Multimodal General Anesthesia: Theory and Practice. Anesth Analg. 2018;127:1246-1258. [PMID: 30252709 PMCID: PMC6203428 DOI: 10.1213/ane.0000000000003668]

Pain assessment during physiotherapy and noxious stimuli in patients with disorders of consciousness: A preliminary study

Objectives

The primary purpose of this study is to determine whether patients with disorders of consciousness (DOC) (unresponsive wakefulness syndrome, UWS; minimally conscious state, MCS) experience pain during physiotherapy and noxious stimuli in a larger patient population.

Materials and methods

The patients’ level of consciousness was measured with the Coma Recovery Scale-Revised (CRS-R). Additionally, the Nociception Coma Scale-revised (NCS-R) was used to assess their pain response. The NCS-R total scores between UWS and MCS at baseline, physiotherapy and noxious stimulus were compared using the Mann-Whitney U test (Wilcoxon rank-sum test) and the Kruskal-Wallis H test with Bonferroni correction.

Results

The study enrolled 93 participants. There was a statistically significant difference in NCS-R total scores between the three conditions (H = 215.25, p < 0.001). At baseline, there was no statistically significant difference between MCS and UWS (U = 378, z = –1.35, p = 0.178). While there was a statistically significant difference between MCS and UWS during physiotherapy (U = 1,362, z = –3.06, p < 0.01) and under noxious stimuli (U = 5142.5, z = –11.22, p < 0.001).

Conclusion

Physiotherapy improved the activity responsiveness of DOC patients, and patients experienced less potential pain. However, some DOC patients, especially MCS patients, perceived pain under the noxious stimuli.

Effect of scalp nerve block with ropivacaine on postoperative pain in pediatric patients undergoing craniotomy: A randomized controlled trial

Background

Scalp nerve block (SNB) is widely used for postoperative pain control, intraoperative hemodynamic control, and opioid-sparing in adult craniotomies. However, there are few studies of SNB in pediatric patients undergoing craniotomy. In the present study, we aimed to investigate the effect of SNB on postoperative pain, intraoperative hemodynamic stability, and narcotic consumption in pediatric craniotomy under general anesthesia.

Methods

This trial is a single-center, prospective, randomized, and double-blind study. A total of 50 children aged between 2 and 12 years who are undergoing elective brain tumor surgery will be randomly allocated in a 1:1 ratio to receive either 0.2% ropivacaine for SNB (group SNB, intervention group, n = 25) or the same volume of saline (group Ctrl, control group, n = 25). The primary outcome was to assess the score of postoperative pain intensity at time 1, 4, 8, 12, 24, and 48 h postoperatively using the FLACC score method. Secondary outcomes were to record intraoperative hemodynamic variables (MAP and HR) during skull-pin fixation, skin incision and end of skin closure, intraoperative total consumption of remifentanil and propofol, postoperative opioid consumption, and the incidence of postoperative nausea and vomiting.

Results

Fifty patients were analyzed (n = 25 in SNB group; n = 25 in control group). Compared to the control group, postoperative pain intensity was significantly relieved in the SNB group up to 8 h post-operatively. In addition, SNB provided good intraoperative hemodynamic stability, reduced intraoperative overall propofol and remifentanil consumption rate, and postoperative fentanyl consumption compared to the control group. However, the incidence of postoperative nausea and vomiting was not different between SNB and the control group.

Conclusions

In pediatric craniotomies, SNB with 0.2% ropivacaine provides adequate postoperative pain control and good intraoperative hemodynamic stability during noxious events compared to the control group.

Clinical trial registration

Chinese Clinical Trial Registry [No: ChiCTR2100050594], Prospective registration.

The effects of ultrasound-guided serratus anterior plane block on intraoperative opioid consumption and hemodynamic stability during breast surgery: A randomized controlled study

AIM

To determine effect of ultrasound-guided serratus anterior plane block (SAPB) on intraoperative opioid consumption in patients undergoing oncoplastic breast surgery under general anesthesia.

METHODS

This study was conducted as a prospective, randomized controlled trial. Forty-four patients enrolled, aged 18 to 75 years with American Society of Anesthesiologists physical status I to III, undergoing elective oncoplastic breast surgery. Patients were randomly allocated to receive SAPB with 20 mL of 0.25% bupivacaine + general anesthesia (group SAPB) or only general anesthesia (group control). The primary outcome was assessing the effect of SAPB on intraoperative remifentanil consumption. Patients were assessed for emergence time, hemodynamic parameters, doses of rescue drugs used to control hemodynamic parameters, and duration of stay in the recovery room.

RESULTS

Preoperative SAPB with 0.25% bupivacaine reduced intraoperative opioid consumption (851.2 ± 423.5 vs 1409.7 ± 756.1 µg, P = .019). Emergence time was significantly shorter in group SAPB (6.19 ± 1.90 minutes) compared to group control (9.50 ± 2.39 minutes; P < .001). There were no significant differences in the doses of rescue drugs used for systolic blood pressure and heart rate between the groups.

CONCLUSIONS

Preoperative SAPB with bupivacaine reduced intraoperative opioid consumption and shortened emergence time and duration of stay in the recovery unit, and hemodynamic stability was maintained without block-related complications.

Transcutaneous electrical nerve inhibition using medium frequency alternating current

Transcutaneous medium-frequency alternating electrical current is defined as an alternating current between 1 and 10 kHz and is capable of producing an instant, reversible block. This study aims to evaluate the efficacy of sensory perception and force production of the index and middle finger after transcutaneous medium-frequency alternating electrical current stimulation of the distal median nerve. A single-center prospective interventional cohort study was conducted in adult healthy volunteers at the Jessa Hospital, Hasselt, Belgium. Two different electrodes (PALS & 3M) were placed on the distal median nerve, which was located using a Sonosite X-Porte Ultrasound transducer, with the first electrode being placed on the skin at the level of the transverse carpal ligament and the second electrode 7 cm proximally to the first electrode. The tactile sensation was evaluated with Semmes–Weinstein monofilament test and sensation of pressure/pain was evaluated with an algometer. Peak force production was assessed with an electronic dynamometer. All measurements were performed at baseline and tMFAEC stimulation frequencies of 2 and 10 kHz in a randomized manner. Statistical analysis was performed with a one-way ANOVA with repeated measures test or a Friedman rank sum test, followed by the Wilcoxon signed rank test adjusted with Bonferroni correction. A p-value < 0.05 was considered statistically significant. From 9 to 13th of April 2021, 25 healthy volunteers were included in the Jessa Hospital, Hasselt, Belgium. A statistically significant reduction in tactile sensation during 2 kHz and 10 kHz stimulation compared to baseline was observed (2.89 ± 0.22 (PALS2); 3.35 ± 0.25 (3M2) and 2.14 ± 0.12 (PALS10); 2.38 ± 0.12 (3M10) versus − 1.75 ± 0.09 (baseline), p < 0.0001). 3M electrodes showed a tendency towards the elevation of pressure pain threshold compared to baseline. No significant difference in mean peak forces of the index and middle fingers after transcutaneous medium-frequency alternating electrical current stimulation with 2 and 10 kHz was found. This study demonstrates that transcutaneous medium-frequency alternating electrical current stimulation on the distal median nerve inhibits tactile sensory nerve activity in the index and middle finger when stimulation of 2 kHz and, to a lesser extent, 10 kHz was applied. A reduction of motor nerve activity was not observed but force production measurements may be prone to error.

Trial registration: clinicaltrials.gov on 01/04/2021. NCT-Number: NCT04827173.

Effect of intravenous lidocaine on pain after head and neck cancer surgery (ELICO trial): A randomised controlled trial

BACKGROUND

Treatment of postoperative pain after ear, nose and throat (ENT) cancer surgery is mainly morphine administration. Additional systemic lidocaine has shown promising results in some surgical procedures.

OBJECTIVE

The main objective was to evaluate morphine consumption in the first 48 postoperative hours after intra-operative lidocaine infusion during major ENT cancer surgery.

DESIGN

A randomised, double-blind, placebo-controlled trial.

SETTING

Bicentric study including a university hospital and a major cancer centre, conducted from December 2016 to December 2019.

PATIENTS

A total of 144 patients undergoing major ENT cancer surgery were included.

INTERVENTION

The patients were randomly assigned to receive intravenous lidocaine or placebo during surgery and in the recovery room.

MAIN OUTCOME MEASURES

Endpoints were postoperative morphine consumption in the first 24 and 48 h postoperatively, intra-operative remifentanil consumption, adverse events occurrence and assessment 3 to 6 months after surgery with the McGill pain questionnaire.

RESULTS

A total of 118 patients were included (lidocaine n  = 57; placebo n  = 61, 26 patients were excluded). There was no significant difference in morphine consumption during the first 48 postoperative hours in the lidocaine group compared with the placebo group with a median [IQR] of 0.60 [0.30 to 1.03] mg kg -1 vs. 0.57 [0.37 to 0.96] mg kg -1 , total dose 44 [21 to 73.3] mg vs. 38 [23.3 to 56.5] mg, P  = 0.92.There was no significant difference between the two groups in any of the other endpoints, including at follow up 3 to 6 months after surgery.

