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Neuromuscular
Terms modified by Neuromuscular Selected AbstractsAcceleromyography and mechanomyography for establishing potency of neuromuscular blocking agents: a randomized-controlled trialACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 4 2009C. CLAUDIUS Background: Acceleromyography (AMG) is increasingly being used in neuromuscular research, including in studies establishing the potency of neuromuscular blocking and reversal agents. However, AMG is insufficiently validated for use interchangeably with the gold standard, mechanomyography (MMG) for this purpose. The aim of this study was to compare AMG and MMG for establishing dose,response relationship and potency, using rocuronium as an example. Methods: We included 40 adult patients in this randomized-controlled single-dose response study. Anaesthesia was induced and maintained with propofol and opioid. Neuromuscular blockade was induced with rocuronium 100, 150, 200 or 250 ,g/kg. Neuromuscular monitoring was performed with AMG (TOF-Watch® SX) with pre-load (Hand Adapter) at one arm and MMG (modified TOF-Watch® SX) on the other, using 0.1 Hz single twitch stimulation. Dose,response relationships were determined for both recording methods using log (dose) against probit (maximum block). The obtained slopes of the regression lines, ED50, ED95 and the maximum block were compared. Results: The ED50 and ED95 [95% confidence interval (CI)] for AMG were 185 ,g/kg (167,205 ,g/kg) and 368 ,g/kg (288,470 ,g/kg), compared with 174 ,g/kg (159,191 ,g/kg) and 338 ,g/kg (273,418 ,g/kg) for MMG. There were no statistically significant biases in maximum block, ED50, ED95 or slopes obtained with the two methods. Conclusion: Our results indicate that any possible difference between AMG and MMG is so small that it justifies AMG to be used for establishing the potency of neuromuscular blocking agents. However, the wide CIs show that we cannot rule out a 13% higher ED50 and a 26% higher ED95 for AMG. [source] Reversal of rocuronium with edrophonium during propofol versus sevoflurane anesthesiaACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 2 2001T. J. Zhou Background: The use of volatile anesthetics for maintenance of anesthesia can enhance the action of non-depolarizing muscle relaxants and interfere with the reversal of neuromuscular blockade. In this study, we studied the antagonism of rocuronium with edrophonium-atropine during propofol- versus sevoflurane-based anesthesia. Methods: Following induction of anesthesia with propofol (2,2.5 mg kg,1, iv) and fentanyl (1,2 ,g kg,1 iv), rocuronium 0.6 mg kg,1 iv was administered to facilitate tracheal intubation. Patients were then randomized to receive either a propofol infusion (100 ,g kg,1 min,1) or sevoflurane (1.0%, end-tidal) in combination with nitrous oxide 66% for maintenance of anesthesia. Neuromuscular blockade was monitored using electromyography at the wrist, and reversed with edrophonium 1.0 mg kg,1 and atropine 0.015 mg kg,1 when the first twitch hight (T1) of the train-of-four (TOF) stimulation recovered to 25% of the baseline value. Anesthetic maintenance with propofol or sevoflurane was continued following reversal until a TOF ratio of 0.7 was attained. Results: The clinical duration of action (i.e., time to 25% T1 recovery) was similar during both propofol- (39.3±14.6 min) and sevoflurane-based (48.1±19.7 min) anesthesia. However, the reversal time from 25% T1 to TOF ratio of 0.7 was significantly longer with sevoflurane [Median 2.8 (range 0.5,18.8) min] compared with propofol [1.5 (0.75,3) min] (P<0.05). Conclusions: We conclude that the clinical duration of action after a single dose of rocuronium, 0.6 mg kg,1 iv, was similar during both propofol- and sevoflurane-based anesthesia. However, the reversal of rocuronium-induced residual blockade was slower and more variable in the presence of sevoflurane. [source] Consensus guidelines for sustained neuromuscular blockade in critically ill childrenPEDIATRIC ANESTHESIA, Issue 9 2007STEPHEN PLAYFOR Summary Background:, The United Kingdom Paediatric Intensive Care Society Sedation, Analgesia and Neuromuscular Blockade Working Group is a multidisciplinary expert panel created to produce consensus guidelines on sedation, analgesia and neuromuscular blockade in critically ill children and forward knowledge in these areas. Neuromuscular blockade is recognized as an important element in the care of the critically ill and adult clinical practice guidelines in this area have been available for several years. However, similar clinical practice guidelines have not previously been produced for the critically ill pediatric patient. Methods:, A modified Delphi technique was employed to allow the Working Group to anonymously consider draft recommendations in up to three Delphi rounds with predetermined levels of agreement. This process was supported by a total of four consensus conferences and once consensus had been achieved, a systematic review of the available literature was carried out. Results:, A set of consensus guidelines was produced including six key recommendations. An evaluation of the existing literature supporting these recommendations is provided. Conclusions:, Multidisciplinary consensus guidelines for maintenance neuromuscular blockade in critically ill children (excluding neonates) have been successfully produced and are supported by levels of evidence. The Working Group has highlighted the paucity of high quality evidence in these important clinical areas and this emphasizes the need for