The Effect of Precurarization With Rocuronium on the Incidence and Severity of Succinylcholine-Induced Fasciculations and Myalgias in a High Volume ERCP Center
Phase: PHASE3
Conditions: Myalgia
Sponsor: Indiana University

 
 
 
The Effect of Precurarization with Rocuronium on the 
incidence and severity of Succinylcholine-Induced 
Fasciculations and Myalgias in a High Volume ERCP 
center 
 
 
Dr. Leighan Bye 
Department of Anesthesiology 
 
Dr. Yar Yeap 
Department of Anesthesiology 
 
Dr. Jennifer Stewart 
Department of Anesthesiology 
 
Dr. Elizabeth Kroepfl  
Department of Anesthesiology 
 
Zonair Khan 
MS2, Indiana University School of Medicine 
 
 
 
V3-2/19/21 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

 
 
 
1.0 Background 
 
Since its clinical introduction in the early 1950s, succinylcholine, a short-acting depolarizing muscle 
relaxant, has become commonly used for rapid sequence intubation during general anesthesia1,2. In 
addition to its paralytic effects, succinylcholine administration in general anesthesia carries a multitude of 
risks, among which are muscle fasciculation and postoperative myalgia3,4. Currently, anesthesiologists are 
divided in whether rocuronium, a nondepolarizing muscle relaxant, effectively reduces both 
succinylcholine-induced fasciculations and postoperative myalgias in procedures under general 
anesthesia. There is sparse and inconsistent literature supporting the efficacy of rocuronium pretreatment 
for the prevention of succinylcholine-induced fasciculations and postoperative myalgias.  .  
 
Research into managing the side-effects of using succinylcholine first appeared in 1990 when Pace 
demonstrated, through a meta-analysis of 45 clinical trials, that nondepolarizing muscle relaxants reduced 
the frequency of postoperative myalgias by 30%5.  Rocuronium, while not assessed in Pace’s study, is 
now commonly used to prevent fasciculations and myalgias associated with succinylcholine. Motamed, 
(1998) demonstrated that pretreatment with rocuronium in elective general surgery reduced the incidence 
of succinylcholine-induced fasciculations6. In laparoscopic procedures in female patients under general 
anesthesia, Martin et. Al (1998), demonstrated that rocuronium prevented fasciculations but not 
postoperative myalgias7. Likewise, Joshi et. Al (1999) showed that rocuronium prevented 
succinylcholine-induced fasciculations but failed to prevent myalgias in patients undergoing elective 
ambulatory surgery with general anesthesia.8. 
 
In response to the growing literature pertinent to pretreatment of succinylcholine, Schreiber et. al(2005) 
performed a meta-analysis of 52 randomized trials between 1971 and 2003 to update the aforementioned 
meta-analysis performed by Pace. Schreiber concluded that doses of 10-30% of the effective dose of 
nondepolarizing muscle relaxants do significantly decrease the postoperative myalgias and fasciculations.  
Further, of the nondepolarizing muscle relaxants, rocuronium significantly demonstrated relative risks 
conferring both effectiveness in reduced fasciculations and 24 hours postoperative myalgia9. In 2009, 
Abbas et. al demonstrated that pretreatment of rocuronium in patients undergoing elective general 
surgical procedures under general anesthesia decreased the incidence of succinylcholine-induced 
fasciculations and myalgias10; however, in 2014, Kim in elective surgery with general anesthesia, 
demonstrated that pretreatment with rocuronium  reduced fasciculations but did not significantly decrease 
the incidence of postoperative myalgias11.  
 
