The optimal dose of succinylcholine for rapid sequence induction: a systematic review and meta-analysis of randomized trials.

BACKGROUND: The evidence base for the widely accepted standard regimen of succinylcholine for rapid sequence induction (1.0 mg kg- 1) remains unclear. METHODS: We performed a systematic review and meta-analysis of randomized trials comparing any succinylcholine regimen with the standard regimen (1.0 mg kg- 1) and reporting on intubating conditions and/or apnoea times. Results were expressed as absolute risk differences (ARD) for dichotomous data and mean differences (MD) for continuous data. RESULTS: We retrieved six trials with relevant data of 864 patients (ASA 1 or 2, aged 18-65 years, body mass index < 30 kg m- 2). Four regimens (0.3, 0.4, 0.5, 0.6 mg kg- 1) were compared with 1.0 mg kg- 1 in at least three trials each, and three (0.8, 1.5, 2 mg kg- 1) in one each. With 0.3 to 0.5 mg kg- 1, the likelihood of excellent intubating conditions was significantly decreased (ARD - 22% to - 67%). With 0.3 and 0.4 mg kg- 1, but not with 0.5, 0.6, 0.8, 1.5 and 2.0 mg kg- 1, the likelihood of unacceptable intubating conditions was significantly increased (ARD + 22% and + 32%, respectively). With 2.0 mg kg- 1, but not with 0.8 or 1.5 mg kg- 1, the likelihood of excellent intubating conditions was significantly increased (ARD + 23%). Apnoea times were significantly shorter with regimens ≤0.8 mg kg- 1 (MD - 1.0 to - 3.4 min) but were not reported with 1.5 or 2.0 mg kg- 1. CONCLUSIONS: With succinylcholine regimens ≤0.5 mg kg- 1, excellent intubating conditions are less likely and apnoea times are shorter, compared with 1 mg kg- 1. With 0.3 and 0.4 mg kg- 1, unacceptable intubating conditions are more common. Succinylcholine 1.5 mg kg- 1 does not produce more often excellent conditions compared with 1 mg kg- 1, while 2.0 mg kg- 1 does, but the database with these regimens is weak and apnoea times remain unknown. Limited information size and strong statistical heterogeneity decrease the certainty of the evidence.

Dose-response assessment for impaired memory from chronic exposure to domoic acid among native American consumers of razor clams.

Domoic acid (DA) is a marine neurotoxin that accumulates in filtering shellfish during harmful algal blooms. A health protection limit of 20 ppm DA in razor clams (RC) has been set based principally upon an episode of acute DA toxicity in humans that included Amnesic Shellfish Poisoning among survivors. The objective of this study was to determine the dose-response relationship between estimated DA exposure through RC consumption and memory loss in Washington state Native Americans from 2005 to 2015. Results from total learning recall (TLR) memory scores were compared before and after the highest DA exposures. A decrease in TLR was related to DA dose (p < 0.01) regardless whether the effect was assumed to be transient or lasting, and whether the dose was expressed as an average daily dose or an average dose per meal. Benchmark dose modeling identified BMDL10 values of 167 ng/kg-day and 2740 ng/kg-meal assuming a transient effect, and 196 ng/kg-day and 2980 ng/kg-meal assuming no recovery of function occurs. These DA dose thresholds for a measurable memory function reduction observed in this study of clam consumers are well below the safe acute dose underpinning the current regulatory DA limit of 20 ppm (ca. 60 µg/kg).

Impact of Paralytic Agent on Postintubation Sedation.

OBJECTIVE: The aim of this study was to evaluate the difference in the time to postintubation sedation between patients receiving etomidate and either succinylcholine or rocuronium in the prehospital setting. SETTING: Patients who received rapid sequence intubation medications from transport service personnel and were subsequently intubated were included. The critical care transport agency operates 8 helicopter- and 3 ground-based emergency medical service units. METHODS: This retrospective cohort study compared the time to the first sedative in patients intubated with etomidate and succinylcholine versus etomidate and rocuronium. Enrollment of 64 patients per arm was needed to achieve 80% power with a 2-tailed alpha of 0.05. RESULTS: Sixty-four and 38 patients received succinylcholine or rocuronium, respectively. The median time to postetomidate sedation was 10 (range, 5.0-16.0) and 13.5 (range, 7.0-20.8) minutes for succinylcholine and rocuronium patients, respectively (P = .13). Given the average duration of effect of etomidate, succinylcholine, and rocuronium, 0 (0%) succinylcholine versus 33 (86.8%) rocuronium patients were found to be at risk of wakeful paralysis. CONCLUSIONS: This study suggests rocuronium's long duration of effect puts patients at risk for wakeful paralysis once the short effects of etomidate have subsided.

