Rapid tracheal intubation with large-dose rocuronium: a probability-based approach

[Neuromuscular Blockade in Paediatric Patients]

The administration of muscle relaxants has been used in anesthesia for decades and continues to play an important role in modern anaesthesia. Special patient populations, such as infants or very young patients require adapted use. The article discusses the specifics of muscle relaxant administration in these patient groups.

Rocuronium ≤1.5 mg/kg versus >1.5 mg/kg and inadequate paralysis in prehospital and retrieval intubation: A retrospective study

OBJECTIVE

Greater Sydney Area Helicopter Emergency Medical Service encouraged an increased dose of rocuronium for rapid sequence intubations (RSIs) from 1.5 mg/kg to 2.0 mg/kg from the end of 2017 in response to a number of inadequately paralysed patients identified by our airway audit processes. Subsequent protocol change incorporated 2.0 mg/kg rocuronium. This retrospective observational study was undertaken to see if doses over 1.5 mg/kg rocuronium were associated with a reduction in the number of inadequately paralysed patients.

METHODS

Retrospective review of patient prehospital notes and airway database records from 2017 to 2018 for all cases using rocuronium for RSI. Primary outcome of interest was physician notes describing skeletal muscle activity at laryngoscopy. Patients with tissued vascular access were excluded. Dose of rocuronium, estimated patient actual weight and grade of laryngoscopy were recorded. Comparisons were made between rocuronium doses ≤1.5 mg/kg and >1.5 mg/kg by estimated weight.

RESULTS

From 211 patients receiving rocuronium ≤1.5 mg/kg, five cases were inadequately paralysed, compared with two cases from 384 patients receiving >1.5 mg/kg rocuronium.

CONCLUSIONS

Although there were fewer inadequately paralysed patients with rocuronium doses >1.5 mg/kg, this did not reach statistical significance, presumably because of the low event rate. Further investigation into rocuronium dose for RSI is warranted.

Rapid sequence induction with a "modified timing principle" of rocuronium provides excellent intubating conditions: A randomised trial

The present study was designed to compare the intubating conditions of rocuronium giving by "a modified timing principle" in rapid induction and intubation (RSII) with that of the gold standard, succinylcholine. One hundred and twenty-four patients were randomly divided into rocuronium group (group R, n = 62) or succinylcholine group (group S, n = 62). In group R, after rocuronium 0.6 mg kg^-1 was given, anaesthesia was induced with propofol 2 mg kg^-1 and remifentanil 2 μg kg^-1, and tracheal intubation was performed 60 s after rocuronium administration. In group S, succinylcholine 1.5 mg kg^-1 was given after patient lost consciousness induced by the same regimen of group R, and tracheal intubation was performed 60 s after succinylcholine administration. Our primary endpoint was the intubating conditions. The numbers of patients with excellent and good intubating conditions in group R were 90.0% and 6.7%, respectively, which were comparable with those in group S (91.7% and 5.0% respectively). The apnoea time in group S (79.7 ± 5.1 s) was longer than that of group R (56.6 ± 4.6 s) (p = 0.0063). The average BIS values at the time of intubation in group R (64.1 ± 4.1) was higher than that of group S (43.2 ± 5.5) (p = 0.018). In the context of a RSII with lidocaine-remifentanil-propofol, the application of this "modified timing principle" with rocuronium 0.6 mg kg^-1 could provide comparable intubating conditions with those achieved by succinylcholine 1.5 mg kg^-1. Additionally, this modified timing principle with rocuronium was associated with shorter apnoea time.

Integration of ophthalmology in ocular trauma to improve patient care: A narrative review

Introduction

Ocular trauma can cause significant morbidity and is a leading cause of unilateral blindness. In multi-trauma, life- and sight-threatening injuries can co-occur causing increased complexity in the assessment and management of ocular injuries as the competing priorities in the severely injured must be balanced. We conducted a narrative review to determine how ophthalmology may be further integrated into a trauma service and/or the organisation of an ocular trauma service.

Methods

The literature was reviewed via EMBASE, MEDLINE, CINAHL and Google Scholar utilising comprehensive search strategies and keyword searches. Our review was conducted in compliance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement.

Results

The search yielded 437 articles, 30 studies met selection criteria and were included in the review. The included literature comprised guidelines, observational studies and reviews of registry data from Australia, England, the United States, Singapore, Iran and Israel.

