2022 Society of Critical Care Medicine Clinical Practice Guidelines on Prevention and Management of Pain, Agitation, Neuromuscular Blockade, and Delirium in Critically Ill Pediatric Patients With Consideration of the ICU Environment and Early Mobility.

RATIONALE: A guideline that both evaluates current practice and provides recommendations to address sedation, pain, and delirium management with regard for neuromuscular blockade and withdrawal is not currently available. OBJECTIVE: To develop comprehensive clinical practice guidelines for critically ill infants and children, with specific attention to seven domains of care including pain, sedation/agitation, iatrogenic withdrawal, neuromuscular blockade, delirium, PICU environment, and early mobility. DESIGN: The Society of Critical Care Medicine Pediatric Pain, Agitation, Neuromuscular Blockade, and Delirium in critically ill pediatric patients with consideration of the PICU Environment and Early Mobility Guideline Taskforce was comprised of 29 national experts who collaborated from 2009 to 2021 via teleconference and/or e-mail at least monthly for planning, literature review, and guideline development, revision, and approval. The full taskforce gathered annually in-person during the Society of Critical Care Medicine Congress for progress reports and further strategizing with the final face-to-face meeting occurring in February 2020. Throughout this process, the Society of Critical Care Medicine standard operating procedures Manual for Guidelines development was adhered to. METHODS: Taskforce content experts separated into subgroups addressing pain/analgesia, sedation, tolerance/iatrogenic withdrawal, neuromuscular blockade, delirium, PICU environment (family presence and sleep hygiene), and early mobility. Subgroups created descriptive and actionable Population, Intervention, Comparison, and Outcome questions. An experienced medical information specialist developed search strategies to identify relevant literature between January 1990 and January 2020. Subgroups reviewed literature, determined quality of evidence, and formulated recommendations classified as "strong" with "we recommend" or "conditional" with "we suggest." Good practice statements were used when indirect evidence supported benefit with no or minimal risk. Evidence gaps were noted. Initial recommendations were reviewed by each subgroup and revised as deemed necessary prior to being disseminated for voting by the full taskforce. Individuals who had an overt or potential conflict of interest abstained from relevant votes. Expert opinion alone was not used in substitution for a lack of evidence. RESULTS: The Pediatric Pain, Agitation, Neuromuscular Blockade, and Delirium in critically ill pediatric patients with consideration of the PICU Environment and Early Mobility taskforce issued 44 recommendations (14 strong and 30 conditional) and five good practice statements. CONCLUSIONS: The current guidelines represent a comprehensive list of practical clinical recommendations for the assessment, prevention, and management of key aspects for the comprehensive critical care of infants and children. Main areas of focus included 1) need for the routine monitoring of pain, agitation, withdrawal, and delirium using validated tools, 2) enhanced use of protocolized sedation and analgesia, and 3) recognition of the importance of nonpharmacologic interventions for enhancing patient comfort and comprehensive care provision.

Efficacy of magnesium sulfate as an adjuvant to rocuronium in general anaesthesia: a meta-analysis.

OBJECTIVE: Magnesium sulfate is considered to be an effective adjuvant to rocuronium in general anaesthesia. We conducted a meta-analysis to clarify its efficacy. METHODS: We searched the PubMed, Embase, Web of Science, Cochrane Library, WanFang, Chinese Biomedical Literature, and China National Knowledge Infrastructure databases for randomized controlled trials (RCTs) of magnesium sulfate as an adjuvant to rocuronium from the start of the database establishment until May 2020. RESULTS: Eleven RCTs were analysed. The pooled meta-analysis showed that using magnesium sulfate as an adjuvant significantly shortened the onset time and prolonged the clinical duration of neuromuscular blockade by rocuronium compared with the control group without magnesium sulfate. However, there was no significant difference in recovery index of neuromuscular block between the magnesium and control groups. Furthermore, magnesium sulfate significantly increased the rates of excellent and clinically acceptable intubation conditions. CONCLUSION: Adding magnesium sulfate to rocuronium during general anaesthesia can alter the neuromuscular parameters, including shortening the anaesthesia-onset time and prolonging the clinical duration, without significantly increasing the recovery time. Pretreatment with magnesium sulfate may also improve intubation conditions during general anaesthesia.

