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Dear Parents,

The Department of Anesthesiology at CHEO is conducting a study looking at how well a medication called clonidine, reduces the amount of pain a child may experience after undergoing hernia or hydrocoele repair surgery.

Typically, during the operation, children receive “freezing” of the nerves at the site of surgery to reduce pain for up to 6 hours afterwards. At home they are given pain medications including acetaminophen (Tylenol®), ibuprofen (Advil®) or opioids such as morphine. In some children, morphine may result in unwanted side effects including nausea and vomiting, constipation, itchiness and excessive sleepiness. Medications that reduce the need for opioids may result in fewer side effects. Clonidine may be one such medication.

We are interested in clonidine because when it is mixed with “freezing” and applied to nerves at the surgery site, it has been shown to prolong pain relief compared to the “freezing” by itself. This method of pain relief has been routinely used in children in the United States of America and Europe with good success for more than ten years. Health Canada has approved this study to see if clonidine would be beneficial here in Canada as well. Clonidine is considered to be an investigational drug in this setting, meaning that the drug is not currently approved for this use.

Our goal is to evaluate whether adding clonidine to a “freezing” medication called ropivacaine will prolong pain relief after surgery. As part of the study, your child would receive pain medications according to the usual standard of care at CHEO and, in addition, they would have a 1 in 2 chance of receiving clonidine mixed with the “freezing” medication vs “freezing” alone.

If you are interested in learning more about how this study can potentially benefit your child, please talk to the Clinic clerk, visit our website at or email us at You can also contact our research staff directly at 613-737-7600 ext 3755.

Thank-you for your interest.

Dr. Kimmo Murto and his research team

Frequently Asked Questions

Why are you doing the study?

We are doing this study to determine whether Clonidine, when added to “freezing” reduces the amount of pain children may experience after undergoing hernia or hydrocoele repair surgery.

What is Clonidine?

Clonidine is part of a group of drugs called alpha-2 adrengeric agonists. Clonidine in liquid form is being used safely and successfully in the United States and Europe as a sedative before surgery and for pain relief in children. It is known to work together with local anesthetics to provide a longer duration of pain relief.

What are the risks?

The doses that we are using in this study have very few side effects. They include sedation (uncommon), low blood pressure (very uncommon), and a low heart rate (very uncommon). Typically these side effects are mild, require no treatment, are short lived, and occur within 1 to 2 hours of injection. They should be resolved before you leave the hospital.

Do we have to take part in the study?

No, you are free to choose whether you would like to participate or to not participate in this or any study at the Children’s Hospital of Eastern Ontario. Your child will always receive the best possible care at CHEO.

If my child takes part in the study does that mean he won’t get traditional pain management?

No, your child will have equal access to the pain management options available to children undergoing the same procedure. There is no risk that they will experience more pain than those not in the study.

If my child receives the placebo does that mean he will experience more pain than children not in the study?

No, patients in the placebo group will still receive the routine freezing that all patients receive. They will also have access to the same post surgical pain relief available to all children undergoing the same procedure. There is no risk that they will experience more pain than children who are not in the study.

Consent Form and Study Description

The study involves the addition of clonidine to 0.2% ropivacaine for wound instillation after minor lower abdominal surgery in children.

Principal Investigator: Dr. Kimmo Murto 613-239-7951
Dept of Anesthesiology
Co-Investigators: Dr. Jarmila Kim 613-239-6426
Dept of Anesthesiology
Dr. Juan Bass 613-737-7600 #2670
Dept of Surgery
Dr. Luis Guerra 613-737-7600 #1353
Dept of Surgery
Dr. William Splinter 613-782-9019
Dept of Anesthesiology

Coordinators: Kelly-Ann Ramakko B.SC, CCRC 613-759-0791
Tracy Jackson, CCRP 613-239-6029

You are being asked to take part in a research study. Participation in this study is voluntary. Take as much time as you need to make your decision. Ask as many questions as you like before deciding whether to participate.

Why is this study being done?