CONCLUSION

Intravenous lidocaine in ENT cancer surgery did not show any additional analgesic or morphine-sparing effect 48 h after surgery. Three to six months after surgery, there was no significant difference in pain scores or consumption of analgesics. Patients treated pre-operatively with opioids were not evaluated in the study.

TRIAL REGISTRATION

Clinicaltrials.gov identifier: NCT02894710 and EUDRACT number 2015-005799-90.

Opioid-free total intravenous anesthesia for thyroid and parathyroid surgery: Protocol for a randomized, double-blind, controlled trial

Background

Opioid-free anesthesia (OFA) may improve postoperative outcomes by reducing opioid-related adverse effects. This study aims to evaluate the effects of OFA on postoperative nausea and vomiting (PONV), postoperative pain, and 30-day outcomes after thyroid and parathyroid surgery.

Methods

This two-center, randomized, double-blind, controlled trial will include 400 adult patients scheduled for thyroid and parathyroid surgery. Patients will be randomly assigned, 1:1 and stratified by sex and site, to an OFA group (esketamine, lidocaine, and dexmedetomidine) or a control group (opioid-based anesthesia with sufentanil). All patients will receive propofol-based total intravenous anesthesia and PONV prophylaxis with dexamethasone and ondansetron. The primary outcome is the incidence of PONV (defined as experiencing any event of nausea, retching, or vomiting) during the first 48 h postoperatively. The secondary outcomes include the severity of PONV, antiemetic rescue therapy, pain scores at rest and while coughing, need for rescue analgesia, perioperative adverse effects related to anesthetics or analgesics (hypotension, bradycardia, hypertension, tachycardia, desaturation, dizziness, headache, hallucination, and nightmare), time to extubation, length of post-anesthesia care unit stay, length of postoperative hospital stay, patient satisfaction, and a composite of 30-day major adverse events (myocardial infarction, cardiac arrest, cerebrovascular accident, coma, acute renal failure, pulmonary embolism, sepsis, septic shock, deep neck space infection, reintubation, reoperation, blood transfusion, failure to wean off ventilator, and death). Analyses will be performed in the modified intention-to-treat population.

Discussion

We hypothesize that our OFA regimen reduces PONV after thyroid and parathyroid surgery. We will also investigate whether OFA leads to improvements in postoperative pain and major adverse events. Our results will offer evidence for optimizing anesthesia regimens in patients who undergo thyroid and parathyroid surgical procedures.

Clinical trial registration

http://www.chictr.org.cn, identifier: ChiCTR2200059656.

Opioid-free anesthesia for open radical cystectomy in morbid obesity

Opioid-free anaesthesia shows evidence about its efectivity and security, even though its risks and benefits are not well defined. Neither are the patient profile or sort of surgery where it could be superior to the conventional opioid-based anaesthetic technique. Aggressive and/or long-lasting surgeries set out several queries on this technique regarding sudden hemodynamic changes, as it does not produce sympatholysis through μ receptor and there is modest experience in this technique. A morbidly obese patient received open radical cystectomy with Bricker-type urinary diversion using infraumbilical incision under OFA protocol, maintaining an adequate hemodynamic stability and excellent analgesia in postoperatory care without using any intraoperative opioids. Opioid-free anaesthesia technique is developing its evidence. However, it is necessary to keep on researching its clinical applications, different drug combinations and solutions to its expected complications.

Proceedings of the Second Curing Coma Campaign NIH Symposium: Challenging the Future of Research for Coma and Disorders of Consciousness

This proceedings article presents actionable research targets on the basis of the presentations and discussions at the 2nd Curing Coma National Institutes of Health (NIH) symposium held from May 3 to May 5, 2021. Here, we summarize the background, research priorities, panel discussions, and deliverables discussed during the symposium across six major domains related to disorders of consciousness. The six domains include (1) Biology of Coma, (2) Coma Database, (3) Neuroprognostication, (4) Care of Comatose Patients, (5) Early Clinical Trials, and (6) Long-term Recovery. Following the 1st Curing Coma NIH virtual symposium held on September 9 to September 10, 2020, six workgroups, each consisting of field experts in respective domains, were formed and tasked with identifying gaps and developing key priorities and deliverables to advance the mission of the Curing Coma Campaign. The highly interactive and inspiring presentations and panel discussions during the 3-day virtual NIH symposium identified several action items for the Curing Coma Campaign mission, which we summarize in this article.

Local and Regional Anaesthetic Techniques in Canine Ovariectomy: A Review of the Literature and Technique Description

Simple Summary

This review stems from a general trend of increasing attention toward surgical nociception in the veterinary field. Indeed, veterinarian anaesthetists are becoming more careful in relieving perioperative nociception, improving the analgesic protocols and therefore optimising surgical outcomes. Canine ovariectomy is a common surgical procedure with a moderate level of pain. Therefore, intraoperative analgesia is very important because pain causes various systemic inflammatory effects that slow patient recovery. This review aims to collect all recent information about local and regional anaesthetic/analgesic techniques in a review of the literature describing the technique utilised. In addition, the present review aims to provide practical guidelines for veterinary practitioners to improve the anaesthetic techniques in canine neutering through an overview of the available literature. In fact, the methods described, considering the relative simplicity of execution, can be used in daily routine practice.

Abstract

Canine ovariectomy is an elective surgery with a moderate level of pain. Despite its relative simplicity, it requires surgical pain management. This study aimed to collect all recent information about local and regional anaesthetic/analgesic techniques in a review of the literature describing the technique utilised. The various procedures described in this review use local anaesthetics to improve analgesia in the routine systemic anaesthetic protocol. The approach described in this paper is called multimodal analgesia and is used in addition to the normal standard anaesthetic protocol. These techniques proved effective in minimising responses to the surgical stimulus and ensured adequate intraoperative and postoperative analgesia. The routine use of multimodal analgesia is considered a useful alternative for pain management in canine ovariectomy, in that it minimises patient suffering, improves the recovery of rescue analgesia, increases drug savings, and improves animal outcomes. In addition, the use of these local and regional techniques ensures satisfactory analgesic coverage that lasts for the first hours postoperatively.

Impact of Opioid-Free Anesthesia on Analgesia and Recovery Following Bariatric Surgery: a Meta-Analysis of Randomized Controlled Studies

This meta-analysis aimed at exploring the impact of opioid-free anesthesia (OFA) on pain score and opioid consumption in patients undergoing bariatric surgery (BS). Literature search identified eight eligible trials. Forest plot revealed a significantly lower pain score (mean difference (MD) =  - 0.96, p = 0.0002; 318 patients), but not morphine consumption (MD =  - 5.85 mg, p = 0.1; 318 patients) at postoperative 24 h in patients with OFA than in those without. Pooled analysis also showed a lower pain score (p = 0.002), morphine consumption (p = 0.0003) in the postanesthetic care unit, and risk of postoperative nausea/vomiting (p = 0.0003) in the OFA group compared to the controls. In conclusion, this meta-analysis demonstrated that opioid-free anesthesia improved pain outcomes immediately and at 24 h after surgery without a beneficial impact on opioid consumption at postoperative 24 h. KEY POINTS: • Roles of opioid-free anesthesia (OFA) in bariatric surgery (BS) were investigated. • Outcomes included postoperative pain score, opioid use, and nausea/vomiting risk. • OFA was associated with lower 24-h pain score but not opioid consumption. • Lower pain score and opioid consumption were noted in the postanesthetic care unit. • OFA correlated with a lower risk of postoperative nausea/vomiting.

Quality of recovery in patients administered remimazolam versus those administered an inhalant agent for the maintenance of general anesthesia: a randomized control trial

Background

Remimazolam is a novel intravenous benzodiazepine that is appropriate for the maintenance of anesthesia. Quality of recovery is an important component of health care quality, but there is no published randomized control trial focused on the quality of recovery in patients undergoing total intravenous anesthesia with remimazolam.

Methods

This parallel-group, single-blind randomized control trial at a tertiary care medical center in South Korea was conducted to determine the difference in the quality of recovery between the patients administered remimazolam and those administered an inhalant anesthetic agent. A total of 168 patients aged 19–65 years who underwent elective laparoscopic cholecystectomy or robotic gynecologic surgery were considered for enrollment. Randomization was performed using sealed envelopes containing computer-generated random allocation sequences.

Remimazolam was administered for the maintenance of anesthesia in the remimazolam group (Group R), and desflurane was administered in the desflurane group (Group D). The induction protocol and the target value of the bispectral index were identical in both groups. Patients were blinded to the drug that was administered until they finished the postoperative questionnaire.

The main outcome measure was the decrement of the QoR-40 score on postoperative day 1 compared to the QoR-40 score on the day before surgery.

Results

A total of 165 patients were analyzed. The preoperative and postoperative global QoR-40 scores were 183 and 152 (IQR 173–192 and 136–169), respectively. The perioperative decrement of the global QoR-40 score was 29.96 ± 22.49. The decrement of the QoR-40 score was smaller in Group R than in Group D (26.99 versus 32.90, respectively; mean difference 5.91, 95% confidence interval -0.96–12.79). After adjustment for sex, the type of surgery and surgical time, the administration of remimazolam resulted in a 7.03-point (95% CI 0.35–13.72) less decrement of the QoR-40 score than desflurane. There were no severe adverse events in either group.