Prevalencia de bloqueo residual en la Unidad de Cuidados Postanestésicos del Hospital Metropolitano / Prevalence of residual blockade in the Postanesthetic Care Unit of the Hospital Metropolitano

RESUMEN El bloqueo residual se define como la debilidad muscular postoperatoria producida por un antagonismo incompleto de los relajantes neu-romusculares, siendo sus principales complicaciones las respiratorias. Actualmente, el mejor método de evaluación objetiva del bloqueo neuromuscular es el Tren de Cuatro (TOF). El objetivo de este estudio fue describir la prevalencia de bloqueo residual en la Unidad de Cuidados Postanestésicos (UCPA) en pacientes ASA I y ASA II sometidos a cirugía electiva y de emergencia bajo anestesia general en el Hospital Metropolitano. Se realizó un estudio observacional, descriptivo y prospectivo en 211 sujetos, donde mediante el TOF se deter-minó que la prevalencia de bloqueo residual en la UCPA fue del 8,5%, valor que se relacionó con la falta de monitorización de la función neuromuscular, determinando además que el empleo de fármacos que revierten el bloqueo neuromuscular no excluye la presencia de bloqueo residual. Se recomienda el uso rutinario de monitorización de la relajación neuromuscular para prevenir y diagnosticar el bloqueo residual, además de la administración de reversión farmacológica independientemente del tiempo quirúrgico.

ABSTRACT Residual blockade is defined as postoperative muscle weakness caused by incomplete antagonism of neuromuscular relaxants, its main complications being respiratory, currently the best method of objective evaluation of neuromuscular blockade is the Train of Four (TOF). The objective of this study was to describe the prevalence of residual block in the Post Anesthesia Care Unit (UCPA) in patients with ASA I and ASA II undergoing elective and emergency surgery under general anesthesia at the Metropolitan Hospital. An observational, descrip-tive and prospective study was conducted in 211 subjects, where it was determined that the prevalence of residual block in UCPA was 8.5% with TOF, a value that was related to the lack of monitoring of neuromuscular function, also determining that the use of drugs that reverse neuromuscular blockade does not exclude the presence of residual blockade. Routine use of neuromuscular relaxation monitoring is recommended to prevent and diagnose residual block, in addition to drug reversal administration regardless of surgical time.

Identifying high dose neostigmine as a risk factor for post-operative respiratory complications: a case-control study.

INTRODUCTION: Neostigmine, an acetylcholinesterase inhibitor, is used to reverse the effects of non-depolarizing neuromuscular blocking agents. Inappropriate dosing of neostigmine can lead to post-operative respiratory complications. Post-operative respiratory complications are associated with major morbidity and mortality. The purpose of this case-control study was to determine neuromuscular blockade-related risk factors associated with post-operative respiratory complications (specifically, reintubation, respiratory insufficiency, hypoxia, and/or aspiration). MATERIAL AND METHODS: We performed an Institutional Review Board-approved case-control study of all patients who underwent a general anesthetic requiring neuromuscular blockade at Tufts Medical Center between March 22, 2013 and June 1, 2019. Cases were patients who experienced post-operative complications. We identified 58 controls and 116 cases from a database of 130,178 patients during the 74-month study period. RESULTS: After adjusting for covariates, the administration of high dose neostigmine (> 60 mg per kg ideal body weight) was associated with increased odds of post-operative respiratory complications (odds ratio = 8.2; 95% CI: 2.5-26.6, P < 0.001). Rocuronium dose and the use of train-of-four peripheral nerve stimulator were not associated with post-operative respiratory complications. CONCLUSIONS: High dose neostigmine was identified as an independent risk factor for post-operative respiratory complications. Our study suggests that inappropriate dosing of neostigmine continues to be a problem despite growing evidence of an association with respiratory complications.

Reducing the dose of neuromuscular blocking agents with adjuncts: a systematic review and meta-analysis.

