title: Effects of OSA, inhalational anesthesia, and fentanyl on the airway and ventilation of children.
abstract: To assess effects of anesthesia and opioids, we studied 13 children with obstructive sleep apnea (OSA, age 4.0 +/- 2.2 yr, mean +/- SD) and 24 age-matched control subjects (5.8 +/- 4.0 yr). Apnea indexes of children with OSA were 29.4 +/- 18 h-1, median 30 h-1. Under inhalational anesthetic, closing pressure at the mask was 2.2 +/- 6.9 vs. -14.7 +/- 7.8 cmH2O, OSA vs. control (P < 0.001). After intubation, spontaneous ventilation was 115.5 +/- 56.9 vs. 158.7 +/- 81.6 ml x kg-1 small middle dot min-1, OSA vs. control (P = 0.02), despite elevated PCO2 (49.3 vs. 42.1 Torr, OSA vs. control, P < 0.001). Minute ventilation fell after fentanyl (0.5 microg/kg iv), with central apnea in 6 of 13 OSA cases vs. 1 of 23 control subjects (P < 0.001). Consistent with the finding of reduced spontaneous ventilation, apnea was most likely when end-tidal CO2 exceeded 50 Torr during spontaneous breathing under anesthetic. Thus children with OSA had depressed spontaneous ventilation under anesthesia, and opioids precipitated apnea in almost 50% of children with OSA who were intubated but breathing spontaneously under inhalational anesthesia.
authors.affiliation: Department of Sleep Medicine, The Children's Hospital at Westmead, NSW 2145, Australia. kaw@mail.med.usyd.edu.au
authors.forename: Karen A
authors.initials: KA
authors.lastname: Waters
authors.forename: Fergus
authors.initials: F
authors.lastname: McBrien
authors.forename: Penny
authors.initials: P
authors.lastname: Stewart
authors.forename: Murray
authors.initials: M
authors.lastname: Hinder
authors.forename: Sally
authors.initials: S
authors.lastname: Wharton
mesh_terms: D000701:Analgesics, Opioid / Q000009:adverse effects*; D018685:Anesthetics, Inhalation / Q000009:adverse effects*; D001049:Apnea / Q000139:chemically induced*; D002245:Carbon Dioxide / Q000032:analysis; D002648:Child; D002675:Child, Preschool; D004357:Drug Synergism; D005260:Female; D005283:Fentanyl / Q000009:adverse effects*; D006221:Halothane / Q000009:adverse effects; D006801:Humans; D006935:Hypercapnia / Q000139:chemically induced / Q000175:diagnosis; D008297:Male; D009609:Nitrous Oxide / Q000009:adverse effects; D012121:Respiration, Artificial; D012129:Respiratory Function Tests; D020181:Sleep Apnea, Obstructive / Q000503:physiopathology*; D011795:Surveys and Questionnaires; D013990:Tidal Volume
chemical_list: D000701:Analgesics, Opioid; D018685:Anesthetics, Inhalation; D002245:Carbon Dioxide; D009609:Nitrous Oxide; D005283:Fentanyl; D006221:Halothane