Conclusion

Total intravenous anesthesia maintained with remimazolam provides a better quality of recovery than anesthesia maintained with an inhalant agent in patients undergoing laparoscopic surgery. Additionally, postoperative nausea and vomiting were largely reduced with remimazolam.

Trial registration

KCT0006288, Clinical Research Information Service (CRIS), Republic of Korea

Registration date: 23/06/2021

Drug Repurposing: The Mechanisms and Signaling Pathways of Anti-Cancer Effects of Anesthetics

Cancer is one of the leading causes of death worldwide. There are only limited treatment strategies that can be applied to treat cancer, including surgical resection, chemotherapy, and radiotherapy, but these have only limited effectiveness. Developing a new drug for cancer therapy is protracted, costly, and inefficient. Recently, drug repurposing has become a rising research field to provide new meaning for an old drug. By searching a drug repurposing database ReDO_DB, a brief list of anesthetic/sedative drugs, such as haloperidol, ketamine, lidocaine, midazolam, propofol, and valproic acid, are shown to possess anti-cancer properties. Therefore, in the current review, we will provide a general overview of the anti-cancer mechanisms of these anesthetic/sedative drugs and explore the potential underlying signaling pathways and clinical application of these drugs applied individually or in combination with other anti-cancer agents.

An Entropy-Based Prospective Randomized Controlled Trial to Evaluate the Analgesic and Hypnotic Effects of Equipotent Doses of Sevoflurane and Isoflurane in Patients Presenting for Spine Surgeries

Objectives  Minimal alveolar concentration (MAC) of anesthetic agents has been considered a suitable measure of the potency of inhalational anesthetics. Furthermore, it is assumed that equi-MAC concentrations of different anesthetic agents have a similar potency in suppressing responses to painful stimuli. Isoflurane and sevoflurane are two commonly used volatile anesthetic agents in spine surgeries. Therefore, these agents' hypnotic and analgesic potencies should be distinguished and comprehended for the optimal administration of anesthesia. Consequently, we undertook this study to compare the analgesic and hypnotic potencies between these agents at equi-MAC concentrations, using the entropy monitor.

Materials and Methods  Forty patients undergoing lumbar spine surgery were randomly assigned to two groups receiving either isoflurane ( n  = 20) or sevoflurane ( n  = 20). After induction, maintenance of anesthesia was done with age-corrected 1.0 MAC of either isoflurane or sevoflurane. A standardized noxious stimulus was provided to all the patients after achieving a steady state of 1.0 MAC. The state entropy (SE), response entropy (RE), and RE–SE were recorded at baseline, prestimulus, and poststimulus time points in both groups.

Statistical Analyses  Data are presented as frequency and percentages for categorical variables and mean ± standard deviation for continuous variables. The comparison of categorical variables between the two groups was made using the Fisher's exact test, and the Student's t -test was used for continuous variables. A p -value of < 0.05 was considered to be statistically significant.

Results  At age-corrected 1.0 MAC, there was no significant difference in the SE, RE, and RE–SE in both the groups at any time point.

Conclusion  Our study shows that during a steady state of age-corrected 1.0 MAC single-agent anesthesia, sevoflurane and isoflurane have comparable analgesic and hypnotic potencies as measured by entropy indices when a standardized nociceptive stimulus is provided.

Safety of general anaesthetics on the developing brain: are we there yet?

Thirty years ago, neurotoxicity induced by general anaesthetics in the developing brain of rodents was observed. In both laboratory-based and clinical studies, many conflicting results have been published over the years, with initial data confirming both histopathological and neurodevelopmental deleterious effects after exposure to general anaesthetics. In more recent years, animal studies using non-human primates and new human cohorts have identified some specific deleterious effects on neurocognition. A clearer pattern of neurotoxicity seems connected to exposure to repeated general anaesthesia. The biochemistry involved in this neurotoxicity has been explored, showing differential effects of anaesthetic drugs between the developing and developed brains. In this narrative review, we start with a comprehensive description of the initial concerning results that led to recommend that any non-essential surgery should be postponed after the age of 3 yr and that research into this subject should be stepped up. We then focus on the neurophysiology of the developing brain under general anaesthesia, explore the biochemistry of the observed neurotoxicity, before summarising the main scientific and clinical reports investigating this issue. We finally discuss the GAS trial, the importance of its results, and some potential limitations that should not undermine their clinical relevance. We finally suggest some key points that could be shared with parents, and a potential research path to investigate the biochemical effects of general anaesthesia, opening up perspectives to understand the neurocognitive effects of repetitive exposures, especially in at-risk children.

Medical disease and ambulatory surgery, new insights in patient selection based on medical disease

PURPOSE OF REVIEW

Improvements in perioperative care contributed to enlarge the eligibility criteria for day case surgery and more and more patients with comorbidities may be concerned. However, underlying medical diseases may influence postoperative outcomes, and therefore, must be considered when selecting patients to undergo ambulatory surgery.

RECENT FINDINGS

To limit postoperative complications, rigid patient selection criteria are often applied in ambulatory surgery. In practice, however, most of these criteria predict the occurrence of treatable perioperative adverse events but not the need for unanticipated admission or readmission.

SUMMARY

The underlying medical diseases should not be considered as sole criteria but they should rather be regarded as a dynamic process, which includes the surgical procedure as well as the experience and expertise of the perioperative setting.

Effects of general anesthesia on behavioral circadian rhythms and clock-gene expression in the suprachiasmatic nucleus in rats

The suprachiasmatic nucleus (SCN) of the hypothalamus is a nucleus that regulates circadian rhythms through the cyclic expression of clock genes. It has been suggested that circadian-rhythm-related, adverse postoperative events, including sleep disturbances and delirium, are partly caused by anesthesia-induced disruption of clock-gene expression. We examined the effects of multiple general anesthetics on the expression cycle of Period2 (Per2), one of the clock genes that regulate circadian rhythms in the SCN, and on the behavioral rhythms of animals. Rats were treated with sevoflurane, propofol, and dexmedetomidine for 4 h. The expression of Per2 in SCN was analyzed using in situ hybridization, and the behavioral rhythm before and after anesthesia was analyzed. Per2 expression in the SCN decreased significantly immediately after anesthesia in all groups compared with corresponding control groups. However, Per2 returned to normal levels within 24 h, and there was no phase change in the gene expression cycle or behavioral rhythm. This study suggests that acute suppression of Per2 expression may be a general phenomenon induced by general anesthesia, but that the molecular mechanism of the body clock is resilient to disturbances to some extent.

Pain management during a bromelain-based selective enzymatic debridement in paediatric and adult burn patients

BACKGROUND

Pain associated with surgical or enzymatic burn wound debridement prevents many burn centres from working outside an operating theatre, creating a burden. Alternatives for general anaesthesia to manage pain in burn patients treated with enzymatic debridements, such as regional anaesthesia, have not been studied in detail. This study explores the different possibilities for pain management during a bedside NexoBrid™ procedure.

MATERIAL AND METHODS

We performed a single-centre retrospective study that included 82 paediatric, adolescent, and adult patients with deep dermal and full-thickness burns treated bedside with NexoBrid™ under regional or general anaesthesia. Outcome measures were pain during the NexoBrid™ procedure, the safety of the anaesthesia and the NexoBrid™ procedure, logistics of the bedside NexoBrid™ procedure, and time to wound closure.

RESULTS

Forty-three patients in the adult group (43/67, 64%) only presented with burn wounds on one upper or the one or two lower extremities. In 29 of them (29/43, 67%), a NexoBrid™ procedure was performed under regional anaesthesia, which resulted in low pain levels without any adverse events. All seven patients in the paediatric group, where only one upper or one or two lower limbs were involved (7/15, 47%), underwent a NexoBrid™ procedure performed under regional anaesthesia where no adverse events were reported. In these children, the use of regional anaesthesia was associated with a significant decrease in time to wound closure (average treatment effect on the treated = -22.5 days, p = 0.021).

CONCLUSION

This study highlights that regional anaesthesia administered at the bedside should be the method of choice for pain management during NexoBrid™ procedures because often, it can be adequately and safely performed in all age groups. This approach will reduce the burden on operating theatres. A flow chart has been developed to guide pain management during a NexoBrid™ procedure.

How to Study the Brain While Anesthetizing It?! A Scoping Review on Running Neuroanesthesiologic Studies and Trials That Include Neurosurgical Patients

This scoping review addresses the challenges of neuroanesthesiologic research: the population, the methods/treatment/exposure, and the outcome/results. These challenges are put into the context of a future research agenda for peri-/intraoperative anesthetic management, neurocritical care, and applied neurosciences. Finally, the opportunities of adaptive trial design in neuroanesthesiologic research are discussed.

