2007 OPEN FORUM Abstracts
BENCH STUDY OF A HEATED BLAND AEROSOL TRACHEOSTOMY COLLAR (ATC) SET-UP.
J. M. Brown 1, J. S. Emberger1, A. Patel1
Background: Providing proper humidification is a common concern when caring for a patient with a tracheostomy. Currently there are several commercially available systems that offer optimal humidification conditions. These systems can be very expensive and require specialized circuit which motivates clinicians to search for more cost effective methods of providing humidification. In this study we evaluated a heated ATC set-up to see if it could effectively deliver humidified gas to our patients. This system is comprised of a Venturi driven bland aerosol generator (AirLife Nebulizer Cap), a point aerosol generator heating element (Allegiance 2M8021 Nebulizer Heater), two 120cm links corrugated tubing with a water trap, and an adult tracheostomy collar.
Methods: A heated and humidified test lung model was used. Both heated and non-heated ATC circuit was placed on the test lungs tracheostomy. A high quality hygrometer (TSI Air Quality Meter Model 8760/8762 IAQ-Calc) was placed in the tracheostomy collar environment adjacent to the test lungs airway. The average temperature in Fahrenheit (F) and Relative Humidity (RH) was electronically obtained from the hygrometer every 5 seconds and logged into an excel spread sheet throughout the trials. The amount of water vapor produced and water in the circuit due to condensation was determined.
Results: The test lung was set at the following setting: RR= 16 bpm, Vt= 400ml. The FIO2 on the bland aerosol generator was set at 0.30 and a flow 8 Lpm. Total humidity produced by the aerosol generator was approximately 60g of water without the heater device and 65g with the heater device attached. The non-heated ATC set-up had an average temperature of 64.6 F (± 1.3), average RH of 96.6 % (± 11.2), and total rain out in the circuit due to condensation was 28g of water. The heated ATC set-up had an average temperature of 72.6 F (± 2.3), average RH of 61.1 % (± 15.1), and the total rain out in the circuit due to condensation was 46.2 g of water. See graph for additional data.
Conclusion: Our bench study suggests that this system is not an effective method of providing humidification for patients with tracheostomies. The temperature and RH were less than optimal which can result in less water vapor delivered to the patient. Later we will continue our investigation to evaluate whether the RH of this system is effected by conditions of the room air and the length of the circuit tubing.