Peripheral Nerve Blocks in Pediatric Orthopedic Patients

Overview

Context: Single shot peripheral nerve blocks have limited duration of action depending on the local anesthetic agent used in the block. But it rarely lasts longer than 12 hrs. Patients need oral analgesics at home once the block wears off to control the pain. Objectives: Primary Objective To determine if peripheral nerve blocks have any advantage in terms of decreasing oral analgesic requirements in the post operative period even after the effects of the block have worn off Secondary Objective To determine if inclusion of single shot regional technique improves patient/family satisfaction with post operative pain management . Study Design: Prospective randomized single blinded study. Inclusion Criteria * Children aged between 6 yr and 17yr scheduled for ambulatory peripheral orthopedic surgery with moderate to severe postoperative pain. * Surgery of moderate duration (\<2hr) * Surgery associated with minimal blood loss or fluid shifts (\<10% total blood volume) * American Society of Anesthesiologists (ASA) classification 1 or 2 * Parents able to understand follow up instructions and are able to reach at home by phone Exclusion Criteria * Known allergy to local anesthetics * Preexisting neuropathy with sensory or motor deficits * Skin infection at site of needle placement * Parents refusal for peripheral nerve blocks

80 children between the ages of 6yr and 17 yrs. scheduled for ambulatory peripheral orthopedic procedures in the operating rooms of Batson Children's Hospital will be enrolled in the study. Written informed consent will be obtained from the parents or legal guardian and assent will be obtained from patients when possible. Once enrolled in the study, patients will be randomly assigned to one of two groups General anesthesia only (GA group) and General Anesthesia combined with regional anesthesia (RA group). Once the patients are brought to the operating room standard ASA monitors will be applied. After mask induction with O2/Nitrous oxide(N2O)/Sevoflurane(Sevo), a peripheral intravenous line will be inserted and secured. Additional IV medication propofol 2-3mg/kg will be given prior to insertion of appropriate size laryngeal mask airway (LMA). Patients in GA group will undergo the procedure under general anesthesia with Sevo/O2. Patients in the RA group will receive a peripheral nerve block appropriate for the procedure after induction of general anesthesia with O2/N2O/Sevo. The attending anesthesiologists will perform the nerve block under ultrasound guidance (Sonosite machine with high frequency probe) using 22G stimulating needle under aseptic precautions. 0.5% ropivacaine up to a total dose of 3mg/kg will be used for the block. Anesthesia is maintained in both groups with O2/Sevo titrated to minimum alveolar concentration (MAC of) 1.5 . After surgical incision, doses of 0.05mg/kg morphine is given IV every 5 min as needed titrated to HR and BP within 10% change from baseline. Additional IV morphine at the dose of 0.05mg/kg will be given every 10 minutes in the recovery room (PACU) as needed for pain ( Visual Analog score -VAS score \>4). Total morphine consumption, length of recovery room stay and side effects such as nausea or vomiting will be recorded in the PACU. The patients in the study will be given the following 1. A prescription for oral analgesics (lortab: hydrocodone 5mg with acetaminophen 325mg). 2. A handout about the nerve block and post op care (for patients in RA group) 3. A handout depicting the visual analog scale 4. Data sheet with date, time, pain scale and pain meds , satisfaction scale, documentation of side effects along with a stamped return envelope. The parents will be educated about assessing pain and visual analog scale score. The parents will be instructed to give one or two pills depending on the weight (one pill for weight \<50kg and 2 pills for weight \>50kg)every 4-6 hrs. as needed for pain (VAS score more than 2). The patients will be followed by phone by research nurse blinded to the group on postoperative day 2 and day 8. They will be asked about the total use of analgesics at the end of day 2 (first 48hrs) and day 7. Family satisfaction on a scale of 1 to10, Incidence of other side effects such as nausea, vomiting, sleep disturbance, feeding difficulty and prolonged numbness or motor block will also be collected. The parents will also be requested to return the data sheet in the stamped return envelope to the research team.