Effect of Dexmedetomidine of Gastrointestinal Motility
Phase: PHASE4
Conditions: Anesthesia
Sponsor: Boston Children's Hospital

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TITLE:  Effect of Dexmedetomidine of Gastrointestinal Motility 
NCT04798482 
Version Date: 09/07/2022 

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CHeRP IRB Additional Protocol Information: 
     In addition to the CHeRP SmartForms, all protocols must include the following sections. If a section is not 
applicable for the current protocol please indicate why this is the case. Please note that a complete protocol* 
consists of the CHeRP forms and the information provided in this form. 
TITLE:  Effect of Dexmedetomidine of Gastrointestinal motility 
A. Specific Aims/Objectives  
Primary objective: To examine the effects of dexmedetomidine on intra-anal pressure and the 
dose response curve to balloon distention by comparing the baseline measurements with those after 
dexmedetomidine administration. 
 
Dexmedetomidine is an alpha-2 agonist that is considered to be a smooth muscle relaxant. It’s a 
potential use as a sedative for endoscopies has been considered. It is important to know whether or 
not it has effect on smooth muscle tone and would affect manometry studies in those patients who 
could receive it. We hypothesize that dexmedetomidine will have minimal effects in the dosing that 
we are administering. 
 
B. Background and Significance  
Anorectal manometry requires that the patient be able to respond to command and not receive any 
medications which could alter muscle tone or motility. These patients typically have the manometry 
performed without any adjuvant sedatives, anesthetics or medications. In the pediatric population, 
anorectal manometry can be psychologically challenging to parents and their child, particularly 
without adjuvant sedation or anesthesia. There are some exceptional circumstances which require 
sedation/anesthesia administration for these procedures, either because the children are young (< 5 
years), they have behavioral issues (like autism) or because they have severe anxiety.  In those 
patients with severe issues even general anesthesia may be needed. The risk of administering any 
medication to these patients is that they can alter motility and smooth muscle activity, consequently 
artificially altering the results of the anal manometry. It is important to know which medications 
can be administered without affecting anal muscle tone. Dexmedetomidine is a newer sedative and 
anxiolytic. It could be valuable for anxiolysis for anal manometry. Its effect on anal smooth muscle, 
however, has never been studied. It would be important to determine whether it spares smooth 
muscle function, as it would provide a viable option to provide sedation to children while still 
preserving their ability to respond to command.   
 
Dexmedetomidine is one of the standard drugs administered for sedation in children who require 
sedation for diagnostic (gastroendoscopic upper and lower procedures) and radiologic diagnostic 
imaging studies (MRI, CT and Nuclear Medicine). Over 17,000 infants, children and 
developmentally compromised young adults have been sedated with dexmedetomidine at Boston 
Children’s Hospital without a cardiac or respiratory arrest, or a need to provide positive pressure 
assisted ventilation. 

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C. Preliminary Studies  
      There are currently no preliminary studies available on the effects of dexmedetomidine 
gastrointestinal motility and manometry in children.  
D. Design and Methods  
 
(1) 
Study Design 
This is a prospective, open label, interventional study. 
 (2) 
Patient Selection and Inclusion/Exclusion Criteria  
       Inclusion Criteria 
 
 
Ages 3-18 years who are scheduled to have an anorectal manometry followed by a 
gastrointestinal procedure in the Gastroenterology Procedure Unit (GPU)at Boston Children's 
Hospital  
 
Patients are cooperative to do the anorectal manometry without sedation (with the exception of 
pre-med midazolam) 
 
Anticipates to receive standard sedation with dexmedetomidine and propofol for a 
gastrointestinal procedure in the GPU  
 
Provides written consent to participate in the research study 
 
In females of reproductive age, pregnancy testing (carried out per routine clinical care by the 
anesthesia department) must be negative. 
 
Exclusion Criteria 
 
 
Do not meet established sedation criteria 
 
Patients who require sedation prior to their anal manometry testing (with the exception of pre-
med midazolam) 
 
History of allergy, intolerance, or reaction to dexmedetomidine  
 
Current, repaired or risk of Moya-Moya disease 
 
Recent stroke (cerebrovascular accident) within past 6 months 
 
Uncontrolled hypertension 
 
Concomitant use of opioids, beta antagonist, alpha 2 agonist or calcium channel blocker 
 
BMI greater than 30 or weight above 110th percentile 
 
Refuses insertion of intravenous catheter while awake 
 
Currently receiving pharmacologic agents for hypertension or cardiac disease  
 
Currently receiving or has received digoxin within the past 3 months 
 
Active, uncontrolled gastroesophageal reflux (an aspiration risk), requiring endotracheal 
intubation. 
 
