title: The temperature of inspired air influences respiratory water loss in young lambs.
abstract: The temperature of inspired air influences respiratory water loss (RWL) in young lambs. Water loss from the airways, oxygen consumption and carbon dioxide production were measured using an open flow-through system with a mass spectrometer, specially equipped with a water channel, for gas analysis. Measurements were made in 9 newborn lambs at 3 different inspired air temperatures keeping all other environmental factors stable, including the ambient air temperature. The water content of the inspired air was also kept constant. RWL was found to be 9.9 +/- 3.9 (SD) mg/kg/min when the temperature of the inspired air was 30 degrees C and its humidity 30%. At 40 degrees C this loss increased to 11.5 +/- 3.6 mg/kg/min, and at about 60 degrees C it increased further to 26.0 +/- 8.2 mg/kg/min. The oxygen consumption was 10.0 +/- 0.8 (SD) ml/kg/min at 30 degrees C and 10.4 +/- 2.0 ml/kg/min at 60 degrees C, a change which is not significant. Thus RWL is influenced by the temperature of the inspired air, with greater loss at higher temperatures.
authors.affiliation: Department of Paediatrics, University of Uppsala, Sweden.
authors.forename: T
authors.initials: T
authors.lastname: Riesenfeld
authors.forename: K
authors.initials: K
authors.lastname: Hammarlund
authors.forename: T
authors.initials: T
authors.lastname: Norsted
authors.forename: G
authors.initials: G
authors.lastname: Sedin
mesh_terms: D000388:Air; D000818:Animals; D000831:Animals, Newborn; D006358:Hot Temperature; D006813:Humidity; D010101:Oxygen Consumption; D012119:Respiration; D012756:Sheep; D013312:Stress, Physiological / Q000503:physiopathology; D013696:Temperature; D014870:Water Loss, Insensible