Sugammadex shortens operation time and improves operation turnover efficacy in video-assisted thoracoscopic surgery

BACKGROUND

This study compared sugammadex and neostigmine as agents for routine neuromuscular blockade reversal in video-assisted thoracoscopic surgery (VATS) to determine the optimal choice that achieves a shorter operation time and improved turnover efficiency while enhancing postoperative outcomes and ensuring patient safety during thoracic surgery.

METHODS

This prospective study, conducted from July 2022 to March 2023, compared the effect of sugammadex and neostigmine on operation time and turnover efficiency in VATS, involving 60 participants randomly assigned to either group, with the primary objective of identifying the optimal anesthesia reversal choice for improved outcomes and patient safety during thoracic surgery.

RESULTS

In the study, the sugammadex group showed a significantly shorter total operation room occupancy time (130 ± 7 vs 157 ± 7 minutes; p = 0.009) than the neostigmine group. Patients in the neostigmine group had higher mean pulse rates when leaving the operation room (85 ± 3 vs 73 ± 3 beats/min; p = 0.002) and 120 minutes later in the postanesthesia care unit (76 ± 2 vs 68 ± 2; p = 0.016).

CONCLUSION

This study's findings suggest that sugammadex may enhance total operating room occupancy time, operation turnover efficacy, and respiratory recovery outcomes in VATS, potentially improving patient care and anesthesia management.

Development and Validation of Stability Indicating RP-HPLC Method for the Estimation of Glycopyrrolate and Neostigmine in Bulk and Injection

A stability indicating RP-HPLC method is suggested for determination of Glycopyrrolate-Neostigmine (GLY/NEO) in bulk drugs and injection formulation. GLY/NEO were eluted from a Chromolith High Resolution RP-18e (100 mm×4.6 mm) with buffer solution (pH 3.0) as mobile phase A and a mixture of HPLC grade acetonitrile and water mixture (90:10) as mobile phase B. The gradient was optimized with a flowrate of 0.5 mL/min and wavelength of 222 nm. A complete analytical method validation was effectively carried out as per ICH Q2 (R1) guidelines. Recovery studies were performed at 50-150% level of working concentrations, and results were in the range of 99-101%. The linearity was detected in the range of LOQ to 200% of the specification limits i.e., 0.5% each for NEO and GLY, 0.01% for NEO Impurity B and 1.0% for rest of the impurities with respect to the test concentration of the respective components. For stability study, various stress conditions such as acid, base, oxidation and thermal as per ICH guidelines were studied. The high recovery and low relative standard deviation confirm the suitability of proposed method that can be employed for the routine analysis in bulk and pharmaceutical formulation.

Myositis in H1N1 Infection Compounds to Myasthenic Crisis

ABSTRACT

Infection is an important trigger of myasthenic crisis (MC), and those infections manifest with pneumonia and muscle involvement may result in more frequent MC. We report two myasthenia gravis (MG) patients with H1N1 infection, and highlight the reasons for deterioration. Two patients with MG had H1N1 infection. The diagnosis of MG was confirmed by neostigmine, repetitive nerve stimulation, and anti-acetylcholine receptor antibody tests. H1N1 was confirmed by nucleic acid detection study, and myositis by creatinine kinase. The patient with pneumonia and myositis had MC needing mechanical ventilation for 10 days, and the other patient without myositis did not have MC. They were treated with oseltamivir 75 mg twice daily for 5 days, and the patients with MC received ceftriaxone intravenously. Both the patients were on prednisolone and azathioprine, and none received prior H1N1 vaccination. The lady with MC with myositis was discharged on day 27 in wheelchair bound state, and the other one patient without myositis or MC was discharged on 6th day with full recovery. These patients highlight the need for evaluation for myositis along with pneumonia in the MG patients with H1N1 infection. Vaccination in MG patients on immunosuppression may be useful.

Development of Different Separation Techniques for Impurity Profiling of Neostigmine Methylsulfate: A Comparative Study

Different separation techniques have been employed to resolve mixtures of multicomponent preparations over the last few decades. They could be efficiently applied for impurity profiling of active drug substances. Impurity profiling has become a critical procedure in pharmaceutical companies to comply with numerous regulatory standards. Isolation and characterization of impurities are crucial for obtaining data that proves biological safety and efficacy. In this contribution, different HPLC, capillary electrophoresis (CE) and TLC-densitometric methods were developed for the determination of neostigmine methylsulfate (NEO) along with 3-hydroxyphenyltrimethyl ammonium methylsulfate (3-HPA) and 3-dimethylaminophenol (DAP) as its impurities in the presence of citric acid. The linearity for NEO was attained in the range of 5-120 μg/mL and 10-60 μg/mL for the HPLC and CE methods, respectively. Regarding the impurities, linearity was obtained over the range of 10-30 μg/mL for 3-HPA and 5-30 μg/mL for DAP in the two proposed methods. For the TLC method, NEO and DAP were determined within the range of 1-11 μg/band, whereas 3-HPA was assayed over the range of 2-12 μg/band. The suggested methods can be securely utilized for routine analysis of the cited components in quality control laboratories.

Case Report: Extraocular muscles paralysis associated with GAD65 antibody: a case series study

Objective

To explore the clinical manifestations of glutamic acid decarboxylase 65 (GAD65) antibody-positive patients with extraocular symptoms and the possible mechanism.

Method

Assays for the presence of GAD65 antibodies were performed on patients' serum and cerebral spinal fluid (CSF). The brain and ocular structures involved in eye movement were assessed via magnetic resonance imaging (MRI). Tests such as electromyography (EMG), particularly repetitive nerve stimulation (RNS), and neostigmine tests were utilized for differential diagnosis. Additionally, the interaction of GAD65 antibodies with muscle tissue was confirmed using immunofluorescence techniques.