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

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

Avoidance versus use of neuromuscular blocking agents for improving conditions during tracheal intubation or direct laryngoscopy in adults and adolescents.

BACKGROUND: Tracheal intubation during induction of general anaesthesia is a vital procedure performed to secure a patient's airway. Several studies have identified difficult tracheal intubation (DTI) or failed tracheal intubation as one of the major contributors to anaesthesia-related mortality and morbidity. Use of neuromuscular blocking agents (NMBA) to facilitate tracheal intubation is a widely accepted practice. However, because of adverse effects, NMBA may be undesirable. Cohort studies have indicated that avoiding NMBA is an independent risk factor for difficult and failed tracheal intubation. However, no systematic review of randomized trials has evaluated conditions for tracheal intubation, possible adverse effects, and postoperative discomfort. OBJECTIVES: To evaluate the effects of avoiding neuromuscular blocking agents (NMBA) versus using NMBA on difficult tracheal intubation (DTI) for adults and adolescents allocated to tracheal intubation with direct laryngoscopy. To look at various outcomes, conduct subgroup and sensitivity analyses, examine the role of bias, and apply trial sequential analysis (TSA) to examine the level of available evidence for this intervention. SEARCH METHODS: We searched CENTRAL, MEDLINE, Embase, BIOSIS, International Web of Science, LILACS, advanced Google, CINAHL, and the following trial registries: Current Controlled Trials; ClinicalTrials.gov; and www.centerwatch.com, up to January 2017. We checked the reference lists of included trials and reviews to look for unidentified trials. SELECTION CRITERIA: We included randomized controlled trials (RCTs) that compared the effects of avoiding versus using NMBA in participants 14 years of age or older. DATA COLLECTION AND ANALYSIS: Two review authors extracted data independently. We conducted random-effects and fixed-effect meta-analyses and calculated risk ratios (RRs) and their 95% confidence intervals (CIs). We used published data and data obtained by contacting trial authors. To minimize the risk of systematic error, we assessed the risk of bias of included trials. To reduce the risk of random errors caused by sparse data and repetitive updating of cumulative meta-analyses, we applied TSA. MAIN RESULTS: We identified 34 RCTs with 3565 participants that met our inclusion criteria. All trials reported on conditions for tracheal intubation; seven trials with 846 participants described 'events of upper airway discomfort or injury', and 13 trials with 1308 participants reported on direct laryngoscopy. All trials used a parallel design. We identified 18 dose-finding studies that included more interventions or control groups or both. All trials except three included only American Society of Anesthesiologists (ASA) class I and II participants, 25 trials excluded participants with anticipated DTI, and obesity or overweight was an excluding factor in 13 studies. Eighteen trials used suxamethonium, and 18 trials used non-depolarizing NMBA.Trials with an overall low risk of bias reported significantly increased risk of DTI with no use of NMBA (random-effects model) (RR 13.27, 95% CI 8.19 to 21.49; P < 0.00001; 508 participants; four trials; number needed to treat for an additional harmful outcome (NNTH) = 1.9, I2 = 0%, D2 = 0%, GRADE = moderate). The TSA-adjusted CI for the RR was 1.85 to 95.04. Inclusion of all trials resulted in confirmation of results and of significantly increased risk of DTI when an NMBA was avoided (random-effects model) (RR 5.00, 95% CI 3.49 to 7.15; P < 0.00001; 3565 participants; 34 trials; NNTH = 6.3, I2 = 70%, D2 = 82%, GRADE = low). Again the cumulative z-curve crossed the TSA monitoring boundary, demonstrating harmful effects of avoiding NMBA on the proportion of DTI with minimal risk of random error. We categorized only one trial reporting on upper airway discomfort or injury as having overall low risk of bias. Inclusion of all trials revealed significant risk of upper airway discomfort or injury when an NMBA was avoided (random-effects model) (RR 1.37, 95% CI 1.09 to 1.74; P = 0.008; 846 participants; seven trials; NNTH = 9.1, I2 = 13%, GRADE = moderate). The TSA-adjusted CI for the RR was 1.00 to 1.85. None of these trials reported mortality. In terms of our secondary outcome 'difficult laryngoscopy', we categorized only one trial as having overall low risk of bias. All trials avoiding NMBA were significantly associated with difficult laryngoscopy (random-effects model) (RR 2.54, 95% CI 1.53 to 4.21; P = 0.0003; 1308 participants; 13 trials; NNTH = 25.6, I2 = 0%, D2= 0%, GRADE = low); however, TSA showed that only 6% of the information size required to detect or reject a 20% relative risk reduction (RRR) was accrued, and the trial sequential monitoring boundary was not crossed. AUTHORS' CONCLUSIONS: This review supports that use of an NMBA may create the best conditions for tracheal intubation and may reduce the risk of upper airway discomfort or injury following tracheal intubation. Study results were characterized by indirectness, heterogeneity, and high or uncertain risk of bias concerning our primary outcome describing difficult tracheal intubation. Therefore, we categorized the GRADE classification of quality of evidence as moderate to low. In light of defined outcomes of individual included trials, our primary outcomes may not reflect a situation that many clinicians consider to be an actual difficult tracheal intubation by which the patient's life or health may be threatened.