You are being asked to take part in this study because your child will be undergoing surgery for repair of a one-sided hernia or hydrocoele. They will have a 60-70 % chance of experiencing some amount of pain afterwards. Typically, the surgeon injects local anesthetics (“freezing”) into the surgical wound before closing it. On average, this “freezing” provides pain relief for four to six hours. The purpose of this study is to learn if adding clonidine to the “freezing” will improve pain relief after your child's surgery.

Clonidine in liquid form has been used safely and successfully in hospitals in the United States of America and Europe as a sedative before surgery and for pain relief in children. Liquid clonidine has yet to be approved for use among Canadian children. The goal of this study is to evaluate he risks and benefits of the use of Clonidine among children. 

How many people will take part in this study?

We hope to enroll 140 children into this study. We expect the study to last two years.

Who will be enrolled?

Children to be included in this study will be health, range in age from 1-12 years of age and who are undergoing minor lower abdominal surgery. They will be excluded if they have known allergies to any of the drugs that will be administered; if they take pain relievers on a chronic basis; if they are taking clonidine; if they are on medications to treat attention deficit hyperactivity disorder; if they are undergoing hernia/hydrocoele repair on both sides or if they are very obese.

What is the study procedure?

Your child will experience the same high standards of care that every patient receives here at CHEO. They will have the same access to pain relief as other children not in this study.

If you agree to let your child participate, they will be 'randomized' into one of two study groups. One group will receive “freezing” plus clonidine, and the other group will receive “freezing” only. Randomization means that you are put into a group by chance. Neither you nor your doctor can choose the group you will be in. You will have an equal (1 in 2) chance of being placed in any group. This is done to ensure that those receiving the study medication and those receiving placebo are identical in every other respect. That way, we can know for certain that any differences that we observe between the two groups are due to the study medication and nothing else. A placebo has no treatment value. It is an inactive substance that may look like medicine but contains no medicine. A placebo is used in research to compare the effects of a given treatment (in this case the drug, clonidine) against no treatment at all.

During surgery we will collect two milliliters (half a teaspoon) of blood from your child. It will be used to look at your child’s genetic make-up of how they break down clonidine. There is a small risk of a release of information from your research records. Health and research records have been used against patients and their families. For example, in Canada, insurance companies may deny insurance to patient's with a certain illness or those that have a genetic risk of disease. Your hospital medical records cannot, however, be released unless required or permitted by law or if you sign a release of information. However, in this study, the genetic testing has no relation to a genetic disease link and we do not believe that this would cause any insurance risks to children or their families. The researchers of this study will protect your research records so that your name, address and phone number will be kept private.

What is the parent’s role?

Your surgeon will prescribe pain medication for your child. You will be asked to give your child pain medication only when they feel uncomfortable. The same will apply for any over the counter medications you prefer to use for pain (e.g. Tylenol®) or nausea and vomiting (e.g. Gravol®).

We need to record the effect of the study medication on your child’s pain relief and if there are any side effects. You and your child (if they are 5 years of age or older) will be asked to complete a daily pain and side effect diary at home during the first week after surgery. This should take no more than 5 minutes of your time each day. A research assistant for the study will contact you the day after the surgery to make sure you are comfortable filling out the diary. In addition, on the day of surgery and 7 days later you and your child (if they are 5 years of age or older) will be asked to complete two short questionnaires about their fatigue and quality of life.

You will be provided with a pre-paid courier envelope to return the diary after completion. On the 7th day after surgery you will be sent a questionnaire by mail or email asking you to comment on your overall experience and satisfaction. If you have any concerns related to the medication you are encouraged to contact Dr. Kimmo Murto at 613-239-7951.

What are the potential benefits?

We expect that adding clonidine to the “freezing” will improve pain relief after surgery. Your child may or may not benefit from participating in the study. Information that we learn from the study will allow us to better understand how clonidine works when combined with “freezing”. Based on our current knowledge, we do not know if the use of clonidine with “freezing” will be significantly better than “freezing” alone in terms of either effectiveness or side effects. If we learned that there was one group of children who clearly experienced less pain than the other, the study would be stopped.

What are the risks and discomforts?