BACKGROUND: Acute global shortages of neuromuscular blocking agents (NMBA) threaten to impact adversely on perioperative and critical care. The use of pharmacological adjuncts may reduce NMBA dose. However, the magnitude of any putative effects remains unclear. METHODS: We conducted a systematic review and meta-analysis of RCTs. We searched Medline, Embase, Web of Science, and Cochrane Database (1970-2020) for RCTs comparing use of pharmacological adjuncts for NMBAs. We excluded RCTs not reporting perioperative NMBA dose. The primary outcome was total NMBA dose used to achieve a clinically acceptable depth of neuromuscular block. We assessed the quality of evidence using the GRADE (Grades of Recommendation, Assessment, Development, and Evaluation) criteria. Data are presented as the standardised mean difference (SMD); I2 indicates percentage of variance attributable to heterogeneity. RESULTS: From 3082 records, the full texts of 159 trials were retrieved. Thirty-one perioperative RCTs met the inclusion criteria for meta-analysis (n=1962). No studies were conducted in critically ill patients. Reduction in NMBA dose was associated with use of magnesium (SMD: -1.10 [-1.44 to -0.76], P<0.001; I2=85%; GRADE=moderate), dexmedetomidine (SMD: -0.89 [-1.55 to -0.22]; P=0.009; I2=87%; GRADE=low), and clonidine (SMD: -0.67 [-1.13 to -0.22]; P=0.004; I2=0%; GRADE=low) but not lidocaine (SMD: -0.46 [-1.01 to -0.09]; P=0.10; I2=68%; GRADE=moderate). Meta-analyses for nicardipine, diltiazem, and dexamethasone were not possible owing to the low numbers of studies. We estimated that 30-50 mg kg-1 magnesium preoperatively (8-15 mg kg h-1 intraoperatively) reduces rocuronium dose by 25.5% (inter-quartile range, 14.7-31). CONCLUSIONS: Magnesium, dexmedetomidine, and clonidine may confer a clinically relevant sparing effect on the required dose of neuromuscular block ing drugs in the perioperative setting. SYSTEMATIC REVIEW REGISTRATION: PROSPERO: CRD42020183969.

The effect of local anesthetic solution volume applied in retrobulbar block in cataract surgery on the duration of anesthesia and patient comfort / Efeito do volume da solução anestésica local aplicada no bloqueio retrobulbar na cirurgia de catarata na duração da anestesia e no conforto do paciente

Abstract Objective: To compare the use of 2 different local anesthetic solution (LAS) volumes of 1.5 mL and 3 mL in retrobulbar block in patients undergoing cataract surgery in terms of anesthesia, akinesia, and pain levels. Methods: 80 patients between 18-90 years old, ASA I-II-III, were included in the study. For retrobulbar anesthesia, 1.5 mL LAS was applied to one group (Group LV), and 3 mL LAS to the other group (Group HV). The patients' ocular and eyelid motion scores were evaluated and recorded in the first, third, fifth, and tenth minutes after the block, and at 30-minute intervals for 4 hours post-operatively. One day later, the first hour of analgesic need and the number of times they took analgesic agents were asked and recorded. In addition, side effects were questioned and recorded. Results: The 39 (48.75%) patients were male and 41 (51.25%) patients were female. The criteria determined in terms of ocular motor score after the retrobulbar block (ocular motor score≤4) were met in 92.5% of patients in Group LV in all patients in Group HV, and the time to fulfill the determined criteria in Group HV was found to be significantly lower compared to Group LV (p=0.004). The movements of the eye in all direction except the inward movement recovered in Group LV in a significantly shorter time than Group HV (p=0.004). There was no significant difference in pain levels and side effects between the groups (p=0.34). Conclusions: After 1.5 mL LAS administration in retrobulbar block, adequate akinesia was not achieved in about one tenth of patients, but no significant difference was found between 1.5 mL and 3 mL LAS volumes in analgesic efficacy and side effects.