Conclusion

The Australian Trauma Model has clear guidelines for referral of trauma patients to ensure appropriate care of the severely injured. However, there are no clear guidelines for the integration of ophthalmology into trauma. Therefore, early referral to ophthalmology and streamlining of referral pathways of specialist care would improve the care of patients with ocular trauma.

The association of rocuronium dosing and first-attempt intubation success in adult emergency department patients

BACKGROUND

The recommended rocuronium dose for rapid sequence intubation is 1.0 mg/kg; however, the optimal dose for emergency airway management is not clear. We assessed the relationship between rocuronium dose and first-attempt success among emergency department (ED) patients undergoing rapid sequence intubation.

METHODS

This is a secondary analysis of the National Emergency Airway Registry (NEAR), an observational 25-center registry of ED intubations. Ninety percent recording compliance was required from each site for data inclusion. We included all patients > 14 years of age who received rocuronium for rapid sequence intubation from 1 Jan 2016 to 31 Dec 2018. We compared first-attempt success between encounters using alternative rocuronium doses (< 1.0, 1.0-1.1, 1.2-1.3 and ≥1.4 mg/kg). We performed logistic regressions to control for predictors of difficult airways, indication, pre-intubation hemodynamics, operator, body habitus and device. We also performed subgroup analyses stratified by device (direct vs. video laryngoscopy). We calculated univariate descriptive statistics and odds ratios (OR) from multivariable logistic regressions with cluster-adjusted 95% confidence intervals (CI).

RESULTS

19,071 encounters were recorded during the 3-year period. Of these, 8,034 utilized rocuronium for rapid sequence intubation. Overall, first attempt success was 88.4% for < 1.0 mg/kg, 88.1% for 1.0-1.1 mg/kg, 89.7% for 1.2-1.3 mg/kg, and 92.2% for ≥1.4 mg/kg. Logistic regression demonstrated that when direct laryngoscopy was used and when compared to the standard dosing range of 1.0-1.1 mg/kg, the adjusted odds of a first attempt success was significantly higher in ≥1.4 mg/kg group at 1.9 (95% CI 1.3-2.7) relative to the other dosing ranges, OR 0.9 (95% CI 0.7-1.2) for < 1.0 mg/kg and OR 1.2 (95% CI 0.9-1.7) for the 1.2-1.3 mg/kg group. First-attempt success was similar across all rocuronium doses among patients utilizing video laryngoscopy. Patients who were hypotensive (SBP < 100 mmHg) prior to intubation had higher first-attempt success 94.9% versus 88.6% when higher doses of rocuronium were used. The rates of all peri-intubation adverse events and desaturation were similar between dosing groups, laryngoscope type utilized and varying pre-intubation hemodynamics.

CONCLUSIONS

Rocuronium dosed ≥1.4 mg/kg was associated with higher first attempt success when using direct laryngoscopy and among patients with pre-intubation hypotension with no increase in adverse events. We recommend further prospective evaluation of the dosing of rocuronium prior to offering definitive clinical guidance.

Emergency Airway Management Outside the Operating Room: Current Evidence and Management Strategies

Emergency airway management outside the operating room (OR) is often associated with an increased risk of airway related, as well as cardiopulmonary, complications which can impact morbidity and mortality. These emergent airways may take place in the intensive care unit (ICU), where patients are critically ill with minimal physiological reserve, or other areas of the hospital where advanced equipment and personnel are often unavailable. As such, emergency airway management outside the OR requires expertise at manipulation of not only the anatomically difficult airway but also the physiologically and situationally difficult airway. Adequate preparation and appropriate use of airway management techniques are important to prevent complications. Judicious utilization of pre- and apneic oxygenation is important as is the choice of medications to facilitate intubation in this at-risk population. Recent study in critically ill patients has shown that postintubation hemodynamic and respiratory compromise is common, independently associated with poor outcomes and can be impacted by the choice of drugs and techniques used. In addition to adequately preparing for a physiologically difficult airway, enhancing the ability to predict an anatomically difficult airway is essential in reducing complication rates. The use of artificial intelligence in the identification of difficult airways has shown promising results and could be of significant advantage in uncooperative patients as well as those with a questionable airway examination. Incorporating this technology and understanding the physiological, anatomical, and logistical challenges may help providers better prepare for managing such precarious airways and lead to successful outcomes. This review discusses the various challenges associated with airway management outside the OR, provides guidance on appropriate preparation, airway management skills, medication use, and highlights the role of a coordinated multidisciplinary approach to out-of-OR airway management.

