Skip Navigation LinksHome > September 1989 - Volume 71 - Issue 3 > Passive and Active Inspired Gas Humidification in Infants an...

Passive and Active Inspired Gas Humidification in Infants and Children.

Bissonnette, Bruno M.D.; Sessler, Daniel I. M.D.; LaFlamme, Pierre M.D.

Collapse Box


The hypothesis that both active and passive airway humidification prevents hypothermia in infants and children, but that neither decreases the duration of postoperative recovery was tested. Twenty-seven ASA physical status 1 or 2 patients were studied who weighed between 5 and 30 kg, underwent superficial operations, were anesthetized with halothane and 70% N2O, and whose lungs were ventilated via a Rees modification of an Ayre's t-piece. The children were randomly assigned to receive active airway humidification and warming using an MR450 Servo(R) airway heater and humidifier set at 37[degrees] C (n = 10), passive airway humidification using the Humid-Vent(R) 1 heat and moisture exchanger placed between the Ayre's t-piece and the endotracheal tube (n = 8), or no airway humidification and heating (control, n = 9). Distal tracheal and tympanic membrane temperatures and airway humidity were recorded during the first 90 min of surgery. Rectal temperature was measured during the postanesthetic recovery period. Relative humidity of inspired respiratory gases was approximately 30% in the control group and approximately 90% in the group given active airway humidification. Initial inspired humidity in the passive humidification group (50%) increased to approximately 80%, a level not significantly different from that in the active group after 80 min of anesthesia. Central body temperature increased 0.25[degrees] C during active active airway humidification and heating, whereas temperature decreased 0.25[degrees] C during passive humidification and 0.75[degrees] C without airway humidification. Distal tracheal temperature was significantly higher in the groups given passive and active humidification than in the control group. Recovery was rapid in all patients and did not correlate with the type of humidification. Heat and moisture exchangers are less effective than active heating and humidification but significantly better than no humidification.
(C) 1989 American Society of Anesthesiologists, Inc.
Publication of an advertisement in Anesthesiology Online does not constitute endorsement by the American Society of Anesthesiologists, Inc. or Lippincott Williams & Wilkins, Inc. of the product or service being advertised.

Article Tools


Search for Similar Articles
You may search for similar articles that contain these same keywords or you may modify the keyword list to augment your search.