The doses of clonidine that we are using in this study have very few side effects. They include sedation (uncommon), low blood pressure (very uncommon) and low heart rate (very uncommon). Typically, these side effects are mild, require no treatment, are short lived and occur within 1-2 hours of injection. Your child should experience no additional discomfort other than what is to be expected with regards to the surgery.

In the event that you suffer injury as a direct result of participating in this study, normal legal rules on compensation will apply. By signing this consent form you are in no way waiving your legal rights or releasing the investigator (Dr. Kimmo Murto) from their legal and professional responsibilities. You will be provided with any new information that may affect your willingness to participate in this study. You will be provided with a copy of this consent.

Can I withdraw from the study?

Your decision to participate or not in this study will not affect the care you receive at CHEO. You are free to withdraw from the study at any time and there will be no penalty to you or your child. We will inform you of any new information that might influence your decision to continue to participate in this research project. To withdraw you will need to contact Dr. Kimmo Murto or your child’s anesthesiologist at 613-737-2431. Your child can also be withdrawn by the study investigators.

Token of appreciation:

For participating in this study you will be provided with a parking pass worth $6 on the day of your child’s surgery. In addition, following completion of the survey on day 7 you will be enrolled in a draw for a $100 Montana’s gift certificate.

Future Studies

The blood sample obtained for this study is to be used for the express purpose of looking at your child’s genetic make-up of how they break down clonidine.

What about Confidentiality and Privacy?

Research records will be kept for 25 years in a secure area according to the federal drug regulations, and then would be destroyed. Your child’s personal information will be kept strictly confidential except as required or permitted by law. Representatives of the company that provides clonidine and/or Health Canada as well as representatives from the CHEO Research Ethics Board can have access to your child’s personal information. Your child will not be identified in any publication or presentation of this study. Any personal information about your child that leaves the hospital will be coded so that they cannot be identified by name.


The CHEO Research Ethics Board (REB) has reviewed and approved this research project. The REB is a committee of the hospital that includes individuals from different professional backgrounds. The Board reviews all research that takes place at the hospital. Its goal is to ensure the protection of the rights and welfare of people participating in research. The Board’s work is not intended to replace a parent or child’s judgment about what decisions and choices are best for them. You may contact the Chair of the Research Ethics Board, for information regarding patient’s rights in research studies at (613) 737-7600 (3272), although this person cannot provide any health-related information about the study.

Click here to download the consent form.

Assent for ages 8 to 12 Years of Age

Why would we like to speak with you?

We want to talk with you about being a part of something called a research study. A research study is a way to test new ideas. Research helps us learn new things. Doctors who do research are also called researchers.

Why am I being asked to be in this research study?

You are being asked to be in this study because you are having an operation on your tummy that may cause you some pain afterwards. We have a medication called clonidine that may reduce the amount of this pain and make you generally feel better.

If you have any questions about this study, we want you to ask them at any time.

What is this study about?

In an operation like the one you are having the surgeon will squirt “freezing” into the wound before they close it. We want to find out if clonidine can be used with the “freezing” to help children like you experience less pain after an operation. Also, we want to find out if there is something special about you that makes clonidine work better.

What if I don't want to be in the study?

It’s okay to say 'NO' if you don't want to be in the study. No one will be upset with you and the doctors will still give you the very best care. Also, it is okay to be in the study now and change your mind at any time before your operation. Talk to your parents/guardians about your decision.

What will happen to me?

If you agree to be in the study:

1) You will receive one of two different mixtures of study medication. One mixture has “freezing” that surgeons use on patients during operations and the other has a mixture of “freezing” plus clonidine. You won’t know which one you receive and neither will we.
2) The surgeon will squirt the study medication into your wound before they close it.
3) You will have a blood test while you are sleeping during your operation.
4) Before and every day for 7 days after your operation we will ask you and your parents to fill out a study diary to keep track of how you are feeling.

Will this study hurt?

Nothing that you do for this study should cause pain.

Who should I ask if I have any questions?

If you have any questions about the study, you or your parents can call Dr. Kimmo Murto at 613-737-2431.

Click here to download assent form.

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