Resumo Objetivo: Comparar o uso de 2 volumes diferentes de solução anestésica local (LAS) de 1,5 mL e 3 mL no bloqueio retrobulbar em pacientes submetidos à cirurgia de catarata em termos de anestesia, acinesia e níveis de dor. Métodos: 80 pacientes entre 18 e 90 anos, ASA I-II-III, foram incluídos no estudo. Para anestesia retrobulbar, 1,5 mL de LAS foi aplicado em um grupo (Grupo LV) e 3 mL de LAS no outro grupo (Grupo HV). Os escores de movimento ocular e palpebral dos pacientes foram avaliados e registrados no primeiro, terceiro, quinto e décimo minutos após o bloqueio e em intervalos de 30 minutos por 4 horas no pós-operatório. Um dia depois, a primeira hora de necessidade de analgésico e o número de vezes que eles tomaram analgésicos foram solicitados e registrados. Além disso, os efeitos colaterais foram questionados e registrados. Resultados: 39 (48,75%) pacientes eram do sexo masculino e 41 (51,25%) do sexo feminino. Os critérios determinados em termos de escore motor ocular após o bloqueio retrobulbar (escore motor ocular≤4) foram atendidos em 92,5% dos pacientes do Grupo LV em todos os pacientes do Grupo HV, e foi encontrado o tempo para atender aos critérios determinados no Grupo HV ser significativamente menor em comparação ao grupo LV (p = 0,004). Os movimentos do olho em todas as direções, exceto o movimento interior, se recuperaram no Grupo LV em um tempo significativamente menor que o Grupo HV (p = 0,004). Não houve diferença significativa nos níveis de dor e efeitos colaterais entre os grupos (p = 0,34). Conclusões: Após administração de 1,5 mL de LAS no bloqueio retrobulbar, não foi alcançada acinesia adequada em cerca de um décimo dos pacientes, mas não foi encontrada diferença significativa entre os volumes de 1,5 mL e 3 mL de LAS na eficácia analgésica e efeitos colaterais.

The future of neuromuscular blocking agents.

PURPOSE OF REVIEW: The present review provides a summary of the literature on recent development of new neuromuscular blocking agents and presents clinically well established and new reversal agents. RECENT FINDINGS: Anesthesiologists are still waiting for the ideal neuromuscular blocking agent with a succinylcholine-like rapid onset and offset without side effects. Recent drug development led to a new series of neuromuscular compounds, called the chlorofumarates such as gantacurium, CW002, and CW011. These drugs have a promising pharmacodynamic profile; importantly, they can rapidly be reversed by L-cysteine adduction without relevant side effects. In addition, a new spectrum of reversal agents are currently examined in preclinical studies: adamgammadex sodium, a modified γ-cyclodextrin derivate that forms an inactive tight inclusion complex with rocuronium or vecuronium and calabadions, capable of reversing both benzylisoquinolines and steroidal neuromuscular blocking agents. SUMMARY: Although the recent advancements in neuromuscular research are very promising, to date, the presented drugs are currently not available for clinical use. Clinical studies will determine the role of these developments in anesthesia practice. Therefore, well established combinations such as rocuronium-sugammadex are popular in clinical practice to offer quick paralysis for intubation and to optimize surgical conditions, while providing a fast neuromuscular recovery at the end of surgery.

Effect of pretreatment with magnesium sulphate on the duration of intense and deep neuromuscular blockade with rocuronium: A randomised controlled trial.