further randomized clinical trials in this area. [source] Neuromuscular blockade and minimal monitoringANAESTHESIA, Issue 3 2010B. P. Sweeney No abstract is available for this article. [source] Poster session 2: Nursing (P136); Neuromuscular (P137,P140); Neurodevelopment (P141,P142)ANNALS OF NEUROLOGY, Issue S11 2007Article first published online: 29 AUG 200 No abstract is available for this article. [source] The interaction of central command and the exercise pressor reflex in mediating baroreflex resetting during exercise in humansEXPERIMENTAL PHYSIOLOGY, Issue 1 2006Kevin M. Gallagher Central command and the exercise pressor reflex can independently reset the carotid baroreflex (CBR) during exercise. The present investigation assessed the interactive relationship between these two neural mechanisms in mediating baroreflex resetting during exercise. Six men performed static leg exercise at 20% maximal voluntary contraction under four conditions: control, no perturbation; neuromuscular blockade (NMB) induced by administration of the neuromuscular blocking agent Norcuron (central command activation); MAST, application of medical antishock trousers inflated to 100 mmHg (exercise pressor reflex activation); and Combo, NMB plus MAST (concomitant central command and exercise pressor reflex activation). With regard to CBR control of heart rate (HR), both NMB and Combo conditions resulted in a further resetting of the carotid,cardiac stimulus,response curve compared to control conditions, suggesting that CBR,HR resetting is predominately mediated by central command. In contrast, it appears that CBR control of blood pressure can be mediated by signals from either central command or the exercise pressor reflex, since both NMB and MAST conditions equally augmented the resetting of the carotid,vasomotor stimulus,response curve. With regard to the regulation of both HR and blood pressure, the extent of CBR resetting was greater during the Combo condition than during overactivation of either central command or the exercise pressor reflex alone. Therefore, we suggest that central command and the exercise pressor reflex interact such that signals from one input facilitate signals from the other, resulting in an enhanced resetting of the baroreflex during exercise. [source] Fish venom: pharmacological features and biological significanceFISH AND FISHERIES, Issue 2 2009Gisha Sivan Abstract Nearly 1200 species of marine fish are venomous and they account for two-third of the population of venomous vertebrates. Fish venoms are focused as a potential source of pharmacological agents and physiological tools that have evolved to target vital processes in the human body that appear to have more electivity than many drugs. Fish venoms possess cardiovascular, neuromuscular, oedematic and cytolytic activity. Lethal toxins have been isolated and purified, with some having LD50 values comparable to that of snake venoms. Cardiovascular activity seems to be the dominant effect of fish venoms in experimental models. Piscine venom acts both pre- and post-junctionally to produce depolarization of cell membranes. Studies on cytolytic activity of fish venom found that it produces lysis by forming hydrophilic pores in cell membranes which then result in cell lysis. Almost all fish venoms with neuromuscular activity also possesses cytolytic activity, and it is very likely that the two activities are related. Fish venom is known to induce intense and sustained edematogenic response. As piscine venoms have evolved for the same purpose, they show a number of similarities pharmacologically and it seems likely that most of the biological activities of any given toxin can be traced back to its cytolytic activity. A variety of toxins have been isolated from piscine venom. Although there is a complex balance between the components present in the venom of different fish, all of them seem to share similar activity , functionally and pharmacologically as well as structurally. [source] Knowledge of residual curarization: an Italian surveyACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 3 2010P. DI MARCO Background: The use of neuromuscular blocking agents (NMBAs) is widespread in anesthetic practice; little is known about the current use of these drugs in Italy. This survey was conducted to obtain information about the most commonly used clinical tests and the train-of-four (TOF) ratios that are considered as being reliable for assessing recovery from neuromuscular blockade at the end of anesthesia and the estimated occurrence rates of post-operative paralysis in Italian hospitals. Methods: The questionnaire was given to Italian anesthesiologists attending the 62nd National Congress of the Italian Society of Anesthesia, Analgesia and Intensive Therapy. Collected data were stratified by age and the total number of surgical procedures performed in the hospitals concerned. Results: Seven hundred and fifty-four correctly compiled questionnaires were collected (response rate 88.7%). Seventy three percent of the respondents only used clinical tests for monitoring the level of neuromuscular blockade. The main clinical tests cited for the evaluation of residual paralysis were keeping the head lifted up for 5 s, protruding the tongue and opening the eyes. TOF was used by 35% of the respondents on a routine basis. Only 24% of the interviewed anesthesiologists reported that before extubation, a TOF ratio of at least 0.9 should be reached. Conclusions: Most Italian anesthetists assess the recovery from neuromuscular blockade only by clinical signs. There is poor