Result

Each patient exhibited symptoms akin to extraocular myasthenia gravis (MG), with two individuals reporting diplopia and two experiencing ptosis. GAD65 antibodies were detected in either the serum or CSF, which were shown to bind with monkey cerebellum slides and mouse muscle slides. Neuroimaging of the brain and extraocular muscles via MRI showed no abnormalities, and all patients tested negative for the neostigmine test, RNS via EMG, and the presence of MG antibodies. However, thyroid-related antibodies were found to be abnormal in four of the patients.

Conclusion

Our results showed that GAD65 antibodies are not only associated with encephalitis, cerebellum ataxia or stiff-person syndrome caused by the decrease of GABAergic transmission but also diplopia and ptosis. Therefore, we should pay more attention to extraocular muscle paralysis patients without pathogenic antibodies directed against the components of neuromuscular junctions.

The lesion site of organophosphorus-induced central apnea and the effects of antidotes

Organophosphorus poisoning kills individuals by causing central apnea; however, the underlying cause of death remains unclear. Following findings that the pre-Bötzinger complex impairment alone does not account for central apnea, we analyzed the effect of paraoxon on the brainstem-spinal cord preparation, spanning the lower medulla oblongata to phrenic nucleus. Respiratory bursts were recorded by connecting electrodes to the ventral 4th cervical nerve root of excised brainstem-spinal cord preparations obtained from 6-day-old Sprague-Dawley rats. We observed changes in respiratory bursts when paraoxon, neostigmine, atropine, and 2-pyridine aldoxime methiodide were administered via bath application. The percentage of burst extinction in the paraoxon-poisoning group was 50% compared with 0% and 18.2% in the atropine and 2-pyridine aldoxime methiodide treatment groups, respectively. Both treatments notably mitigated the paraoxon-induced reduction in respiratory bursts. In the neostigmine group, similar to paraoxon, bursts stopped in 66.7% of cases but were fully reversed by atropine. This indicates that the primary cause of central apnea is muscarinic receptor-mediated in response to acetylcholine excess. Paraoxon-induced central apnea is hypothesized to result from neural abnormalities within the inferior medulla oblongata to the phrenic nucleus, excluding pre-Bötzinger complex. These antidotes antagonize central apnea, suggesting that they may be beneficial therapeutic agents.

Shock waves as treatment of mouse myofascial trigger points

INTRODUCTION

An abnormal increase in spontaneous neurotransmission can induce subsynaptic knots in the myocyte called myofascial trigger points. The treatment of choice is to destroy these trigger points by inserting needles. However, 10% of the population has a phobia of needles, blood, or injuries. Therefore, the objective of this study is to verify the usefulness of shock waves in the treatment of myofascial trigger points.

METHODS

Two groups of mice have been developed for this: healthy muscles treated with shock waves; trigger points affected muscles artificially generated with neostigmine and subsequently treated with shock waves. Muscles were stained with methylene blue, PAS-Alcian Blue, and labeling the axons with fluorescein and the acetylcholine receptors with rhodamine. Using intracellular recording the frequency of miniature endplate potentials (mEPPs) was recorded and endplate noise was recorded with electromyography.

RESULTS

No healthy muscles treated with shock waves showed injury. Twitch knots in mice previously treated with neostigmine disappeared after shock wave treatment. Several motor axonal branches were retracted. On the other hand, shock wave treatment reduces the frequency of mEPPs and the number of areas with endplate noise.

DISCUSSION

Shock waves seem to be a suitable treatment for myofascial trigger points. In the present study, with a single session of shock waves, very relevant results have been obtained, both functional (normalization of spontaneous neurotransmission) and morphological (disappearance of myofascial trigger points). Patients with a phobia of needles, blood, or injuries who cannot benefit from dry needling may turn to noninvasive radial shock wave treatment.

An educational intervention to reduce the incidence of postoperative residual curarisation: a cluster randomised crossover trial in patients undergoing general anaesthesia

BACKGROUND

The incidence of postoperative residual curarisation remains unacceptably high. We assessed whether an educational intervention on perioperative neuromuscular block management can reduce it.

METHODS

In this multicentre, cluster randomised crossover trial, centres were allocated to receive an educational intervention either in a first or a second period. The educational intervention consisted of a lecture about neuromuscular management key points, including quantitative neuromuscular monitoring and use of reversal agents. The lecture was streamed to allow repetition. Additionally, memory cards were distributed in each operating theatre. The primary outcome was postoperative residual curarisation in the PACU. Secondary outcomes were frequency of quantitative neuromuscular monitoring, use of reversal agents, and incidence of postoperative pulmonary complications during hospital stay. Measurements were performed before randomisation and after the first and the second period. The effect of the educational intervention was estimated using multivariable mixed effects logistic regression models.

RESULTS

We included 2314 subjects in 34 Spanish centres. Postoperative residual curarisation incidence was not affected by the educational intervention (odds ratio [OR] 0.90 [95% confidence interval {CI}: 0.51-1.58]; P=0.717 and 1.30 [0.73-2.30]; P=0.371] for first and second time-period interaction). The educational intervention increased the quantitative neuromuscular monitor usage (OR 2.04 [95% CI: 1.31-3.19]; P=0.002), the use of reversal agents was unchanged (OR 0.79 [95% CI: 0.50-1.26]; P=0.322), and the incidence of postoperative pulmonary complications decreased (OR 0.19 [95% CI: 0.10-0.35]; P<0.001).

CONCLUSIONS

An educational intervention on perioperative neuromuscular block management did not reduce the incidence of postoperative residual curarisation nor increase reversal, despite increased quantitative neuromuscular monitoring. Sugammadex reversal was associated with reduced postoperative residual curarisation. The educational intervention was associated with a decrease in postoperative pulmonary complications.

CLINICAL TRIAL REGISTRATION

NCT03128151.

Duration of neuromuscular block is more variable and recovery time is shorter with rocuronium than cisatracurium in anesthetized dogs

OBJECTIVE

To compare the variability in the duration of action of a single dose of rocuronium or cisatracurium, and duration of subsequent top-up doses in anesthetized dogs.