BACKGROUND: Magnesium sulphate is an important adjuvant drug in multimodal anaesthesia. In combination with rocuronium it can enhance neuromuscular blockade (NMB). Limited data exist concerning the effect of magnesium sulphate on the duration of deep or intense NMB and the period of no response. OBJECTIVE(S): To determine the role of magnesium sulphate on the duration of rocuronium-induced deep and intense NMB, and the period of no response to nerve stimulation. DESIGN: A randomised controlled trial. SETTING: A public tertiary care hospital, Rio de Janeiro, Brazil, from February 2017 to March 2018. PATIENTS: All patients between 18 and 65 years of age scheduled to undergo elective otorhinolaryngological surgery, with a BMI between 18.5 and 24.9 kg m and an American Society of Anesthesiologists physical status classification of I or II. INTERVENTION(S): Before induction of anaesthesia 60 patients were pretreated with an intravenous infusion of either 100 ml 0.9% saline (saline group), or 60 mg kg magnesium sulphate (magnesium group). After loss of consciousness, a bolus of rocuronium (0.6 mg kg) was administered. Neuromuscular function was measured by TOF-Watch SX monitor. MAIN OUTCOME MEASURES: The primary and secondary outcomes were the duration of the period of no response to nerve stimulation and intense and deep NMB, respectively. An additional outcome was the NMB onset time. RESULTS: Median [IQR] durations of deep NMB were 20.3 [12.0 to 35.4] and 18.3 [11.2 to 26.3] min in the magnesium and saline groups, respectively (P = 0.18). Median durations of intense NMB were 21.7 [0.0 to 32.2] min and 0.0 [0.0 to 6.2] min (P = 0.001) in the magnesium and saline groups, respectively. Median durations of the period of no response were 40.8 [51.4 to 36.0] min and 28.0 [21.9 to 31.6] min (P = 0.0001) in the magnesium and saline groups, respectively. CONCLUSION: Magnesium sulphate increased both the duration of intense NMB and the period of no response. The duration of deep NMB was similar in the magnesium sulphate group and saline group. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT02989272.

Preclinical Pharmacology in the Rhesus Monkey of CW 1759-50, a New Ultra-short Acting Nondepolarizing Neuromuscular Blocking Agent, Degraded and Antagonized by L-Cysteine.

WHAT WE ALREADY KNOW ABOUT THIS TOPIC: WHAT THIS ARTICLE TELLS US THAT IS NEW: BACKGROUND:: Structure-activity studies were performed to identify a new neuromuscular blocking agent retaining the ultra-short acting characteristics of gantacurium, including degradation and reversal by L-cysteine, but lacking its histaminoid properties in man. CW 1759-50 has emerged from this program. METHODS: Adduction of CW 1759-50 with L-cysteine was studied by high-performance liquid chromatography and mass spectrometry. Institutional Animal Care and Use Committee-approved comparisons of CW 1759-50 to gantacurium were performed in rhesus monkeys. ED95 for neuromuscular blockade was established. Spontaneous recovery was compared to reversal by L-cysteine in paired studies of boluses or infusions. In addition, changes in mean arterial pressure and heart rate after very large doses of 15 to 60 × ED95 were compared. RESULTS: The half-time of adduction of L-cysteine to CW 1759-50 in vitro was 2.3 min. The ED95 of CW 1759-50 was 0.069 ± 0.02 mg/kg; ED95 of gantacurium was 0.081 ± 0.05 mg/kg (P = 0.006). Duration of action (recovery to 95% twitch height after 98 to 99% blockade) was as follows: CW 1759-50, 8.2 ± 1.5 min; and gantacurium, 7.4 ± 1.9 min; (n = 8 and 9, P = 0.355). Administration of L-cysteine (30 mg/kg) shortened recovery (i.e., induced reversal) from CW 1759-50 after boluses or infusions (P always less than 0.0001). Recovery intervals (5 to 95% twitch) ranged from 6.1 to 6.7 min (and did not differ significantly) after boluses of 0.10 to 0.50 mg/kg, as well as control infusions (P = 0.426 by analysis of variance). Dose ratios comparing changes of 30% in mean arterial pressure or heart rate to ED95 for neuromuscular blockade (ED 30% Δ [mean arterial pressure or heart rate]/ED95) were higher for CW 1759-50 than for gantacurium. CONCLUSIONS: CW 1759-50, similar to gantacurium, is an ultra-short acting neuromuscular blocking agent, antagonized by L-cysteine, in the monkey. The circulatory effects, however, are much reduced in comparison with gantacurium, suggesting a trial in humans.

Train-of-four guard-controlled sugammadex reversal in patients with multiple sclerosis.

