Comparing the duration of pain relief from caudal analgesia when adjuncts like dexamethasone, clonidine, or saline (salt water) are added to ropivacaine.

The local anesthetic, which is currently used for caudal analgesia, is called ropivacaine. It works well and is safe in infants and children. Doctors commonly add small amounts of other medication to ropivacaine to prolong the duration of pain relief provided by a single injection of caudal analgesia.

In this study, the length of duration of pain relief the child receives from caudal analgesia will be examined when different medications are added to ropivacaine. Specifically, dexamethasone, clonidine, or saline (salt water) will be added to ropivicaine and the length of time it takes before the child needs more pain medication will be determined.

Clonidine has been added to caudal analgesia for infants and children for many years. It increases the duration of pain relieving effect of ropivicaine by itself, however, it may lead to prolonged sedation following the surgical procedure (an undesired effect) and it is expensive.

Dexamethasone has been used for adult epidurals and nerve blocks and in spine surgeries. It prolongs the duration of pain relief and causes less sedation. It is commonly administered to children during surgery to help decrease nausea and vomiting after surgery. It is also much cheaper than clonidine.

Inclusion Criteria:

• The subject will receive presurgical caudal block
• American Society of Anesthesiologists (ASA) 1 or 2
• Day surgery unit
• weight 30 kg or less

Exclusion Criteria:

• Neuromuscular disease
• Back problem
• Caudal area skin infection
• Mental retardation
• Developmental delay
• Bleeding disorder