ANIMALS

Thirty dogs requiring ophthalmic surgery with neuromuscular block.

PROCEDURES

Neuromuscular function was monitored with train-of-four (TOF) and acceleromyography. Dogs received an initial dose of rocuronium 0.6 mg/kg, or cisatracurium 0.15 mg/kg IV, which produced complete neuromuscular block. Upon return of the first response (T1) of TOF, a third of the initial dose was repeated. The duration of the initial dose and its variability were compared between agents. Duration of subsequent top-up doses was assessed with mixed effect models. Spontaneous (from last return of T1) or neostigmine-enhanced (from administration to complete recovery) recovery times were measured for each agent.

RESULTS

Duration of action of the initial dose was [median (range)] 25 (10-60) min with rocuronium and 35 (15-45) min with cisatracurium (p = .231). The variability of rocuronium was 3.25 times larger than cisatracurium (p = .034). Duration of top-up doses did not vary for either agent. Spontaneous recovery was shorter for rocuronium [15 (10-20) min] than cisatracurium [25 (15-45) min] (p = .02). Neostigmine-enhanced recovery times were 5 (5-25) for rocuronium and 10 (5-10) for cisatracurium (p = .491).

CONCLUSIONS

Duration of action for a single dose is significantly more variable with rocuronium than cisatracurium. Time to spontaneous recovery was longer for cisatracurium, and cases of unexpectedly long recovery times were observed with both agents. Objective monitoring is recommended.

Reversal of neuromuscular block: what are the costs?

Patients requiring neuromuscular block for anaesthesia have a higher risk of adverse postoperative outcomes. The choice of reversal drug and its corresponding dose is critical for improving clinical outcomes. Although drug costs are higher for sugammadex relative to neostigmine, additional factors need to be considered when choosing one drug over the other. New data from a recent study in the British Journal of Anaesthesia indicate cost advantages for sugammadex in low-risk and ambulatory patients, but for neostigmine in high-risk patients. These findings highlight the need to take local and temporal factors into consideration in addition to clinical effectiveness when performing cost analyses for administrative decision-making.

Peri-operative management of neuromuscular blockade: A guideline from the European Society of Anaesthesiology and Intensive Care

Recent data indicated a high incidence of inappropriate management of neuromuscular block, with a high rate of residual paralysis and relaxant-associated postoperative complications. These data are alarming in that the available neuromuscular monitoring, as well as myorelaxants and their antagonists basically allow well tolerated management of neuromuscular blockade. In this first European Society of Anaesthesiology and Intensive Care (ESAIC) guideline on peri-operative management of neuromuscular block, we aim to present aggregated and evidence-based recommendations to assist clinicians provide best medical care and ensure patient safety. We identified three main clinical questions: Are myorelaxants necessary to facilitate tracheal intubation in adults? Does the intensity of neuromuscular blockade influence a patient's outcome in abdominal surgery? What are the strategies for the diagnosis and treatment of residual paralysis? On the basis of this, PICO (patient, intervention, comparator, outcome) questions were derived that guided a structured literature search. A stepwise approach was used to reduce the number of trials of the initial research ( n  = 24 000) to the finally relevant clinical studies ( n  = 88). GRADE methodology (Grading of Recommendations, Assessment, Development and Evaluation) was used for formulating the recommendations based on the findings of the included studies in conjunction with their methodological quality. A two-step Delphi process was used to determine the agreement of the panel members with the recommendations: R1 We recommend using a muscle relaxant to facilitate tracheal intubation (1A). R2 We recommend the use of muscle relaxants to reduce pharyngeal and/or laryngeal injury following endotracheal intubation (1C). R3 We recommend the use of a fast-acting muscle relaxant for rapid sequence induction intubation (RSII) such as succinylcholine 1 mg kg -1 or rocuronium 0.9 to 1.2 mg kg -1 (1B). R4 We recommend deepening neuromuscular blockade if surgical conditions need to be improved (1B). R5 There is insufficient evidence to recommend deep neuromuscular blockade in general to reduce postoperative pain or decrease the incidence of peri-operative complications. (2C). R6 We recommend the use of ulnar nerve stimulation and quantitative neuromuscular monitoring at the adductor pollicis muscle to exclude residual paralysis (1B). R7 We recommend using sugammadex to antagonise deep, moderate and shallow neuromuscular blockade induced by aminosteroidal agents (rocuronium, vecuronium) (1A). R8 We recommend advanced spontaneous recovery (i.e. TOF ratio >0.2) before starting neostigmine-based reversal and to continue quantitative monitoring of neuromuscular blockade until a TOF ratio of more than 0.9 has been attained. (1C).

An appraisal of neostigmine versus sugammadex for neuromuscular blockade reversal in patients with a prior heart transplant

INTRODUCTION

Heart transplant recipients present unique perioperative challenges for surgery. Specifically, autonomic system denervation has significant implications for commonly used perioperative drugs. This study investigates neuromuscular blocking antagonists in this population when undergoing subsequent non-cardiac surgery.

MATERIAL AND METHODS

A retrospective review was performed for the period 2015-2019 across our health care enterprise. Patients with previous orthotopic heart transplant and subsequent non-cardiac surgery were identified. A total of 185 patients were found, 67 receiving neostigmine (NEO) and 118 receiving sugammadex (SGX). Information of patient characteristics, prior heart transplant, and subsequent non-cardiac surgery was collected. Our primary outcome was the incidence of bradycardia (heart rate < 60 bpm) and/or hypotension (mean blood pressure (MAP) < 65 mmHg) following neuromuscular blockade reversal. Secondary outcomes included need of intra-operative inotropic agents, arrhythmia, cardiac arrest, hospital length of stay (hLOS), ICU admission, and death within 30 postoperative days.