awareness about the inability of such techniques to indicate even a significant amount of residual neuromuscular block. A more extensive use of quantitative instrumental monitoring is required for the more rational use of NMBAs. [source] Immunocytochemical evidence for biogenic amines and immunogold labeling of serotonergic synapses in tentacles of Aiptasia pallida (Cnidaria, Anthozoa)INVERTEBRATE BIOLOGY, Issue 4 2000Jane A. Westfall Abstract. Evidence for classical neurotransmitters in sea anemones remains controversial. We used high performance liquid chromatography with electrochemical detection (HPLC-EC) and electron microscopical imunocytochemistry to determine the presence of serotonin and precursor synthetic enzymes of other biogenic amines in tentacles of the sea anemone Aiptasia pallida. Using HPLC-EC we found dopamine and serotonin (5-hydroxytryptamine, 5-HT) in both tentacles and whole animal homogenates. Antibodies to tyrosine hydroxylase, dopamine ,-hydroxylase, phenylethanolamine N-methyltransferase, and 5-HT were used with the peroxidase-antiperoxidase method to reveal positive immunoreactivity to these substances in neurons of tentacles. Immunogold labeling of serial thin sections with the anti-5,HT antibody revealed reactive products in synaptic vesicles at interneuronal, neuromuscular, and neurospirocyte synapses. These results suggest that both catecholamine and indolamine neurotransmitters occur in sea anemones in addition to the neuropeptide Antho-RFamide, indicating the presence of multiple types of transmitter substances in an early nervous system. [source] Extremely prolonged neuromuscular blockade after rocuronium: a case reportACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 7 2009A. C. MORALES MARTÍN It is known that the duration of rocuronium action can be prolonged in elderly patients and that such action shows important interindividual variability. We report a case of prolonged neuromuscular block lasting 11 h, in a woman subjected to kidney transplantation. The possible causes of such prolonged action, inherent to the drug, or related to external factors, are commented. [source] Anaesthesiological considerations on tocolytic and uterotonic therapy in obstetricsACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 6 2009M. VERCAUTEREN Aim: Significant side effects of tocolytic and uterotonic substances may be of concern to the anaesthesiologist. Recently, new drugs have been introduced having less side effects for both the mother and the neonate. Methods: A literature search was undertaken mainly focusing on meta-analyses, to review the possible side effects that might affect the course of anaesthesia and to suggest which precautions should be considered to prevent the occurrence of significant interactions with anaesthetic manipulations and drugs. Results: Magnesium sulphate has a proven benefit in lowering systolic blood pressure and preventing the occurrence of eclampsia, but not as a tocolytic. ,-adrenergic agonists are being abandoned due to the availability of tocolytic agents causing less side effects. Calcium channel blockers (CCB) are frequently used but can cause major maternal cardiovascular complications. Nitroglycerin seems to be appreciated as an acute tocolytic rather than a routine substance during pre-term labour. Cyclo-oxygenase-2 inhibitors are still under investigation but their tocolytic benefit is questionable mainly due to foetal side effects. Atosiban is considered the first-choice tocolytic. With respect to oxytocic drugs, oxytocine, prostaglandines and methylergometrine may all cause serious side effects especially when combined. The cardiovascular side effects of prostaglandins and methylergometrine can be life-threatening. Both oxytocin and carbetocin have a rather low risk for maternal complications. Conclusion: Atosiban and CCB are at least as effective tocolytic agents as ,-mimetics but have significantly less side effects. Magnesium sulphate can cause neuromuscular blockade, especially when combined with CCB. Concerning oxytocic agents, short-acting oxyctocin and long-acting carbetocin have the least side effects as compared with prostaglandins and methylergometrine. [source] Aging in inbred strains of mice: study design and interim report on median lifespans and circulating IGF1 levelsAGING CELL, Issue 3 2009Rong Yuan Summary To better characterize aging in mice, the Jackson Aging Center carried out a lifespan study of 31 genetically-diverse inbred mouse strains housed in a specific pathogen-free facility. Clinical assessments were carried out every 6 months, measuring multiple age-related phenotypes including neuromuscular, kidney and heart function, body composition, bone density, hematology, hormonal levels, and immune system parameters. In a concurrent cross-sectional study of the same 31 strains at 6, 12, and 20 months, more invasive measurements were carried out followed by necropsy to assess apoptosis, DNA repair, chromosome fragility, and histopathology. In this report, which is the initial paper of a series, the study design, median lifespans, and circulating insulin-like growth factor 1 (IGF1) levels at 6, 12, and 18 months are described for the first cohort of 32 females and 32 males of each strain. Survival curves varied dramatically among strains with the median lifespans ranging from 251 to 964 days. Plasma IGF1 levels, which also varied considerably at each time point, showed an inverse correlation with a median lifespan at 6 months (R = ,0.33, P = 0.01). This correlation became stronger if the short-lived strains with