The Effect of Dexamethasone on Cortisol Levels in Patients Undergoing Thyroid Surgery
Many drugs are used to prevent nausea and vomiting and pain after surgery. In this study the investigators will be looking at a drug, dexamethasone, which is commonly used to prevent nausea and vomiting and pain after surgery but has other side effects. Dexamethasone is a man-made drug that is commonly used during surgery but also can affect naturally occuring hormones. In this study the investigators will be looking at dexamethasone's effect on a number of naturally occuring hormones over a twenty four hour period after thyroid surgery. The investigators hypothesize that plasma cortisol levels will be decreased following administration of dexamethasone.
|Study Design:||Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double Blind (Subject, Caregiver, Investigator, Outcomes Assessor)
|Official Title:||The Effect of Dexamethasone on Plasma Cortisol Levels, Pain and PONV in Female Patients Undergoing Thyroid Surgery|
- Plasma Cortisol level. [ Time Frame: One, eight and twenty-four hours following Dexamethasone administration. ] [ Designated as safety issue: No ]
- Incidence of postoperative nausea and vomiting. [ Time Frame: Twenty-four hours following surgery. ] [ Designated as safety issue: No ]
- Pain intensity measured on the visual analogue scale. [ Time Frame: Twenty-four hours following surgery ] [ Designated as safety issue: No ]
- Plasma Estradiol level. [ Time Frame: One, eight and twenty-four hours following dexamethasone administration. ] [ Designated as safety issue: No ]
- Plasma Progesterone level. [ Time Frame: One, eight and twenty-four hours following dexamethasone administration ] [ Designated as safety issue: No ]
- Plasma ACTH level [ Time Frame: One, eight and twenty-four hours following dexamethasone administration. ] [ Designated as safety issue: No ]
|Study Start Date:||May 2010|
|Estimated Study Completion Date:||February 2016|
|Estimated Primary Completion Date:||February 2014 (Final data collection date for primary outcome measure)|
One dose of 8 mg of Dexamethasone intravenously at induction of anesthesia
|Placebo Comparator: Placebo||
2 ml of 0.9% Saline Solution administered intravenously at induction of anesthesia
Purpose To examine the effect of dexamethasone, on plasma cortisol levels, postoperative pain, nausea and vomiting in patients undergoing thyroid surgery.
Hypothesis That dexamethasone administered at induction of anesthesia will result in reduced plasma cortisol levels, postoperative pain, nausea and vomiting.
Justification Dexamethasone is a synthetic steroid medication used routinely to prevent nausea and vomiting in patients undergoing general anesthetic. Administration of exogenous steroids can suppress production of endogenous steroids including cortisol.
Currently, no data exists describing the degree of suppression of cortisol production by a single preoperative dose of dexamethasone. This information would guide physicians prescribing dexamethasone in the perioperative period.
Objectives To compare plasma cortisol levels in patients receiving dexamethasone versus placebo at induction of anesthesia. To investigate the effect of dexamethasone on postoperative pain, nausea and vomiting.
Research Methods A prospective, randomized, controlled, double-blinded study conducted at a single center. Thirty patients will be recruited and randomly assigned to dexamethasone or placebo groups, in accordance with sample size calculations. A placebo group is necessary to eliminate the effects of potential confounding factors.
Statistical Analysis An interim analysis will be conducted to confirm the sample size calculation. Plasma cortisol level will be analyzed using 2-way analysis of variance (ANOVA). Secondary outcome measures will be analyzed with appropriate parametric or nonparametric methods.
|Contact: Jill Osborn, MDfirstname.lastname@example.org|
|Contact: Eleanor C Cleary, MBemail@example.com|
|Canada, British Columbia|
|St Paul's Hospital||Recruiting|
|Vancouver, British Columbia, Canada, V6Z 1Y6|
|Principal Investigator:||Jill A Osborn, MD||St Paul's Hospital, Vancouver and University of British Columbia|