Current (or within past 3 months) history of apnea requiring an apnea monitor  
 
Unstable cardiac status (life threatening arrhythmias, abnormal cardiac anatomy, significant 
cardiac dysfunction)  
 
Craniofacial anomaly, which could make it difficult to effectively establish a mask airway for 
positive pressure ventilation if needed 

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 
Active, current respiratory issues that are different from the baseline status (pneumonia, 
exacerbation of asthma, bronchiolitis, respiratory syncytial virus).  
 
Methods 
 
As part of standard of care, patients will undergo the usual anal manometry study prior to any 
anesthetic or sedative administration. Pre-med midazolam may be administered at the 
discretion of the clinical care team. Once manometry measurements are completed, the 
anesthesiologist will administer a single dose of dexmedetomidine. The research team and 
clinical care team will observe and record any changes in manometry. After these 
measurements are collected, the anesthesiologist will continue standard anesthesia maintenance 
with propofol and dexmedetomidine per approved protocol for children undergoing 
gastrointestinal procedures requiring sedation. 
   
As it is routine in these cases, subjects will have an intravenous catheter inserted pre-induction 
and  standard of care anesthesia monitor (pulse oximetry, heart rate, ECG, NIBP, capnography 
via nasal cannula) applied and monitored prior to induction (in the GI suite).  
 
 Table 1.  Data Elements to be Collected 
Age 
Height 
Weight  
Body Mass Index (BMI) 
Sex 
ASA status 
NPO status 
Current Medication list 
Primary diagnosis 
Coexisting diagnoses 
Procedure(s) performed 
Sedation start and end time 
Time of dexemedetomidine administration 
 Ramsay sedation scale 
 UMSS sedation scale 
 
 
 
Recruitment Methods 
 
i. HOW, WHERE and WHEN will potential subjects be recruited?  
 
All outpatients who are scheduled for anorectal manometry followed by upper or lower 
endoscopy will be screened for eligibility to participate in the study.  
 Patients that are new to Dr. Nurko will learn about the study during their pre-procedure 
clinic visit with Dr. Nurko. 
 Patients that have already seen Dr. Nurko in the past and do not have a pre-procedure 
appointment will be emailed or mailed information about the study (consent form, 
brochure, and cover letter). A member of the research team will then contact the 

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families via telephone to discuss the study in further detail and answer any questions 
families may have.   
 Add-on patients will be approached by a member of the research team in pre-op 
holding.  
All families will be given ample time to decide if they would like to participate in the study, 
if families need more time to make a decision the research team will coordinate a time to call 
the family back. The consent form will be signed by the parent or patient if the patient is 
older than 18 years of age (and assent given by the child where appropriate). 
 
ii. WHAT recruitment methods and materials (e.g. posters, fliers) will be used? 
 
The consent form along with an informational brochure containing a brief description of the 
study will be distributed via secure email or traditional mail in advance to subjects that do not 
have a pre-procedure clinic visit.  
 
iii. WHO will be responsible for subject recruitment?  
 
Subject recruitment will be and the responsibility of designated members of the research team 
working within Dr. Nurko and/or the Department of Anesthesiology. 
 
(3) 
Description of Study Treatments or Exposures/Predictors  
Intravenous catheters will be initiated as per standard clinical protocol in gastrointestinal 
endoscopy unit. Patients may also choose not to have any adjuvant local anesthesia prior to 
initiation of intravenous access. All patients will have baseline vital signs (already described) 
documented prior to induction. Those undergoing upper endoscopy will have 2 sprays of 
Cetacaine to posterior oropharynx prior to induction as part of standard clinical care. All 
patients will receive 4 L of supplemental oxygen by nasal cannula throughout the procedure. 
 
Participation in this study involves an additional 15 minutes of manometry testing as well as 15 
minutes of additional sedation in addition to what is clinically indicated.  
 
Anorectal manometry 
 
Patients will fast the night before. All patients receive the administration of a phosphate enema 
the night prior to the procedure. With the patient in the left lateral position, after lubrication the 
high resolution anorectal manometry probe will be gently inserted into the anal canal. It will 
slowly advance until the upper and lower borders of the high intra-anal-pressure zone are 
identified. The probe is held manually in place throughout the study. 
 
