboratively developed by critical care, cardiology, and regional anesthesia teams. METHODS: We conducted a retrospective cohort study of patients who underwent an SGB for electrical storm between January 2020 and April 2022 in our cardiovascular intensive care unit. The primary outcome was the sustained cessation of electrical storm for 24 hours. RESULTS: Upon chart review, 27 patients were identified and 11 met inclusion criteria. Cessation of electrical storm for 24 hours was achieved in 90% (n=10) of patients after left SGB. Similarly, 90% (n=10) had no documented episodes of ventricular arrhythmias requiring intervention within 6 hours after SGB. CONCLUSIONS: SGBs can interrupt or treat electrical storm. SGB catheters allow for prolonged arrhythmia cessation without repeated blocks and decrease the risk of repeat episodes of ventricular arrhythmias.

Anaesthesia cart standardisation expedites supply retrieval: A simulation study with patient safety implications.

BACKGROUND: Anaesthesia providers often work at a variety of perioperative and procedural locations. However, the layout of anaesthesia supplies and equipment is often inconsistent from operating theatre to operating theatre. This lack of standardisation may create delays in identification and retrieval of supplies. The primary goal of this study was to compare the duration of time required by anaesthesia providers to identify and retrieve a list of anaesthesia supplies prior to and after standardisation of the location for anaesthesia supplies. METHODS: In this observational simulation study, a pre-set list of ten items that may be rapidly needed when caring for patients was created. Volunteer anaesthesia providers were then timed retrieving these in two different operating theatres before and after anaesthesia cart standardisation. Cumulative time to retrieve all items was recorded in seconds. Participants were evaluated regarding mean time to compete the task before and after supply standardisation. Paired t-test were used to assess mean time to retrieve the ten items both before and after standardisation and between the two operating theatre locations. Providers were also evaluated on their familiarity with the operating theatre location, and this was assessed by chi-square tests of homogeneity. Multivariable generalised linear modelling was used to evaluate the impact of covariables on the change in time. RESULTS: Data from 18 anaesthesia providers was collected. Mean (95% confidence interval) time in seconds to retrieve items was decreased by 45% after supply standardisation (105.3 [88.6, 121.9 vs 57.1 [50.8, 63.5]; p < 0.001) with a mean (95% confidence interval) reduction of 48.1 seconds (30.6, 65.6; p < 0.001). Providers who worked primarily at that location also had faster times to complete the task. In a multivariable regression model that considered both the provider's familiarity with the location and the simulation attempt (Operating theatre 1 or Operating theatre 2), the mean time to retrieve all items remained reduced by 48.1 seconds (95% confidence interval: 31.9-64.4) after supply standardisation (p < 0.001). CONCLUSION: Standardisation of the location for anaesthesia supplies decreased the time for on-demand item retrieval. Retrieval times were most improved after standardisation for providers in an unfamiliar area. Supply standardisation of anaesthesia carts across perioperative and procedural sites could result in more timely interventions in patient care and efficiency.

Comparison of lateral quadratus lumborum and lumbar plexus blocks for postoperative analgesia following total hip arthroplasty: a randomized clinical trial.

INTRODUCTION: Effective analgesia after total hip arthroplasty must minimize pain and optimize early ambulation. Lumbar plexus blocks (LPBs) provide analgesia but may cause motor weakness. Quadratus lumborum blocks (QLBs) may provide analgesia with preserved motor strength. METHODS: This trial randomized subjects scheduled for elective hip arthroplasty to receive an LPB or lateral QLB for postoperative analgesia. The primary outcome was opioid consumption at 12-hour postoperative. Non-inferiority of lateral QLBs compared with LPBs was conducted using a one-sided two-sample t-test. Secondary outcomes included pain scores, cumulative opioid consumption, quadriceps strength, time to ambulation, and distance ambulated. Differences in pain scores and opioid consumption over time between groups were evaluated using a linear mixed model. RESULTS: The trial consented and randomized 111 subjects and 103 completed the study: LPB (n=50) and lateral QLB (n=53). Mean (95% CI) cumulative opioid consumption (mg) at 12-hour postoperative was not found to be non-inferior in the lateral QLB (15.9 (12.7 to 19.2)) vs the LPB (12.7 (10.2 to 15.1)) group (p=0.625). Pain scores in postoperative anesthetic care unit (PACU) and 24-hour postoperative did not differ. The maximum distance ambulated did not differ, but lateral QLB patients were 2.4 times more likely to ambulate in the first 12 hours (p=0.024) and had significantly greater quadriceps strength in PACU (p<0.001). DISCUSSION: Although we were unable to demonstrate non-inferiority for opioid consumption at 12-hour postoperative, strength and mobilization were improved in lateral QLB subjects. TRIAL REGISTRATION NUMBER: NCT04402437.