[New aspects of rapid sequence induction including treatment of pulmonary aspiration]

Pulmonary aspiration of solid components leads to displacement of the tracheobronchial tree, the aspiration of acidic gastric juices to chemical pneumonitis (Mendelson's syndrome) and the aspiration of oropharyngeal secretions or gastrointestinal pathogens to aspiration pneumonia. Principally, pulmonary aspiration can occur at any stage of anesthesia. In the clinical routine the aim must therefore be to identify those patients who have an increased risk of aspiration. When this is successful, measures can be taken to reduce the risk; these can be regional anaesthesia or the performance of general anaesthesia as rapid sequence induction (RSI). If severe pulmonary aspiration occurs despite all preventive measures, mostly during induction of anaesthesia, extensive experience and rapid action are necessary. This can only be achieved if the induction to RSI is performed by three persons with supervision of the trainee anaesthetist by a consultant anaesthetist.

Perioperative Effects of Induction with High-dose Rocuronium during Laparoscopic Cholecystectomy

Objective

We aimed to investigate the effects of high-dose rocuronium administration on intra-abdominal pressure (IAP) and surgical conditions during anaesthesia induction and laparoscopic cholecystectomy anaesthesia induction, respectively. Further, we aimed to determine postoperative nausea and vomiting (PONV) and pain scores following the laparoscopic cholecystectomy.

Methods

Patients with American Society of Anesthesiologists (ASA) score of I–III, aged 18 to 75 years and who were scheduled for surgery under general anaesthesia were included in the study. Patients were randomised and a high-dose of 1.2 mg kg⁻¹ rocuronium was given to Group A and 0.6 mg kg⁻¹ rocuronium to Group B. The intraoperative train of four (TOF) ratio and post-tetanic count (PTC) were measured. Surgery was initiated with a low IAP of 7 mmHg. The surgeon evaluated surgical conditions with a 4-step surgical field scale and increased the IAP when necessary. PONV at 4, 12 and 24 hours and postoperative pain at 2 and 24 hours and 3 days were evaluated.

Results

There were no significant differences in the demographic and haemodynamic parameters between the groups. In high-dose rocuronium Group A, IAP values were significantly lower in the first 20 minutes compared to Group B. The duration of operations was significantly shorter in Group A (29.00±7.39 minute vs. 34.63±12.00 minute, p=0.044). PONV in the first 12 hours was significantly lower in Group A (p<0.05).

Conclusion

High-dose rocuronium-induced deep neuromuscular block helped perform laparoscopic cholecystectomy operations with lower values of IAP compared to a normal dose rocuronium. It also shortened duration of operation and reduced PONV and pain.

The effect of low-dose rocuronium on rapid tracheal intubation using a video laryngoscope: A randomized double blind controlled study

BACKGROUND

The aim of this study was to investigate the clinical effectiveness of rocuronium in low doses on conditions during rapid tracheal intubation using video laryngoscope.

METHODS

Ninety-eight patients undergoing otolaryngologic surgery were randomly divided into 2 groups: group L using 0.3 mg/kg of rocuronium intravenously (n = 49) and group C using 0.6 mg/kg of rocuronium (n = 49). Sixty seconds after rocuronium administration, tracheal intubation was performed using a video laryngoscope. The overall intubation condition was evaluated along with specific conditions, including laryngoscopy condition, vocal cord position, and intubation response. Intubation profiles, including Cormack-Lehane grade, 1st attempt success rate, and intubation time, were also evaluated.

RESULTS

Overall intubation conditions showed a significant difference between group L and group C (P = .003). Although the incidence of vigorous response after tracheal intubation was higher in group L than in group C (P = .022), laryngoscopy condition and vocal cord position were similar between the 2 groups (P = .145 and .070, respectively). Intubation profiles showed no differences between the 2 groups. The frequency and amount of additional rocuronium administration during surgery were also similar.

CONCLUSIONS

Low-dose rocuronium provided significantly worse overall intubation conditions compared to the conventional dose of rocuronium for rapid tracheal intubation. However, when using a video laryngoscope, it may provide clinically acceptable laryngeal muscle relaxation.

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.

Dose requirements of alfentanil to eliminate autonomic responses during rapid-sequence induction with thiopental 4 mg/kg and rocuronium 0.6 mg/kg

STUDY OBJECTIVE

Opioids are integral part of anesthesia induction, but information on optimal dosing is limited. We aimed to determine doses of alfentanil needed to eliminate increases in 5 autonomic response variables (plasma concentrations of epinephrine, norepinephrine and vasopressin, arterial blood pressure [ABP], and heart rate) during rapid-sequence induction of anesthesia with thiopental 4 mg/kg and rocuronium 0.6 mg/kg.