Once the probe is in place, a resting period of at least 90 seconds is allowed until the patients 
are conformable and relaxed. The high-pressure zone is identified, and thirty seconds of resting 
pressures is obtained.  To evaluate conscious sensation, the balloon is rapidly inflated and 
deflated with serial volumes of 5, 10, 15, 20, 25, 30, 40, 50, 60, 90, 120, and 180 ml. The 
balloon inflations are achieved with a 60 mL syringe that was connected to the probe via 

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stopcock that allows the administration of increasing balloon volumes. Threshold of sensation 
(minimum balloon volume that could be felt in 2 of 3 trials) is identified. The patients are then 
instructed to squeeze. Their ability to squeeze is determined and the squeeze pressure 
characteristics are recorded. To evaluate the recto-anal inhibitory reflex (RAIR) the balloon is 
again rapidly inflated and deflated with series of volumes mentioned previously and a full dose 
response curve is obtained. 
 
After the baseline ARM is completed, the catheter will remain in place. The research team will 
confirm with the subject that they are still interested in participating in the additional 15 
minutes of anal manometry testing.  If subjects meet any of the following criteria, then the 
study will not proceed: 
 Child verbalizes they no longer want to participate  
 Child is visibly distressed after clinical manometry  
 Parent expresses desire to not proceed 
 Clinical care team does not agree to move forward 
 
Once the subject has confirmed it is ok to proceed, dexmedetomidine will be administered as 
detailed below. The intra-anal pressure will be continuously measured through administration 
of DEX until 15 minutes following administration. This is the experimental portion of the 
present study. 
 
 
 Manometry associated with Lower endoscopy procedure: 
 
Patients will undergo the usual anal manometry study, with no adjuvant medications, per 
routine practice currently in the gastrointestinal unit. Following completion of manometry, 0.5 
mcg/kg DEX will be administered over 1 minute followed by an infusion of 0.15 mcg/kg/hr.  
Manometry measurements will be followed for 15 minutes in response to DEX. Following 
completion of research manometry, patients will resume the standard of care and receive 
propofol at the discretion of the anesthesiologist.   
 
Manometry associated with Upper endoscopy procedure: 
 
Patients presenting for upper gastrointestinal endoscopy with manometry, will receive a routine 
anesthetic with intravenous propofol (bolus and infusion) and endotracheal intubation (at the 
discretion of the anesthesiologist). Propofol will be administered and used for maintenance of 
the anesthetic.. If necessary for endotracheal intubation and to minimize aspiration risk, 
neuromuscular blockade will be administered. Following completion of the manometry, 
dexmedetomidine will be administered per above protocol (same as used for the anal 
manometry) for the remainder of the anesthetic. Manometry will be measured in response to 
dexmedetomidine and followed for 15 minutes.  
  
No narcotics, no benzodiazepines and no dexamethasone will be administered during the 
anesthetic management for either group.   
 
. 
(4) 
Definition of Primary and Secondary Outcomes/Endpoints  
Primary outcome: To examine the effects of dexmedetomidine on intra-anal pressure and the 
dose response curve to balloon distention by comparing the baseline measurements with those 
after dexmedetomidine administration. The pressure measurements will be recorded by the 

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research team member who will be present, every 30 seconds starting from 5 minutes prior to 
DEX to 15 minutes following DEX administration. 
 
(5) 
Data Collection Methods, Assessments, Interventions and Schedule (what 
assessments performed, how often)  
Manometry Data Collection for Analysis: 
• 
Analysis of the high-resolution manometry will be done in a blind manner. 
• 
The anal verge is defined as the most distal and the rectum as the most proximal part of the anal 
canal. The manometry probe allows a standard high-resolution visualization of the anal canal. 
The high-pressure zone (HPZ) of the anal canal at rest will be determined. Intra-anal pressure 
will be measured at each balloon inflation, and the percent anal relaxation at each inflation will 
be determined, and a dose response for the relaxation will be determined.  
 