RESULTS

In unadjusted analysis, no significant differences were found between the two groups in change in heart rate [0 (-26, 14) vs. 1 (-19, 10), P = 0.59], change in MAP [0 (-22, 28) vs. 0 (-40, 47), P = 0.96], hLOS [2 days (1, 72) vs. 2 (0, 161), P = 0.92], or intraoperative hypotension [4 (6.0%) vs. 5 (4.2%), OR = 0.70, P = 0.60] for NEO and SGX respectively. After multivariable analysis, the results were similar for change in heart rate ( P = 0.59) and MAP ( P = 0.90).

CONCLUSIONS

No significant differences in the incidence of bradycardia and hypotension were found in the NEO versus SGX groups. NEO and SGX may have similar safety profiles in patients with prior heart transplant undergoing non-cardiac surgery.

Postoperative hypotonia in a patient with stiff person syndrome: a case report and literature review

PURPOSE

Stiff person syndrome (SPS), an autoimmune disease that manifests with episodic muscle rigidity and spasms, has anesthetic considerations because postoperative hypotonia may occur. This hypotonia has been linked to muscle relaxants and volatile anesthetics and may persist in spite of neostigmine administration and train-of-four (TOF) monitoring suggesting full reversal. We present a patient with SPS who experienced hypotonia following total intravenous anesthesia (TIVA), which was promptly reversed with sugammadex. These observations are considered in light of the relevant medical literature.

CLINICAL FEATURES

A 46-yr-old female patient with SPS underwent breast lumpectomy and sentinel node biopsy. Anesthesia consisted of TIVA (propofol/remifentanil) with adjunctive administration of rocuronium 20 mg to obtain adequate intubating conditions. Despite return of the TOF ratio to 100% within 30 min, hypotonia was clinically evident at conclusion of surgery two hours later. Sugammadex 250 mg reversed residual muscle relaxation permitting uneventful extubation. A literature review identified six instances of postoperative hypotonia (TIVA, n = 3; volatile anesthetics, n = 3) in spite of neostigmine administration (n = 2) and TOF monitoring suggesting full reversal (n = 4).

CONCLUSIONS

Patients with SPS may show hypotonia regardless of general anesthetic technique (TIVA vs inhalational anesthesia), which can persist despite recovery of the TOF ratio and may be more effectively reversed by a chelating agent than with an anticholinesterase. If general anesthesia is required, we suggest a cautious approach to administering muscle relaxants including using the smallest dose necessary, considering the importance of clinical assessment of muscle strength recovery in addition to TOF monitoring, and discussing postoperative ventilation risk with the patient prior to surgery.

Sugammadex for reversing neuromuscular blockages after lung surgery: A systematic review and meta-analysis

BACKGROUND

This study determined whether sugammadex was associated with a lower risk of postoperative pulmonary complications and improved outcomes in lung surgeries.

METHODS

A systematic literature search was conducted using PubMed, Embase, Web of Science, and the Cochrane Library from January 2000 to March 2022. The characteristics of lung surgeries using sugammadex treatment compared with control drugs and postoperative outcomes were retrieved. The primary outcome was estimated through a pooled odds ratio (OR) and its 95% confidence interval (CI) was identified using a random-effects model.

RESULTS

From 465 citations, 7 studies with 453 patients receiving sugammadex and 452 patients receiving a control were included. The risk of postoperative pulmonary complication (PPCs) was lower in the sugammadex group than in the control group. Also, it showed that the effect of sugammadex on PPCs in the subgroup analysis was significantly assessed on the basis of atelectasis or non-atelectasis. Furthermore, subgroup analysis based on the relationship between high body mass index (BMI) and PPCs also showed that sugammadex had less occurrence in both the high BMI (defined as BMI ≥ 25) and low BMI groups. No difference in length of hospital stay (LOS) between the two groups was observed.

CONCLUSION

This study observed that although reversing neuromuscular blockages with sugammadex in patients undergoing thoracic surgery recorded fewer PPCs and shorter extubation periods than conventional reversal agents, no difference in LOS, postanaesthesia care unit (PACU) stay length and chest tube insertion duration in both groups was observed.

Urinary Retention Following Inguinal Herniorrhaphy: Role of Neuromuscular Blockade Reversal

BACKGROUND

Nondepolarizing neuromuscular blockade is reversed with neostigmine/glycopyrrolate or sugammadex. Anticholinergic glycopyrrolate decreases bladder detrusor muscle contractility, potentially leading to postoperative urinary retention (POUR). POUR commonly complicates inguinal herniorrhaphy. In this study we assess association between reversal technique and POUR.

METHODS

Records of adult patients undergoing unilateral inguinal herniorrhaphy with neuromuscular blockade from January 2013 to September 2020 were reviewed for POUR (unplanned postoperative insertion of urinary catheter). A propensity-adjusted analysis was performed to assess POUR in neostigmine/glycopyrrolate versus sugammadex using inverse probability of treatment weighting (IPTW) to adjust for potential confounding.

RESULTS

We identified 181 patients who underwent herniorrhaphy with amnio-steroidal neuromuscular blockers, 75 (41.4%) who received sugammadex and 106 (58.6%) neostigmine/glycopyrrolate. Compared with sugammadex, neostigmine/glycopyrrolate group had longer surgical course [unweighted standardized difference (USTD)=0.38, P=0.004], received more intraoperative opioids (USTD=0.704, P<0.001), more often performed via laparoscopic approach (USTD=0.407, P=0.012), and less often with periprocedural urinary catheter insertion (USTD=0.452, P=0.003). POUR was observed in 2 (3%) of patients in the sugammadex group, and 16 (15%) in neostigmine/glycopyrrolate [unadjusted odds ratio (OR)=0.15; 95% confidence interval (CI): 0.03-0.69; P=0.015, and IPTW OR=0.13; 95% CI: 0.03-0.64; P=0.012]. Results remained similar with further analysis adjusted for opioid administration in the postanesthesia care unit (adjusted IPTW OR=0.18; 95% CI: 0.04-0.88; P=0.034). Of the POUR patients, 9 required unplanned overnight admission and 4 emergency room visit.