OBJECTIVE: Multiple sclerosis (MS) is a chronic inflammatory and demyelinating autoimmune disease of the central nervous system. It is known that the disease, which is manifested by a wide variety of symptoms, may exacerbate after anesthesia and show different responses to muscle relaxants in the normal population. It is planned to measure train-of-four (TOF) values of MS patients to be operated under general anesthesia before sugammadex application. MATERIALS AND METHODS: With the approval of the local ethics committee of the University of Health Sciences Bagcilar Training and Research Hospital and with written consents of participants, we anesthetized ten patients (from April 2014 to March 2017) with MS and ten American Society of Anesthesiologists I-III patients without MS. Neuromuscular conduction was assessed by the acceleromyometric method using a TOF-Guard apparatus (Organon, Holland). The patients were extubated after recovery of TOF higher than 0.9. The primary efficacy variable was the time from the start of administration of sugammadex to recovery of the TOF ratio to 0.9. RESULTS: The demographic characteristics of both groups, the type and duration of surgery and anesthesia applied, and the temperature of the operation room were similar. Similar characteristics of both groups were of concern for postoperative residual paralysis, and therefore we did not notice any difference between time to TOF> 90/s for both groups. CONCLUSION: Sugammadex and TOF patients will increase patient safety in general anesthesia practice.

Extreme variability in succinylcholine dose for muscle relaxation in electroconvulsive therapy.

OBJECTIVES: To determine what dose of succinylcholine falls outside the range of 2 SD above or below the mean optimal dose of 0.9 mg/kg used for electroconvulsive therapy (ECT). METHODS: In this retrospective chart review, for all patients who received ECT at our institution within the 5-year study period, the initial dose of succinylcholine in milligrams per kilogram was compared with subsequent doses after adjustments were made for individual patient responses. Mean and SD were calculated using the dose of succinylcholine, once the optimal dose for each patient had been determined, based on clinical response. RESULTS: Five hundred patients treated during the 5-year period met inclusion criteria, 180 (36%) of whom required an adjustment of the succinylcholine dosing either above (119 patients) or below (61 patients) the 0.9 mg/kg standard after their first treatment. CONCLUSIONS: In those patients who required an adjustment of 2 SD either above or below the mean dose of succinylcholine (29 patients, 5.8%), adequate neuromuscular blockade was only achieved with either an increased dose of up to 2.10 mg/kg or a decreased dose as low as 0.29 mg/kg.

Updated review of resistance to neuromuscular blocking agents

Since neuromuscular blocking agents (NMBAs) were introduced to the surgical field, they have become almost mandatory for the induction and maintenance of anesthesia. However, resistance to NMBAs can develop in certain pathological states, such as central nerve injury, burns, and critical illnesses. During such pathological processes, quantitative and qualitative changes occur in the physiology of acetylcholine and the acetylcholine receptor (AChR) at the neuromuscular junction. Up-regulation of AChR leads to changes in the pharmacokinetics and pharmacodynamics of NMBA. As NMBA resistance may result in problems during anesthesia, it is of utmost importance to understand the mechanisms of NMBA resistance and their associations with pathological status to maintain adequate neuromuscular relaxation. This review presents the current knowledge of pharmacokinetic and pharmacodynamic changes and pathological status associated with NMBA resistance.

Rocuronium is more hepatotoxic than succinylcholine in vitro.

BACKGROUND: The development of liver failure is a major problem in critically ill patients. The hepatotoxicity of many drugs, as one important reason for liver failure, is poorly screened for in human models. Rocuronium and succinylcholine are neuromuscular blocking agents used for tracheal intubation and for rapid-sequence induction. OBJECTIVE: We used an in-vitro test with a permanent cell line and compared rocuronium and succinylcholine for hepatotoxicity. DESIGN: In-vitro study. SETTING: A basic science laboratory, University Hospital Rostock, Germany. MATERIAL/(PATIENTS): The basic test compound is the permanent human liver cell line HepG2/C3A. In a standardised microtitre plate assay the toxicity of different concentrations of rocuronium, succinylcholine and plasma control was tested. INTERVENTIONS: After two incubation periods of 3 days, the viability of cells (XTT test, lactate dehydrogenase release and trypan blue staining), micro-albumin synthesis and the cytochrome 1A2 activity (metabolism of ethoxyresorufin) were measured. MAIN OUTCOME MEASURES: Differences between rocuronium and succinylcholine were assessed using the Kruskal-Wallis one-way test and two-tailed Mann-Whitney U test. RESULTS: Rocuronium, but not succinylcholine, led to a significant dose-dependent decrease of viability, albumin synthesis and cytochrome 1A2 activity of test cells. CONCLUSION: An in-vitro test with a cell line showed hepatotoxicity of rocuronium that was dose-dependent. Further studies are needed to investigate the underlying mechanisms of the effects of rocuronium on hepatic cellular integrity. TRIAL REGISTRATION: Not suitable.

