Slower administration of propofol preserves adequate respiration in children.
BACKGROUND
Propofol is a versatile anesthetic agent used in pediatric practice to facilitate investigational and interventional procedures. Propofol can cause significant respiratory depression, the management of which may require advanced airway management skills. This investigation aimed to increase the safety of propofol administration by developing a dosing schedule that would preserve spontaneous respiration in at least 95% of subjects.


METHODS
With Research Ethics Board approval and informed consent, American Society of Anesthesiologists' Status I and II children aged 6-15 years presenting for upper or lower gastrointestinal endoscopy were enrolled. An intravenous loading dose of propofol (4 mg·kg(-1) ) was administered at a rate determined by a randomization schedule in a two-phased study. Following the loading dose, additional propofol was infused at 200 mcg·kg(-1) ·min(-1) for 5 min or until respiratory insufficiency was observed. In Phase I, the infusion rate was modified by 100 mcg·kg(-1) ·min(-1) increments depending upon the respiratory response of the previous subject. In Phase II, the duration of infusion was randomized according to a Biased Coin Design principle to determine the 95% threshold for respiratory insufficiency.


RESULTS
Fifty subjects were included in the analysis. Infusion rates ranged from 1000 to 2300 mcg·kg(-1) ·min(-1) . Seven subjects experienced respiratory insufficiency. The mean (sd) time to respiratory insufficiency was 104 (36) s and duration was 93 (51) s. A propofol loading dose administered over 3.0 min (CI = 1.9-3.4 min) maintained spontaneous respiration in 95% of subjects.


CONCLUSIONS
The respiratory response to propofol is highly variable in children. Slower infusion of propofol will result in a lower risk of respiratory depression.
Dosani
Maryam
M
Department of Anesthesiology, Pharmacology and Therapeutics, The University of British Columbia, Vancouver, BC, Canada.
McCormack
Jon
J
Reimer
Eleanor
E
Brant
Rollin
R
Dumont
Guy
G
Lim
Joanne
J
Mark Ansermino
J
J
D000293:Adolescent; D000771:Anesthesia, Intravenous; D018686:Anesthetics, Intravenous / Q000008:administration & dosage*; D001794:Blood Pressure / Q000187:drug effects; D002245:Carbon Dioxide / Q000097:blood; D002648:Child; D013505:Digestive System Surgical Procedures; D004311:Double-Blind Method; D004569:Electroencephalography / Q000187:drug effects; D019277:Entropy; D005260:Female; D006801:Humans; D008297:Male; D016343:Monitoring, Intraoperative; D015742:Propofol / Q000008:administration & dosage*; D012129:Respiratory Function Tests; D012131:Respiratory Insufficiency / Q000503:physiopathology; D015656:Respiratory Mechanics / Q000187:drug effects*; D018401:Sample Size; D013990:Tidal Volume / Q000187:drug effects; D016896:Treatment Outcome
D018686:Anesthetics, Intravenous; D002245:Carbon Dioxide; D015742:Propofol