DESIGN

Prospective, randomized, observer-blinded, interventional clinical study.

SETTING

Large academic institution.

PATIENTS

Eighty-four healthy patients, aged 18 to 55 years, received 1 of 7 assessor-blinded doses of alfentanil (0, 10, 20, 30, 40, 50, and 60 μg/kg) together with thiopental 4 mg/kg and rocuronium 0.6 mg/kg, administered in rapid succession (15 seconds). Laryngoscopy was initiated 40 seconds after rocuronium, and tracheal intubation was concluded within 15 seconds thereafter.

MEASUREMENTS

An indwelling radial artery catheter was used for hemodynamic monitoring and blood sampling. Relationships between alfentanil dose and response variables were tested with linear regression, and the influence of covariates (sex, body weight, and age) was determined. Alfentanil dose needed to prevent increases in ABP >10% above baseline with 95% probability was estimated with logistic regression.

MAIN RESULTS

Significant relationships were determined between alfentanil dose and response variables. Clinically interesting influence of covariates was not found. Alfentanil 55 μg/kg was needed to prevent increases in ABP postintubation >10% above baseline with 95% probability. One individual needed a bolus of vasopressor postintubation.

CONCLUSIONS

Optimal control of autonomic responses during rapid-sequence induction was achieved with clinically relevant doses of alfentanil in healthy patients anesthetized with thiopental 4 mg/kg and rocuronium 0.6 mg/kg.

Intraoperative hemodynamics with vecuronium bromide and rocuronium for maintenance under general anesthesia

Aims:

The present study is undertaken to compare the hemodynamic effects using vecuronium versus rocuronium for maintenance in patients undergoing general surgical procedures.

Settings and Design:

It is a prospective, randomized, and cohort study.

Subjects and Methods:

100 patients were randomly divided into two groups. All patients were induced with 5 mg/kg of thiopentone sodium, and intubation conditions were achieved with 1.5 mg/kg of suxamethonium, using a well-lubricated cuffed endotracheal tube of appropriate size. When the patient started to breathe spontaneously, they were administered either 0.6 mg/kg of rocuronium (Group A) or 0.1 mg/kg of vecuronium (Group B). Hemodynamic parameters (heart rate and mean arterial pressure [MAP]) were monitored before administering the drug; at 1, 5, 10, 15, and 20 min after the drug and at the end of the surgery.

Statistical Analysis Used:

Data were compiled, analyzed and presented as frequency, proportions, mean, standard deviation, percentages, and t-test using SPSS (version 16). A P < 0.05 was considered as significant.

Results:

The heart rate increased significantly at 1-min and 5-min after administration of rocuronium (83.76 ± 10.37 and 86.8 ± 9.98), unlike vecuronium. However, it gradually declined towards normal, and change in heart rate with either drug was not significant beyond 10 min. The MAP decreased significantly at 1-min after administration of rocuronium (96.68 ± 7.57) which later showed a gradual increasing trend when compared to vecuronium which had no statistically significant change at any time.

Conclusions:

For short surgical procedures rocuronium is a good alternative to vecuronium, as the drug is reasonably cardio stable, produces excellent intubation conditions, has a shorter duration of action, and shows minimal cumulative effect.

Comparison of rocuronium at two different doses and succinylcholine for endotracheal intubation in adult patients for elective surgeries

Background:

The effects of rocuronium at two different doses, that is, 0.6 mg/kg (2 × ED95) and 0.9 mg/kg (3 × ED95), were compared with succinylcholine (2 mg/kg) when used for endotracheal intubation in adult patients for elective surgeries under general anesthesia.

Materials and Methods:

Ninety patients were divided into three groups of 30 each. Groups A, B received injection rocuronium at 0.6 mg/kg, 0.9 mg/kg respectively and Group C received succinylcholine at 2 mg/kg. Onset of action of relaxant, intubation conditions, time taken to intubate and duration of action were compared.

Statistical Analysis Used:

To compare the statistical difference in the age, weight, height of the study subjects, onset of action of relaxant, intubation conditions, time taken to intubate, and duration of action analysis of variance and unpaired t-test were used.