The Role of Dexmedetomidine in the Structure of Anesthesia for Hip and Knee Arthroplastyс Surgery in Patients with Diabetes

Hip and knee arthroplasty (HKA) is a surgical procedure when damaged parts of the joint are replaced with artificial ones that replicate the shape of a normal joint and restore its function. Every year more than 1.5 million endoprosthetic operations are performed in the world. Replacement of a damaged joint allows patients to return to the normal life, freeing from pain and limited mobility. However, one of the common diseases that negatively affect the results of these operations is diabetes mellitus (DM). The aim of the study: to determine the efficacy and safety of the combined multimodal low opioid anesthesia with dexmedetomidine sedation in patients with diabetes undergoing HKA surgery. Materials and methods. The study included 45 patients who underwent HKA surgery. Patients were divided into three groups according to the scheme of anesthesia. In patients of the 1st group (n = 15) multicomponent low-flow anesthesia with artificial lung ventilation was performed, in the patients of the 2nd group (n = 15) spinal anesthesia was used, in the 3rd group (n = 15) – combined spinal – epidural anesthesia with dexmedetomidine sedation. The groups of patients were identical in anthropometric and gender characteristics, duration of surgery and anesthesia, baseline somatic status. Statistical analysis was performed using the IBM SPSS Statistics suite (SPSS v.16.0). Results. The course of anesthesia in patients in all groups was satisfactory, but patients in group 3 were less likely to experience hyperdynamic reactions (tachycardia and hypotension), postoperative nausea and vomiting (PONV). Only one patient from group 3 required ondansetron for the treatment of PONV against 3 and 2 patients from groups 1 and 2, respectively (p <0.05). Conclusions. Any of the proposed techniques can be used for anesthesia during hip and knee arthroplasty, but the best results have been obtained with combined spinal-epidural anesthesia with dexmedetomidine sedation. In addition, the use of dexmedetomidine can significantly reduce the use of opioids diring the intraoperative and postoperative period.

End-tidal Anesthetic Concentration: Monitoring, Interpretation, and Clinical Application

Age-adjusted fraction of minimum alveolar concentration derived from end-tidal anesthetic partial pressure measurement remains a useful drug advisory display to help prevent awareness if interpreted with proper understanding of the quantal and probabilistic nature of minimum alveolar concentration, semantics, drug interactions, and hysteresis.

Perioperative parameters to consider for enhanced recovery in surgery (ERS) in gynecology (excluding breast surgery)

The current review explores the Enhanced Rehabilitation in Surgery (ERS) approach in the specific context of gynecological surgery. Implementation of an ERS protocol in gynecological surgery reduces postoperative complications and length of stay without increasing morbidity. An ERS approach is based on maintaining an adequate diet and hydration before the operation, according to the recommended time frame, to reduce the phenomenon of insulin resistance, and to optimize patient comfort. On the other hand, the use of anxiolytic treatment as premedication is not recommended. Systematic preoperative digestive preparation, a source of patient discomfort, is not associated with an improvement in the postoperative functional outcome or with a reduction in the rate of complications. A minimally invasive surgical approach is preferrable in the context of ERS. Prevention of surgical site infection includes measures such as optimized antibiotic prophylaxis, skin disinfection with alcoholic chlorhexidine, reduction in the use of drainage of the surgical site, and prevention of hypothermia. Early removal of the bladder catheter is associated with a reduction in the risk of urinary tract infection and a reduction in the length of hospital stay. Prevention of postoperative ileus is based on early refeeding, and prevention of postoperative nausea-vomiting in a multimodal strategy to be initiated during the intraoperative period. Intraoperative hydration should be aimed at achieving euvolemia. Pain control is based on a multimodal strategy to spare morphine use and may include locoregional analgesia. Medicines should be administered orally during the postoperative period to hasten the resumption of the patient's autonomy. The prevention of thromboembolic risk is based on a strategy combining drug prophylaxis, when indicated, and mechanical restraint, as well as early mobilization. However, the eclectic nature of the implementation of these measures as reported in the literature renders their interpretation difficult. Furthermore, beyond the application of one of these measures in isolation, the best benefit on the postoperative outcome is achieved by a combination of measures which then constitutes a global strategy allowing the objectives of the ERS to be met.

Geraniol enhances inhibitory inputs to the paraventricular thalamic nucleus and induces sedation in mice

BACKGROUND

Plant extracts with sedative effects have a long history of clinical use for treating insomnia and epilepsy. Geraniol (GE), a plant-derived acyclic monoterpene, reduces locomotion and prolongs barbiturate-induced anesthesia in rats. However, the mechanisms of GE in sedation remain elusive.

PURPOSE

This study aimed to investigate the mechanisms of GE in sedation in mice.

METHODS

GE was administered systemically by nebulization and intraperitoneal injection. Open field tests, acute seizure tests, and electroencephalogram (EEG) recordings were performed to examine the sedative effects of GE in mice. The time of loss of the righting reflex and return of the righting reflex were recorded in anesthesia experiments to examine the effect of GE on anesthesia. In vitro c-Fos staining and in vivo fiber photometry recordings were performed to detect the activity change of the paraventricular thalamic nucleus (PVT). Microinjection of GE into PVT and related behavioral tests were performed to confirm that PVT was a critical target for GE. Whole-cell recordings were performed to dissect the effects of GE on PVT neurons via GABAA receptors. Molecular docking was performed to examine the interaction between GE and GABAA receptor subunits.

RESULTS

We found that GE reduced locomotion, relieved acute seizures, altered the EEG, and facilitated general anesthesia in mice. Next, we found that GE decreased c-Fos expression and suppressed the calcium activity in PVT. Microinjection of GE into PVT reduced locomotion and facilitated anesthesia. Furthermore, electrophysiology results showed that GE induced dramatic membrane hyperpolarization and suppressed the activity of PVT neurons, mainly by prolonging spontaneous inhibitory postsynaptic currents and inducing tonic inhibitory currents. Molecular docking results indicated that the β3 subunit might be a potential target for GE.

CONCLUSION

By combined using behavioral tests, immunohistochemistry, calcium recording, and electrophysiology, we systematically revealed that GE inhibits PVT and induces sedation in mice. Essential oils have long been considered part of traditional medicine, and they are playing a critical role in aromatherapy. Since GE has a comparatively ideal safety property and multiple delivery methods, GE has great application potential in aromatherapy. Our study also provides a potential candidate for further development of sedatives and anaesthetics.

Brain-based measures of nociception during general anesthesia with remifentanil: A randomized controlled trial

BACKGROUND

Catheter radiofrequency (RF) ablation for cardiac arrhythmias is a painful procedure. Prior work using functional near-infrared spectroscopy (fNIRS) in patients under general anesthesia has indicated that ablation results in activity in pain-related cortical regions, presumably due to inadequate blockade of afferent nociceptors originating within the cardiac system. Having an objective brain-based measure for nociception and analgesia may in the future allow for enhanced analgesic control during surgical procedures. Hence, the primary aim of this study is to demonstrate that the administration of remifentanil, an opioid widely used during surgery, can attenuate the fNIRS cortical responses to cardiac ablation.

METHODS AND FINDINGS

We investigated the effects of continuous remifentanil on cortical hemodynamics during cardiac ablation under anesthesia. In a randomized, double-blinded, placebo (PL)-controlled trial, we examined 32 pediatric patients (mean age of 15.8 years,16 females) undergoing catheter ablation for cardiac arrhythmias at the Cardiology Department of Boston Children's Hospital from October 2016 to March 2020; 9 received 0.9% NaCl, 12 received low-dose (LD) remifentanil (0.25 mcg/kg/min), and 11 received high-dose (HD) remifentanil (0.5 mcg/kg/min). The hemodynamic changes of primary somatosensory and prefrontal cortices were recorded during surgery using a continuous wave fNIRS system. The primary outcome measures were the changes in oxyhemoglobin concentration (NadirHbO, i.e., lowest oxyhemoglobin concentration and PeakHbO, i.e., peak change and area under the curve) of medial frontopolar cortex (mFPC), lateral prefrontal cortex (lPFC) and primary somatosensory cortex (S1) to ablation in PL versus remifentanil groups. Secondary measures included the fNIRS response to an auditory control condition. The data analysis was performed on an intention-to-treat (ITT) basis. Remifentanil group (dosage subgroups combined) was compared with PL, and a post hoc analysis was performed to identify dose effects. There were no adverse events. The groups were comparable in age, sex, and number of ablations. Results comparing remifentanil versus PL show that PL group exhibit greater NadirHbO in inferior mFPC (mean difference (MD) = 1.229, 95% confidence interval [CI] = 0.334, 2.124, p < 0.001) and superior mFPC (MD = 1.206, 95% CI = 0.303, 2.109, p = 0.001) and greater PeakHbO in inferior mFPC (MD = -1.138, 95% CI = -2.062, -0.214, p = 0.002) and superior mFPC (MD = -0.999, 95% CI = -1.961, -0.036, p = 0.008) in response to ablation. S1 activation from ablation was greatest in PL, then LD, and HD groups, but failed to reach significance, whereas lPFC activation to ablation was similar in all groups. Ablation versus auditory stimuli resulted in higher PeakHbO in inferior mFPC (MD = 0.053, 95% CI = 0.004, 0.101, p = 0.004) and superior mFPC (MD = 0.052, 95% CI = 0.013, 0.091, p < 0.001) and higher NadirHbO in posterior superior S1 (Pos. SS1; MD = -0.342, 95% CI = -0.680, -0.004, p = 0.007) during ablation of all patients. Remifentanil group had smaller NadirHbO in inferior mFPC (MD = 0.098, 95% CI = 0.009, 0.130, p = 0.003) and superior mFPC (MD = 0.096, 95% CI = 0.008, 0.116, p = 0.003) and smaller PeakHbO in superior mFPC (MD = -0.092, 95% CI = -0.680, -0.004, p = 0.007) during both the stimuli. Study limitations were small sample size, motion from surgery, indirect measure of nociception, and shallow penetration depth of fNIRS only allowing access to superficial cortical layers.

