A Comparative Study of Ketamine Associated to Target Controlled Infusion(TCI) of Propofol and Local Anesthesia During Ambulatory Aesthetic Surgery

Oscar A. Zimman, MD, PhD, Héctor Abramowicz, MD; Pablo Stengele, MD; Brita M. Rüd, MD; Arturo Figueroa, MD

Purpose: Since our previous experience (1) with TCI (Diprifusor®) of propofol, analgesics and sedatives for outpatient conscious or unconscious sedation with appropriate local anesthesia during ambulatory aesthetic surgery in a series of 102 patients (Group A), we included Ketamine(2) in a new series to evaluate the effects of this drug (Group B), comparing both protocols.

Methods: A retrospective review of 67 consecutive patients over a 12-month period (February 2002-February 2003) who underwent ambulatory aesthetic surgery, was compared with the previous experience with 102 patients. In this new series the mean age was 37.4 years and the average weight 121.9 pounds (55.3 kg.). The cases (ASA 1 and ASA 2) included rhinoplasty, endoscopic forehead lift, face-lift, blepharoplasty, breast augmentation, reduction or mastopexy, ultrasonic assisted lipoplasty and abdominal lipectomy as single procedures. Combined procedures were performed as complementary of the same area, as endoscopic and open face-lift (18 cases). The routine procedure was: premedication with midazolam (3 mg.), meperol (50 mg.) in IV bolus, TCI induction dose of propofol between 1.1-5.2 /ml. (mean: 3.50 /ml.), maintenance doses between 1.1-2.7 /ml. (mean: 2.03 /ml.). When the dose of 2-2.5 /ml. of propofol was reached 0.5 mg./kg. of ketamine was injected as an IV bolus. In cases of large volume surgeries an additional dose of 25-50 mg. of ketamine was administered. Recovery time ranged between 1-4 min. (mean 2 min.10 seconds). Local anesthesia was performed with lidocaine with epinephrine at a dilution of 1% to 0.12%. The endpoint of this study included: TCI propofol and ketamine doses required, side effects, post-operative nausea and vomiting (PONV), recovery time, body motion at the time of local anesthesia, oxygen administration or room air, patient welfare and analgesia required and the comparison of both groups: A and B.

Results: Surgical procedures were performed by the same surgical team on prone and supine decubitus without intubation or laryngeal mask. Oxygen supply in almost all the cases or room air at the discretion of the anesthesiologist to maintain normal oxygen tension (FiO2 = 0.3) with spontaneous ventilation. Mean drug consumption was 401.53 mg. of propofol. No postoperative analgesia was required for the procedure, but in 7 cases (10.4%) a cephalalgia required medication. No PONV was observed, and the discharge period was 2 hours 17 min. Duration of the procedures ranged from 45 min. to 4 hours 28 min. (mean: 2 hours, 11 min.) At the time of ketamine administration, local anesthesia was performed with no body motion and no recall of the surgery or hallucinations, with a pleasant awakening.

Conclusions: The comparative study of both groups, indicate that the use of ketamine benefits the anesthetic procedure, diminishing the propofol doses up to 30%. Hemodynamic parameters were particularly stable in both groups as well as the awakening times. In-Group B, there was no PONV (2.94% in group A) or postoperative pain related to the surgery (7.84% in group A), but cephalalgia related to Ketamine dose required analgesics in 10.4% of pts. No hallucinations in this group, since the Ketamine was injected at the time of unconscious sedation.

References :

(1)Zimman, O.A., Abramowicz, H., Stengele, P. The use of

Target Controlled Infusion(TCI) System with Propofol

and local anesthesis during ambulatory aesthetic

surgery. An analysis of 102 consecutive patients.

Plast.Surg.Forum, 25: 369, 2002

(2) Friedberg, B.L. The effect of a dissociative dose of

Ketamine on the bisepctral Index (BIS) during

Propofol hypnosis. J.Clin.Anesth., 11:4, 1999