CONCLUSION

These results suggest that neuromuscular blockade reversal with sugammadex is associated with lower rates of POUR following unilateral inguinal herniorrhaphy. Our results need to be reconfirmed in a randomized prospective study.

A Clinical and Budgetary Impact Analysis of Introducing Sugammadex for Routine Reversal of Neuromuscular Blockade in a Hypothetical Cohort in the US

INTRODUCTION

Sugammadex rapidly reverses the effects of rocuronium- and vecuronium-induced neuromuscular blockade (NMB), offering a more complete and predictable NMB recovery than cholinesterase inhibitors. Despite clinical benefits, cost pressures on hospital budgets influence the choice of the NMB reversal method. This study evaluated clinical and healthcare system payer's budget impacts associated with sugammadex in the US for routine reversal of moderate or deep rocuronium- or vecuronium-induced NMB in adults undergoing surgery.

METHODS

A 1-year decision analytic model was constructed reflecting a set of procedures using rocuronium or vecuronium that resulted in moderate or deep NMB at the end of surgery. Two scenarios were considered for a hypothetical cohort of 100,000 patients: without sugammadex versus with sugammadex. Comparators included neostigmine (+glycopyrrolate) and no neuromuscular blocking agents (NMBAs). Total costs (in 2019 US dollars) to a healthcare system [net of costs of reversal agents and overall cost offsets via reduction in postoperative pulmonary complications (PPC)] were compared.

RESULTS

A total of 9971 surgical procedures utilized rocuronium or vecuronium, resulting in moderate (91.0% of cases) or deep (9.0%) blockade at the end of surgeries. In the with sugammadex scenario, sugammadex replaced neostigmine in 4156 of 9585 procedures versus the without sugammadex scenario that used only neostigmine for NMB reversal. Introducing sugammadex reduced PPC events by 12% (58 cases) among the modeled procedures, leading to a budget impact of -$3,079,703 (-$309 per modeled procedure, or a 10.9% reduction in total costs). The results did not vary qualitatively in one-way sensitivity analyses.

CONCLUSIONS

The additional costs of sugammadex for the reversal of rocuronium- or vecuronium-induced NMB could be offset by improved outcomes (i.e., reduced PPC events), and potentially lead to overall healthcare budgetary savings versus reversal with neostigmine or spontaneous recovery. This study provides insights into savings that can be obtained beyond the anesthesia budget, reducing the broader clinical and budgetary burden on the hospital.

Recovery of early postoperative muscle strength after deep neuromuscular block by means of ultrasonography with comparison of neostigmine versus sugammadex as reversal drugs: study protocol for a randomised controlled trial

INTRODUCTION

Despite the use of quantitative neuromuscular monitoring together with the administration of reversal drugs (neostigmine or sugammadex), the incidence of residual neuromuscular blockade defined as a train-of-four ratio (TOFr) <0.9 remains high. Even TOFr >0.9 cannot ensure adequate recovery of neuromuscular function when T1 height is not recovered completely. Thus, a mathematical correction of TOFr needs to be applied because the return of a normal TOFr can precede the return of a normal T1 twitch height. On the other hand, different muscles have different sensitivities to neuromuscular blockade agents; thus, complete recovery of one specific muscle group does not represent complete recovery of all other muscles. Therefore, our study aims to assess the muscle strength recovery of respiratory-related muscle groups by ultrasound and evaluate global strength using handgrip dynamometry in the early postoperative period when TOFr=0.9 and corrected TOFr (cTOFr)=0.9 with comparison of neostigmine versus sugammadex as reversal drugs.

METHODS AND ANALYSIS

This study will be a prospective, single-blinded, randomised controlled trial involving 60 patients with American Society of Anesthesiologists physical status I-II and aged between 18 and 65 years, who will undergo microlaryngeal surgery. We will assess geniohyoid muscle, parasternal intercostal muscle, diaphragm, abdominal wall muscle and handgrip strength at four time points: before anaesthesia, TOFr=0.9, cTOFr=0.9 and 30 min after admission to the post anaesthesia care unit. Our primary objective will be to compare the effects of neostigmine and sugammadex on the recovery of muscle strength of different muscle groups in the early postoperative period when TOFr=0.9 and cTOFr=0.9. The secondary objective will be to observe the difference of muscle strength between the time points of TOFr=0.9 and cTOFr=0.9 to find out the clinical significance of cTOFr >0.9.

ETHICS AND DISSEMINATION

The protocol was reviewed and approved by the Ethics Committee of The First Affiliated Hospital, Sun Yat-sen University. The findings will be disseminated to the public through peer-reviewed scientific journals.

TRIAL REGISTRATION NUMBER

ChiCTR2000033832.

Residual neuromuscular blockade and late neuromuscular blockade at the post-anesthetic recovery unit: prospective cohort study

Introduction and objectives

The use of neuromuscular blockers during surgery represented a landmark for anesthesiology. However, their use can prompt residual Neuromuscular Blockade (_RNMB) and objective monitoring of neuromuscular function is crucial to warrant the recovery of muscle strength. The present study aimed to estimate the incidence of _RNMB and late Neuromuscular Blockade (_LNMB) at the Post-Anesthetic Recovery Unit (PACU).

Method

The study included 85 patients, 43 of which received cisatracurium and 42 of which, rocuronium. The depth of the Neuromuscular Blockade (NMB) was assessed by Train Of Four (TOF). NMB reversal was performed with the administration of neostigmine and atropine._RNMB was defined when a patient presented TOF below 90% at the PACU.

Results

_RNMB at the PACU was diagnosed in 39.5% and 40.5% of the patients receiving cisatracurium and rocuronium, respectively (p = 1.0). _LNMB at the PACU was found in 32.6% and 16.7% of the patients receiving cisatracurium and rocuronium, respectively (p = 0.131).