The Use of Pectoralis Blocks in Breast Surgery: A Practice Advisory and Narrative Review from the Society for Ambulatory Anesthesia (SAMBA).

Although pectoralis (PECS) blocks are commonly used for breast surgery, recommendations regarding the efficacy of these blocks have thus far not been developed by any professional anesthesia society. Given the potential impact of PECS blocks on analgesia after outpatient breast surgery, The Society for Ambulatory Anesthesia (SAMBA) convened a task force to develop a practice advisory on the use of this analgesic technique. In this practice advisory, we compare the efficacy of PECS blocks with systemic analgesia, local infiltration anesthesia, and paravertebral blockade. Our objectives were to advise on two clinical questions. (1) Does PECS-1 and/or -2 blockade provide more effective analgesia for breast-conserving surgery than either systemic analgesics or surgeon-provided local infiltration anesthesia? (2) Does PECS-1 and/or -2 blockade provide equivalent analgesia for mastectomy compared with a paravertebral block (PVB)? Among patients undergoing breast-conserving surgery, PECS blocks moderately reduce postoperative opioid use, prolong time to analgesic rescue, and decrease postoperative pain scores when compared with systemic analgesics. SAMBA recommends the use of a PECS-1 or -2 blockade in the absence of systemic analgesia (Strength of Recommendation A). No evidence currently exists that strongly favors the use of PECS blocks over surgeon-performed local infiltration in this surgical population. SAMBA cannot recommend PECS blocks over surgical infiltration (Strength of Recommendation C). For patients undergoing a mastectomy, a PECS block may provide an opioid-sparing effect similar to that achieved with PVB; SAMBA recommends the use of a PECS block if a patient is unable to receive a PVB (Strength of Recommendation A).

Preoperative Quadratus Lumborum Block Reduces Initial Postoperative Opioid Consumption Following Hip Arthroscopy: A Retrospective Analysis.

Compare postoperative opioid consumption following hip arthroscopy in patients who received a preoperative, lateral quadratus lumborum block versus those who did not. Patients were retrospectively identified. The primary outcome was postoperative opioid consumption (IV morphine milligram equivalents) in patients with and without a block. Comparisons between groups were conducted with Chi-square tests and Fisher Exact Tests where appropriate. Continuous data were compared with two-sided t-tests and Wilcoxon rank-sum tests. Data were collected on 100 patients. Mean (95% confidence interval) postoperative opioid consumption was reduced in patients with a quadratus lumborum block compared to those without a block (6.6 [5.2 - 8.1] vs 11.8 [10.2 - 13.4]; p < 0.0001; respectively). Eleven percent of patients with a preoperative quadratus lumborum block did not consume any opioids in the post anesthesia care unit. Opioid consumption in the immediate postoperative period was significantly reduced in patients that received a preoperative quadratus lumborum block. Level of Evidence: Level III - Retrospective Cohort Study. (Journal of Surgical Orthopaedic Advances 31(1):017-021, 2022).

Nonopioid Analgesics for the Perioperative Geriatric Patient: A Narrative Review.

Management of acute perioperative pain in the geriatric patient can be challenging as the physiologic and pharmacokinetic changes associated with aging may predispose older patients to opioid-related side effects. Furthermore, elderly adults are more susceptible to postoperative delirium and postoperative cognitive dysfunction, which may be exacerbated by both poorly controlled postoperative pain and commonly used pain medications. This narrative review summarizes the literature published in the past 10 years for several nonopioid analgesics commonly prescribed to the geriatric patient in the perioperative period. Nonopioid analgesics are broken down as follows: medications prescribed throughout the perioperative period (acetaminophen and nonsteroidal anti-inflammatory drugs), medications limited to the acute perioperative setting ( N -methyl-D-aspartate receptor antagonists, dexmedetomidine, dexamethasone, and local anesthetics), and medications to be used with caution in the geriatric patient population (gabapentinoids and muscle relaxants). Our search identified 1757 citations, but only 33 specifically focused on geriatric analgesia. Of these, only 21 were randomized clinical trials' and 1 was a systematic review. While guidance in tailoring pain regimens that focus on the use of nonopioid medications in the geriatric patient is lacking, we summarize the current literature and highlight that some nonopioid medications may extend benefits to the geriatric patient beyond analgesia.

