Influence of air cooling units on air quality--a pilot project.

Air cooling units are said to pose a health risk to humans because of residual water and biological contamination. We measured particles 0.5 and 5 microm, ultrafine particles and bacterial counts near the outlet of 38 air cooling units and at the corresponding workplaces. Control measurements were performed in 17 rooms without air cooling units. There was no difference between bacterial counts measured near the outlet, at the typical workplaces and in control rooms. Measured bacterial counts near the outlet were between 15 and 950 cfu/m(3) (median 150), at the typical workplaces between 20 and 1685 cfu/m(3) (median 213) and in control rooms between 75 and 940 cfu/m(3) (median 240). Concentrations of particles and ultrafine particles were less in rooms with air cooling units than in control rooms. Thus, we could not find an impairment of air quality by air cooling units in our study. These results should be tested again in a greater study, primarily in another building than a hospital.

Laminar air flow provides high air quality in the operating field even during real operating conditions, but personal protection seems to be necessary in operations with tissue combustion.

We measured bacterial and particle concentrations at the level of operative fields during 105 operation procedures under laminar air flow conditions. Measured concentrations were at least a factor of 20 lower than in comparable rooms without ultra-clean air and laminar air flow. Kind of operation (septic/aseptic), number of participating persons and quantity of talking seem to have less influence on air quality than presumed, single use cover improves the air quality. The number of ultra-fine and small particles was dramatically increased when tissue was coagulated during operation. This may pose health risks to surgeons and nurses, needs risk assessment and decisions about personal protection.

Refurbishment works in a hospital during normal operation.

BACKGROUND: Construction and renovation work in hospitals pose risks of fungal airborne infections for immunosuppressed patients. If possible, reconstruction work will be postponed to periods without patient treatment. However, in many situations urgent damage demands immediate refurbishment works before the transferring of patients to other wards or closure of wards is possible. Reported here are infection control related measures and implemented procedures after two incidents of water damage which occurred on a surgical ward and an intensive care unit at the University hospital of Essen. METHODS: Between January and April 2009 and between September and October 2009, respectively, concentration of air-borne particles and number of viable fungi were measured at two surgical wards and one ICU. Preventive Infection Control Measures included erection of protective walls and HEPA filtration of air from the renovation area. RESULTS: During the renovation work on the surgical ward concentrations of moulds and particles ≥5 µm were significantly higher on the left side of the renovation area than on the right side (p=0.036 and p<0.001). Concentrations of particles ≥1 µm and particles ≥5 µm on both sides of the renovation area were significantly increased when compared with the control ward on the same floor but not when compared with the control ward on the other floor. Particles of all size were significantly elevated on the ICU during the renovation work. Aspergillus fumigatus could neither be cultured of the air of cardiac surgery intensive care unit nor of the intermediate care unit (control ward). During renovation works there was no nosocomial mould infection of patients treated on the two wards. CONCLUSION: Provided that the renovation area is tightly insulated from the areas of patient care on a ward, closure does not seem to be necessary during renovation works because variation of airborne fungi is similar to that of outdoor or control air. However a multidisciplinary team should be established. This team should perform risk assessment and determine necessary protective measures before starting any construction, renovation or maintenance work in health care settings.

ATP measurement as method to monitor the quality of reprocessing flexible endoscopes.

Insufficient performance of cleaning and disinfection of flexible endoscopes can pose an infection risk to patients. Actually quality of reprocessing is checked by performing microbiological cultures. Unfortunately, their results are not available on the same day so that more rapid methods are desirable. We compared the ATP (adenosine triphosphate) bioluminescence for hygiene checking of the reprocessing procedures of 108 flexible endoscopes with routine microbiological culture technics. Sensitivity and specifity of ATP bioluminescence was calculated. 28 endoscopes showed bacterial growth of at least one sample. Depending on the applied threshold of bioluminescence between 67 and 28 endoscopes were positive. Sensitivity varied between 0.46 and 0.75 and specifity between 0.43 and 0.81. ATP bioluminescence does not replace routine microbiologic methods but it can indicate the need of immediate check of reprocessing.