a median lifespan < 600 days were removed from the analysis (R = ,0.53, P < 0.01). These results support the hypothesis that the IGF1 pathway plays a key role in regulating longevity in mice and indicates that common genetic mechanisms may exist for regulating IGF1 levels and lifespan. [source] Attenuation of a rocuronium-induced neuromuscular block in patients receiving prednisoloneACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 4 2009S. SOLTÉSZ Background: This study tested the influence of continuous medication (more than 4 weeks) with prednisolone on a rocuronium-induced neuromuscular block. Methods: The time course of a rocuronium-induced neuromuscular blockade (0.3 mg/kg) was investigated in 40 patients with chronic inflammatory bowel disease undergoing elective abdominal surgery. The primary end point was the time from the start of injection of rocuronium until recovery of the TOF ratio to 0.9. Twenty patients received continuous medication with prednisolone (group A), and 20 were without glucocorticoid medication (group B). Additionally, another 20 patients without inflammatory bowel disease and without glucocorticoid medication served as control (group C). Results: The onset time was prolonged in group A [253 (51.2) s] compared with group B [187 (61.3) s]. Twitch height at the onset of the block was higher in group A [16.5 (0,61)%] than that in group B [5.0 (0,33)%]. The duration to 25% twitch height was shorter in group A [12.6 (0,20.7) min] compared with group B [16.7 (0,25.3) min] and group C [16.9 (0,29.3) min]. The recovery to a train-of-four ratio of 0.9 was reduced in group A [25.7 (23,34.3) min] compared with group B [34.7 (32.7,44.2) min] and group C [36.5 (31.7,42.3) min]. Conclusions: Prednisolone treatment in patients with inflammatory bowel disease is associated with a delayed onset and a shorter duration of action of rocuronium. The presence of an inflammatory bowel disease did not influence the neuromuscular block. [source] Assessing the balance capabilities of people with profound intellectual disabilities who have experienced a fallJOURNAL OF INTELLECTUAL DISABILITY RESEARCH, Issue 4 2007L. Hale Abstract Background Although it is common for people with intellectual disability (ID) to fall, the reasons for this have not yet been identified. This pilot study aimed to explore the balance capabilities of a sample of adults with profound ID who had experienced a fall, in order to identify possible reasons for falling and to identify potential tests that could be used to quantify balance capabilities in this population group. Methods The neuromuscular systems and balance capabilities of 20 adults with profound ID were comprehensively assessed with a battery of tests, including computerized posturography. Results Of the 20 participants, 15 described themselves as frequent fallers, and 10 participants reported serious injuries as a result of falling. Formalized assessment of the neuromuscular and balance capabilities proved to be challenging, with many participants unable to comprehend what was required of them in the performance of a number of the tests. All participants were observed to have an abnormal pattern of walking. Nine participants completed posturography testing, the main finding of which was that low motor control composite scores indicated a slowing of motor responses to postural perturbations. Other potential risk factors identified were concurrent medical problems, medication, the context and environment of falling, movement impulsiveness and distractibility, and visual deficits. Conclusion The reason why people with ID frequently fall appears complex and multifactorial. Larger studies are required to verify the potential risk factors identified in this pilot study. Many of the standardized outcome measures commonly used in physiotherapy practice to quantify balance capabilities are not suitable for use in this population group, as participants found it difficult to comprehend what was required of them. Allowing the person to become familiarized with both the test and the tester may help to alleviate this problem. Videotaping and quantifying observations of strategies people use to perform common movements such as walking or turning maybe a more appropriate measurement tool of balance capabilities of people with ID than current standardized measures. This method would require rigorous development. [source] Hepatitis C virus does not infect muscle, the intervertebral disk, or the meniscus in patients with chronic hepatitis CJOURNAL OF MEDICAL VIROLOGY, Issue 12 2007Javier Bartolomé Abstract Chronic infection with hepatitis C virus (HCV) is associated with several extrahepatic manifestations, including neuromuscular and joint disorders, and HCV RNA has been detected in muscle fibers of patients with myosistis and chronic hepatitis C. However, whether HCV infects muscle cells in patients without myosistis is unknown. The presence of HCV in other sites of the musculoskeletal system has not been investigated. In the present study the presence of HCV RNA was sought in muscle (2 cases), intervertebral disk (1 case) and meniscus (1 case) samples from patients with chronic hepatitis C. HCV RNA was not detected by reverse transcription and real-time polymerase chain reaction in any of the samples tested. In conclusion, the results do not support a direct role of HCV in musculoskeletal disorders associated with chronic hepatitis C. J. Med. Virol. 