Preoperative Quadratus Lumborum Block Reduces Opioid Requirements in the Immediate Postoperative Period Following Hip Arthroscopy: A Randomized, Blinded Clinical Trial.

PURPOSE: To examine acute postoperative opioid consumption in patients undergoing hip arthroscopy and randomized to either receive a preoperative lateral quadratus lumborum block or sham injection. METHODS: This trial randomized 46 subjects undergoing hip arthroscopy with a single surgeon to receive a preoperative lateral quadratus lumborum block (40 mL, ropivacaine 0.25%) or sham injection. The primary outcome was postoperative opioid consumption in patients with and without a block. All opioid medications were converted to morphine milligram equivalents for comparisons. Categorical data were compared with χ2 tests and Fisher exact tests where appropriate. Continuous data were compared with 2-sided t-test and Wilcoxon rank-sum tests. RESULTS: Forty-six subjects scheduled for elective hip arthroscopy were successfully consented and randomized. Demographic and clinical characteristics did not differ. Postoperative opioid consumption decreased 28.3% in patients who received a preoperative lateral quadratus lumborum block (P = .04). Total perioperative opioid consumption (intraoperative and postoperative combined) was reduced 20% in the block group; however, this did not achieve statistical significance (P = .05). Three subjects in the sham group (12.5%) required unblinding for a rescue block in the postoperative anesthetic care unit (PACU) for uncontrolled pain despite systemic analgesics. While cold sensation was decreased postoperatively over the abdomen (P < .001) and anterior thigh (P = .03) in the block group, other PACU variables did not differ, including VAS pain scores, motor function, side effects, PACU duration, and patient satisfaction. CONCLUSIONS: Opioid consumption was reduced in patients who received a preoperative lateral quadratus lumborum block combined with a standardized, multimodal protocol as compared with patients who did not receive a block. Our findings support the growing evidence that quadratus lumborum blocks are an effective component of multimodal analgesia options for patients undergoing elective hip arthroscopy. LEVEL OF EVIDENCE: Level I, randomized controlled trial.

Mechanisms, diagnosis, prevention and management of perioperative opioid-induced hyperalgesia.

Opioid-induced hyperalgesia (OIH) occurs when opioids paradoxically enhance the pain they are prescribed to ameliorate. To address a lack of perioperative awareness, we present an educational review of clinically relevant aspects of the disorder. Although the mechanisms of OIH are thought to primarily involve medullary descending pathways, it is likely multifactorial with several relevant therapeutic targets. We provide a suggested clinical definition and directions for clinical differentiation of OIH from other diagnoses, as this may be confusing but is germane to appropriate management. Finally, we discuss prevention including patient education and analgesic management choices. As prevention may serve as the best treatment, patient risk factors, opioid mitigation, and both pharmacologic and non-pharmacologic strategies are discussed.

Lay abstract Opioid-induced hyperalgesia (OIH) occurs when opioid medications worsen rather than decrease pain. We present an educational review of the disorder. Although mechanisms of OIH are thought to primarily start in the brain or brainstem before traveling through the spinal cord to the area of pain in the body, there are likely many causes. We provide a suggested clinical definition and a pathway for clinical differentiation of OIH from other diagnoses to help with management. Finally, we discuss prevention including patient education and medication management choices. As prevention may serve as the best treatment, patient risk factors for OIH, decreased opioid use, and both medication and non-medication strategies are discussed.

Positive or Negative? Implementation Processes and Pitfalls of Preoperative SARS-CoV-2 Testing at a Single Academic Institution.