 
(6) Study Timeline (as applicable) 
We plan to enroll 25 subjects for this study at Boston Children’s Hospital.  We anticipate that this 
study will take up to 1 year to complete.  
E. Adverse Event Criteria and Reporting Procedures 
All adverse events will be reported to the Radiology and Hospital Sedation Committee.  These 
events will be reviewed by an Independent Committee set up by the Department of Anesthesia and 
will be reported to the IRB by this Committee as appropriate. According to the recommendations 
laid out in the Safety Reporting Requirements for INDs and BA/BE Studies guide, adverse events 
that are both serious and unexpected, associated with the use of the drug will be reported to the 
FDA.  According to 21 CFR 312.32, an “adverse event or suspected adverse reaction is considered 
"serious" if, in the view of either the investigator or sponsor, it results in any of the following 
outcomes: Death, a life-threatening adverse event, inpatient hospitalization or prolongation of 
existing hospitalization, a persistent or significant incapacity or substantial disruption of the ability 
to conduct normal life functions, or a congenital anomaly/birth defect.” 
 
Subjects/parents may opt to remove themselves/their child from the study at any point in time.  
F. Data Management Methods  
Patient demographic, adverse events and motility data will be entered into an InForm database and 
then exported into the SAS system for statistical analysis (version 9.4, SAS Institute, Cary, NC).  
G. Quality Control Method  
To ensure that data will be of the highest quality and accuracy, research team personnel will routinely 
check and monitor data entry, missing data, and any inconsistencies. 
H. Data Analysis Plan  
Data will be analyzed after the completion of the study. The manometry measurements will be done 
blindly by one of the investigators.  

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Summary statistics for continuous variables and frequency counts for categorical variables will be 
calculated. Appropriate statistical testing will be performed where applicable.  
I. Statistical Power and Sample Considerations  
The study was powered and sample size calculated assuming a mean intra-anal pressure of 90 mmHg, 
with a mean reduction to 65 mmHg, and a standard deviation of 32. With a significance level of 0.05, 
it would require approximately 15 subjects to achieve power of 80.3%.  
J. Study Organization  
The principal investigator for this study is Dr. Keira Mason from the Department of Anesthesia, 
Perioperative and Pain Medicine at Boston Children’s Hospital. The co-PI is Dr. Samuel Nurko, 
Director of the Center for Motility and Functional Gastrointestinal Disorders at BCH. Collaborators 
will be Drs. Chineyere Egbuta, Ray Park, Karen Boretsky and Cornelius Sullivan. The Pediatric 
Anesthesia Research Center will provide research staff support in the form of research nurses and/or 
research assistants.  
K. Data and Safety Monitoring Plan 
Dr. Mason, Dr. Nurko, and approved members of the research team will be responsible for all data and 
safety monitoring. An independent data monitor will also be part of this group. Data and safety 
monitoring will be reviewed every 3-6 months or more frequently if a specific problem is identified. 
Data and safety monitoring will be performed after every patient if a serious side effect has been noted 
and no more patients will be recruited, enrolled or studied until the cause been thoroughly investigated. 
If, after careful review by the data and safety monitor, there is a probability that the study might have 
caused or contributed to the serious reaction, then this will be reported to the IRB and the study halted 
until a risk/benefit assessment can be made.  
L. Risks and Discomforts 
The common side effects from dexmedetomidine are similar to other anesthetics, which include an 
increase or decrease in heart rate, an increase or decrease in blood pressure, a slower breathing rate and 
dry mouth. Serious, rare adverse events that have occurred with dexmedetomidine include anaphylaxis 
and sinus arrest (heart stops sending the electrical impulses that signal it to beat). Study patients will be 
monitored at all times by an anesthesiologist.  
 
There are limited studies for administering dexmedetomidine to pediatric patients; however, these 
studies have shown dexmedetomidine to be a safe and effective agent with beneficial effects. 
 
M. Potential Benefits 
 
By receiving dexmedetomidine, there is the potential to reduce irritability that the participant may have 
while waking up, decrease the amount of pain medication that is needed, and decrease the amount of 
other sedation medications.  
 
 N. Privacy Provisions 

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Access to the electronic database will be restricted to IRB approved study staff and will be password 
protected. Study folders will be maintained by the study team and be stored in a lock cabinet within a 
locked office.  
O. Confidentiality Provisions 
The privacy of the study subjects will be maintained. Only the investigators and IRB approved 
members of the study team will know the identity of the subject whose data is being analyzed. Prior to 
analysis, all HIPAA identifiers will be removed. Data will be stored securely in a locked cabinet in a 
locked office. Research subject identifiers will be removed, linked or destroyed as soon as possible. 
The only document that contains a link to the identity of subjects will be kept securely in a locked 
cabinet in a locked office. 

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