Rocuronium is more hepatotoxic than succinylcholine in vitro.

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

Minimum Effective Doses of Succinylcholine and Rocuronium During Electroconvulsive Therapy: A Prospective, Randomized, Crossover Trial.

BACKGROUND: Neuromuscular blockade is required to control excessive muscle contractions during electroconvulsive therapy (ECT). In a crossover, assessor-blinded, prospective randomized study, we studied the minimum effective dose (MED) of succinylcholine and rocuronium for ECT. The MED was the lowest dose to provide a predefined qualitative measure of acceptable control of muscle strength during induced convulsions. METHODS: Succinylcholine (0.8 mg kg) or rocuronium (0.4 mg kg) was randomly administered in 227 ECT sessions to 45 patients. The dose was incrementally increased or decreased by 10% based on 2 psychiatrists' (blinded to treatment) assessment of "acceptable" or "not acceptable" control of evoked muscle contractions (sufficient versus insufficient or excessive paralysis). The neuromuscular transmission was monitored quantitatively until full recovery. RESULTS: In our study, the MEDs of succinylcholine and rocuronium to produce acceptable ECT conditions in 50% of patients (MED50ECT) were 0.85 mg kg (95% confidence interval [CI], 0.77-0.94) and 0.41 mg kg (95% CI, 0.36-0.46) and in 90% of patients (MED90ECT) were 1.06 mg kg (95% CI, 1.0-1.27) and 0.57 mg kg (95% CI, 0.5-0.6), respectively. Nadir twitch height for acceptable muscle activity was 0% (0-4) and 4% (0-30; P < 0.001), respectively, and the time to recovery of the neuromuscular transmission was 9.7 ± 3.5 and 19.5 ± 5.7 minutes, respectively. CONCLUSIONS: A twitch suppression of >90% is needed for control of motor contractions during ECT. The initial ECT dose of succinylcholine should be selected based on each patient's preprocedural condition, ranging between 0.77 and 1.27 mg kg to produce acceptable muscle blockade in 50% to 90% of patients. Rocuronium-neostigmine combination is a safe alternative if appropriately dosed (0.36-0.6 mg kg) and monitored.

Pharmacological and non-pharmacological interventions for reducing rocuronium bromide induced pain on injection in children and adults.

