Effects of perioperative intravenous low dose of ketamine on postoperative analgesia in children.

BACKGROUND AND OBJECTIVE: Low dose of ketamine reduces postoperative pain and opioid consumption in adult studies. However, there are only a few data with controversial results in the paediatric population. The aim of this randomized controlled trial was to evaluate the use of low doses of intravenous ketamine on postoperative pain in children after surgery on the lower part of the body. METHODS: Thirty-seven children with ASA 1 or 2 from 6 to 60 months of age, undergoing scheduled surgery, were prospectively enrolled in a double blind sequential trial using a triangular test, with analysis every 10 patients treated. The children were randomly assigned to intravenously receive saline or 0.15 mg kg(-1) ketamine before surgery, followed by a continuous infusion of 1.4 microg kg(-1) min(-1) over 24 h. After sevoflurane induction and tracheal intubation, a caudal anaesthesia was performed in all children (1 ml kg(-1) of bupivacaine 0.25% with epinephrine). The postoperative analgesic technique was standardized with intravenous paracetamol 15 mg kg(-1) 6 h(-1), rectal morniflumate (20 mg kg(-1) 12 h(-1)) and intravenous nalbuphine infusion 1.2 mg kg(-1) 24 h(-1) for 24 h. The Children's Hospital of Eastern Ontario Pain Scale (CHEOPS) scores, additional bolus of nalbuphine (if CHEOPS >7) and side effects were recorded from eye opening every 2 h over 24 h. The primary endpoint was the CHEOPS area under the curve. RESULTS: There was no difference in terms of additional bolus of nalbuphine as well as CHEOPS score area under the curve between groups, that is, 76 +/- 10 in the ketamine group versus 74 +/- 7 in the control group. No psychomimetic side effects were noted. CONCLUSION: The study failed to show any evidence of benefit of ketamine to improve analgesia in children when given in addition to a multimodal analgesic therapy with paracetamol, a NSAID and an opiate.

Single-breath vital capacity rapid inhalation induction with sevoflurane: feasibility in children.

BACKGROUND: Single-breath vital capacity technique is currently administered for inhalation induction of anesthesia with sevoflurane in adults. Because sevoflurane is used in children, the aim of this open nonrandomized trial was to explore the feasibility and acceptance of this technique in midazolam premedicated patients aged from 4 to 15 years old. METHODS: A pediatric population (n = 118) was instructed in the vital capacity technique after their arrival in the induction room in a standardized and playful manner. Induction was performed with a circle-absorber breathing circuit, primed with sevoflurane 7% in 100% O2. Success of the single-breath vital capacity, delay of induction, hemodynamic and airway tolerance, acceptance by the children and side effects were analyzed. A multivariate logistic regression model was used to identify independent risk factors associated with the failure of the vital capacity technique. RESULTS: Single-breath vital capacity technique was achieved by 57% of the children. The success rate highly correlated with age and ranged from 10% in 4-5 years old to 75% at 11 years and 95% by 14 years. Other factors for success were cooperation and understanding. The need for more than two explanations of the technique was predictive of failure. Delays in the loss of the eyelash reflex and central pupil myosis were obtained in 34 s (18-50) and 242 s (145-278), respectively [median (interquartile ranges)]. Hemodynamic tolerance was good with few airway complications. CONCLUSION: Rapid anesthesia induction using a single-breath technique with 7% sevoflurane is effective and well tolerated in children, particularly in those above 9 years of age, and in fact, success rate was markedly lower in the young age groups.