Results:

The onset time was considerably shorter with rocuronium 0.9 mg/kg than 0.6 mg/kg. The onset time of rocuronium 0.9 mg/kg was found to be significantly longer than succinylcholine 2 mg/kg. Time taken to intubate was shortest with succinylcholine 2 mg/kg. The time taken to intubate with the rocuronium 0.9 mg/kg was found to be comparable to that of rocuronium 0.6 mg/kg. Intubation score of rocuronium 0.9 mg/kg was the best (17.75), which was comparable with succinylcholine. However, the intubation score obtained with rocuronium 0.6 mg/kg was inferior. Duration of action was shortest with succinylcholine. The duration of action is prolonged when the dose of rocuronium is increased from 0.6 to 0.9 mg/kg.

Conclusion:

Rapid sequence induction of anesthesia with propofol and fentanyl, succinylcholine allowed a more rapid endotracheal intubation sequence and created superior intubation conditions than rocuronium. However, the technique of using a large dose of rocuronium to achieve perfect conditions for tracheal intubation may have application whenever succinylcholine is relatively contraindicated.

Alfentanil during rapid sequence induction with thiopental 4 mg/kg and rocuronium 0.6 mg/kg: tracheal intubation conditions

BACKGROUND

Opioids have become an integral part of anaesthesia induction. We aimed to determine the dose of alfentanil needed to obtain perfect tracheal intubation conditions during rapid sequence induction with standard doses of thiopental and rocuronium, where laryngoscopy was initiated 55 s after commencement of drug administration. The influence of covariates (sex, body weight, age, alfentanil plasma concentration at laryngoscopy) was tested.

METHODS

Eighty-four healthy individuals were randomly assigned to receive one of the seven assessor-blinded alfentanil doses (0, 10, 20, 30, 40, 50 and 60 μg/kg) in conjunction with thiopental 4 mg/kg and rocuronium 0.6 mg/kg. For drug administration, 15 s was allowed. Laryngoscopy was initiated 40 s after rocuronium and tracheal intubation concluded within 70 s after commencement of drug administration. Alfentanil doses associated with 50%, 90% and 95% probability of perfect intubation conditions were determined with logistic regression. Multiple logistic regressions were used to test the influence of covariates. The relationship between alfentanil dose and concentration at laryngoscopy was analysed with linear regression. The effects of covariates on plasma concentrations of alfentanil were tested with multiple linear regressions.

RESULTS

Perfect intubation conditions of 95% probability was obtained with 56 μg/kg (confidence intervals 44-68). None of the covariates were significant predictors of perfect intubation conditions. Alfentanil plasma concentration correlated with dose and increased with increasing body weight (1.7 ng/ml/kg).

CONCLUSION

Perfect intubation conditions during rapid sequence induction can be obtained with clinically relevant doses of alfentanil in most healthy patients anaesthetized with thiopental 4 mg/kg and rocuronium 0.6 mg/kg.

Development of a standard operating procedure and checklist for rapid sequence induction in the critically ill

INTRODUCTION

Rapid sequence induction (RSI) of critically ill patients outside of theatres is associated with a higher risk of hypoxia, cardiovascular collapse and death. In the prehospital and military environments, there is an increasing awareness of the benefits of standardised practice and checklists.

METHODS

We conducted a non-systematic review of literature pertaining to key components of RSI preparation and management. A standard operating procedure (SOP) for in-hospital RSI was developed based on this and experience from large teaching hospital anaesthesia and critical care departments.

RESULTS

The SOP consists of a RSI equipment set-up sheet, pre-RSI checklist and failed airway algorithm. The SOP should improve RSI preparation, crew resource management and first pass intubation success while minimising adverse events.

CONCLUSION

Based on the presented literature, we believe the evidence is sufficient to recommend adoption of the core components in the suggested SOP. This standardised approach to RSI in the critically ill may reduce the current high incidence of adverse events and hopefully improve patient outcomes.

Comparison of intubating conditions between rocuronium with priming and without priming: Randomized and double-blind study

BACKGROUND

Rocuronium produces faster neuromuscular blockade compared with other neuromuscular blocking drugs. It produces comparable intubating conditions to that of succinylcholine, but does not have the short intubation time of the latter. Hence, it may not be preferable for rapid sequence intubation, but rocuronium with priming may produce comparable intubating time and conditions to that of succinylcholine. Rocuronium with priming may be an alternative to succinylcholine in rapid sequence intubation in conditions where succinylcholine is contraindicated. The present study was conducted to compare the intubating conditions and intubation time of rocuronium with and without priming.