BACKGROUND: Rocuronium bromide is a routinely used muscle relaxant in anaesthetic practice. Its use, however, is associated with intense pain on injection. While it is well established that rocuronium bromide injection causes pain in awake patients, anaesthetized patients also tend to show withdrawal movements of the limbs when this muscle relaxant is administered. Various strategies, both pharmacological and non-pharmacological, have been studied to reduce the incidence and severity of pain on rocuronium bromide injection. We wanted to find out which of the existing modalities was best to reduce pain on rocuronium injection. OBJECTIVES: The objectives of this review were to assess the ability of both pharmacological and non-pharmacological interventions to reduce or eliminate the pain that accompanies rocuronium bromide administration. SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL 2013, Issue 7), MEDLINE via Ovid SP (1966 to July 2013) and EMBASE via Ovid SP (1980 to July 2013). We also searched specific websites. We reran the searches in February 2015 and will deal with the 11 studies of interest found through this search when we update the review. SELECTION CRITERIA: We included all randomized controlled trials (RCTs) that compared the use of any drug or a non-pharmacological method with control patients, or those receiving no treatment to reduce the severity of pain with rocuronium injection. Our primary outcome was pain on rocuronium bromide injection measured by a pain score assessment. Our secondary outcomes were rise in heart rate and blood pressure following administration of rocuronium and adverse events related to the interventions. DATA COLLECTION AND ANALYSIS: We used the standardized methods for conducting a systematic review as described in the Cochrane Handbook for Systematic Reviews of Interventions. Two authors independently extracted details of trial methodology and outcome data from reports of all trials considered eligible for inclusion. We made all analyses on an intention-to-treat basis. We used a fixed-effect model where there was no evidence of significant heterogeneity between studies and a random-effects model if heterogeneity was likely. MAIN RESULTS: We included 66 studies with 7840 participants in the review, though most analyses were based on data from fewer participants. In total there are 17 studies awaiting classification. No studies were at a low risk of bias. We noted substantial statistical and clinical heterogeneity between trials. Most of the studies reported the primary outcome pain as assessed by verbal response from participants in an awake state but some trials reported withdrawal of the injected limb as a proxy for pain after induction of anaesthesia in response to rocuronium administration. Few studies reported adverse events and no study reported heart rate and blood pressure changes after administration of rocuronium. Lidocaine was the most commonly studied intervention drug, used in 29 trials with 2256 participants. The risk ratio (RR) of pain on injection if given lidocaine compared to placebo was 0.23 (95% confidence interval (CI) 0.17 to 0.31; I² = 65%, low quality of evidence). The RR of pain on injection if fentanyl and remifentanil were given compared to placebo was 0.42 (95% CI 0.26 to 0.70; I² = 79%, low quality of evidence) and (RR 0.10, 95% CI 0.04 to 0.26; I² = 74%, low quality of evidence), respectively. Pain on injection of intervention drugs was reported with the use of lidocaine and acetaminophen in one study. Cough was reported with the use of fentanyl (one study), remifentanil (five studies, low quality evidence) and alfentanil (one study). Breath holding and chest tightness were reported with the use of remifentanil in two studies (very low quality evidence) and one study (very low quality evidence), respectively. The overall rate of complications was low. AUTHORS' CONCLUSIONS: The evidence to suggest that the most commonly investigated pharmacological interventions reduce pain on injection of rocuronium is of low quality due to risk of bias and inconsistency. There is low or very low quality evidence for adverse events, due to risk of bias, inconsistency and imprecision of effect. We did not compare the various interventions with one another and so cannot comment on the superiority of one intervention over another. Complications were reported more often with use of opioids.

Prolonged Paralysis Following Emergent Cesarean Section with Succinylcholine Despite Normal Dibucaine Number.

Prolonged paralysis due to a quantitative or qualitative deficiency of pseudocholinesterase activity is an uncommon but known side effect of succinylcholine. We describe a patient who experienced prolonged paralysis following administration of succinylcholine for general anesthesia and endotracheal intubation for an emergent cesarean section despite laboratory evidence of normal enzyme function. The patient required mechanical ventilation in the intensive care unit for several hours following surgery. The patient was extubated following return of full muscle strength and had a good outcome. The enzyme responsible for the metabolism of succinylcholine, pseudocholinesterase, was determined to be low in quantity in this patient but was functionally normal. This low level, by itself, was unlikely to be solely responsible for the prolonged paralysis. The patient likely had an abnormal pseudocholinesterase enzyme variant that is undetectable by standard laboratory tests.

Quantitative Intraoperative Torsional Forced Duction Test.