Psoas compartment and sacral plexus block via electrostimulation for pelvic limb amputation in dogs.

OBJECTIVE: To assess the efficacy of psoas compartment and sacral plexus block for pelvic limb amputation in dogs. STUDY DESIGN: Prospective clinical study. ANIMALS: A total of 16 dogs aged 8±3 years and weighing 35±14 kg (mean±standard deviation). METHODS: Dogs were administered morphine (0.5 mg kg-1) and atropine (0.02 mg kg-1); anesthesia was induced with propofol and maintained with isoflurane. Regional blocks were performed before surgery in eight dogs with bupivacaine (2.2 mg kg-1) and eight dogs were administered an equivalent volume of saline. The lumbar plexus within the psoas compartment was identified using electrolocation lateral to the lumbar vertebrae at the fourth-fifth, fifth-sixth and sixth-seventh vertebral interspaces. The sacral plexus, ventrolateral to the sacrum, was identified using electrolocation. Anesthesia was monitored using heart rate (HR), invasive blood pressure, electrocardiography, expired gases, respiratory frequency and esophageal temperature by an investigator unaware of the group allocation. Pelvic limb amputation by coxofemoral disarticulation was performed. Dogs that responded to surgical stimulation (>10% increase in HR or arterial pressure) were administered fentanyl (2 µg kg-1) intravenously for rescue analgesia. Postoperative pain was assessed at extubation; 30, 60 and 120 minutes; and the morning after surgery using a visual analog scale (VAS). RESULTS: The number of intraoperative fentanyl doses was fewer in the bupivacaine group (2.7±1.1 versus 6.0±2.2; p<0.01). Differences in physiologic variables were not clinically significant. VAS scores were lower in bupivacaine dogs at extubation (0.8±1.9 versus 3.8±2.5) and at 30 minutes (1.0±1.4 versus 4.3±2.1; p<0.05). CONCLUSIONS AND CLINICAL RELEVANCE: Psoas compartment (lumbar plexus) and sacral plexus block provided analgesia during pelvic limb amputation in dogs.

Reversal of Vecuronium-induced Neuromuscular Blockade with Low-dose Sugammadex at Train-of-four Count of Four: A Randomized Controlled Trial.

BACKGROUND: Rocuronium-induced neuromuscular block that spontaneously recovered to a train-of-four count of four can be reversed with sugammadex 0.5 or 1.0 mg/kg. We investigated whether these doses of sugammadex can also reverse vecuronium at a similar level of block. METHODS: Sixty-five patients were randomly assigned, and 64 were analyzed in this controlled, superiority study. Participants received general anesthesia with propofol, sevoflurane, fentanyl, and vecuronium. Measurement of neuromuscular function was performed with acceleromyography (TOF-Watch-SX, Organon Teknika B.V., The Netherlands ). Once the block recovered spontaneously to four twitches in response to train-of-four stimulation, patients were randomly assigned to receive sugammadex 0.5, 1.0, or 2.0 mg/kg; neostigmine 0.05 mg/kg; or placebo. Time from study drug injection to normalized train-of-four ratio 0.9 and the incidence of incomplete reversal within 30 min were the primary outcome variables. Secondary outcome was the incidence of reparalysis (normalized train-of-four ratio less than 0.9). RESULTS: Sugammadex, in doses of 1.0 and 2.0 mg/kg, reversed a threshold train-of-four count of four to normalized train-of-four ratio of 0.9 or higher in all patients in 4.4 ± 2.3 min (mean ± SD) and 2.6 ± 1.6 min, respectively. Sugammadex 0.5 mg/kg reversed the block in 6.8 ± 4.1 min in 70% of patients (P < 0.0001 vs. 1.0 and 2.0 mg/kg), whereas neostigmine produced reversal in 11.3 ± 9.7 min in 77% of patients (P > 0.05 vs. sugammadex 0.5 mg/kg). The overall frequency of reparalysis was 18.7%, but this incidence varied from group to group. CONCLUSIONS: Sugammadex 1.0 mg/kg, unlike 0.5 mg/kg, properly reversed a threshold train-of-four count of four vecuronium-induced block but did not prevent reparalysis.