79:1818,1820, 2007. © Wiley-Liss, Inc. [source] Beneficial effects of high positive end-expiratory pressure in lung respiratory mechanics during laparoscopic surgeryACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 2 2009L. F. MARACAJÁ-NETO Background: The effect of neuromuscular blockade (NMB) and positive end-expiratory pressure (PEEP) on the elastic properties of the respiratory system during pneumoperitoneum (PnP) remains a controversial subject. The main objective of the present study was to evaluate the effects of NMB and PEEP on respiratory mechanics. Methods: We performed a dynamic analysis of respiratory mechanics in patients subjected to PnP. Twenty-one patients underwent cholecystectomy videolaparoscopy and total intravenous anesthesia. The respiratory system resistance (RRS), pulmonary elastance (EP), chest wall elastance (ECW), and respiratory system elastance (ERS) were computed via the least squares fit technique using an equation describing the motion of the respiratory system, which uses primary signs such as airway pressure, tidal volume, air flow, and esophageal pressures. Measurements were taken after tracheal intubation, PnP, NMB, establishment of PEEP (10 cmH2O), and PEEP withdrawal [zero end-expiratory pressure (ZEEP)]. Results: PnP significantly increased ERS by 27%; both EP and ECW increased 21.3 and 64.1%, respectively (P<0.001). NMB did not alter the respiratory mechanic properties. Setting PEEP reduced ERS by 8.6% (P<0.05), with a reduction of 10.9% in EP (P<0.01) and a significant decline of 15.7% in RRS (P<0.05). These transitory changes in elastance disappeared after ZEEP. Conclusions: We concluded that the 10 cmH2O of PEEP attenuates the effects of PnP in respiratory mechanics, lowering RRS, EP, and ERS. These effects may be useful in the ventilatory approach for patients experiencing a non-physiological increase in IAP owing to PnP in laparoscopic procedures. [source] The optimal bolus dose of alfentanil for tracheal intubation during sevoflurane induction without neuromuscular blockade in day-case anaesthesiaACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 1 2008J. Y. KIM Background: The purpose of this study was to determine the optimal bolus dose of alfentanil required to provide successful intubating conditions following inhalation induction of anaesthesia using 5% sevoflurane and 60% nitrous oxide without neuromuscular blockade in adult day-case anaesthesia. Methods: Twenty-four adults, aged 18,60 years, undergoing general anaesthesia for short ambulatory surgery were enroled into the study. After vital capacity induction, with sevoflurane 5% and 60% nitrous oxide in oxygen, pre-determined dose of alfentanil was injected over 30 s. The dose of alfentanil was determined by modified Dixon's up-and-down method (2 ,g/kg as a step size). Ninety seconds after the end of bolus administration of alfentanil, the trachea was intubated. Systolic blood pressure, heart rate and SpO2 were recorded at anaesthetic induction, before, 1 min and 3 min after intubation. Results: The bolus dose of alfentanil for successful tracheal intubation was 10.7±2.1 ,g/kg in 50% of patients during inhalation induction. From probit analysis, 50% effective dose (ED50) and ED95 values (95% confidence limits) of alfentanil were 10.7 ,g/kg (8.0,12.9 ,g/kg) and 14.9 ,g/kg (12.9,31.1 ,g/kg), respectively. Conclusions: Using the modified Dixon's up-and-down method, the bolus dose of alfentanil for successful tracheal intubation was 10.7±2.1 ,g/kg in 50% of adult patients during inhalation induction using 5% sevoflurane and 60% nitrous oxide in oxygen without neuromuscular blocking agent in day-case anaesthesia. [source] Effects of SZ1677, a new non-depolarizing steroidal neuromuscular blocking drug, and rocuronium on two laryngeal muscles and the anterior tibial muscle in guinea pigsACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 4 2006A. Michalek-Sauberer Background:, SZ1677 is a new neuromuscular blocking drug structurally related to rocuronium. We compared the effect of an ED90 of SZ1677 (25 ,g/kg) with that of rocuronium (100 ,g/kg) in guinea pig laryngeal and peripheral muscles. Methods:, Electromyography was used to quantify neuromusc-ular blockade at the posterior cricoarytenoid muscle, the thyroarytenoid muscle and the anterior tibial muscle after SZ1677 (n = 10) and rocuronium (n = 9). Results:, Maximum neuromuscular blockade was similar after SZ1677 and rocuronium (83 ± 11% vs. 89 ± 11%; thyroarytenoid muscle: 91 ± 8% vs. 97 ± 3%; anterior tibial muscle: 91 ± 15% vs. 96 ± 3%, respectively). Onset time of neuromuscular blockade at the laryngeal muscles was similar for the two neuromuscular blocking drugs; it was shorter at the thyroarytenoid muscle (67 ± 32 s vs. 42 ± 40 s) than at the posterior cricoarytenoid muscle (101 ± 26 s vs. 102 ± 108 s). Onset time at the anterior tibial muscle was longer after SZ1677 (114 ± 34 s) than after rocuronium (68 ± 46 s); P < 0.05. Neuromuscular recovery was faster after SZ1677 (interval 25%,75%: posterior cricoarytenoid muscle: 222 ± 66 s; thyroarytenoid muscle: 192 ± 92 s; tibial muscle 149 ± 55 s) than after rocuronium (450 ± 148 and 464 ± 183 s, 292 ± 86 s, respectively); P < 0.05. Conclusions:, In guinea pigs, SZ1677 offers a rapid onset of neuromuscular blockade at a laryngeal adductor muscle with a shorter duration than rocuronium. Regardless of the drug used, the course of neuromuscular blockade differs not only between peripheral muscles and the larynx but also between antagonistic laryngeal muscles. The differences seem to be species specific. [source] Reversal of rocuronium with edrophonium during propofol versus sevoflurane anesthesiaACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 