PURPOSE: We developed a method for quantifying intraoperative torsional forced ductions and validated the new test by comparing patients with oblique dysfunction and controls. DESIGN: Comparative case series. SUBJECTS: We studied 33 eyes with oblique dysfunction (9 with presumed congenital superior oblique palsy [SOP], 13 with acquired SOP, 7 with Brown syndrome, and 4 with inverted Brown syndrome) and 31 controls. We also studied 6 eyes after superior oblique (SO) disinsertion and 2 eyes after inferior oblique (IO) disinsertion. METHODS: Under deep general anesthesia, the 12 and 6 o'clock positions at the limbus were marked and the globe was maximally excyclorotated and incyclorotated without retroplacement until the first resistance was felt, and the angle of rotation (in degrees) was read on a Mendez ring by the surgeon. A photograph was taken in each position to be read by a masked observer. MAIN OUTCOME MEASURES: Maximal excyclorotation and maximal incyclorotation in each oblique dysfunction and in controls by both surgeon's report and photographic assessment. We duplicated the photographs to evaluate test-retest reliability and to evaluate agreement between the surgeon's assessments and the photographic assessment. RESULTS: Surgeon's assessment revealed greater maximal excyclorotation in eyes with presumed congenital SOP than in controls (median, 40 vs. 30 degrees). Maximal excyclorotation in eyes with acquired SOP was similar to that in controls (30 degrees in both). Eyes with Brown syndrome and inverted Brown syndrome had lower maximal excyclorotation than in controls (10 and 20 vs. 30 degrees, respectively). Maximal incyclorotation in eyes with inverted Brown syndrome was lower than in controls (12.5 vs. 30 degrees), whereas it was similar to that of controls in eyes with presumed congenital SOP, acquired SOP, and Brown syndrome (30 degrees in each condition). Median maximal excyclorotation after SO disinsertion was 62.5 degrees, and maximal incyclorotation after IO disinsertion was 60 degrees. Photographic assessment yielded findings essentially identical to the surgeon's report. Test-retest reliability of the photographic reading was excellent, and agreement between the surgeon's report and the photographic reading was also excellent (95% limits of agreement, 4.4 and 11.6; intraclass correlation coefficient, 0.97 and 0.82, respectively). CONCLUSIONS: The new torsional forced duction test enables quantitative assessment of SO and IO tightness and laxity.

Rocuronium versus succinylcholine for rapid sequence induction intubation.

BACKGROUND: Patients often require a rapid sequence induction (RSI) endotracheal intubation technique during emergencies or electively to protect against aspiration, increased intracranial pressure, or to facilitate intubation. Traditionally succinylcholine has been the most commonly used muscle relaxant for this purpose because of its fast onset and short duration; unfortunately, it can have serious side effects. Rocuronium has been suggested as an alternative to succinylcholine for intubation. This is an update of our Cochrane review published first in 2003 and then updated in 2008 and now in 2015. OBJECTIVES: To determine whether rocuronium creates intubating conditions comparable to those of succinylcholine during RSI intubation. SEARCH METHODS: In our initial review we searched all databases until March 2000, followed by an update to June 2007. This latest update included searching the Cochrane Central Register of Controlled Trials (CENTRAL; 2015, Issue 2), MEDLINE (1966 to February Week 2 2015), and EMBASE (1988 to February 14 2015 ) for randomized controlled trials (RCTs) or controlled clinical trials (CCTs) relating to the use of rocuronium and succinylcholine. We included foreign language journals and handsearched the references of identified studies for additional citations. SELECTION CRITERIA: We included any RCT or CCT that reported intubating conditions in comparing the use of rocuronium and succinylcholine for RSI or modified RSI in any age group or clinical setting. The dose of rocuronium was at least 0.6 mg/kg and succinylcholine was at least 1 mg/kg. DATA COLLECTION AND ANALYSIS: Two authors (EN and DT) independently extracted data and assessed methodological quality for the 'Risk of bias' tables. We combined the outcomes in Review Manager 5 using a risk ratio (RR) with a random-effects model. MAIN RESULTS: The previous update (2008) had identified 53 potential studies and included 37 combined for meta-analysis. In this latest update we identified a further 13 studies and included 11, summarizing the results of 50 trials including 4151 participants. Overall, succinylcholine was superior to rocuronium for achieving excellent intubating conditions: RR 0.86 (95% confidence interval (CI) 0.81 to 0.92; n = 4151) and clinically acceptable intubation conditions (RR 0.97, 95% CI 0.95 to 0.99; n = 3992, 48 trials). A high incidence of detection bias amongst the trials coupled with significant heterogeneity provides moderate-quality evidence for these conclusions, which are unchanged from the previous update. Succinylcholine was more likely to produce excellent intubating conditions when using thiopental as the induction agent: RR 0.81 (95% CI: 0.73 to 0.88; n = 2302, 28 trials). In the previous update, we had concluded that propofol was the superior induction agent with succinylcholine. There were no reported incidences of severe adverse outcomes. We found no statistical difference in intubation conditions when succinylcholine was compared to 1.2 mg/kg rocuronium; however, succinylcholine was clinically superior as it has a shorter duration of action. AUTHORS' CONCLUSIONS: Succinylcholine created superior intubation conditions to rocuronium in achieving excellent and clinically acceptable intubating conditions.