Previous studies looking at the efficacy of pretreatment with rocuronium to prevent succinylcholine 
fasciculations and / or myalgia were limited in many ways including, but not limited to, low numbers in 
the study groups, a lack of uniformity in the length of the case, and a lack of uniformity in the 
presence/absence or size of a surgical incision.  Studies have demonstrated that patients with little surgical 
pain are more likely to complain of post-succinylcholine myalgias compared to patients who are 
preoccupied with terrible pain from surgical wounds.  The length of the case also seems to impact the 
severity of post-surgical muscle pain independent of succinylcholine use.   The actual etiology of post-
succinylcholine myalgia has not been fully elucidated.  It was originally thought that the induction of 
fasciculations by the acetylcholine-like action of succinylcholine at the neuromuscular junction caused 
muscle damage leading to myalgias, however, studies looking at the correlation between fasciculations 
and myalgias showed only a weak correlation.   We hope to address some of these questions with this 
proposed study.   Our group provides anesthesia to patients coming to Indiana University Hospital for 
ERCP (endoscopic retrograde pancreatography).  ERCP cases are generally short (under 2 hours), are 
uniformly positioned, and do not result in a surgical wound.  Because they are such short cases, yet still 
require general endotracheal anesthesia, succinylcholine is the drug of choice in our group as it results in 
rapid intubating conditions with a very short duration of action.  As this is a high volume center, we have 
a unique opportunity to study the effect of pretreatment with a nondepolarizing neuromuscular blocker 

 
 
 
(rocuronium) on succinylcholine induced myalgias while enjoying a mitigation of the confounding 
variables mentioned above.   
 
Risks: 
There is huge variability in the care of patients receiving succinylcholine in the anesthesia community at 
large and within our own group.  Some people believe that succinylcholine should always be pretreated 
with a non-depolarizing neuromuscular blocker to prevent myalgias, while others believe that it should 
never be pretreated because, they believe, that the pretreatment doesn’t work and is ineffective.  This is a 
proposal to structure that variability into randomized groups and study the outcomes which will lead to a 
reduction of said variability going forward.   There is no added risk to the patient as there is currently no 
standardization of the practice within our own group.  Pretreating and not pretreating are both practiced 
daily. 
 
2.0 Rationale and Specific Aims 
 
Our hypothesis is that precurarization with rocuronium, followed by a 2 minute interval prior to 
administering succinylcholine will prevent, or ameliorate, succinylcholine induced myalgias compared to 
not pretreating, or pretreating with a shorter time interval prior to succinylcholine administration.   
 
Primary endpoint:  Does the patient have myalgias post succinylcholine administration with 
pretreatment with Rocuronium 2 minutes prior?   
 
Secondary endpoint? 
 
 
*Severity of myalgias 
 
 
*Onset of myalgias postop relative to succinylcholine administration 
*Correlation of myalgias with the presence of skeletal muscle fasciculation upon 
succinylcholine administration 
 
3.0 Inclusion/Exclusion Criteria: 
 
Inclusion Criteria: 
• 
Undergoing elective Endoscopic Retrograde Cholangiopancreatography (ERCP) under general 
anesthesia 
• 
Have been informed of the nature of the study and informed consent has been obtained 
• 
ASA 1, 2 and 3  
 
Exclusion Criteria: 
• 
Patients will be excluded if they have chronic pain requiring daily opioid use greater than 30 mg 
PO morphine equivalent.   
• 
Patients will also be excluded if their comorbid medical conditions require a true rapid sequence 
induction as precurarization with rocuronium increases the time to intubation which is 
undesirable in a patient who is at high risk for aspiration.   
• 
Patients taking muscle relaxants at home for spasticity. 
• 
Patients under the age of 18 years old. 
• 
Any contraindication for using succinylcholine or rocuronium. 
• 
Less than 50kg or greater than 120kg 
  
4.0 Enrollment/Randomization 
 
All Endoscopic Retrograde Cholangiopancreatography (ERCP) procedures scheduled at IU Health 
University Hospital on adult patients (18+ years old) will be identified. Subjects will be contacted face-to-
face prior to surgery by one of the research team members. They will be informed about the study and all 
questions will be answered. The potential subjects will be given a copy of the informed consent form and 

 
 
 
authorization form. The subjects will then be contacted face-to-face in POCU on the day of surgery and if 
participation is agreed upon, written consent will be taken.  All patients will receive general endotracheal 
anesthesia consistent with acceptable standards of care.  
 