CONCLUSIONS

We observed cortical activity related to nociception during cardiac ablation under general anesthesia with remifentanil. It highlights the potential of fNIRS to provide an objective pain measure in unconscious patients, where cortical-based measures may be more accurate than current evaluation methods. Future research may expand on this application to produce a real-time indication of pain that will aid clinicians in providing immediate and adequate pain treatment.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02703090.

Perioperative Multimodal Analgesia for Adults undergoing surgery of the Spine- Systematic Review and Meta-analysis of Three or More Modalities

BACKGROUND

Multimodal analgesia is a strategy which may be employed to improve pain management in the perioperative period in patients undergoing surgery of the spine. However, there is no review evidence available on quantitative models of multimodal analgesia within this clinical setting. We conducted a systematic review and meta-analysis to examine the impact of maximal (three or more analgesic agents) multimodal analgesic medication in patients undergoing surgery of the spine.

METHODS

We included randomized controlled trials (RCT's) evaluating the use of three or more multimodal analgesia components (maximal multi modal analgesia) in patients undergoing spinal surgery. We excluded patients receiving neuraxial or regional analgesia. The control group consisted of placebo, standard care (any therapeutic modality including two or less analgesic components). Primary outcomes were post-operative pain scores at rest, at twenty-four, and forty eight hours. We searched the MEDLINE via Ovid SP; EMBASE via Ovid SP; and Cochrane Library (Cochrane Database of Systematic Reviews and CENTRAL). We used Cochrane's standard methods.

RESULTS

We identified consistently improved analgesic endpoints across all pre-determined primary and secondary outcomes. A total of eleven eligible studies evaluated the primary outcome of pain at rest at twenty four hours. Patients receiving maximal multimodal analgesia were identified to have lower pain scores with an average of MD [-1.03], p<0.00001. Length of hospital stay was decreased in patients receiving multimodal analgesia MD [-0.55], p<0.00001.

CONCLUSION

Perioperative maximal multimodal analgesia consistently improves visual analogue scale outcomes in adult population in the immediate post-operative period, with a moderate quality of evidence. There is significant decrease in hospital length of stay in patients receiving maximal multimodal analgesia with a high level of evidence and no statistical heterogeneity.

Effectiveness of Ultrasound-Guided Retrolaminar Block and Erector Spinae Plane Block in Retroperitoneal Laparoscopic Surgery: A Randomized Controlled Trial

Purpose

Retrolaminar block (RLB) and erector spine plane block (ESPB) share a similar block site, but their analgesia principle may differ. This study compared the postoperative analgesic effects of ultrasound-guided RLB and ESPB for retroperitoneal laparoscopic surgery.

Patients and Methods

The study included patients who scheduled for laparoscopic nephrectomy from July 2020 to January 2021. Patients in RLB group received a three-point block at the posterior surface of T8-T10 lamina, and those in ESPB group received at the T9 level. The primary result was the score of visual analogue scale (VAS). Secondary results included information on intraoperative and postoperative analgesia consumption and rescue analgesia usage, skin temperature, serum interleukin (IL)-1β, prostaglandin E2 (PGE2) level and the occurrence of safety events.

Results

There was no significant difference between the two groups in the postoperative VAS scores at both the rest and cough state (All P>0.05). The skin surface temperature of the affected side and the healthy side in ESPB group was higher than that in the RLB group at the end of the surgery (P=0.002) and after surgery (P=0.016). The RLB group had a higher ephedrine usage than the ESPB group (P=0.027). Compared with the ESPB group, the RLB group had a shorter time to exhaust (P=0.045) and lower serum IL-1β level (P=0.049). Patients in neither group developed severe adverse event.

Conclusion

Ultrasound-guided RLB and ESPB can provide safe and effective postoperative analgesia for retroperitoneal laparoscopic surgery. ESPB has more stable intraoperative hemodynamics, while RLB has more potential research value for patients’ rapid recovery.

Migration of Hospital Total Hip and Knee Arthroplasty Procedures to an Ambulatory Surgery Center Setting and Postsurgical Opioid Use: A Private Practice Experience

Background

An enhanced recovery pathway using individualized multimodal pain management with scheduled nonopioid and opioid regimens previously enabled reproducible same-day discharge of Medicare beneficiaries and commercially insured patients undergoing total hip arthroplasty (THA) or total knee arthroplasty (TKA) procedures in the hospital or in ambulatory surgery center settings.

Objective

To analyze the migration trends for TKA and THA procedures from a hospital to an ambulatory surgery center facility and to assess perioperative outcomes before and after incorporating liposomal bupivacaine into a multimodal pain management regimen for these procedures.

Methods

This retrospective medical chart review study included patients undergoing THA or TKA with an enhanced recovery pathway in a hospital or an ambulatory surgery center between 2013 and 2019. The outcome measures included length of stay at the hospital or the ambulatory center, and opioid consumption. We compared the outcomes before and after the addition of liposomal bupivacaine to surgeon-applied periarticular intraoperative local anesthetic field blocks between in-hospital patients who received and patients who did not receive liposomal bupivacaine in 2013 and 2014, and the impact of liposomal bupivacaine use in the hospital versus the ambulatory center from 2015 to 2019.

Results

In 2013 and 2014, the addition of liposomal bupivacaine increased the same-day hospital discharge rate to 32% versus 4% without liposomal bupivacaine (odds ratio, 14.3; 95% confidence interval, 5.9-33.3; P <.0001); the same-day hospital discharge rates increased to 73% in 2015. From 2015 through 2019, 89% of all patients were discharged on the same day from the hospital. In-hospital opioid use was 22% lower in the liposomal bupivacaine cohort than in the patients who did not receive this medication (P = .0035). In 2018 and 2019, same-day discharge from the hospital or the ambulatory surgery center rates were 96% and 100%, respectively, and 84% of the patients used postsurgical opioid prescriptions of 30 or fewer tablets. The complication rates and healthcare resource utilization did not increase with the incorporation of liposomal bupivacaine into the enhanced recovery pathway and increased same-day discharge rates.

Conclusion

An enhanced recovery pathway using individualized, scheduled multimodal pain management protocol in patients undergoing THA or TKA facilitated reproducible, high same-day discharge rates and low postoperative opioid consumption. These results suggest that the use of liposomal bupivacaine for intraoperative field blocks supports predictable same-day discharge rates after THA or TKA. This protocol could facilitate same-day hospital discharge and the migration of THA and TKA procedures from the hospital to lower-cost ambulatory surgery centers.

Immediate Postoperative Analgesia of Nalbuphine-Ketamine Combination Compared with Ketamine Alone in Xylazine-Sedated Goats Undergoing Left Flank Laparotomy

Goats have been used as animal models in research, and the need for achieving safer anesthesia for research or surgical intervention is gaining much attention. The objective of this study was to evaluate intraoperative effects and the immediate postoperative analgesia of nalbuphine–ketamine regimen in goats. Twenty clinically healthy adult female crossbred goats weighing 14 ± 2 kg were allocated randomly into each of two equally sized groups. All animals were sedated with intramuscular (IM) xylazine (0.07 mg/kg), then anesthesia was intravenously (IV) induced with ketamine alone (10 mg/kg) (XK group), or a combination of nalbuphine (0.5 mg/kg) and ketamine (5 mg/kg) (XNK group). Following induction, left flank laparotomy was performed and then sutured. The quality of anesthesia and immediate postoperative analgesia was evaluated. Immediate postoperative analgesia was assessed up to 5 h after standing, using a modified Unesp–Botucatu acute composite pain scale (USAPS). Serum cortisol, glucose, insulin, and C-reactive protein (CRP) were measured at ½, 1, 2, 4, 6, 12, and 24 h, postoperatively (PO). The USAPS pain scores were significantly lower in the XNK compared to the XK group (p < 0.05). The XNK group exhibited a statistically significant difference in the level of serum cortisol at ½ and 1 h PO (p = 0.018 and 0.045, respectively) compared to the XK group. At 2, 4, 6 h PO, CRP significantly decreased (p = 0.023, 0.040 and 0.005, respectively) in the XNK compared to the XK group. Nalbuphine–ketamine produced an acceptable induction of anesthesia and recovery compared to ketamine. Recovery with nalbuphine–ketamine was faster and better quality. The USAPS pain scores were lower in nalbuphine–ketamine, indicating that this novel combination produces better postoperative pain control than ketamine alone.

