hospital

The risk of contaminant deposition (10 microns particles) on an operating room surgical site is evaluated for different ventilation systems - conventional, laminar, non-aspirating, displacement -, using airflow modeling and particle tracking methodologies. Results show that laminar flows are the most appropriate to avoid particles deposition.

The ventilation system of a community hospital deteriorated progressively over a period of years until it no longer met regulatory guidelines. The publicly funded military facility hospital asked for funding for repairs but they were not available. The funding request was met when an increase in infections was identified and high-risk operations had to be curtailed. The problems were solved entirely when the new ventilation system was in place.

In seven hospitals in the eastern United States air filters of various types, selected by discoloration, were collected from the primary and secondary filter banks of the HVAC systems. The samples were then examined with direct microscopy for fungal colonization. Results showed that filters from five of the hospitals were colonized with fungi. Several of the species had not previously been reported to colonize air filters.

A study examined by chemical analysis (without prior culture) bacterial levels in dust collected from hospital air conditioning filters. Gas chromatography-mass spectrometry methods were used to analyse the dust. Concludes that there is potential for the chemical assessment of the microbial content of airborne dust.

States that on using the ELISA inhibition test against Aspergillus fumigatus, the study found that air samples from air conditioned rooms showed inhibition of the serum activity of a highly sensitized patient. Concludes that although an important fraction of aeroplankton particles can be filtered out of air conditioning systems, airborne allergens can nevertheless pass both coarse and fine filters.

Deterioration of air conditioning system in a hospital in Boston was found to derive from a strain of Pseudomonas sp. on heat transfer tubes of the closed chilled water system. Growth was stimulated by ethylene glycol antifreeze. The source was a warm expansion tank. The organism has been related to hospital-acquired infections.

Studies the relationship between sick building syndrome symptoms and both personal and environmental factors in 225 female hospital workers in eight hospitals in the south of Sweden. The method used a self-administered questionnaire and a building survey and measurements of room temperature, supply air temperature, air humidity and exhaust air flow. Eye irritation was more common in buildings with a high ventilation flow and a high noise level from the ventilation system. Throat symptoms were more common in buildings with a high ventilation flow, among others.

Describes the microbioligic surveillance of the central air handling systems in a hospital, prompted by an increase in the rates of nosocomial infection caused by filamentous fungi in immunocompromised patients. Heavy contamination by Penicillium was found in ventilation ducts and terminal unit lined with fiberglass in the operating room air handling system, as well as Aspergillus species. The contamination was corrected using filter replacement and decontamination with aerosolized chlorine solution.

This study utilizes Computational Fluid Dynamics (CFD) and particle tracking procedure to study the effects of ventilation system and ultraviolet germicidal irradiation (UVGI) on minimizing the risk from airborne organism in isolation rooms.

This paper assesses the performance of the ventilation system as applied to a typical patient room using Computational Fluid Dynamics technique (CFD) coupled with the calculation of various ventilation indices.