Predictors of the variability in neuromuscular block duration following succinylcholine: A prospective, observational study.

BACKGROUND: The duration of neuromuscular block (NMB) following succinylcholine administration is characterised by a high interindividual variability. However, this has not yet been quantified in a large sample of surgical patients. The significance of underlying clinical factors is unknown. OBJECTIVE: The objective of this study was to profile the variability in NMB duration following a standard dose of succinylcholine and to investigate contributing clinical and genetic factors. DESIGN: A prospective, observational study. SETTING: Tertiary referral centre. PATIENTS: In a total of 1630 surgical patients undergoing a rapid sequence induction and intubation, clinical risk factors for a prolongation in NMB duration following succinylcholine were assessed. In a subset of 202 patients, additional biochemical and molecular genetic investigations of butyrylcholinesterase were performed. INTERVENTION: A standard 1 mg kg dose of succinylcholine after administration of an induction drug and an opioid. MAIN OUTCOME: NMB duration measured as the time between administration of succinylcholine until reappearance of palpable muscular response to supramaximal transcutaneous ulnar nerve stimulation. RESULTS: NMB varied from 80 s to 44 min with a median duration of 7.3 min. Sixteen percent of patients had NMB duration in excess of 10 min. A multivariable survival model identified physical status, sex, age, hepatic disease, pregnancy, history of cancer and use of etomidate or metoclopramide as independent risk factors for a prolonged NMB. Three novel butyrylcholinesterase variants were identified: p.Ile5Thr; p.Val178Ile; and p.Try231Ser. CONCLUSION: Neuromuscular blockade duration in excess of 10 min occurred in 16% of a general surgical population following a single dose of succinylcholine. The multivariable model of clinical risk factors for prolonged NMB revealed a negative predictive value of 87%, thereby indicating that absence of such risk factors may reliably predict a shorter duration of NMB. In patients with clinical risk factors for a prolonged NMB or with butyrylcholinesterase mutations, an alternative to succinylcholine should be considered.

Paramedic rapid sequence intubation in patients with non-traumatic coma.

INTRODUCTION: Pre-hospital intubation by paramedics is widely used in comatose patients prior to transportation to hospital, but the optimal technique for intubation is uncertain. One approach is paramedic rapid sequence intubation (RSI), which may improve outcomes in adult patients with traumatic brain injury. However, many patients present to emergency medical services with coma of non-traumatic cause and the role of paramedic RSI in these patients remains uncertain. METHODS: The electronic Victorian Ambulance Clinical Information System was searched for the term 'suxamethonium' between 2008 and 2011. We reviewed the patient care records and included patients with suspected non-traumatic coma who were treated and transported by road-based paramedics. Demographics, intubation conditions, vital signs (before and after drug administration) and complications were recorded. Younger patients (<60 years) were compared with older patients. RESULTS: There were 1152 paramedic RSI attempts of which 551 were for non-traumatic coma. The success rate for intubation was 97.5%. There was a significant drop in blood pressure in younger patients (<60 years) with the mean systolic blood pressure decreasing by 16 mm Hg (95% CI 11 to 21). In older patients, the systolic blood pressure also decreased significantly by 20 mm Hg (95% CI 17 to 24). Four patients suffered brief cardiac arrest during pre-hospital care, all of whom were successfully resuscitated and transported to hospital. CONCLUSIONS: Paramedic RSI in patients with non-traumatic coma has a high procedural success rate. Further studies are required to determine whether this procedure improves outcomes.