Chemotherapy alters cisatracurium induced neuromuscular blockade characteristics: A prospective cohort study.

STUDY OBJECTIVE: To compare the characteristics of NMDR induced muscle paralysis in breast cancer patients with and without a history of recent chemotherapy with cyclophosphamide, doxorubicin and 5-fluorouracil (CAF) regimen. DESIGN: This is a non-randomized prospective cohort study. SETTING: Operating room of a university-affiliated teaching hospital. PATIENTS: Out of a total of 50 patients who had undergone mastectomy, 22 patients were allocated to the "Chemo group" and 28 patients to the "Non-Chemo group", based on a valid history of recent chemotherapy. INTERVENTION: After induction of anesthesia with thiopental and cisatracurium, neuromuscular monitoring was started for all patients. MEASUREMENTS: Initially the time to 100% single-twitch (ST) suppression was measured. Then, the time for the appearance of the first response to post-tetanic count (PTC) stimulation, Train-of-Four (TOF) stimulation, and TOF50% were measured consequently. MAIN RESULTS: Time to get STzero was significantly longer in the Chemo group than in the Non-chemo group. Time for the appearance of the first response of PTC and TOF and TOF50% was significantly shorter in the Chemo group than the other group. The mean duration of intense block was 27.66 minutes in the Chemo group versus 42.47 minutes in the Non-chemo group. CONCLUSION: This research demonstrated that in patients having undergone chemotherapy, the effect of NDMRs starts with a longer lag time and finishes earlier too. Thus, these patients are ready for intubation after a longer time. Moreover, we have to repeat cisatracurium injections after shorter intervals to maintain the desired level of blockade.

Failed Vocalis Muscle Monitoring During Thyroid Surgery Resulting From Residual Muscle Relaxation.

Postoperative paralysis of the vocal cords resulting from intraoperative surgical injury of the recurrent laryngeal nerve is one of the most serious complications of elective thyroid surgery. The chance of injury is reduced by using intraoperative neuromonitoring (IONM). This educational report describes a case of IONM failure resulting from residual muscle relaxation that was restored by administration of sugammadex. It discusses possible pharmacology explanations and provides recommendations for how to prevent this situation in daily practice.

Incidence of postoperative residual paralysis in a nigerian teaching hospital.

BACKGROUND: Postoperative residual paralysis (PORP) is a known risk factor after general anesthesia (GA) for critical respiratory events and increased postoperative morbidity. PORP is defined as a train-of-four ratio (TOFR) of <0.9 using acceleromyography (AMG). TOFR <0.9 has been associated with increased risk of aspiration, obstruction of the upper airway and an impaired hypoxic ventilatory response. AIM: The aim of this study was to determine the incidence of PORP, associated factors related with its occurrence and critical respiratory events in the postanesthesia recovery room (PAR) at our institution. METHODOLOGY: Forty-one adult patients were scheduled for elective surgeries requiring GA with the use of at least 1 dose of a nondepolarizing neuromuscular blocking drug (NMBD). An independent anesthetist quantitatively measured TOFR of recruited patients postoperatively in the recovery room using the TOF-watch SX acceleromyograph (Organon Teknika) 5 min after arrival. RESULTS: The incidence of PORP was 75.6% (n = 31), with severe PORP (TOFR <0.7) seen in 41.5% (n = 17) of patients. Median time to full recovery in the PAR was 33 min (range 5-164 min). There was no statistical difference in the incidence of PORP related to the choice of NMBD (P = 0.186) or duration of surgery (P = 0.175). No respiratory complications or events were observed in patients with residual blockade. CONCLUSION: The incidence of PORP is quite high and undetected in our environment. Quantitative monitoring for residual paralysis is advocated as part of routine monitoring with the use of NMBDs for improved patient safety.