title: Efficacy of single-dose, multilevel paravertebral nerve blockade for analgesia after thoracoscopic procedures.
abstract: BACKGROUND
  Although video-assisted thoracoscopic surgery for pulmonary resection is increasingly chosen over thoracotomy, the optimal analgesia regimen for thoracoscopy is unknown. The purpose of this trial was to compare the efficacy of analgesia from preoperative bupivacaine paravertebral nerve blockade with that from placebo injections.
  
  
  METHODS
  Eighty adult patients undergoing unilateral thoracoscopic procedures were enrolled in a prospective, double-blinded, randomized clinical trial of preoperative, multilevel, single-dose paravertebral nerve blockade. Patients received six paravertebral injections with 5 ml of either 0.5% bupivacaine with 0.0005% epinephrine (treated, n = 40) or preservative-free saline (control, n = 40). Cumulative weight-adjusted intraoperative fentanyl and postoperative patient-controlled morphine usage, visual analog pain scores, and spirometry were used to compare efficacy of analgesia between groups.
  
  
  RESULTS
  The treated group received significantly less intraoperative fentanyl compared with the control group (P = 0.003) and had a 31% smaller cumulative patient-controlled morphine dose (P = 0.03) in the 6 h after block placement. Within 6 h, treated patients also reported lower maximum pain scores (P = 0.02) and demonstrated less pain score variability (P = 0.01). No statistically significant difference in cumulative morphine usage existed at 12 or 18 h after block placement. No significant difference in spirometry, cortisol levels, or cytokine production was found between treatments.
  
  
  CONCLUSIONS
  Single-dose paravertebral nerve blockade with bupivacaine is effective in reducing pain after thoracoscopic surgery, but only during the first 6 h after nerve blockade. Because of the limited duration of effect with currently available local anesthetic agents, the current data suggest that, at present, this technique is not indicated in the setting of thoracoscopic surgery.
authors.affiliation: Department of Anesthesiology, Duke University Medical Center, Durham, North Carolina 27710, USA. hill0012@mc.duke.edu
authors.forename: Steven E
authors.initials: SE
authors.lastname: Hill
authors.forename: Rebecca A
authors.initials: RA
authors.lastname: Keller
authors.forename: Mark
authors.initials: M
authors.lastname: Stafford-Smith
authors.forename: Katherine
authors.initials: K
authors.lastname: Grichnik
authors.forename: William D
authors.initials: WD
authors.lastname: White
authors.forename: Thomas A
authors.initials: TA
authors.lastname: D'Amico
authors.forename: Mark F
authors.initials: MF
authors.lastname: Newman
mesh_terms: D000328:Adult; D000368:Aged; D016058:Analgesia, Patient-Controlled; D000701:Analgesics, Opioid / Q000008:administration & dosage / Q000627:therapeutic use; D000779:Anesthetics, Local; D002045:Bupivacaine; D005260:Female; D006801:Humans; D007249:Inflammation / Q000517:prevention & control; D008297:Male; D008875:Middle Aged; D009020:Morphine / Q000008:administration & dosage / Q000627:therapeutic use; D009407:Nerve Block; D010147:Pain Measurement; D010149:Postoperative Pain / Q000188:drug therapy*; D011183:Postoperative Complications / Q000503:physiopathology / Q000517:prevention & control; D011184:Postoperative Period; D012129:Respiratory Function Tests; D018401:Sample Size; D013906:Thoracoscopy
chemical_list: D000701:Analgesics, Opioid; D000779:Anesthetics, Local; D009020:Morphine; D002045:Bupivacaine