Lack of enrollment/lack of potential subjects fitting criteria

Caudal injection of local anesthetic is a neuraxial technique routinely performed on young children for postoperative analgesia after lower abdominal and lower extremity surgical procedures. One of the major limitations of the use of single shot neuraxial injections for this purpose is the limited duration of action of the injected local anesthetic. Adjuvant medications, such as clonidine and epinephrine, have been added to the local anesthetic to prolong the duration of the neuraxial block, with varying results. Dexamethasone is a synthetic glucocorticoid steroid commonly used in the perioperative setting for a multitude of indications, including the prolongation of local anesthetic based analgesia. It has been shown that the administration of dexamethasone either intravenously or via perineural injection can significantly increase the duration of analgesia derived from a local anesthesia based peripheral nerve block. Literature also suggests that the effect of dexamethasone is equivalent whether given intravenously or perineurally. Interest in dexamethasone enhanced caudal analgesia exists and a previous study noted that caudal anesthesia can be prolonged by intravenous dexamethasone. The study was criticized for using a higher dose of dexamethasone (0.5 mg/kg) than is routinely used in the pediatric population outside of airway procedures, which may expose patients to dose related side effects of dexamethasone. A large meta-analysis has suggested that 0.1 mg/kg is effective for analgesic prolongation, but no direct study of low dose intravenous dexamethasone in combination with caudal anesthesia has been performed.

As dexamethasone is an inexpensive and commonly used medication, it would be beneficial to know if a similar prolongation of analgesia occurs when a local anesthetic is given neuraxially in combination with low dose intravenous dexamethasone. This project will investigate the efficacy of low dose intravenous (IV) dexamethasone in prolonging the duration of post operative analgesia provided by an intraoperative caudal injection of local anesthetic. All patients will be enrolled in the study the day of surgery, in the preoperative waiting area. The study will be explained by an anesthesiologist with extensive knowledge of the protocol. Computer randomization will occur for each patient. Randomization will not increase the risk to either group as all medications and techniques utilized for this study are commonly accepted for routine care for these patients.

Inclusion Criteria:

• age 2 to 10 years
• Scheduled for elective inpatient genitourinary surgical procedure
• Caudal anesthesia standard of care for surgical procedure
• have provided parental consent and assent in accordance with the institutional review board requirements

Exclusion Criteria:

• Abnormal/difficult anatomy
• known allergy to ropivacaine or dexamethasone
• history of documented chronic pain
• existing infection at site of intended injection

24 hours

The study was abandoned/terminated. Enrollment in the trial did not reach the target number of subjects needed to achieve target power and was insufficient to produce statistically reliable results. No participants were analyzed.