Spontaneous respiration during intravenous anesthesia in children.
OBJECTIVE
Maintaining spontaneous respiration during intravenous anesthesia for investigative and surgical procedures may avoid the need for airway instrumentation and reduce the risk of desaturation. In addition, when performing airway endoscopic procedures in children, maintaining spontaneous respiration while using intravenous anesthesia can reduce the need for endotracheal intubation. This facilitates improved access to the smaller airway, allows assessment of the dynamic function of the airway, and reduces exposure of personnel to inhaled anesthetic agents.


RESULTS
Anesthetic hypnotic and analgesic agents are potent dose-dependent depressants of respiration. Infants have historically been considered to be at a higher risk of respiratory depression, especially from opioid analgesics. However, recent evidence suggests that infants and younger children outside the neonatal period are more resistant to the effects of remifentanil, even when combined with propofol. Spontaneous respiration can be maintained at doses adequate to suppress somatic responses to painful procedures. The large inter-individual variation in respiratory depressant effects necessitates individualized dose titration. The drug dose is more linearly related to variation in the respiratory rhythm and respiratory rate than to minute volume or end-tidal carbon dioxide. Apneic episodes are less likely when respiratory depressant drugs are administered slowly, as this allows time for the end-tidal carbon dioxide level to rise to a new apneic threshold. Hypnotic anesthetics and opioid analgesics act synergistically to cause respiratory depression and suppression of the somatic response.


CONCLUSIONS
Spontaneous respiration can be maintained when anesthetizing children using intravenous anesthesia.
Department of Anesthesia, British Columbia Children's Hospital, 4480 Oak Street, Vancouver, British Columbia V6H 3V4, Canada. anserminos@yahoo.ca
John Mark
JM
Ansermino
William
W
Magruder
Maryam
M
Dosani
D000771:Anesthesia, Intravenous; D018685:Anesthetics, Inhalation; D018686:Anesthetics, Intravenous / Q000009:adverse effects*; D002648:Child; D004347:Drug Interactions; D006801:Humans; D010880:Piperidines; D015742:Propofol; D000077208:Remifentanil; D015656:Respiratory Mechanics / Q000187:drug effects / Q000502:physiology*
D018685:Anesthetics, Inhalation; D018686:Anesthetics, Intravenous; D010880:Piperidines; D000077208:Remifentanil; D015742:Propofol