2 2001T. J. Zhou Background: The use of volatile anesthetics for maintenance of anesthesia can enhance the action of non-depolarizing muscle relaxants and interfere with the reversal of neuromuscular blockade. In this study, we studied the antagonism of rocuronium with edrophonium-atropine during propofol- versus sevoflurane-based anesthesia. Methods: Following induction of anesthesia with propofol (2,2.5 mg kg,1, iv) and fentanyl (1,2 ,g kg,1 iv), rocuronium 0.6 mg kg,1 iv was administered to facilitate tracheal intubation. Patients were then randomized to receive either a propofol infusion (100 ,g kg,1 min,1) or sevoflurane (1.0%, end-tidal) in combination with nitrous oxide 66% for maintenance of anesthesia. Neuromuscular blockade was monitored using electromyography at the wrist, and reversed with edrophonium 1.0 mg kg,1 and atropine 0.015 mg kg,1 when the first twitch hight (T1) of the train-of-four (TOF) stimulation recovered to 25% of the baseline value. Anesthetic maintenance with propofol or sevoflurane was continued following reversal until a TOF ratio of 0.7 was attained. Results: The clinical duration of action (i.e., time to 25% T1 recovery) was similar during both propofol- (39.3±14.6 min) and sevoflurane-based (48.1±19.7 min) anesthesia. However, the reversal time from 25% T1 to TOF ratio of 0.7 was significantly longer with sevoflurane [Median 2.8 (range 0.5,18.8) min] compared with propofol [1.5 (0.75,3) min] (P<0.05). Conclusions: We conclude that the clinical duration of action after a single dose of rocuronium, 0.6 mg kg,1 iv, was similar during both propofol- and sevoflurane-based anesthesia. However, the reversal of rocuronium-induced residual blockade was slower and more variable in the presence of sevoflurane. [source] A fish bone embedded in the mobile tongue mimicking a neoplasmORAL SURGERY, Issue 4 2008Yan Wang Abstract Foreign bodies embedded in a mobile tongue as an enlarged tongue mass are rarely presented to either a laryngologist or a dentist, because such bodies are commonly lodged superficially and are easily removed by the patients themselves or removed by a laryngologist by means of indirect laryngoscope or endoscope. We have described a 63-year-old female with an 8-month history of an enlarged mass in the anterior right tongue. Physical examination demonstrated a mass located in the anterior right tongue without clear margin, with superficially intact mucosa and normal colour. A benign tongue neoplasm was first considered. However, a fish bone totally embedded in the mobile tongue with granuloma formation was encountered during the incisional biopsy operation. Complete removal of the foreign body with granuloma was achieved under general anaesthesia. There was no neuromuscular or neurosensory dysfunction of the tongue in the follow-up period of 2 years. Although an embedded foreign body in the mobile tongue is a rare condition, it should be considered in the work-up of a patient with an enlarged tongue mass, with or without a history of swallowing a foreign body. [source] Reversal of rocuronium-induced neuromuscular blockade by pyridostigmine in patients with Duchenne muscular dystrophyPEDIATRIC ANESTHESIA, Issue 3 2008TINO MUENSTER MD Summary Background:, The aim of this study was to investigate the effect and safety of pyridostigmine for the reversal of a neuromuscular block (NMB) in patients with Duchenne muscular dystrophy (DMD). In patients with DMD recovery from a rocuronium-induced NMB is markedly delayed. Methods:, Fourteen DMD patients (aged between 11 and 19 years) scheduled for elective scoliosis repair were studied. Following tracheal intubation without muscle relaxant, all patients received a single dose of rocuronium 0.6 mg·kg,1. NMB was monitored by acceleromyography at the adductor pollicis muscle. When the first twitch height (T1) of the train-of-four (TOF) had recovered to 25% seven patients received either pyridostigmine 0.1 mg·kg,1 (the anticholinergic drug with a long duration of action) or saline in a blinded manner. The times to attain TOF ratio of 0.9 were recorded. For comparison the Mann,Whitney U -test was used. Results:, Recovery to TOF ratio of 0.9 was significantly (P < 0.05) accelerated by pyridostigmine [84 (median), 57,141(range)] compared with controls (148, 84,243 min). The recovery time (time between T1 of 25% and TOF of 90%) was also significantly (P < 0.01) shortened by pyridostigmine (15, 8,49 vs 76, 43,144 min, respectively). Time to recovery of T1 to 90% was not different between the groups (108, 63,134 vs 169. 61,208 min, respectively). Conclusions:, Pyridostigmine 0.1 mg·kg,1 effectively reversed a rocuronium-induced NMB in DMD patients. [source] Consensus guidelines for sustained neuromuscular blockade in critically ill childrenPEDIATRIC ANESTHESIA, Issue 9 2007STEPHEN PLAYFOR Summary Background:, The United Kingdom Paediatric Intensive Care Society Sedation, Analgesia and Neuromuscular Blockade Working Group is a multidisciplinary expert panel created to produce consensus guidelines on sedation, analgesia and neuromuscular blockade in critically ill children and forward knowledge in these areas. Neuromuscular blockade is recognized as an important element in the care of the critically ill and adult clinical practice guidelines in this area have been available for several years. However, similar clinical practice guidelines have not previously been produced for the critically ill pediatric patient. Methods:, A modified Delphi technique was employed to allow the Working Group to anonymously consider