Safe resumption of maintenance electroconvulsive therapy 12 days after surgical repair of hip fracture.

Hip fractures are a common injury affecting older individuals, especially women with osteoporosis. When patients who are at risk for hip fractures or who have had such a fracture that was recently repaired require electroconvulsive therapy, care must be taken to ensure complete muscle relaxation. Adequate muscle relaxation can be achieved using a dose of succinylcholine of approximately 1 mg/kg in most patients, but for patients who are at risk for complications resulting from inadequate muscle relaxation, the dose of succinylcholine may need to be increased by 40% to 50% to ensure complete relaxation.

Rocuronium Versus Suxamethonium: A Survey of First-line Muscle Relaxant Use in UK Prehospital Rapid Sequence Induction.

INTRODUCTION: Prehospital anaesthesia in the United Kingdom (UK) is provided by Helicopter Emergency Medical Service (HEMS) and British Association for Immediate Care (BASICS), a road-based service. Muscle relaxation in rapid sequence induction (RSI) has been traditionally undertaken with the use of suxamethonium; however, rocuronium at higher doses has comparable intubating conditions with fewer side effects. HYPOTHESIS/PROBLEM: The aim of this survey was to establish how many prehospital services in the UK are now using rocuronium as first line in RSI. METHODS: An online survey was constructed identifying choice of first-line muscle relaxant for RSI and emailed to lead clinicians for BASICS and HEMS services across the UK. If rocuronium was used, further questions regarding optimal dose, sugammadex, contraindications, and difference in intubating conditions were asked. RESULTS: A total of 29 full responses (93.5%) were obtained from 31 services contacted. Suxamethonium was used first line by 17 prehospital services (58.6%) and rocuronium by 12 (41.4%). In 11 services (91.7%), a dose of 1 mg/kg of rocuronium was used, and in one service, 1.2 mg/kg (8.3%) was used. No services using rocuronium carried sugammadex. In five services, slower relaxation time was found using rocuronium (41.7%), and in seven services, no difference in intubation conditions were noted (58.3%). Contraindications to rocuronium use included high probability of difficult airway and anaphylaxis. CONCLUSION: Use of rocuronium as first-line muscle relaxant in prehospital RSI is increasing. Continued auditing of practice will ascertain which services have adopted change and identify if complications of failed intubation increase as a result.

The increases in potassium concentrations are greater with succinylcholine than with rocuronium-sugammadex in outpatient surgery: a randomized, multicentre trial.

BACKGROUND: Succinylcholine provides rapid onset of neuromuscular blockade and short duration of action, but its administration may be associated with hyperkalemia. Rocuronium is not known to increase potassium concentration, has fast onset of activity, and can be rapidly reversed by sugammadex. This study evaluated changes in plasma potassium concentrations in patients randomized either to rocuronium followed by sugammadex reversal or to succinylcholine in ambulatory surgery. METHODS: In this multicentre randomized active-controlled study, adult patients undergoing short surgical procedures in an outpatient setting received either rocuronium 0.6 mg·kg(-1) for intubation with sugammadex 4.0 mg·kg(-1) for reversal (n = 70) or succinylcholine 1.0 mg·kg(-1) with spontaneous recovery (n = 80). Blood potassium concentrations were assessed at baseline (before study drug administration) and at intervals up to 15 min after rocuronium, sugammadex, and succinylcholine. RESULTS: At the primary endpoint, five minutes post-administration, the changes in potassium concentrations from baseline were significantly smaller in patients treated with rocuronium than in those given succinylcholine [mean (SD): -0.06 (0.32) vs 0.30 (0.34) mmol·L(-1), respectively; P < 0.0001]. At baseline, potassium concentrations were similar in both groups, but they were greater at two, five, ten, and 15 min after succinylcholine than after rocuronium (P < 0.0001) for all time points. After sugammadex administration, there were no significant changes in mean potassium concentration from the pre-rocuronium baseline. No adverse effects related to hyperkalemia were observed. CONCLUSION: Succinylcholine was associated with a modest increase in potassium concentration; these changes were not seen after rocuronium or sugammadex ( CLINICAL TRIAL REGISTRATION NUMBER: NCT00751179).

