bilateral paravertebral blockade (t7-10) vs. incisional local anesthetic administration for pediatric patients

Conditions: Pain, Postoperative

Summary: the objective of this study is to assess the efficacy of paravertebral nerve blocks, single shot, with ropivacaine 0.5% for postoperative pain control after elective laparoscopic cholecystectomy as compared with incisional administration of same local anesthetic at laparoscopic insufflation ports by the surgeon.

pain after laparoscopic cholecystectomy is a result of many mechanisms such as tissue injury, local trauma to gallbladder removal, chemical irritation of the peritoneum, pneumoperitoneum. effective analgesia in the immediate post-operative period following laparoscopic cholecystectomy is necessary for optimal recovery. many methods for pain control after laparoscopic cholecystectomy have been evaluated, but none of them provided optimal postoperative analgesia. when used as a complement to general anesthesia, bilateral paravertebral blockade t5-t6 for adult laparoscopic cholecystectomy has been found to improve postoperative pain control. whether this is also the case with pediatric patients is not certain. analgesia from administration of local anesthetic by surgeon at insufflations ports is of short duration and may not provide sufficient pain relief. cholecystectomy. 84 pediatric patients (8-17 yrs old) will be randomly assigned to two groups: group 1 (treatment group): 42 patients will have six paravertebral nerve blocks with ropivacaine 0.5%, and incisional administration of placebo / normal saline at all four laparoscopic ports. group 2 (control group): 42 patients will have placebo/normal saline in paravertebral space, same amount, and injection at incision sites for all for insufflation ports with ropivacaine 0.5%. both the anesthesiologist and the surgeon will be blinded to patient randomization. additional postoperative pain control will be provided via patient administered dilaudid pca, for 12 hours after paravertebral block. after pca is discontinued, the patient will receive oxycodone po and dilaudid iv for breakthrough pain. pain assessment will continue until 24 hours after paravertebral block or patient discharge if earlier than 24 hours. the primary end-point of this research is the amount of dilaudid (ng/kg/min) administered via patient controlled analgesia (pca), 12 hours after administration of ropivacaine 0.5% /normal saline in paravertebral space and administration of normal saline/ropivacaine 0.5% at all four laparoscopic ports. the secondary end points will be also for total amount of fentanyl (mcg/kg), dilaudid (mcg/kg), oxycodone (mg/kg) and morphine (mg/kg) (after conversion of above opioids to morphine based on opioids potency) used intraoperatively and 24 hours postoperatively (or until the patient is discharged, if sooner). postoperative pain scores will be assessed and compared at 4, 8, 12, 18 and 24 hr after paravertebral block using visual analog scale (vas). other secondary end-points will be possible side effects from opioids administration (nausea, emesis, itching, and episodes of respiratory depression) and possible complications associated with nerve blocks: pleural and vascular punctures, pneumothorax, back pain, bruises, and intravascular administration of local anesthetic.

Eligibility criteria:
inclusion criteria: * pediatric patients scheduled for elective laparoscopic cholecystectomy under general anesthesia * 8-17 yrs, female and male * asa 1, 2, 3 * more than 30 kg * bmi less than 36 (to calculate will use http://www.globalrph.com/bmi.htm ) * the patient must be able to self administer opioids via patient control analgesia (pca) * the patient must be able to complete postoperative questionnaires for pain score, pain type, location, patient satisfaction * the patient will to be admitted for 24 hrs after surgery exclusion criteria: * patient refusal * parental/guardian refusal * history of coagulopathy, inr more than 1.5, platelets less than 100 000, pt , ptt more than normal value, patient on coumadin, heparin or low molecular weight heparin ( lmwh) * local infection at the planned block site * vertebral anomalies, (e.g. scoliosis) * bmi more or equal 36 * patient unable to self administer medications via pca * allergy to dilaudid, oxycodone, acetaminophen, ropivacaine * chronic opioid use * current weight less than 30 kg * acute pain (pain on day of surgery that requires pain medication) * pregnancy test positive

Keywords: paravertebral nerve blocks laparoscopic cholecystectomy