Efficacy of the Shinki bioclean room for preventing infection in neutropenic patients.

Aim of the study. To investigate the effectiveness of a new type of bioclean room named Shinki bioclean room (SBCR) for the prevention of infection during neutropenia after intensive chemotherapy in comparison with a standard laminar air flow room (LAFR). Background. Recently, a new industrial technology, wherein a dust-free and aseptic environment is created by circulating air containing nanometre order ultra fine water droplets with abundant negative air ions, has been developed in Japan. Methods. The air cleanliness of SBCR was examined by measuring airborne particles and microorganisms. Bacteriological samples for environment culture were taken by means of exposed settle-plates. In addition, the frequency of pneumonia and fever higher than 38degreesC were examined in 34 patients with acute leukaemia who received intensive chemotherapy in SBCR or LAFR. Results. The number of airborne particles (greater than or equal to0.5 mum) was 70 particles/ft(3), and that of airborne microorganisms was 0.00 colony forming unit/ft(3) in SBCR, and neither bacteria nor fungi were detected. The numbers of colonies of bacteria and fungi on air settle-plates were fewer in the SBCR than in the LAFR regardless of the presence of patients or the nurse entering. The frequency of pneumonia during chemotherapy for acute leukaemia was lower in the SBCR group (0%, 0/19 cases) than in the LAFR group (27%, 4/15 cases) (P=0.0294) and the frequency of fever higher than 38degreesC also tended to be lower in the SBCR group (53%, 10/19 cases) than in the LAFR group (80%, 12/15 cases) (P=0.0973). Conclusion. The SBCR is equal or superior to LAFR in preventing infection during neutropenia. Other advantages for SBCR are a low level of noise (40 dB), easy control of temperature and humidity, and efficient removal of odour. In addition to the quiet and comfortable atmosphere, expected favourable effects of negative air ions may give higher quality of life for patients in SBCR than those in LAFR. Further studies will be needed to examine the safety, benefits and effects of the negative ion exposure.