Search results for "Fresh gas flow"
showing 3 items of 3 documents
Heated breathing tubes affect humidity output of circle absorber systems.
1993
Abstract Study Objective: To verify whether the airway climate in circle systems can be improved with heated breathing tubes. Design: Randomized, controlled, prospective clinical study. Setting: Operating theater of the Department of Maxillofacial Surgery. Patients: 26 adult patients undergoing prolonged anesthesia. Interventions: A total of 26 prolonged anesthetics were conducted in adult patients using a minimal fresh gas flow rate (0.6 L/min) and silicon breathing tubes (16 mm internal diameter) containing a heated coil. Group 1 ( n = 10 patients) was the control group; breathing tubes were unheated. In Group 2 ( n = 10 patients), breathing tubes were heated to 30°C. In Group 3 ( n = 6 p…
'Anestheticography': on-line monitoring and documentation of inhalational anesthesia.
1988
The safe practice of inhalational anesthesia requires control over the amount of volatile anesthetic delivered to the patient. With minimal fresh gas flow this is facilitated by continuous monitoring and recording of the agent's concentration ('Anestheticography'). Alterations brought about by routine clinical maneuvers become visible. We recorded the course of the inspiratory and expiratory concentration of volatile anesthetic (Isoflurane) by infrared absorption and a trend recorder. Changing the carrier gas composition during high flow from 75% to 25% nitrous oxide in oxygen resulted in a 10% increase of the inspiratory isoflurane concentration. Activating the oxygen bypass or exchanging …
Humidity of Anaesthetic Gases with Respect to Low Flow Anaesthesia
1994
It has been demonstrated in an experimental study in swine using the scanning electron microscope that a rebreathing technique utilising minimal fresh gas flowrates significantly improves climatization of anaesthetic gases. Consequently, effects of various anaesthetic techniques on airway climate must be assessed, which covers the need for suitable measuring devices. Basic principles and methods of humidity measurement in flowing anaesthetic gases include gravimetric hygrometry, dew point hygrometry, wet-dry bulb psychrometry, mass spectrometry, spectroscopic hygrometry and electrical hygrometry. A custom-made apparatus for continuous measurement of humidity and temperature in the inspired…