By Louise Gagnon
TORONTO, CANADA -- May 9, 2007 -- A randomised, controlled, double-blinded, crossover study shows it is safer if children with acute leukaemia can be sedated with propofol and fentanyl when undergoing a lumbar puncture.
The research was presented here as a poster session at the annual meeting of the Pediatric Academic Societies.
The study found the combination of propofol and fentanyl resulted in fewer cases of hypotension and airway obstruction and a reduction in the severity of oxygen desaturation. Moreover, patients getting the combination as sedation recovered more quickly after the procedure - 26 minutes (propofol/fentanyl) vs. 36 minutes (propofol/placebo), P =.047.
"We wanted to see the effect of decreasing the dose of a sedative by adding an opiate," explained says Meredith Schultz, BSc, a fourth-year medical student at the University of Wisconsin School of Medicine in Madison and study investigator. "We wanted to see if adding the opiate would decrease the amount of adverse events because the dose of propofol would be less. Fentanyl would blunt the pain effects of the lumbar puncture, and in this way we can use less sedative."
Schultz noted children with acute leukaemia require frequent sedation because they are getting multiple lumbar punctures and added that no protocol existed for critical care physicians at the University of Wisconsin Children's Hospital in Madison in terms of how to sedate these children. Some use propofol alone and some add fentanyl to the propofol.
The study included 22 patients, 14 were male and eight were female, received 44 lumbar punctures. All patients were subject to both types of sedation, propofol and placebo (saline) being one type and propofol/fentanyl being the other. The mean age of patients was 6.4 years. The mean dose of propofol was 5.2 mg/kg in the propofol/placebo arm and 3.4 mg/kg for propofol/fentanyl (P <.001).
A total of 12 adverse events occurred in 11 patients when they received propofol with placebo compared to six adverse events occurring in four patients when they received the combination of propofol/fentanyl (50.0% or 11/22 vs. 18.2% or 4/22, p = 0.0196). The most common adverse event was hypotension, with six cases occurring in patients when they received propofol/placebo and four cases occurring in patients which had fentanyl added to their sedation.
One of the patients who experienced oxygen desaturation in the propofol/placebo group also experienced airway obstruction, and two of the four patients who experienced hypotension in the combination group also had mild oxygen desaturation. There was one case of emesis and three cases of airway obstruction in the propofol/placebo group.
The combination therapy was the preferred option for parents of the children: 16 of the 22 families or 72.7% preferred propofol/fentanyl for any future sedation (P =.05, 95% CI: 0.05-0.89). One family preferred propofol alone, and one family did not state a preference for either sedation.
The key to success with using two agents for sedation is how they are given, said Schultz. "We made sure we gave the fentanyl (1.0 mcg/kg) at least five minutes before the induction of propofol, so that the fentanyl would have time to work," said Schultz. "The fault in other studies is that they started induction immediately after giving fentanyl."
The National Institutes of Health funded the study.
[Presentation title: Propofol/Fentanyl vs. Propofol Alone for Lumbar Puncture Sedation in Children with Acute Leukemia: A Randomized Double-Blind Crossover Study. Poster 8419.2]
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