[Anterior dislocation of a Incarcerated Retroverted Uterus at 21 weeks of amenorrhea : Case Report. ]. / Luxation antérieure d'un utérus rétroversé incarcéré à 21 semaines d'aménorrhée : à propos d'un cas.

BACKGROUND: An incarcerated uterus refers to the retroversion of a pregnant uterus within the pelvis due to the absence of a forward tilt at the end of the first trimester. An incarcerated uterus that is overlooked or only discovered perpartum can cause severe obstetrical complications. Several authors have shared their experience with uterine incarceration management at 12, 14, and 16 weeks of amenorrhea. CASE: Our report concerns a case of uterine incarceration management at 21 weeks of amenorrhea, achieved by way of a specific anesthesia protocol and the positioning of the patient, which allowed the disimpaction of the uterus with the help of external maneuvers. No recurrence was observed. CONCLUSION: Uterine incarceration management is possible beyond 16 weeks of amenorrhea.

Background: An incarcerated uterus refers to the retroversion of a pregnant uterus within the pelvis due to the absence of a forward tilt at the end of the first trimester. An incarcerated uterus that is overlooked or only discovered perpartum can cause severe obstetrical complications. Several authors have shared their experience with uterine incarceration management at 12, 14, and 16 weeks of amenorrhea. Case: Our report concerns a case of uterine incarceration management at 21 weeks of amenorrhea, achieved by way of a specific anesthesia protocol and the positioning of the patient, which allowed the disimpaction of the uterus with the help of external maneuvers. No recurrence was observed. Conclusion: Uterine incarceration management is possible beyond 16 weeks of amenorrhea.

Comparative evaluation of prophylactic use of pregabalin, gabapentin and diclofenac sodium for prevention of succinylcholine-induced myalgia: a randomized, double-blinded study.

CONTEXT: Succinylcholine a depolarizing muscle relaxant with rapid onset, predictable course and short duration of action is associated with myalgia. AIM: The aim of this study is to evaluate the efficacy of pregabalin, gabapentin and diclofenac on the incidence and severity of succinylcholine-induced myalgia. SETTINGS AND DESIGN: Tertiary Care Teaching Hospital. MATERIALS AND METHODS: A total of 120 patients undergoing laparoscopic cholecystectomy were randomly assigned into three groups: Pregabalin group received 150 mg of pregabalin, gabapentin group received 600 mg of gabapentin and diclofenac group received 100 mg of diclofenac sodium orally 2 h prior to surgery. Anesthesia was induced with fentanyl 3 µg/kg, propofol 2-2.5 mg/kg and succinylcholine 1.5 mg/kg and was maintained with oxygen with sevoflurane in the air and intermittent vecuronium bromide. A blinded observer recorded post-operative pain scores on visual analog scale at different time intervals and myalgia at 24 h. Post-operative pain relief was provided with fentanyl based patient-controlled analgesia. Fentanyl consumption in 24 h was recorded as a primary outcome. STATISTICAL ANALYSIS: Patients' characteristics and total fentanyl consumption were compared using one-way ANOVA followed by post-hoc test. Pain score was compared amongst the groups using Kruskal Wallis test. RESULTS: The myalgia occurred in 15, 14 and 13 patients in pregabalin, gabapentin and diclofenac sodium group respectively (P > 0.85). Patients in diclofenac group had significantly higher fentanyl consumption (674.85 ± 115.58 µg) compared with pregabalin group (601.87 ± 129.57 µg) (95% confidence interval [CI] = 34.8-120.7) and gabapentin group (612.29 ± 105.12 µg) (95% CI = 14.9-170.5). However, there was no significant difference in fentanyl consumption between pregabalin and gabapentin groups (95% CI = -34.8-120.7). There was a significant difference in visual analog score at time points 12, 18 and 24 h among the study groups. CONCLUSION: Pre-treatment with pregabalin, gabapentin and diclofenac had equal efficacy in reducing the incidence and severity of succinylcholine-induced myalgia. However, pre-treatment with pregabalin and gabapentin decreased post-operative pain scores and fentanyl consumption.