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Sponsored by: |
Samuel Lunenfeld Research Institute, Mount Sinai Hospital |
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Information provided by: | Samuel Lunenfeld Research Institute, Mount Sinai Hospital |
ClinicalTrials.gov Identifier: | NCT00403663 |
Combined spinal - epidural (CSE) anesthesia is a well established technique used for elective Cesarean section. As its name suggests, it combines two anesthesia techniques - spinal and epidural. Adjusting the dose of freezing medication for body size is not as simple as giving a larger dose to a larger person. This study asks a simple, yet important question: does your body mass index (BMI) influence the amount of freezing medication needed for adequate CSE anesthesia for Cesarean section? BMI is a number calculated from your height and weight. In patients with a higher BMI, freezing medication appears to spread farther (to a higher level) in the spinal fluid. When freezing is too high, it can cause unwanted side effects. Therefore, in order to provide optimal spinal anesthesia to patients with a higher BMI, it may be advisable to administer less freezing medication. In this study, we want to find the ideal dose of freezing medication for patients with a higher body mass index, and compare it to the dose found to be ideal for patients with normal body mass index.
Condition | Intervention |
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Pain Obesity |
Drug: bupivacaine 0.75% with fentanyl and morphine |
Study Type: | Interventional |
Study Design: | Treatment, Non-Randomized, Single Blind (Subject), Dose Comparison, Parallel Assignment, Safety/Efficacy Study |
Official Title: | Effect of Body Mass Index on the ED95 of Intrathecal Hyperbaric Bupivacaine for Elective Cesarean Section |
Estimated Enrollment: | 40 |
Study Start Date: | October 2006 |
Estimated Study Completion Date: | December 2007 |
Spinal anesthesia is the most common anesthetic technique used for Cesarean section. It offers many advantages over epidural and general anesthesia. However, one of the limitations of spinal anesthesia in Obstetrics is the use of a single shot technique as the continuous technique is associated with unacceptable incidence of PDPH. It is difficult to predict the exact level of sensory block because many factors affect the spread of local anesthetic injected into the CSF. Theoretically, obese patients may have greater intra-abdominal pressure, leading to compression of the inferior vena cava and engorgement of the epidural venous plexus, which in turn increases the pressure inside the epidural space. This augmented pressure is transmitted to the dural sac and diverge the CSF from the lumbosacral region, leading to a decrease in CSF volume. It has been demonstrated that the volume of CSF in lumbosacral region is an important factor affecting intrathecal spread of anesthetics.
Our hypothesis is that obese women require less intrathecal hyperbaric bupivacaine than do normal weight women to achieve satisfactory surgical anesthesia for elective Cesarean section.Two groups of patients will be studied separately. Patients with BMI greater than or equal to 30 will be included in the obese group, also denominated study group. Patients with BMI less than 25 will be included in the normal weight group, also denominated control group. BMI will be calculated based on the patient's pre-pregnancy weight. For each group, the up-down sequential allocation method based on the Narayana rule will be used to find the minimum effective dose of intrathecal hyperbaric bupivacaine 0.75% associated with opioids necessary for satisfactory outcome in 95% of the pregnant women undergoing cesarean section, i.e. ED95.
There are two possible outcomes in our study: a satisfactory outcome is defined if the sensory block reaches at least at T6 and the patient does not complain of any pain or discomfort that requires intraoperative supplemental drugs; an unsatisfactory outcome is defined if the sensory block reaches a level lower than T6 or the patient complains of pain or discomfort that requires intraoperative supplemental drugs. The decision whether or not the supplementation is required will be made exclusively by the patient, and not by the physician in charge.
Ages Eligible for Study: | 18 Years to 40 Years |
Genders Eligible for Study: | Female |
Accepts Healthy Volunteers: | Yes |
Inclusion Criteria:
Exclusion Criteria:
Contact: Jose CA Carvalho, MD PhD | 416-586-4800 ext 2631 | jose.carvalho@uhm.on.ca |
Contact: Yung Lee, MD | 416-586-4800 ext 2338 | yung.lee@uhn.on.ca |
Canada, Ontario | |
Mount Sinai Hospital | Recruiting |
Toronto, Ontario, Canada, M5G 1X5 | |
Contact: Jose CA Carvalho, MD PhD 416-586-4800 ext 2931 jose.carvalho@uhn.on.ca | |
Principal Investigator: Jose CA Carvalho, MD PhD | |
Sub-Investigator: Yung Lee, MD | |
Sub-Investigator: Mrinalini Balki, MD | |
Sub-Investigator: Robert Parkes |
Principal Investigator: | Jose CA Carvalho, MD PhD | Department of Anesthesia and Pain Management, Mount Sinai Hospital, University of Toronto |
Study ID Numbers: | 06-02, 06-0206-E |
Study First Received: | November 23, 2006 |
Last Updated: | November 7, 2007 |
ClinicalTrials.gov Identifier: | NCT00403663 |
Health Authority: | Canada: Ethics Review Committee |
Body mass index Combined Spinal-Epidural Anesthesia Cesarean section Obesity |
Body Weight Morphine Signs and Symptoms Obesity Fentanyl |
Nutrition Disorders Bupivacaine Overweight Overnutrition Pain |
Sensory System Agents Therapeutic Uses Physiological Effects of Drugs Central Nervous System Depressants Anesthetics Narcotics |
Analgesics Peripheral Nervous System Agents Central Nervous System Agents Analgesics, Opioid Pharmacologic Actions Anesthetics, Local |