METHODS

Sixty patients of ASA physical status I and II, aged between 18 and 60 years, of both sexes, were divided into priming and control groups of 30 each. Patients in the priming group received 0.06 mg/kg of rocuronium and those in the control group received normal saline. All patients received fentanyl 1 μg/kg, followed by thiopentone 5 mg/kg for induction. Intubating dose of rocuronium 0.54 mg/kg in the priming group and 0.6 mg/kg in the control group were administered 3 min after priming. Onset time of intubation was assessed using a Train of Four stimuli, and the intubating conditions were compared by the Cooper scoring system.

RESULTS

The onset time of intubation was 50.67±7.39 s in the priming group and 94.00±11.62 s in the control group, with excellent intubating conditions in both the groups and without any adverse effects.

CONCLUSIONS

Priming with rocuronium provides excellent intubating conditions in less than 60 s with no adverse effects.

A randomised controlled trial comparing rocuronium priming, magnesium pre-treatment and a combination of the two methods

We investigated whether magnesium sulphate combined with rocuronium priming shortens the onset of neuromuscular blockade, compared with these methods used alone. Ninety-two patients scheduled for general anaesthesia were randomly allocated to one of four groups: controls were given 0.6 mg.kg(-1) rocuronium; patients in the prime group were given 0.06 mg.kg(-1) rocuronium three minutes before a further dose of 0.54 mg.kg(-1) rocuronium; patients in the magnesium group were given an infusion of 50 mg.kg(-1) magnesium sulphate before rocuronium and patients in the magnesium and prime group were given both the magnesium sulphate and the priming dose of rocuronium. Tracheal intubation was attempted 40 s after the rocuronium injection. The time to onset of neuromuscular blockade was the primary outcome; duration of blockade and tracheal intubating conditions were also measured. The group allocation and study drugs were coded and concealed until statistical analyses were completed. The magnesium and prime group had the shortest mean (SD) onset time (55 (16)s; p < 0.001), and best tracheal intubating conditions (p < 0.05). No statistical difference was found for the duration of blockade. As for adverse events, a burning or heat sensation was reported in eight (35%) and six (26%) patients in the magnesium and magnesium and prime groups, respectively. The combination of magnesium sulphate and rocuronium priming accelerated the onset or neuromuscular blockade and improved rapid-sequence intubating conditions, compared with either magnesium sulphate or priming used alone.

[Evaluation of tracheal intubation conditions in morbidly obese patients: a comparison of succinylcholine and rocuronium]

OBJECTIVE

To compare tracheal intubation conditions in morbidly obese patients 60 seconds after administration of succinylcholine or rocuronium doses based on real weight or ideal weight.

METHOD

We evaluated patients with a body mass index (BMI) of 40 kg x m(-2) or more but no other indications of difficult-intubation risk. Induction was performed under fentanyl and propofol at doses calculated based on real weight. Patients were assigned to 1 of 4 groups for tracheal intubation. Group 1 received 1 mg of succinylcholine per kilogram of ideal weight, group 2 received 1 mg of succinylcholine per kilogram of real weight, group 3 received 0.6 mg of rocuronium per kilogram of ideal weight, and group 4 received 0.6 mg of rocuronium per kilogram of real weight. Tracheal intubation was performed 60 seconds later and intubation conditions were recorded using a clinical scoring system.

RESULTS

Eighty patients with a mean BMI of 47.5 kg x m(-2) were enrolled. The difficult intubation rate was 3.75%. All patients were intubated. Laryngoscopy conditions and position and movement of vocal cords were similar in all 4 groups. Reaction to cuff inflation revealed intergroup differences; group 3 presented slight limb movements, diaphragm movement, and sustained cough for more than 10 seconds.

CONCLUSION

These results suggest that administration of succinylcholine calculated based on real weight or ideal weight and rocuronium based on real weight can provide clinically acceptable conditions for tracheal intubation in morbidly obese patients with no other difficult-intubation criteria.

Sugammadex in clinical practice

The availability of sugammadex allows greater flexibility in the use of rocuronium and vecuronium during anaesthesia and surgery. The neuromuscular block induced by both drugs can be reversed from both superficial and deep levels of block by adjusting the dose of sugammadex. The dose of sugammadex for reversal of shallow block produced by these neuromuscular blocking drugs is approximately 2 mg.kg(-1) and for deep block the dose is 4 mg.kg(-1). A larger dose of sugammadex (16 mg.kg(-1)) administered 3 min after the neuromuscular blocking drug allows rapid reversal of a neuromuscular block induced by 1-1.2 mg.kg(-1) of rocuronium, thereby raising the possibility of using rocuronium as a replacement for suxamethonium. The use of sugammadex has not been reported to be associated with recurrence of block provided a dose that is adequate for reversal has been used. Sugammadex appears to have an acceptable safety profile. There are no requirements for dose adjustment for age or the use of potent volatile anaesthetic agents.