draft recommendations in up to three Delphi rounds with predetermined levels of agreement. This process was supported by a total of four consensus conferences and once consensus had been achieved, a systematic review of the available literature was carried out. Results:, A set of consensus guidelines was produced including six key recommendations. An evaluation of the existing literature supporting these recommendations is provided. Conclusions:, Multidisciplinary consensus guidelines for maintenance neuromuscular blockade in critically ill children (excluding neonates) have been successfully produced and are supported by levels of evidence. The Working Group has highlighted the paucity of high quality evidence in these important clinical areas and this emphasizes the need for further randomized clinical trials in this area. [source] Current United Kingdom sedation practice in pediatric intensive carePEDIATRIC ANESTHESIA, Issue 7 2007IAN A. JENKINS FRCPE FRCA Summary Background:, The aim of this study was to investigate the current practice of sedation, analgesia, and neuromuscular blockade in critically ill children on pediatric intensive care units (PICUs) in the UK and identify areas that merit further study. Methods:, Data were gathered in a prospective observational study of 338 critically ill children in 20 UK PICUs. Results:, There is considerable variation in clinical practice. A total of 24 different sedative and analgesic agents were used during the study. The most commonly used sedative and analgesic agents were midazolam and morphine. Four different neuromuscular blockers (NMBs) were used, most commonly vecuronium. There were differences in treatment between cardiac and noncardiac children, but there were a greater number of infants and neonates in the cardiac group. NMBs were used in 30% of mechanically ventilated patients. Withdrawal symptoms were reported in 13% of ventilated patients, relatively early in their stay; weaning sedative agents (,tapering') was apparently of no benefit. The use of clonidine in this setting was noted. Physical restraints were used in 7.4%. Propofol was used but in only 2.6% of patients, all over the age of 4 years, and not exceeding 2 mg·kg,1·h,1. No side effects attributable to ,propofol syndrome' were noted. Conclusions:, There is considerable heterogeneity of sedation techniques. NMBs are used in a large portion of this population. Withdrawal symptoms were associated with higher doses of sedation and greater lengths of stay and were not ameliorated by withdrawing sedation gradually (,tapering'). [source] Sedation and neuromuscular blockade in paediatric intensive care; practice in the United Kingdom and North AmericaPEDIATRIC ANESTHESIA, Issue 6 2004Peter Crean MDArticle first published online: 20 MAY 200 First page of article [source] Sedation and neuromuscular blockade in paediatric intensive care: a review of current practice in the UKPEDIATRIC ANESTHESIA, Issue 2 2003MBBS, Stephen D. Playfor DM SummaryBackground: Our aim was to investigate the current practice of sedation and neuromuscular blockade in critically ill children in paediatric intensive care units (PICUs) in the UK. Methods: A postal questionnaire was sent to all PICUs in the UK. Results: The most commonly used sedative agents were midazolam in combination with morphine. Written clinical guidelines for the sedation of critically ill children were available in 45% of units. Sedation is formally assessed in 40% of units. Vecuronium is the most commonly used neuromuscular blocking agent. In the UK, 31% of critically ill children are likely to receive neuromuscular blocking agents. Depth of neuromuscular blockade is routinely assessed in 16% of patients. Conclusions: Relatively few units possess clinical guidelines for the sedation of critically ill children, and only a minority formally assess sedation levels. Where neuromuscular blocking agents are administered, sedation is frequently inadequately assessed and the depth of neuromuscular blockade is rarely estimated. [source] Dynamic in-hand movements in adult and young juvenile chimpanzees (Pan troglodytes)AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 3 2009Jessica Crast Abstract Descriptions of manual function in nonhuman primates have largely focused on static precision and power grasping (as first defined by Napier,1956), while identification and description of dynamic manual function are rare and incomplete. Here, we describe several forms of in-hand movements used by chimpanzees (Pan troglodytes) when manipulating small objects. In-hand movements are defined as the movement of an object within one hand via manipulation of the digits. We presented adult and young juvenile chimpanzees (ages 5,29 years) with a task that required inserting small objects through correspondingly shaped cutouts in a transparent Plexiglas panel. While attempting to insert the objects through the cutouts, the subjects used at least two forms of in-hand movements to change their grip on the object for more precise alignment. We describe in detail the in-hand movements they used and the variability observed in form and execution among the subjects. In general, the adult subjects used in-hand movements more frequently and used a wider variety of forms than did the young juvenile subjects, suggesting that in-hand movements are in the process of fine-tuning around the age of 5 years in chimpanzees. The dexterity exhibited by the adults, however, shows that the neuromuscular and morphological requirements for relatively complex digital manipulation are present in