Procedure-related costs were calculated for an operating theatre with 10 operating rooms. The variable parameter was the different hygiene regimens for the preparation of the anaesthesia circuit. In April 2003 a change was made for the whole anaesthesia area. Either change of the anaesthesia tube system after every patient or the use of a hydrophobic HME-F (heat and moisture exchange filter) with daily or weekly change of the anaesthesia tube system were calculated. All costs were ascertained on real findings and typical procedures. Data according to safety and hygienic value were discussed and supplemented by our own findings about perioperative pneumonia. The additional costs for the HME-F are covered by the savings for CO(2) lines and the reduction of reprocessing expenses and overall material costs were reduced. The operational work on anaesthesia machines decreased considerably. Combined cost types revealed savings up to 9,72 EUR for a single anaesthesia procedure. Filtration of the respiratory gases for particles, bacteria, viruses and airway climatisation is an additional positive effect of HME-F use. Incidence of postoperative pneumonia on intensive care units was monitored by KISS (German hospital infection surveillance system) and the change to the HME-F regimen did not indicate a higher risk of infection. By the implementation of a weekly change of the anaesthesia tube system using HME filters a hygienic management for anaesthesia circuit reprocessing was found which could mobilize considerable resources.

Our results showed that the rate of VAP could be significantly reduced by changing the strategy from active to passive humidification devices, especially concerning patients requiring long-term respirator therapy. A more physiological humidification and a reduced number of airway manipulations are discussed as a possible explanation.

Objectives: Critically ill patients often require mechanical ventilatory support and increased inspiratory 0 2 concentration. Experimentally, continuous breathing of 100% 02 in animals leads to progressive irreversible damage to the lung, ARDS and death. In critical care units 100% 0 2 is often administered for several hours. The mechanism of hyperoxia induced lung injury is unclear. The objective of this study is to explore inflammatory mediator responses following breathing 100% 0 2 in humans. Ten healthy subjects aged 32-46 breathed 100% 0 2 for 60 minutes. Minute ventilation, arterial 02 saturation, blood pressure, heart rate and EKG were continually monitored. Methods: Interleukin-1 beta (IL-1(3) and Interleukin-1 receptor antagonist (IL-ira) were determined by ELISA in the supernatant of whole blood incubated with Endotoxin by the method of Nerad and Dinarello, before (To), at the end of 60 minutes of 100% Oz breathing (F6o) and at 90 (Tso) and 180 (Ttso) minutes following resumption of air breathing. Results: pg/ml 02 Breathing Air Breathing To