Conclusions

The incidence of_RNMB remains significant despite the use of intermediate-acting neuromuscular blockers and reversal agents. There was no statistically significant difference in the incidence of _RNMB or _LNMB in patients receiving cisatracurium or rocuronium. The use of objective NMB monitoring is effective for the diagnosis of _RNMB, as well as for treatment management.

Residual neuromuscular blockade in a real life clinical setting: correlation with sugammadex or neostigmine administration

BACKGROUND

The aim of this study was to identify the frequency of residual neuromuscular blockade (RNMB) in the postanesthesia care unit (PACU) of a tertiary university hospital in Greece, and its correlation with reversal agents. The influence of other perioperative factors was assessed secondarily.

METHODS

Patients >18 years old, undergoing surgery with general anesthesia were prospectively studied during a 6-month period. Immediately after arrival at the PACU, the train-of-four ratio (TOF) was assessed by independent investigators, using accelerometry 3 consecutive times, and the mean value was calculated. When TOF was <0.9, RNMB was diagnosed and further interventions were decided. All perioperative data, including history of patients, anesthetic drugs used and surgical details, were recorded from the patients' files.

RESULTS

Five hundred twenty patients were studied; 90.4% received rocuronium, 9.2% cis-atracurium, and 0.4% succinylcholine. The prevalence of RNMB was 10.8%. A significant difference (P=0.0006) was detected between patients who received neostigmine versus sugammadex, with the latter showing higher TOF values postoperatively, although the actual incidence of RNMB did not differ between the two groups. Patients with coexisting diseases received sugammadex more frequently (P<0.001), while women, and patients ASA>III were more likely to exhibit RNMB (P=0.02 and P=0.05 respectively).

CONCLUSIONS

The frequency of RNMB was 10.8%. Patients who received sugammadex presented with higher TOF values at the PACU, although no difference in RNMB was detected compared to neostigmine. Female gender and the presence of comorbidities increased the possibility to exhibit RNMB at the PACU.

Prognostic significance of cardiovascular biomarkers and renal dysfunction in outpatients with systolic heart failure: a long term follow-up study

OBJECTIVE

To assess whether the prognostic significance of cardiovascular (CV) biomarkers, is affected by renal dysfunction (RD) in systolic heart failure (HF).

BACKGROUND

It is unknown, whether the prognostic significance of CV biomarkers, such as N-terminal-pro-brain-natriuretic-peptide (NT-proBNP), high-sensitive troponin T (hsTNT), pro-atrial natriuretic peptide (proANP), copeptin and pro-adrenomedullin (proADM), is affected by renal function in HF.

METHODS

Clinical data and laboratory tests from 424 patients with systolic HF were collected prospectively. The patients were followed for 4.5 years (interquartile range: 2-7.7 years). CV biomarkers were analyzed on frozen plasma, and renal function was estimated by the Modification of Diet in Renal Disease (MDRD) formula. Cox proportional hazard models for mortality risk were constructed and tests for interaction between each CV biomarker and RD were performed.

RESULTS

Median age was 73 years (51-83), 29% were female, LVEF was 30% (13-45), 74% were NYHA classes I-II and estimated glomerular filtration rate (eGFR) was 68 ml/min/1.73 m(2) (18-157). A total of 252 patients died. All five biomarkers--log(NT-proBNP) (HR: 2.13, 95% CI: 1.57-2.87:, P<0.001), hsTNT (HR: 3.07, 95% CI: 1.90-4.96 P<0.001), proANP (HR: 1.02, 95% CI: 1.01-1.03, P<0.001), copeptin (HR: 1.02, 95% CI: 1.01-1.03, P=0.008) and proADM (HR: 2.37, 95% CI: 1.66-3.38, P<0.001)--were associated with mortality risk, but not affected by RD (P>0.05 for all interactions).

CONCLUSION

Established and new CV biomarkers are closely associated with renal function in HF. However, their prognostic significance is not affected by RD, and all CV biomarkers can be used for risk stratification independently of renal function.

Metabolic syndrome is associated with high grade Gleason score when prostate cancer is diagnosed on biopsy

BACKGROUND

To evaluate the association between metabolic syndrome (MS) and prostate cancer diagnosis and grade in patients undergoing prostate biopsy.

METHODS

From 2009 onwards, a consecutive series of patients undergoing 12-core prostate biopsy for PSA value ≥4 ng/ml and/or positive digital rectal examination (DRE) were prospectively enrolled. Body mass index (BMI), waist circumferences, and blood pressure were measured before the biopsy. Blood samples were tested for: PSA, fasting glucose, triglycerides, and cholesterol HDL. MS presence was defined according to Adult Treatment Panel III criteria.

RESULTS

One hundred ninety five patients were enrolled with a median age and PSA of 69 years and 5.6 ng/ml respectively. Median BMI was 27.6 kg/m(2) with 64 patients (33%) being classified as obese (BMI ≥ 30 kg/m(2) ). Eighty-six patients (44%) had MS. Eighty-three patients (43%) had cancer on biopsy; 37 (45%) with MS and 46 (55%) without (P = 0.48). PSA was independently associated with higher risk of cancer (OR 1.12/1 U PSA, P = 0.01). Out of 83 patients with prostate cancer, 42 (51%) had Gleason score 6 (12 (28.5%) presented a MS) and 41 (49%) a Gleason score ≥7 (25 (61%) presented a MS). The presence of MS was not associated with an increased risk prostate cancer (OR: 0.97, P = 0.94) but with an increased risk of Gleason ≥7 (OR: 3.82; P = 0.013).

CONCLUSIONS

In our single center study, MS is associated with an increased risk of high grade Gleason score when prostate cancer is diagnosed on biopsy. However, these results should be confirmed in a larger multicenter study. .

An Investigation of the Metabolism of Neostigmine in Patients with Myasthenia Gravis

Evidence of two metabolic products of neostigmine has been obtained by paper chromatography of urinary extracts from patients receiving the drug. One product has been identified as m-hydroxyphenyltrimethylammonium bromide and the relevance of this is discussed in relation to the therapeutic effect of oral neostigmine in the treatment of myasthenia gravis. A method is described for extracting neostigmine and related compounds from urine by precipitation with bromine water.