Perioperative care in open aortic vascular surgery: A Consensus Statement by the Enhanced Recovery after Surgery (ERAS®) Society and Society for Vascular Surgery

The Society for Vascular Surgery and the Enhanced Recovery After Surgery (ERAS®) Society formally collaborated and elected an international, multi-disciplinary panel of experts to review the literature and provide evidence-based recommendations related to all of the health care received in the perioperative period for patients undergoing open abdominal aortic operations (both transabdominal and retroperitoneal approaches, including supraceliac, suprarenal, and infrarenal clamp sites, for aortic aneurysm and aortoiliac occlusive disease). Structured around the ERAS® core elements, 36 recommendations were made and organized into preadmission, preoperative, intraoperative, and postoperative recommendations.

Application effect of sevoflurane combined with remifentanil intravenous inhalation anesthesia in patients undergoing laparoscopic radical resection of cervical cancer

OBJECTIVE

To determine the application effect of sevoflurane combined with remifentanil intravenous inhalation anesthesia in patients undergoing laparoscopic radical resection of cervical cancer (LRHCC).

METHODS

The clinical data of 127 patients with cervical cancer (CC) who received LRHCC in Henan Provincial People's Hospital during January 2017 and June 2021 were retrospectively analyzed. Among them, 60 patients anesthetized by propofol combined with remifentanil were assigned to the control group (Con group), while the rest 67 anesthetized by sevoflurane combined with remifentanil to the research group (Res group). The following items of the two groups were compared: the changes of heart rate and blood pressure before anesthesia (T0), at 30 min after anesthesia (T1) and 10 min after surgery (T2), anesthetic effect, stress substance contents, anesthesia recovery, changes in brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF), Mini-Mental State Examination (MMSE) scores, and adverse reactions.

RESULTS

The heart rate and blood pressure at T1 and T2 were notably different between the two groups (P<0.05). In contrast to the Con group, the Res group showed a greatly better recovery effect of anesthesia and presented notably lower levels of adrenaline and GLU (all P<0.05). 10 min after surgery, the Con group showed lower levels of BDNF and NGF than the Con group. After surgery, the MMSE scores in the Res group were higher than that of the Con group, and the two groups had no significant difference in the incidence of adverse reactions (P>0.05).

CONCLUSION

In contrast to propofol combined with remifentanil anesthesia, intravenous inhalational anesthesia with sevoflurane combined with remifentanil can exert a stronger anesthetic effect in patients receiving LRHCC, with a high safety.

Effect of opioid-free anesthesia on postoperative analgesia after laparoscopic gynecologic surgery

BACKGROUND

We performed this randomised controlled trial to evaluate the effect of opioid-free anesthesia (OFA) on postoperative analgesia after laparoscopic gynecologic surgery.

METHODS

78 patients undergoing laparoscopic gynecologic surgery were randomized to receive either OFA (Group OF) or opioid-inclusive anesthesia (Group C). Postoperative sufentanil consumption within the first 24 h, visual analogue scale (VAS) for pain, postoperative equivalent milligrams of morphine (EMM), severity of postoperative nausea (PN) and vomiting (PV), prevalence of PONV, use of antiemetics, time to first passage of flatus were compared by a two-tailed Student's t test, Wilcoxon rank-sum tests or Fisher's exact tests. Repeated measures ANOVA was used to assess the effect of allocation of groups over time.

RESULTS

The median [IQR] sufentanil consumption within 24 h was lower in Group OF (4[4.5]) than in Group C (6[8], mean difference [MD]=-2, 95% confidence interval [CI] [-4 to 0], P=0.029). The VAS scores at rest and during coughing at 6 h (P=0.009 at rest; P=0.002 during coughing), VAS scores during coughing at 2h (P=0.013) and 4 h (P=0.008), EMM (P=0.026), severities of PN (P=0.003) and PV (P=0.003), and the mean time to first passage of flatus (P=0.017) was significantly less in Group OF than that in Group C. The prevalence of PONV (26.3% [Group OF], 68.4% [Group C], OR=0.31, 95% CI [0.158 to 0.589], P <0.001), use of antiemetics (5.3% [Group OF], 28.9% [Group C], OR=0.136, 95% CI[0.028 to 0.667], P=0.012) was also significantly different between groups.

CONCLUSIONS

Compared to opioid-inclusive anesthesia during laparoscopic gynecologic surgery, OFA was associated with significant improvement in postoperative analgesia, reduced PONV incidenceprevalence and severity, and faster first passage of flatus.

Effect of intraoperative subhypnotic infusion of propofol on postoperative nausea and vomiting: A retrospective analysis

STUDY OBJECTIVE

To measure the possible association between subhypnotic propofol infusion during general balanced anesthesia and the incidence of PONV.

DESIGN

Retrospective Cohort Analysis Using Propensity Score Matching.

SETTING

Postanesthesia care unit and inpatient unit.

PATIENTS

Patients with American Society of Anesthesiologists (ASA) physical status I-IV, undergoing non-cardiac surgery lasting >2 h were included. Patients were excluded if transferred to the intensive care unit after surgery or received ketamine. Initially 70,976 patients were screened, and a cohort of 51,707 eligible adult patients undergoing non-cardiac surgery under general balanced anesthesia between 2015 and 2019 were included. Using a propensity score matching, 3185 patients who received subhypnotic propofol during general balanced anesthesia were matched with 5826 patients who did not receive subhypnotic propofol in a 1:2 ratio.

INTERVENTIONS

None.

MEASUREMENTS

The primary outcome was the incidence of PONV during PACU stay. The secondary outcome was the incidence of PONV within the first 24 h after surgery. Exploratory outcomes were time-to-extubation and length of hospital stay.

MAIN RESULTS

A total of 9011 patients were included (3185 patients who received propofol infusion, and 5826 patients who did not receive propofol infusion) after propensity score matching. The adjusted odds ratio for PONV incidence was 1.03 (95% CI: 0.90, 1.18; p = 0.635) in PACU, and 1.05 (95% CI: 0.90, 1.23; P = 0.50) within 24 h after surgery. The length of hospital stay was 6 h shorter (ratio of means (95% CI) of 0.92, 0.89, 0.94), p < 0.001) and time-to-extubation was 2 min longer (ratio of means 1.24 (1.20, 1.28), p < 0.001) in patients receiving subhypnotic propofol infusion.

CONCLUSIONS

Our study suggests that subhypnotic propofol infusion during general balanced anesthesia is not associated with a reduction in the incidence of PONV during PACU stay and within the first 24 h after surgery. However, it is associated with decreased LOS and increased time-to-extubation, but differences in neither outcome were clinically important.

Total opioid-free general anaesthesia can improve postoperative outcomes after surgery, without evidence of adverse effects on patient safety and pain management: A systematic review and meta-analysis

BACKGROUND

Opioid-based treatment is used to manage stress responses during surgery and postoperative pain. However, opioids have both acute and long-term side effects, calling for opioid-free anaesthetic strategies. This meta-analysis compares adverse events, postoperative recovery, discharge time from post-anaesthesia care unit, and postoperative pain, nausea, vomiting, and opioid consumption between strict opioid-free and opioid-based general anaesthesia.

METHODS

We conducted a systematic review and meta-analysis. We searched PubMed, Embase, Cinahl, Cochrane Library, selected reference lists, and Google Scholar. We included randomised controlled trials (RCTs) published between January 2000 and February 2021 with at least one opioid-free study arm, i.e. no opioids administered preoperatively, during anaesthesia induction, before skin closure, or before emergence from anaesthesia.

RESULTS

The study comprised 1934 patients from 26 RCTs. Common interventions included laparoscopic gynaecological surgery, upper gastrointestinal surgery, and breast surgery. There is firm evidence that opioid-free anaesthesia significantly reduced adverse postoperative events (OR 0.32, 95% CI 0.22 to 0.46, I²  = 56%, p < 0.00001), mainly driven by decreased nausea (OR 0.27, (0.17 to 0.42), p < 0.00001) and vomiting (OR 0.22 (0.11 to 0.41), p < 0.00001). Postoperative opioid consumption was significantly lower in the opioid-free group (-6.00 mg (-8.52 to -3.48), p < 0.00001). There was no significant difference in length of post-anaesthesia care unit stay and overall postoperative pain between groups.

CONCLUSIONS

Opioid-free anaesthesia can improve postoperative outcomes in several surgical settings without evidence of adverse effects on patient safety and pain management. There is a need for more evidence-based non-opioid anaesthetic protocols for different types of surgery as well as postoperative phases.

