BACKGROUND
Airborne infection isolation rooms (AIIRs) help prevent the spread of infectious agents in hospitals. The performance of 678 AIIRs was evaluated and compared with construction design guidelines.
METHODS
The pressure differentials (DeltaP) between the isolation rooms and adjacent areas were measured, and ventilation and construction details were recorded for each room. Ultrafine particle concentrations were evaluated in the rooms, surrounding areas, and ventilation systems serving the rooms. Measurements were analyzed as a function of room parameters.
RESULTS
Only 32% of the isolation rooms achieved the recommended DeltaP of -2.5 Pascals (Pa) relative to surrounding areas. AIIRs with solid ceilings had an average DeltaP of -4.4 Pa, which was significantly higher than the average DeltaP of -2.0 Pa for rooms with dropped ceilings (P = .0002). Isolation room ultrafine particle concentrations were more highly correlated with particle levels in surrounding areas (R(2) = 0.817) than in the ventilation systems serving the rooms (R(2) = 0.441). Almost all ventilation filters serving AIIRs collected fewer particles than anticipated.
CONCLUSION
The results indicate that hospitals are not all maintaining AIIRs to correspond with current guidelines. The findings also support the contention that having tightly sealed rooms helps maintain appropriate pressure differentials.
[1]
M. Oxtoby,et al.
Identification of Factors That Disrupt Negative Air Pressurization of Respiratory Isolation Rooms
,
2000,
Infection Control & Hospital Epidemiology.
[2]
W C Dunagan,et al.
Evaluation of Rooms with Negative Pressure Ventilation Used for Respiratory Isolation in Seven Midwestern Hospitals
,
1993,
Infection Control & Hospital Epidemiology.
[3]
M. Nicas,et al.
Evaluating the Control of Tuberculosis Among Healthcare Workers: Adherence to CDC Guidelines of Three Urban Hospitals in California
,
1998,
Infection Control & Hospital Epidemiology.
[4]
P. Raynor,et al.
The Long-Term Performance of Electrically Charged Filters in a Ventilation System
,
2004,
Journal of occupational and environmental hygiene.
[5]
A. Streifel,et al.
An Evaluation of Hospital Special-Ventilation-Room Pressures
,
2001,
Infection Control & Hospital Epidemiology.
[6]
Demetrios J. Moschandreas,et al.
Design, construction, and operation of healthy buildings : solutions to global and regional concerns
,
1998
.
[7]
Charles S. Hayden,et al.
Air Volume Migration from Negative Pressure Isolation Rooms during Entry/Exit
,
1998
.