Rocuronium-induced withdrawal movements associated with different Rocuronium injection method

OBJECTIVES

One hundred and twenty patients (3-15 years old) were randomly enrolled (four groups: each group = 30 patients) in the study.

AIM

The aim of this study was to compare the incidence and intensity of rocuronium-induced withdrawal movements in children injected with a typical intravenous bolus injection of rocuronium or with an infusion injection of rocuronium.

BACKGROUND

Intravenous bolus injection of rocuronium produces pain and withdrawal movement.

METHODS

Immediately after loss of consciousness by thiopental sodium (5 mg x kg(-1)), 0.6 mg x kg(-1) (B0.6, I0.6) or 0.9 mg x kg(-1) rocuronium (B0.9, I0.9) was injected by different method, either a bolus injection over 5 s (B0.6, B0.9) or an infusion injection lasting for 1 min (I0.6, I0.9). The withdrawal movement of the patients to the injection of rocuronium was assessed (four-grade score: 0-3). Intubating condition was assessed. Rocuronium-induced muscle relaxation time was measured by single twitch stimulation fade out.

RESULTS

The incidence (group B: 100%, group I: 33.3%) and the intensity of the withdrawal movements were significantly lower in the infusion groups compared with the bolus groups (P < 0.05). The intubating conditions for all groups were clinically acceptable (good to excellent). There was no significant difference in the muscle relaxation time between the different injection groups (I0.6; 105.6 +/- 7.7 vs B0.6; 114.6 +/- 8.0, I0.9; 69.2 +/- 3.6 vs B0.9; 73.4 +/- 1/0).

CONCLUSIONS

The infusion injection of rocuronium for tracheal intubation significantly reduced the incidence and intensity of withdrawal movement on injection of rocuronium, and it neither delays the onset of muscle relaxation nor deteriorates the intubating condition.

Dose of alfentanil needed to obtain optimal intubation conditions during rapid-sequence induction of anaesthesia with thiopentone and rocuronium

BACKGROUND

The primary aim of the present study was to determine the dose of alfentanil that must be added to a rapid-sequence induction (RSI) regimen using thiopentone and rocuronium to obtain optimal intubation conditions in >95% of the individuals.

METHODS

A total of 60 ASA I patients were randomly allocated to five different alfentanil dose groups (0, 15, 30, 45, or 60 microg kg-1). A blinded dose of alfentanil followed by thiopentone 4 mg kg-1 and rocuronium 1 mg kg-1 was administered in rapid succession, and tracheal intubation was attempted 40 s thereafter. The relationship between the alfentanil dose and the probability of optimal intubation conditions was determined by non-linear logistic regression analysis. Blood pressure (BP) changes were recorded continuously using an intra-arterial catheter.

RESULTS

The success rate of optimal intubation conditions increased with increasing doses of alfentanil. The alfentanil dose needed to obtain optimal intubation conditions in >95% of the patients was 36.4 (CI 33.4-39.4) microg kg-1. In 12 patients, the systolic BP declined to <90 mm Hg during the 3 min immediately after intubation.

CONCLUSION

Adding 36-40 microg kg-1 alfentanil to a regimen of thiopentone and rocuronium during RSI of anaesthesia may significantly increase the success rate of optimal intubation conditions. Significant hypotension requiring vasopressor treatment may occur.

Intubation conditions after rocuronium or succinylcholine for rapid sequence induction with alfentanil and propofol in the emergency patient

BACKGROUND AND OBJECTIVE

Previous studies mainly conducted on elective patients recommend doses of 0.9-1.2 mg kg[-1] rocuronium to obtain comparable intubation conditions with succinylcholine 1.0 mg kg[-1] after 60 s during a rapid-sequence induction. We decided to compare the overall intubating conditions of standard doses of rocuronium 0.6 mg kg[-1] and succinylcholine 1.0 mg kg[-1] during a strict rapid-sequence induction regimen including propofol and alfentanil.