A total of 300 subjects will be randomized by a/ computer program into 3 groups (100 in each group): 
 
1. Group 1 (Control): 0 mg/kg of rocuronium pretreatment and 1 mg/kg (rounded up to the nearest 
10 mg) succinylcholine  
2. Group 2: 0.05 mg/kg (rounded up to the next mg) up to 5 mg of rocuronium pretreatment 
followed by 1.0 mg/kg (rounded up to the next 10mg) succinlycholine t = 1 min +/- 10 sec after 
pretreatment.  
3. Group 3: 0.05 mg/kg (rounded up to the next mg) up to 5 mg of rocuronium pretreatment 
followed by 1.0 mg/kg (rounded up to the next 10 mg) succinlycholine t = 2 min +/- 10 sec after 
pretreatment.  
Drug amount rounding takes into account the limitations to accurately measure drug doses in the clinical 
setting.  Rocuronium is measured in a 1 ml tuberculin syringe with 1mg = 0.1ml.  Rounding allows the 
provider to round to the next 0.1ml.  Smaller increments cannot be accurately measured.    Likewise, 
Succinylcholine is 20mg/ml and administered from a pre-labeled, calibrated 10 ml syringe.  The above 
allowable rounding allows the provider to administer the drug to the next nearest 10mg=0.5ml for the 
same reason.    
 
Randomization will be performed using Research Randomizer in blocks of 30. The primary investigator 
will inform the person doing the case as to what group the patients are randomized to. Both the patients 
and the research staff doing assessments will be blinded to the randomization.   
 
5.0 Study Procedures 
After IRB approval from Indiana University Hospital and with written and verbal informed consent from 
each patient, 300 ASA I, II and III outpatients scheduled for elective Endoscopic Retrograde 
Cholangiopancreatography (ERCP) under general anesthesia will be enrolled in this randomized-
controlled study. The patients and the study personnel performing post-op assessments will be blinded.  
Anesthesiologists cannot be blinded during this study since they will be required to draw up the study 
drugs as well as managing the wait time between rocuronium and succinylcholine. Patients are assigned 
to one of three groups (n = 100 each group). Each patient will undergo a standard IV induction of 
anesthesia (Lidocaine 1mg/kg, propofol 1-2 mg/kg titrated to effect, and succinylcholine (administered as 
indicated by study group assignment).   Study group details are as follows:   Group 1 (Control) to receive 
no rocuronium and 1 mg/kg of succinylcholine (rounded up to the next 10mg). Groups 2 and 3 to receive 
0.05 mg/kg (rounded up to the next 1mg) up to 5 mg of rocuronium; patients ranging from 50-120 kg.   In 
Group 2, succinylcholine administration will occur at 1.0 mg/kg (rounded up to the next 10 mg) at t = 1 
minute (+/-10 seconds) after pretreatment with rocuronium.  In Group 3, succinylcholine 1mg/kg 
(rounded to the next 10 mg) will be administered at t = 2 minutes (+/- 10 seconds) after pretreatment. The 
Succinylcholine-induced fasciculations will be noted on study assessment sheet as either present or 
absent. . Myalgia assessment is to occur succinylcholine administration at t =3 hours and t = 24 hours and 
will be rated as described below.   
 
