BACKGROUND: @entity2614 degrades during low-flow anaesthesia to compound A, and high @entity544 absorbent temperatures cause increased degradation. The purpose of this investigation was to determine if larger tidal volumes, without increasing alveolar ventilation, decrease the temperature in the @entity544 absorber during low- and minimal-flow @entity2614 anaesthesia. METHODS: Prospective, randomized study, including 45 @entity1 (ASA 1-2), scheduled for elective general or urology surgery. The @entity1 were randomly assigned to one of three treatments. @entity1 in group 1 (NDS) received fresh gas flow of 1 litre/min without using additional dead-space volumes. In group 2 (DS + 1.0), the @entity1 received fresh gas flow of 1 litre/min using additional dead-space volumes, placed between the Y-piece and the HME, and @entity1 in group 3 (DS + 0.5) received the same technique with a fresh gas flow of 0.5 litre/min. The soda lime temperatures, dead-space volumes, end-tidal @entity544 , @entity2614 concentrations, ventilation volumes and pressures, absorbent weight and ear temperatures were measured. RESULTS: The maximum temperature of the soda lime was 44.1 +/- 1.1 degrees C in the NDS group, 37.8 +/- 0.8 degrees C in the DS + 1.0 group and 38.5 +/- 2.7 degrees C in the DS + 0.5 group (P<0.0001). The dead-space volume between the Y-piece the tracheal tube was 164 +/- 69 ml in the DS + 1.0 group and 196 +/- 15 ml in the DS + 0.5 group (P<0.05). The ventilator pressure were higher in the DS groups compared with the NDS group (P<0.001). Soda lime weight increased in all groups. End-tidal @entity544 , @entity2614 concentrations and ear temperatures were similar between the groups. CONCLUSION: Increasing dead-space volumes can reduce @entity544 absorber temperature during low- and minimal-flow @entity2614 anaesthesia.

Soda lime temperatures during low-flow XXXX anaesthesia and differences in dead-space.

@entity1 :: ('9606', 'Species') :: ['Patients', 'patients'] @entity544 :: ('MESH:D002245', 'Chemical') :: ['carbon dioxide'] @entity2614 :: ('MESH:C009250', 'Chemical') :: ['sevoflurane', 'Sevoflurane']
@entity2614 :: (MESH:C009250,Chemical) :: ['sevoflurane']