[Ocular myasthenia gravis: diagnosis often delayed]

When a patient complains of a fluctuating ptosis or diplopia the diagnosis 'ocular myasthenia gravis' must be considered. The diagnosis can be difficult because of the subtle symptoms and less sensitive diagnostic testing. Because of this, there is often a patient and doctors delay. We describe 3 patients, a 63-year-old man, a 49-year-old woman and a 77-year-old woman, who received the right diagnosis only after 22 months, 4 months and even 9 years after the first symptom occurred. At the neurological examination the provocation tests are of high importance. Confirmation of the diagnosis can be established with the following diagnostic procedures: neostigmine test, serological testing for antibodies against acetylcholine receptors and single fibre EMG.

[Analysis of the clinical manifestations and electrophysiological changes in 32 patients with atypical myasthenia gravis]

OBJECTIVE

To study the clinical characteristics and electrophysiological changes in patients with atypical myasthenia gravis (MG).

METHODS

The characteristics of the clinical symptoms and electrophysiological changes were investigated in 32 patients with atypical MG diagnosed in our hospital from January 2004 to December 2008.

RESULTS

The ages of the patients ranged from 7 to 70 years. Five patients were diagnosed to have ocular MG (OMG), among whom 2 patient only complained of eye discomfort and blurred vision. Twenty-seven patients had generalized MG, and 6 of them showed muscle weakness of the limbs with or without mild difficulty in swallowing or respiratory muscles, but free of muscle dysfunctions in muscles of eyes, head, neck or face. Another 2 patients manifested muscular atrophy. Twenty-three patients (71.9%) displayed both fluctuating symptoms and positive results of fatigue test. Twenty-nine patients (90.6%) have positive results in the neostigmine test. Two patients in the OMG group (40.0%) showed positive results in the low frequency repetitive nerve stimulation (LFRNS), as compared with the 21 patients in the generalized MG group (71.9%) showing positive results. The total positivity rate of LFRNS was 71.9% in the total patients, consistent with the published data.

CONCLUSIONS

In MG patients with atypical clinical symptoms, negative results of neostigmine test and fatigue test, LFRNS test can be an indispensable method to increase detection rate of MG and reduce erroneous or missed diagnosis.

acuelata constituents on neostigmine induced gastrointestinal transit in mice

Background

Lantana camara L. (Verbenaceae), a widely growing shrub which is toxic to some animal species, has been used in the traditional medicine for treating many ailments. The purpose of the present study was to evaluate the antimotility effects of Lantana camara leaf constituents in mice intestine.

Methods

Evaluation of antimotility activity was done in intestine of mice treated with Lantana camara leaf powder, Lantana camara methanolic extract (LCME), lantadene A, neostigmine and neostigmine + LCME. Neostigmine was used as a promotility agent. Intestinal motility was assessed by charcoal meal test and gastrointestinal transit rate was expressed as the percentage of the distance traversed by the charcoal divided by the total length of the small intestine. The antidiarrheal effect of LCME was studied against castor oil induced diarrhea model in mice.

Results

The intestinal transit with LCME at a dose of 500 mg/kg was 26.46% whereas the higher dose (1 g/kg) completely inhibited the transit of charcoal in normal mice. The % intestinal transit in the neostigmine pretreated groups was 24 and 11 at the same doses respectively. When the plant extracts at 125 and 250 mg/kg doses were administered intraperitonealy, there was significant reduction in fecal output compared with castor oil treated mice. At higher doses (500 and 1000 mg/kg), the fecal output was almost completely stopped.

Conclusion

The remarkable antimotility effect of Lantana camara methanolic extract against neostigmine as promotility agent points towards an anticholinergic effect due to Lantana camara constituents and attests to its possible utility in secretory and functional diarrheas and other gastrointestinal disorders. This effect was further confirmed by significant inhibition of castor oil induced diarrhea in mice by various doses of LCME.

Mild interoceptive stressors affect learning and reactivity to contextual cues: toward understanding the development of unexplained illnesses

Contextual learning is evident with repeated experiences with agents and treatments that induce frank illness and interoceptive stress. Here, we examined whether acute treatment with mild interoceptive stressors (low doses of pyridostigmine bromide (PB), neostigmine bromide (NB), and interleukin (IL)-1beta) may serve as unconditional stimuli supporting contextual learning. Rats were exposed to interoceptive and exteroceptive stressors in contexts distinguished by visual or olfactory cues. Acoustic startle responses (ASRs) were measured the day following exposure and 2 weeks thereafter, without delivery of the unconditional stimuli. The appearance, form, and duration of startle potentiation depended on the distinguishing features of the context and the nature of the interoceptive stressor. Rats given cholinesterase inhibitors (PB and NB), but not IL-1beta or exposed to an exteroceptive stressor, exhibited exaggerated ASRs in a novel context distinguished by visual cues. Treatment with either PB or IL-1beta led to potentiated ASRs in the presence of odors congruent with those experiences during exposure to the stressor. Startle potentiation by odor was still apparent 2 weeks after treatment. For contexts differentiated by visual stimuli, cholinomimetics transiently alter reactivity within novel contexts. In the case of contexts differentiated by odors, learning is apparent at least 2 weeks after acute treatment of cholinomimetics and IL-1beta. Contextual learning and changes in reactivity consequent to mild interoceptive stressors such as PB may play a role in the development of nonspecific symptoms typical of unexplained illnesses, such as Gulf War Illness.

Congenital endplate acetylcholinesterase deficiency responsive to ephedrine

The authors describe two patients with congenital myasthenic syndrome (CMS) with end plate acetylcholinesterase (AChE) deficiency caused by mutations in the collagenic tail (ColQ) of AChE: a homozygous C-terminal Y230S mutation in Patient 1 and Y430S and a C-terminal splice-site mutation in Patient 2. In Patient 1, a Prostigmin (neostigmine bromide) test failed to distinguish between AChE deficiency and a slow-channel CMS. Both patients responded dramatically to ephedrine therapy.