BACKGROUND: Preoperative screening and testing for SARS-CoV-2 are important aspects of reopening perioperative and procedural sites to elective cases after the initial wave of the novel coronavirus pandemic. However, given that modern healthcare has never experienced a pandemic of this magnitude, rapid operationalization of mass testing presents unique challenges. We aim to highlight our experiences and challenges for preoperative SARS-CoV-2 testing. METHODS: We describe implementation of widespread screening tools and preoperative polymerase chain reaction (PCR) testing in a single, academic medical center. RESULTS: As of August 2020, we have been able to achieve an over 90% success rate in preoperative SARS-CoV-2 PCR testing for both outpatient and inpatient procedures. However, there are certain challenges in obtaining high levels of compliance both on individual and institutional levels. CONCLUSIONS: Instituting preoperative SARS-CoV-2 testing and maintaining high levels of compliance is possible in the midst of a fluctuating pandemic.

Variable selection methods for identifying predictor interactions in data with repeatedly measured binary outcomes.

INTRODUCTION: Identifying predictors of patient outcomes evaluated over time may require modeling interactions among variables while addressing within-subject correlation. Generalized linear mixed models (GLMMs) and generalized estimating equations (GEEs) address within-subject correlation, but identifying interactions can be difficult if not hypothesized a priori. We evaluate the performance of several variable selection approaches for clustered binary outcomes to provide guidance for choosing between the methods. METHODS: We conducted simulations comparing stepwise selection, penalized GLMM, boosted GLMM, and boosted GEE for variable selection considering main effects and two-way interactions in data with repeatedly measured binary outcomes and evaluate a two-stage approach to reduce bias and error in parameter estimates. We compared these approaches in real data applications: hypothermia during surgery and treatment response in lupus nephritis. RESULTS: Penalized and boosted approaches recovered correct predictors and interactions more frequently than stepwise selection. Penalized GLMM recovered correct predictors more often than boosting, but included many spurious predictors. Boosted GLMM yielded parsimonious models and identified correct predictors well at large sample and effect sizes, but required excessive computation time. Boosted GEE was computationally efficient and selected relatively parsimonious models, offering a compromise between computation and parsimony. The two-stage approach reduced the bias and error in regression parameters in all approaches. CONCLUSION: Penalized and boosted approaches are effective for variable selection in data with clustered binary outcomes. The two-stage approach reduces bias and error and should be applied regardless of method. We provide guidance for choosing the most appropriate method in real applications.

Intravenous vs Oral Acetaminophen for Analgesia After Cesarean Delivery: A Randomized Trial.

OBJECTIVE: Examination of postoperative analgesia with intravenous and oral acetaminophen. DESIGN: Prospective, three-arm, nonblinded, randomized clinical trial. SETTING: A single academic medical center. SUBJECTS: Parturients scheduled for elective cesarean delivery. METHODS: This trial randomized 141 parturients to receive intravenous acetaminophen (1 g every eight hours, three doses), oral acetaminophen (1 g every eight hours, three doses), or no acetaminophen. All patients received a standardized neuraxial anesthetic with intrathecal opioids and scheduled postoperative ketorolac. The primary outcome, 24-hour opioid consumption, was evaluated using the Kruskal-Wallace test and Tukey-Kramer adjustment for multiple comparisons. Secondary outcomes included 48-hour opioid consumption, first opioid rescue, pain scores, patient satisfaction, times to ambulation and discharge, and side effects. RESULTS: Over 18 months, 141 parturients with similar demographic variables completed the study. Median (interquartile range) opioid consumption in intravenous morphine milligram equivalents at 24 hours was 0 (5), 0 (7), and 5 (7) for the intravenous, oral, and no groups, respectively, and differed between groups (global P = 0.017). Opioid consumption and other secondary outcomes did not differ between the intravenous vs oral or oral vs no groups. Opioid consumption was reduced at 24 hours with intravenous vs no acetaminophen (P = 0.015). Patients receiving no acetaminophen had 5.8 times the odds of consuming opioids (P = 0.036), consumed 40% more opioids controlling for time (P = 0.041), and had higher pain scores with ambulation (P = 0.004) compared with the intravenous group. CONCLUSIONS: Intravenous acetaminophen did not reduce 24-hour opioid consumption or other outcomes compared with oral acetaminophen. Intravenous acetaminophen did decrease opioid consumption and pain scores compared with no acetaminophen.