METHODS

Male and female patients (ASA I-III) older than 17 yr scheduled for emergency abdominal or gynaecological surgery and with increased risk of pulmonary aspiration of gastric content were randomized to a rapid-sequence induction with succinylcholine 1.0 mg kg[-1] or rocuronium 0.6 mg kg[-1]. Patients with a predicted difficult airway were excluded. A senior anaesthesiologist 'blinded' for the randomization performed the intubation 60 s after injection of the neuromuscular blocker. Intubating conditions were evaluated according to an established guideline. Tracheal intubation not completed within 30 s was recorded as failed.

RESULTS

222 patients were randomized. Three patients had their operation cancelled and 10 did not fulfil the inclusion criteria. Clinically acceptable intubation conditions were present in 93.5% and 96.1% of patients in the succinylcholine group (n=107) and the rocuronium group (n=102), respectively (P=0.59).

CONCLUSIONS

During a rapid-sequence induction with alfentanil and propofol, both rocuronium 0.6 mg kg[-1] and succinylcholine 1.0 mg kg[-1] provide clinically acceptable intubation conditions in 60 s in patients scheduled for emergency surgery. Under the conditions of this rapid-sequence induction regimen rocuronium may be a substitute for succinylcholine.

Newer neuromuscular blocking agents: how do they compare with established agents?

Rapacuronium bromide (rapacuronium; ORG-9487) is a nondepolarising muscle relaxant (NMBA) with a low potency [90% effective dose (ED90) 1 mg/kg], which to some extent is responsible for its rapid onset of action. Because of the high plasma clearance (5.3 to 11.1 mg/kg/min) of rapacuronium, its clinical duration of action following single bolus doses up to 2 mg/kg in adults is short (i.e. <20 minutes). Rapacuronium forms a pharmacologically active 3-desacetyl metabolite, ORG-9488, which may contribute to a delay in spontaneous recovery after repeat bolus doses or infusions. After rapacuronium 1.5 mg/kg clinically acceptable intubating conditions are achieved within 60 to 90 seconds in the majority of adult and elderly patients undergoing elective anaesthesia. However, in a rapid-sequence setting. intubating conditions are less favourable after rapacuronium 1.5 to 2.5 mg/kg than after succinylcholine. The most prominent adverse effects of rapacuronium (tachycardia, hypotension and bronchospasm) are dose-related, and in particular pulmonary adverse effects are observed more frequently under conditions of a rapid-sequence induction in adults. Therefore, it seems worthwhile to consider only doses of rapacuronium < or = 1.5 mg/kg to facilitate rapid tracheal intubation, and to use succinylcholine or rocuronium rather than rapacuronium in a rapid-sequence setting. Rapacuronium, however, is a suitable alternative to mivacurium chloride (mivacurium) and succinylcholine for short procedures (e.g. ambulatory anaesthesia). Rocuronium bromide (rocuronium) is a relatively low-potent, intermediateacting NMBA. Its main advantage is the rapid onset of neuromuscular block whereby good or excellent intubating conditions are achieved within 60 to 90 seconds after rocuronium 0.6 mg/kg (2 x ED95), and within 60 to 180 seconds after smaller doses (1 to 1.5 x ED95). Larger doses of rocuronium (> or = 1 mg/kg) seem to be suitable for rapid-sequence induction under relatively light anaesthesia. However, it is still a matter of controversy whether, in the case of an unanticipated difficult intubation, the long duration of rocuronium administered in such large doses outweighs the many adverse effects of succinylcholine. Rocuronium has mild vagolytic effects and does not release histamine, even when administered in large doses. Rocuronium is primarily eliminated via the liver and its pharmacokinetic profile is similar to that of vecuronium bromide (vecuronium). Unlike vecuronium, rocuronium has no metabolite. Cisatracurium besilate (cisatracurium), the IR-cis, 1'R-cis isomer of atracurium besilate (atracurium) is approximately 4 times more potent than atracurium. The onset time of cisatracurium is significantly slower than after equipotent doses of atracurium. The recommended intubating dose is 0.15 to 0.2 mg/kg (3 to 4 times ED95). Over a wide range of clinically relevant doses the recovery properties of cisatracurium are affected by neither the size of the bolus dose nor by the duration of infusion. Unlike atracurium, cisatracurium does not trigger histamine release. Like atracurium, cisatracurium undergoes Hofmann elimination. In contrast to atracurium, cisatracurium does not undergo hydrolysis by nonspecific plasma esterases. Moreover, about 77% of the drug is cleared by organ-dependent mechanisms.