Myalgia assessment: 
Subjects will by queried at the above time points about muscle pain and scored based on their answers as 
follows.  
0 – no pain /no muscle stiffness 
1 – mild muscle pain and/or stiffness at 1 or more sites that does not limit daily activity 
2 – Moderate muscle pain and/or stiffness at 1 or more sites that does not limit daily activity 
3 – Moderate generalized muscle pain and/or stiffness limiting daily activity 

 
 
 
4 – Severe muscle pain and/or stiffness at 1 or more sites limiting movement and preventing daily activity 
 
6.0 Statistical Analysis 
 
The statistical analysis will be conducted using SAS. Summary statistics will be calculated for the overall 
cohort, as well as by-treatment group. Categorical variables will be presented as frequencies and 
percentages, and groups will be compared with chi-square or Fisher’s Exact tests. Distributions of the 
continuous variables will be assessed to determine if data transformations or non-parametric tests are 
needed. Continuous variables will be presented as mean and standard deviation and groups will be 
compared with ANOVA unless non-parametric tests are warranted, in which case, median and 
interquartile range will be calculated and Kruskal-Wallis tests will be used to compare groups. For 
variables with multiple measurements, these statistics will be given for each discrete time point. Myalgia 
will be assessed as both a categorical variable (any myalgia vs. none), and as an interval variable. A 
significance level of 5% will be used for all statistical comparisons. 
 
To determine the effect of the treatments over time on the outcomes of interest, mixed models will be 
utilized, with fixed effects for treatment and time, as well as their interaction, and a random effect for 
subject. When necessary, additional variables may be added to adjust the models for other noted 
differences between the treatment groups. 
 
Based on prior observation, the myalgia incident rate is 50%. With 100 patients in each of the three 
groups, will have 80% power to detect an odds ratio of 2.26 between any two groups, with two-sided tests 
and an alpha of 0.05 (5% significance level). 
 
7.0 Reporting of Adverse Events or Unanticipated Problems Involving Risk to Participants or 
Others 
 
Adverse events, other than those measured as end points, should be reported to the principal investigator, 
Dr. Leighan Bye at 317-902-5882. 
 
8.0 Study Withdrawal/Discontinuation 
 
Participants may withdraw at any time. 
 
9.0 Privacy/Confidentiality Issues 
 
Participant privacy is an important goal of the researchers. Only members of the research team will have 
access to identifiable data. All study papers containing patient identifiers will be kept in each subjects 
confidential study file accessible to only the research team. All records will be kept in a locked room in a 
locked cabinet that only authorized staff enters. Collected data from each enrolled participant will be 
recorded on Redcap which is a secure web-based data collection tool. Quality assurance steps of testing 
Redcap will be completed by the study team prior to moving it into production mode. Quality control 
methods of randomly doing double checks of data entered for accuracy will be complete as well as 
extraction and cleaning of data for data analysis every 1 year. All electronic information and paperwork 
containing patient identifiers will be deleted or shredded when data analysis is completed and the 
paperwork is no longer needed, or for 7 years per Indiana law._ 
 
10.0 Follow-Up and Record Retention 
 
Follow-up myalgia assessments will be performed at 3 hour and 24 hours after surgery. 
 

 
 
 
The patient data related to the study will be entered into a secure REDCap database.  Paper copies of 
study data will be kept in the locked anesthesiology offices. Following completion of the study, all copies 
of data collected will be stored for the required amount of time (min. 7 years) and then will be physically 
destroyed. 
 
 
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StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2018 Jan-. 
 
3. Wong SF, Chung F. Succinylcholine-associated postoperative myalgia. Anaesthesia. 2000;55(2):144–
52. 
 
4. Hager HH, Burns B. Depolarizing Muscle Relaxants, Succinylcholine Chloride. [Updated 2018 Jun 
13]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2018 Jan-.  
 
5. Pace NL. Prevention of Succinylcholine Myalgias. Anesthesia & Analgesia. 1990;70(5) 
 
6. Motamed, C., Choquette, R. & Donati, F. Can J Anaesth (1997) 44: 1262. 
 
7. Martin R, Carrier J, Pirlet M, Claprood Y, Tetrault J-P. Rocuronium Is the Best Non-Depolarizing 
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9. Schreiber J-U, Lysakowski C, Fuchs-Buder T, Tramer M. Prevention of Succinylcholine-induced 
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