title: Patient-controlled bupivacaine wound instillation following cesarean section: the lack of efficacy of adjuvant ketamine.
abstract: OBJECTIVE
  To assess the analgesic efficacy of ketamine when administered as an adjuvant to bupivacaine for patient-controlled wound instillation following cesarean section.
  
  
  METHODS
  Prospective, randomized, double-blind study.
  
  
  METHODS
  Large referral hospital.
  
  
  METHODS
  50 term parturients undergoing cesarean section.
  
  
  METHODS
  In all cases, a standard spinal anesthetic was administered. On completion of the surgery, a multihole 20 G epidural catheter (B. Braun, Melsungen, Germany) was placed above the fascia such that the tip was sited at the point which demarcated 50% of the length of the surgical wound. Thereafter, the catheter was connected to a patient-controlled drug delivery device. The device was filled with either 0.125% bupivacaine (bupivacaine group) or 0.125% bupivacaine and ketamine (1 mg/mL) (bupivacaine-ketamine group). Postoperatively, wound instillation was performed via the patient-controlled analgesia device. During the first 6 postoperative hours, a co-investigator administered "rescue" morphine (2 mg IV). Thereafter, "rescue" dipyrone (1 g) was administered on patient request.
  
  
  RESULTS
  At all time intervals, visual analog scale (VAS) for pain at rest, on coughing, and during leg raise were similar between the groups. All patients (100%) in both treatment groups received "rescue" morphine. Similarly, the number of doses of 2 mg "rescue" morphine administered was unaffected by patient randomization. The total "rescue" morphine administered during the first 6 postoperative hours was 11.2 +/- 4.6 mg versus 11.3 +/- 5.6 mg for the bupivacaine group and bupivacaine-ketamine group, respectively. The number of pump infusions during the 24-hour study period was 9 +/- 2 and 9 +/- 3 for the bupivacaine group and bupivacaine-ketamine group, respectively. The volume infused via the delivery device was similar between the groups (81 +/- 18 mL vs. 85 +/- 24 mL for the bupivacaine group and bupivacaine-ketamine group, respectively). Psychomental and cognitive function as measured by the Digit Symbol Substitution and Mini Mental Tests were unaffected by adjuvant ketamine administration. Patient satisfaction was similar between the groups.
  
  
  CONCLUSIONS
  Adjuvant local ketamine does not enhance bupivacaine-induced wound instillation following cesarean section.
authors.affiliation: Department of Anesthesiology and Intensive Care, Meir Hospital, Kfar Saba, Israel.
authors.forename: Edna
authors.initials: E
authors.lastname: Zohar
authors.forename: Ilya
authors.initials: I
authors.lastname: Luban
authors.forename: Igor
authors.initials: I
authors.lastname: Zunser
authors.forename: Arie
authors.initials: A
authors.lastname: Shapiro
authors.forename: Robert
authors.initials: R
authors.lastname: Jedeikin
authors.forename: Brian
authors.initials: B
authors.lastname: Fredman
mesh_terms: D000328:Adult; D016058:Analgesia, Patient-Controlled / Q000706:statistics & numerical data*; D000700:Analgesics / Q000008:administration & dosage*; D000779:Anesthetics, Local / Q000008:administration & dosage*; D002045:Bupivacaine / Q000008:administration & dosage*; D002585:Cesarean Section; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007649:Ketamine / Q000008:administration & dosage*; D008875:Middle Aged; D010147:Pain Measurement; D010149:Postoperative Pain / Q000188:drug therapy*; D017060:Patient Satisfaction; D011247:Pregnancy; D011446:Prospective Studies; D013997:Time Factors
chemical_list: D000700:Analgesics; D000779:Anesthetics, Local; D007649:Ketamine; D002045:Bupivacaine