Effects of OSA, inhalational anesthesia, and fentanyl on the airway and ventilation of children.
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.
Waters
Karen A
KA
Department of Sleep Medicine, The Children's Hospital at Westmead, NSW 2145, Australia. kaw@mail.med.usyd.edu.au
McBrien
Fergus
F
Stewart
Penny
P
Hinder
Murray
M
Wharton
Sally
S
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
D000701:Analgesics, Opioid; D018685:Anesthetics, Inhalation; D002245:Carbon Dioxide; D009609:Nitrous Oxide; D005283:Fentanyl; D006221:Halothane