OBJECTIVE: To study whether tracer amounts of a gas, @entity3810 ( @entity3727 ), might be a suitable marker for absorption of irrigating fluid during endoscopic procedures. MATERIAL AND METHODS: @entity3727 was dissolved to a concentration of 10% in a commercially available irrigating fluid containing 3% @entity2656 and 1% @entity1068 . Seven experiments involving administration of the fluid via either the i.v. or i.p. route were performed in three @entity1707 under general anesthesia. The @entity3727 concentration and, in one @entity1707 , the @entity1068 concentration, were measured in the expired breath. RESULTS: The @entity3727 method readily detected i.v. bolus injections of 2, 10 and 20 ml quantities of irrigating fluid. Continuous administration of the fluid over a 20-min period showed that the @entity3727 concentration increased and decreased very rapidly when the infusions were turned on and off, while a quasi-steady state was reached after approximately 2 min. The maximum breath @entity3727 concentration during a 600-ml infusion was 0.05%. The breath @entity1068 concentration rose as fast as the @entity3727 level but decreased more slowly when the infusion was turned off. As with @entity1068 , the @entity3727 responses were much slower when the fluid was given by i.p. infusion, and the maximum concentration was only one-third of that during i.v. infusion. CONCLUSIONS: Dissolving @entity3727 in irrigating fluid offers the possibility of detecting an administered fluid volume in the exhaled breath in the same way as for @entity1068 . The advantages of @entity3727 include better resolution, lower @entity137 and rapid elimination.

XXXX as a marker for irrigating fluid absorption--an experimental study in the @entity1707 .

@entity2656 :: ('MESH:D008353', 'Chemical') :: ['mannitol'] @entity1707 :: ('9823', 'Species') :: ['pigs', 'pig'] @entity137 :: ('MESH:D064420', 'Disease') :: ['toxicity'] @entity3727 :: ('CHEBI:17045', 'Chemical') :: ['N(2)O'] @entity3810 :: ('MESH:D009609', 'Chemical') :: ['nitrous oxide'] @entity1068 :: ('MESH:D000431', 'Chemical') :: ['ethanol']
@entity3810 :: (MESH:D009609,Chemical) :: ['Nitrous oxide']