the adult chimpanzee. Am J Phys Antropol, 2009. © 2008 Wiley-Liss, Inc. [source] Central command and the cutaneous vascular response to isometric exercise in heated humansTHE JOURNAL OF PHYSIOLOGY, Issue 2 2005Manabu Shibasaki Cutaneous vascular conductance (CVC) decreases during isometric handgrip exercise in heat stressed individuals, and we hypothesized that central command is involved in this response. Seven subjects performed 2 min of isometric handgrip exercise (35% of maximal voluntary contraction) followed by postexercise ischaemia in normothermia and during heat stress (increase in internal temperature ,1°C). To augment the contribution of central command independent of force generation, on a separate day the protocol was repeated following partial neuromuscular blockade (PNB; i.v. cisatracurium). Forearm skin blood flow was measured by laser-Doppler flowmetry, and CVC was the ratio of skin blood flow to mean arterial pressure. The PNB attenuated force production despite encouragement to attain the same workload. During the heat stress trials, isometric exercise decreased CVC by ,12% for both conditions, but did not change CVC in either of the normothermic trials. During isometric exercise in the heat, the increase in mean arterial pressure (MAP) was greater during the control trial relative to the PNB trial (31.0 ± 9.8 versus 18.6 ± 6.4 mmHg, P < 0.01), while the elevation of heart rate tended to be lower (19.4 ± 10.4 versus 27.4 ± 8.1 b.p.m., P= 0.15). During postexercise ischaemia, CVC and MAP returned to pre-exercise levels in the PNB trial but remained reduced in the control trial. These findings suggest that central command, as well as muscle metabo-sensitive afferent stimulation, contributes to forearm cutaneous vascular responses in heat stressed humans. [source] ORIGINAL ARTICLE: Potency and recovery characteristics of rocuronium mixed with sodium bicarbonateANAESTHESIA, Issue 9 2010H. J. Lee Summary Sodium bicarbonate may be added to rocuronium to decrease pain on injection. However, this mixture may result in the formation of carbon dioxide bubbles. We investigated whether the addition of sodium bicarbonate to rocuronium alters neuromuscular blockade, in 120 patients randomly assigned to receive rocuronium mixed with saline or bicarbonate 8.4%, either in varying doses (for dose-response measurements; 60 patients) or a fixed dose of 600 ,g.kg -1 (for time-course measurements; 60 patients). Sodium bicarbonate resulted in a left-shift of the rocuronium dose-response curve. The effective doses of rocuronium to produce 95% twitch depression were 331.6 (95% CI: 310.4,352.8) and 284.3 (95% CI: 262.0,306.6) ,g.kg,1 mixed with isotonic saline or sodium bicarbonate, respectively (p < 0.001). The mean (SD) onset times of rocuronium 600 ,g.kg -1 were 3.6 (0.6) and 2.7 (0.5) min in the corresponding groups, respectively (p < 0.001). The mean (SD) times to 95% recovery were 35.8 (5.8) and 47.9 (7.1) min, respectively (p < 0.001). We conclude that the mixing of sodium bicarbonate with rocuronium enhances the potency, shortens the onset and prolongs the duration of action. [source] ORIGINAL ARTICLE: Can sugammadex save a patient in a simulated ,cannot intubate, cannot ventilate' situation?ANAESTHESIA, Issue 9 2010M. M. A. Bisschops Summary Recent studies have shown that the use of high dose rocuronium followed by sugammadex provides a faster time to recovery from neuromuscular blockade following rapid sequence induction than suxamethonium. In a manikin-based ,cannot intubate, cannot ventilate' simulation, we studied the total time taken for anaesthetic teams to prepare and administer sugammadex from the time of their initial decision to use the drug. The mean (SD) total time to administration of sugammadex was 6.7 (1.5) min, following which a further 2.2 min (giving a total 8.9 min) should be allowed to achieve a train-of-four ratio of 0.9. Four (22%) teams gave the correct dose, 10 (56%) teams gave a dose that was lower than recommended, four (22%) teams gave a dose that was higher than recommended, six (33%) teams administered sugammadex in a single dose, and 12 (67%) teams gave multiple doses. Our simulation highlights that sugammadex might not have saved this patient in a ,cannot intubate, cannot ventilate' situation, and that difficulties and delays were encountered when identifying, preparing and administering the correct drug dose. [source] CASE REPORT: The unrecognised difficult extubation: a call for vigilanceANAESTHESIA, Issue 9 2010J. Antoine Summary Tracheal extubation remains a critical and often overlooked period of difficult airway management. A 66-year-old man, scheduled for C5,C7 anterior fusion, with an easy view of the vocal cords, presented with a sublaryngeal obstruction that required a reduced tracheal tube size. Despite correct tube placement, intra-operative ventilation remained difficult. At the end of surgery a pulsatile tracheal compression was fibreopticially observed above the carina. After discussion with the attending otolaryngologist, neuromuscular blockade was antagonised and the patient was able to maintain normal minute volumes while spontaneously ventilating. With the otolaryngologist present, and with the patient conscious, the trachea was successfully extubated over an airway exchange catheter. A subsequent CT scan revealed an impingement of the trachea by the innominate artery and a mildly ectatic ascending and descending aorta that, in conjunction with tracheomalacia and neuromuscular blockade, could explain the observed signs and symptoms. [source] | |||||||||||||