Effect-site concentration of propofol for recovery of consciousness is virtually independent of fentanyl effect-site concentration

Fentanyl reduces the amount of propofol necessary to prevent responses to surgical stimuli. However, opioids have relatively little effect on consciousness. We, therefore, tested the hypothesis that fentanyl minimally alters the effect-site concentration of propofol associated with awakening. Fifty women having gynecologic laparotomy with propofol anesthesia were randomly allocated into the following target effect-site fentanyl concentrations: 0.8, 1.0, 1.4, 2.0, and 3.0 ng/mL. Fentanyl was continued at the designated rate through the initial postoperative phase. The propofol effect-site concentration associated with eye opening in response to verbal command was regarded as the awakening concentration. The estimated propofol effect-site concentrations at awakening did not differ significantly among the groups and were 1.9 +/- 0.5 micro g/mL with a fentanyl effect-site concentration of 0.8 ng/mL; 1.6 +/- 0.4 micro g/mL with 1.0 ng/mL of fentanyl; 1.6 +/- 0.2 micro g/mL with 1.4 ng/mL of fentanyl; 1.7 +/- 0.4 micro g/mL with 2.0 ng/mL of fentanyl; and 1.6 +/- 0.34 micro g/mL with 3.0 ng/mL of fentanyl (mean +/- SD). Seventy percent of the subjects in the 0.8 ng/mL fentanyl group spontaneously complained of pain, whereas none of the patients in the 2 or 3 ng/mL groups did. Five (56%) of 9 women in the 3 ng/mL group had a postoperative respiratory rate <6 breaths/min. Heart rate in one of these women decreased to <40 bpm. These data suggest that the optimal fentanyl effect-site concentration in patients recovering from gynecologic laparoscopy is between 1.4 and 2.0 ng/mL.

IMPLICATIONS

The effect-site concentration for propofol at awakening was virtually independent of the fentanyl effect-site concentration over the range of 0.8 to 3.0 ng/mL; however, 0.8 ng/mL of fentanyl was associated with inadequate postoperative analgesia, and 3.0 ng/mL of fentanyl was associated with respiratory toxicity. The optimal postoperative fentanyl effect-site concentration during recovery from propofol general anesthesia for laparotomy thus appears to be near 2 ng/mL.

Effects of the venom of a Mygalomorph spider (Lasiodora sp.) on the isolated rat heart

We studied the effect of the venom of the Brazilian spider, Lasiodora sp. (Mygalomorphae, Theraphosidae), on force generation and electrical activity in the isolated rat heart. Previous work showed that this venom is excitotoxic to excitable cells due to Na(+) channel gating modifier activity [Toxicon 39 (2001) 991]. In the isolated heart, the venom (10-100 microg bolus administration) caused a dose-dependent bradycardia, with transient cardiac arrest and rhythm disturbances. The electrocardiogram showed that the reduction of heart rate was due to sinus bradycardia, sinus arrest and partial or complete A-V block. All of the effects were reversible upon washout of the venom. The effect of the venom was potentiated by the anticholinesterase neostigmine (3.3 microM), suppressed by the muscarinic acetylcholine receptor antagonist atropine (1.4 microM), and inhibited by the vesicular acetylcholine transporter inhibitor (-)-vesamicol (10 microM). Tetrodotoxin (200 nM) did not inhibit the effect of the venom. Together, these data suggest that this Lasiodora venom evokes vesicular release of acetylcholine from parasympathetic nerve terminals by activating tetrodotoxin-resistant Na(+) channels.

Intravenous regional anesthesia using prilocaine and neostigmine

Neostigmine has been added to local anesthetics for central and peripheral nerve blocks resulting in prolonged, increased anesthesia and improved analgesia. We conducted this study to evaluate the effects of neostigmine when added to prilocaine for IV regional anesthesia (IVRA). Thirty patients undergoing hand surgery were randomly assigned to two groups to receive IVRA. The control group received 1 mL of saline plus 3 mg/kg of prilocaine diluted with saline to a total dose of 40 mL; the study group received 0.5 mg of neostigmine plus 3 mg/kg of prilocaine diluted with saline to a total dose of 40 mL. Sensory and motor block onset and recovery, anesthesia quality determined by an anesthesiologist, anesthesia quality determined by a surgeon, and dryness of the operative field were noted. Heart rate, mean arterial blood pressure, and oxygen saturation values were noted at 1, 5, 10, 20, and 40 min before surgery and after tourniquet release. Time to first analgesic requirement was also noted. Shortened sensory and motor block onset times, prolonged sensory and motor block recovery times, improved quality of anesthesia, and prolonged time to first analgesic requirement were found in the neostigmine group. We conclude that neostigmine as an adjunct to prilocaine improves quality of anesthesia and is beneficial in IVRA.

IMPLICATIONS

Neostigmine has been added to local anesthetics for central and peripheral nerve blocks. This study was conducted to evaluate the effects of neostigmine when added to prilocaine for IV regional anesthesia (IVRA). Neostigmine as an adjunct to prilocaine improves quality of anesthesia and is beneficial in IVRA.

[Slow channel syndrome due to an autosomal translocation at 2q31-9p27]

A 27-year-old man complained of cervicoscapular and forearm weakness and amyotrophy. Electromyographic evaluation showed neuromuscular transmission dysfunction and a repetitive compound muscle action potential to a single stimulus. Prostigmine did not improve neuromuscular transmission. The genetic analysis of the patient's lymphocytes demonstrated a chromosomic 2q31-9p27 translocation. The combination of the clinical and electrophysiological data as well as the lack of auto-immunity signs against neuromuscular junction constituents led to the diagnosis to congenital postsynaptic myasthenic syndrome also called slow channel syndrome. This congenital myasthenic syndrome is for the first time associated with an autosomal translocation 2q31-9p27.