Drug Interaction between Dexamethasone and Ketoprofen with Thiopental in Male Dogs: Effect on the Recovery from Anesthesia and Pharmacokinetics Parameters

Drug-drug interactions (DDIs) are an important part of clinical veterinary pharmacology. Forty-two healthy mixed breed male dogs were randomly divided into three groups. The control group (C) received normal saline (1 mg/kg) 5 minutes before intravenous administration of thiopental (17 mg/kg), the T1 group received ketoprofen (2.2 mg/kg), and the T2 group received dexamethasone (0.2 mg/kg) 5 minutes before thiopental, respectively. Clinical parameters of anesthesia, heart rate, respiration rate, and electrocardiography were measured. Serum samples were also used to assay thiopental concentration using the high-performance liquid chromatography (HPLC) method, and then, thiopental pharmacokinetic parameters were calculated. Changes in the heart rate and respiration were significant intragroup differences 5 and 10 minutes after anesthesia, respectively. Recovery time parameters showed a significant increase between T1 and control groups (P < 0.05). Elimination rate and half-life of thiopental in the T1 group compared to the control and T2 groups showed a significant decrease and increase, respectively. In addition, the distribution of thiopental in T1 showed a significant increase compared to other groups. However, thiopental clearance in T1 and T2 groups had no significant difference with control (P > 0.05). It can be concluded that drug interaction between ketoprofen and thiopental causes to change in the pharmacokinetics parameters and recovery time from anesthesia in comparison with dexamethasone.

Putative Roles of Astrocytes in General Anesthesia

General anesthetics are a mainstay of modern medicine, and although much progress has been made towards identifying molecular targets of anesthetics and neural networks contributing to endpoints of general anesthesia, our understanding of how anesthetics work remains unclear. Reducing this knowledge gap is of fundamental importance to prevent unwanted and life-threatening side-effects associated with general anesthesia. General anesthetics are chemically diverse, yet they all have similar behavioral endpoints, and so for decades, research has sought to identify a single underlying mechanism to explain how anesthetics work. However, this effort has given way to the 'multiple target hypothesis' as it has become clear that anesthetics target many cellular proteins, including GABAA receptors, glutamate receptors, voltage-independent K+ channels, and voltagedependent K+, Ca2+ and Na+ channels, to name a few. Yet, despite evidence that astrocytes are capable of modulating multiple aspects of neural function and express many anesthetic target proteins, they have been largely ignored as potential targets of anesthesia. The purpose of this brief review is to highlight the effects of anesthetic on astrocyte processes and identify potential roles of astrocytes in behavioral endpoints of anesthesia (hypnosis, amnesia, analgesia, and immobilization).

Continuous action deep reinforcement learning for propofol dosing during general anesthesia

PURPOSE

Anesthesiologists simultaneously manage several aspects of patient care during general anesthesia. Automating administration of hypnotic agents could enable more precise control of a patient's level of unconsciousness and enable anesthesiologists to focus on the most critical aspects of patient care. Reinforcement learning (RL) algorithms can be used to fit a mapping from patient state to a medication regimen. These algorithms can learn complex control policies that, when paired with modern techniques for promoting model interpretability, offer a promising approach for developing a clinically viable system for automated anesthestic drug delivery.

METHODS

We expand on our prior work applying deep RL to automated anesthetic dosing by now using a continuous-action model based on the actor-critic RL paradigm. The proposed RL agent is composed of a policy network that maps observed anesthetic states to a continuous probability density over propofol-infusion rates and a value network that estimates the favorability of observed states. We train and test three versions of the RL agent using varied reward functions. The agent is trained using simulated pharmacokinetic/pharmacodynamic models with randomized parameters to ensure robustness to patient variability. The model is tested on simulations and retrospectively on nine general anesthesia cases collected in the operating room. We utilize Shapley additive explanations to gain an understanding of the factors with the greatest influence over the agent's decision-making.

RESULTS

The deep RL agent significantly outperformed a proportional-integral-derivative controller (median episode median absolute performance error 1.9% ± 1.8 and 3.1% ± 1.1). The model that was rewarded for minimizing total doses performed the best across simulated patient demographics (median episode median performance error 1.1% ± 0.5). When run on real-world clinical datasets, the agent recommended doses that were consistent with those administered by the anesthesiologist.

CONCLUSIONS

The proposed approach marks the first fully continuous deep RL algorithm for automating anesthestic drug dosing. The reward function used by the RL training algorithm can be flexibly designed for desirable practices (e.g. use less anesthetic) and bolstered performances. Through careful analysis of the learned policies, techniques for interpreting dosing decisions, and testing on clinical data, we confirm that the agent's anesthetic dosing is consistent with our understanding of best-practices in anesthesia care.

Guidelines for Perioperative Care in Bariatric Surgery: Enhanced Recovery After Surgery (ERAS) Society Recommendations: A 2021 Update

Background

This is the second updated Enhanced Recovery After Surgery (ERAS®) Society guideline, presenting a consensus for optimal perioperative care in bariatric surgery and providing recommendations for each ERAS item within the ERAS® protocol.

Methods

A principal literature search was performed utilizing the Pubmed, EMBASE, Cochrane databases and ClinicalTrials.gov through December 2020, with particular attention paid to meta-analyses, randomized controlled trials and large prospective cohort studies. Selected studies were examined, reviewed and graded according to the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) system. After critical appraisal of these studies, the group of authors reached consensus regarding recommendations.

Results

The quality of evidence for many ERAS interventions remains relatively low in a bariatric setting and evidence-based practices may need to be extrapolated from other surgeries.

Conclusion

A comprehensive, updated evidence-based consensus was reached and is presented in this review by the ERAS® Society.

Nonopioid analgesics for analgesia in critically ill patients: Friends, enemies, or collaborators

Patients in intensive care units (ICUs) experience pain, which they describe as a significant cause of stress during treatment. It can progress to chronic pain and significantly affect the quality of life. Opioids have long been the backbone of ICU pain therapy. The consequences of their long-term use are known today, such as prolonged ICU stay and mechanical ventilation, resulting in increased treatment costs. Additionally, abstinence syndrome is a consequence of abrupt opioid withdrawal. Also, there is a risk of tolerance and hyperalgesia after prolonged opioid use. Globally, opioid dependence after hospital opioid treatment is alarming, although there is still a lack of data on its incidence after ICU. Multimodal analgesia enables comfort to the patient, opioid-sparing, and avoidance of side effects of non-opioid analgesics. Nonsteroidal anti-inflammatory drugs (NSAIDs) are a broad group of drugs recommended with paracetamol to treat mild to moderate acute postoperative pain. Although often prescribed by intensivists, their use in treating painful conditions in ICU is controversial due to the possible consequences on the organs of critically ill patients. Due to the inhibition of cyclooxygenases, NSAIDs indirectly cause vasoconstriction of the renal arteries and arterioles, leading to kidney damage. NSAIDs inhibit platelet aggregation and may predispose to bleeding. Analgesia of a critically ill patient is a important part of their treatment, however it can be challenging in certain patients. Numerous combinations of pharmacological and non-pharmacological approaches can be adapted to the patient's current characteristics.

Electroencephalography-demonstrated mechanisms of dexmedetomidine-mediated deepening of propofol anesthesia: an observational study

BACKGROUND

Although dexmedetomidine (Dex) is known to reduce bispectral index (BIS) values and propofol dosage, there is little information regarding raw electroencephalography (EEG) changes related to Dex deepening of propofol general anesthesia (GA). This study investigated the Dex effects on propofol GA via analysis of EEG changes.

METHODS

A study cohort of 21 surgical patients (age range, 20-60 years) categorized as American Society of Anesthesiologists (ASA) class I or II was enrolled. We used time-varying spectral and bicoherence methods to compare electroencephalogram signatures 5 min before versus 10 min after intravenous Dex injection under propofol GA. The means and medians are reported with 95% confidence intervals (CIs) and inter-quartile ranges (IQRs), respectively.

RESULTS

Dex augmented the slow waves power and theta (θ) oscillation bicoherence peak from a mean (95% CI) of 22.1% (19.0, 25.2) to 25.2% (21.8, 28.6). Meanwhile, Dex reduced alpha (α) peak power and bicoherence from 3.5 dB (1.0, 6.0) and 41.5% (34.0, 49.0) to 1.7 dB (- 0.6, 4.0) and 35.4% (29.0, 41.8), respectively, while diminishing the median frequency of α oscillation peak values and the mean frequency of α peaks in bicoherence spectra from 12.0 Hz (IQR 11.2, 12.6) and 11.7 Hz (11.3, 12.2) to 11.1 Hz (IQR 10.3, 11.8) and 11.2 Hz (10.9, 11.6), respectively.

CONCLUSIONS

Profound EEG changes support the supposition that Dex enhances propofol-induced GA from a moderate to a deeper state. The present findings provide a theoretical basis and reference regarding protocols aimed at reducing anesthetic/sedative dosage while maintaining sufficient depth of GA.

CLINICAL TRIAL REGISTRATION

ChiCTR, ChiCTR1900026955 . Registered on 27 October 2019.

Impact of Bilateral Subcostal Plus Lateral Transversus Abdominis Plane Block on Quality of Recovery After Laparoscopic Cholecystectomy: A Randomized Placebo-Controlled Trial

BACKGROUND

Previous research has not evaluated the potential effect of transversus abdominis plane (TAP) block on quality of recovery following laparoscopic cholecystectomy. Therefore, we investigated whether addition of the bilateral subcostal and lateral TAP (bilateral dual TAP [BD-TAP]) blocks to multimodal analgesia would improve the quality of recovery as assessed with the Quality of Recovery-40 (QoR-40).

METHODS

Patients age 18 to 60 years who were scheduled to undergo elective laparoscopic cholecystectomy were randomized to the BD-TAP or control group. The BD-TAP group received the BD-TAP block with multimodal analgesia under general anesthesia, using 0.25% ropivacaine, and the control group was treated with the same method, except that they received the sham block using 0.9% normal saline. Both groups had the same multimodal analgesia regimen, consisting of intravenous dexamethasone, propacetamol, ibuprofen, and oxycodone. The primary outcome was the QoR-40 score at 24 hours after surgery. Data were analyzed using the independent t test, Mann-Whitney U test, χ2 test, and Fisher exact test.

RESULTS

Thirty-eight patients in each group were recruited. The mean QoR-40 score decreased by 13.6 (95% confidence interval [CI], 8.3-18.8) in the BD-TAP group and 15.6 (95% CI, 6.7-24.5) in the control group. The postoperative QoR-40 score at 24 hours after surgery did not differ between the 2 groups (BD-TAP group, median [interquartile range], 170.5 [152-178]; control group, 161 [148-175]; median difference, 3 [95% CI, -5 to 13]; P = .427). There were no differences between the 2 groups in the pain dimension of the QoR-40: 30.5 (95% CI, 27-33) in the BD-TAP group and 31 (95% CI, 26-32) in the control group; median difference was 0 (95% CI, -2 to 2); P = .77.

CONCLUSIONS

Our results indicate that the BD-TAP block does not improve the quality of recovery or analgesic outcomes following laparoscopic cholecystectomy. Our results do not support the routine use of the BD-TAP block for this surgery.

General anesthetic techniques for enhanced recovery after surgery: Current controversies

General anesthesia technique can influence not only immediate postoperative outcomes, but also long-term outcomes beyond hospital stay (e.g., readmission after discharge from hospital). There is lack of evidence regarding superiority of total intravenous anesthesia over inhalation anesthesia with regards to postoperative outcomes even in high-risk population including cancer patients. Optimal balanced general anesthetic technique for enhance recovery after elective surgery in adults includes avoidance of routine use preoperative midazolam, avoidance of deep anesthesia, use of opioid-sparing approach, and minimization of neuromuscular blocking agents and appropriate reversal of residual paralysis. Given that the residual effects of drugs used during anesthesia can increase postoperative morbidity and delay recovery, it is prudent to use a minimal number of drug combinations, and the drugs used are shorter-acting and administered at the lowest possible dose. It is imperative that the discerning anesthesiologist consider whether each drug used is really necessary for accomplishing perioperative goals.

Anesthetics mediated the immunomodulatory effects via regulation of TLR signaling

Anesthetics have been widely used in surgery and found to suppress inflammatory injury and affect the outcomes of the surgery and diseases. In contrast, anesthetics are also found to induce neuronal injury and inflammation. However, the immune-modulation mechanism of anesthetics is still not clear. Recent studies have shown that the immune-modulation of anesthetics is associated with the regulation of toll-like receptor (TLR)-mediated signaling. Moreover, the regulation of anesthetics in TLR signaling is related to modulations of non-coding RNAs (nc RNAs). Consistently, nc RNAs are mainly divided into micro RNAs (miRs) and long non-coding RNAs (lnc RNAs), which have been found to exert regulatory effects on the immune system. In this review, we summarize the immunomodulatory functions of the widely used anesthetic agents, which are associated with regulation of TLR signaling. In addition, we also focus on the roles of nc RNAs induced by anesthetics in regulations of TLR signaling.

Electroencephalogram variability analysis for monitoring depth of anesthesia

Objective. In this paper, a new approach of extracting and measuring the variability in electroencephalogram (EEG) was proposed to assess the depth of anesthesia (DOA) under general anesthesia.Approach. The EEG variability (EEGV) was extracted as a fluctuation in time interval that occurs between two local maxima of EEG. Eight parameters related to EEGV were measured in time and frequency domains, and compared with state-of-the-art DOA estimation parameters, including sample entropy, permutation entropy, median frequency and spectral edge frequency of EEG. The area under the receiver-operator characteristics curve (AUC) and Pearson correlation coefficient were used to validate its performance on 56 patients.Main results. Our proposed EEGV-derived parameters yield significant difference for discriminating between awake and anesthesia stages at a significance level of 0.05, as well as improvement in AUC and correlation coefficient on average, which surpasses the conventional features of EEG in detection accuracy of unconscious state and tracking the level of consciousness.Significance. To sum up, EEGV analysis provides a new perspective in quantifying EEG and corresponding parameters are powerful and promising for monitoring DOA under clinical situations.

Measurement of the nociceptive flexion reflex threshold in critically ill patients - a randomized observational pilot study

BACKGROUND

Pain detection and treatment is a major challenge in the care of critically ill patients, rendered more complex by the need to take into consideration the risk of insufficient or excessive analgesia. The nociceptive flexion reflex threshold (NFRT) has become the established basis for measuring the level of analgesia in the perioperative context. However, it remains unclear whether NFRT measurement can be usefully applied to mechanically ventilated, analgosedated critically ill patients who are unable to communicate. Therefore, the aim of the present study was to investigate whether there is an association between the NFRT measurement and the Behavioral Pain Scale (BPS) in critically ill, analgosedated, and mechanically ventilated patients and whether the NFRT measurement can also detect potential excessive analgesia.

METHODS

This prospective, observational, randomized single-center pilot study included patients admitted to the surgical Intensive Care Unit of University Hospital Ulm, Germany, all of whom were analgosedated and intubated. Major exclusion criteria were defined as the need for the administration of neuromuscular blocking agents or neurological diseases associated with peripheral nerve conduction restriction. Initial NFRT and BPS measurements were conducted within 12 h after admission. A structured pain assessment was performed at least twice daily until extubation throughout the observation period thereafter (Group A: BPS + NFRT, Group B: BPS).

RESULTS

114 patients were included in the study. NFRT is associated negatively with BPS. NFRT was almost twice as high in patients with a Richmond Agitation Sedation Scale (RASS) score of -5 than in patients with a RASS score ≥ -4 (RASS -5 - NFRT: 59.40 vs. RASS -4 - NFRT: 29.00, p < 0.001).

CONCLUSIONS

NFRT measurement is associated negatively with the BPS in critically ill patients. NFRT measurement provides guidance for the evaluation of nociceptive processes in patients with RASS scores ≤ -4, in whom analgesia level is often difficult to assess. However, in order to identify excessive analgesia and derive therapeutic consequences, it is necessary to gradually decrease analgesics and sedatives until a stimulus threshold is reached at which the patient does not feel pain.

TRIAL REGISTRATION

Retrospectively registered in the German Clinical Trials Register, registration number DRKS00021149, date of registration: March 26, 2020. https://www.drks.de/drks_web/navigate.do?navigationId=trial.HTML&TRIAL_ID=DRKS00021149 .

An injectable mesoporous silica-based analgesic delivery system prolongs the duration of sciatic nerve block in mice with minimal toxicity

The major limitation of traditional local anesthetics is the finite duration of a single injection. The present study developed two kinds of novel injectable anesthetic nanocomposites based on mesoporous silica, and evaluated their long-lasting analgesic effect and biosafety. The nanoparticulate carriers, mesoporous silica nanoparticles (MSNs) and mesoporous silica-coated gold nanorods (GNR@MSN), were firstly constructed using the oil-water biphase reaction approach and then ropivacaine (RPC), a local anesthetic, was loaded into the mesoporous carriers by vacuum suction. Transmission electron microscopic images showed the well-ordered mesoporous structure for drug loading. RPC-loaded MSNs and RPC-loaded GNR@MSN exhibited a sustained-release pattern in vitro, and the latter also showed a controlled-release manner triggered by near-infrared (NIR) irradiation. RPC-loaded MSNs and RPC-loaded GNR@MSN caused an initial sensory blockade in mice that lasted for 6 h, almost 2.5 folds of that from free RPC solution. Furthermore, upon NIR irradiation, the latter induced three additional periods of the blockade. Neither of them showed motor nerve block, which may be due to the sustained release manner. The low myotoxicity and low neurotoxicity of the two nanocomposites were presented both in vitro and in vivo. These results demonstrate the potential of the mesoporous silica-based analgesic nanocomposites in effectively controlling postoperative pain, maybe RPC-loaded MSNs for moderate pain and RPC-loaded GNR@MSN for severe pain. STATEMENT OF SIGNIFICANCE: Adequate postoperative analgesia helps early functional exercise after surgery and accelerates rapid recovery, while uncontrolled postoperative pain probably develops chronic post-surgical pain that impacts the life quality of patients for a long time. However, postoperative pain management is still a challenge. The current treatment drugs are always accompanied by some side effects due to their systemic effect. Opioids have risks of addiction and respiratory depression, and nonsteroidal anti-inflammatory drugs can lead to gastrointestinal reaction. Therefore, the long-lasting local anesthetic formulation with good biocompatibility is the most promising solution to manage post-surgical pain. The present study developed novel injectable anesthetic nanocomposites based on mesoporous silica, providing long-lasting pain relief in mice with minimal toxicity.