Protective Environment for Hematopoietic Cell Transplant (HSCT) Recipients: The Infectious Diseases Working Party EBMT Analysis of Global Recommendations on Health-Care Facilities

BACKGROUND: An international global perspective for guidelines for health-care facilities in which HSCT recipients are treated was announced in 2009 by Center for International Blood & Marrow Transplant Research, National Marrow Donor Program, European Society for Blood and Marrow Transplantation (EBMT), American Society for Blood and Marrow Transplantation, Canadian Blood and Marrow Transplant Group, Infectious Diseases Society of America, Society for Healthcare Epidemiology of America, Association of Medical Microbiology and Infectious Disease, and Centers for Disease Control. With respect to guidelines on hospital room design and ventilation for HSCT setting, a set of 10 recommendations were presented (Tomblyn et al, 2009).

OBJECTIVE: Since the issue is clearly of practical importance to world-wide transplant community, the IDWP-EBMT created a survey in order to present the current status on protective environment for recipients of HSCT, and to analyze the trends and needs in hospital transplant room design and ventilation.

METHODS: The questionnaire consisted of 37 questions in all and was divided into 6 sections that included the contact information and details of the protective isolation facility including air filtration, air changes, maintenance, combination of isolation, protective environment room/unit and floor.

RESULTS: In all, 177 centres from 36 countries responded to the survey, with average 33% country response rate. Physicians completed 62%, nurses 19% and support staff 19% of the surveys. A total number of 71% of answers were provided to all questions. The total number of unanswered questions was lowest among physicians (23% vs 49%; p<0.001). (A) Among all HSCT centers, in 99.4% patient rooms are equipped with HEPA filters, with central or point-in-use room system in 45.8% and 48%, respectively. The use of HEPA filters with 99.97% efficiency for removing particles ≤0.3µm in diameter, and room ventilation with the rate of at least 12 air changes per hour were confirmed by 70.1% and 71.2% of centers, respectively. Only 29.4% center staff were aware of and could confirm regular replacement of filters based on manufacturers' recommendations, while 53.7% centers have a written procedure for regular filter maintenance and removal and to monitor filtration efficiency in order to best determine appropriate time for replacement, especially in case of ongoing construction. (B) In 59.3% centers, the airflow is directed so that air intake occurs at one side of the room while the air exhaust occurs at the opposite side. Consistent positive air pressure differential between the patient's room and the hallway ≥2.5 Pa (i.e., 0.01 inches by water gauge) was reported by 38.4% centers having a permanently installed device/mechanism to constantly monitor the differential air pressure between the room and the corridor, while the pressure in the anteroom is positive in 19.2% centers, and an air pressure monitoring device/mechanism in the anteroom in addition to the patient room is present in 17.5% of centers. Well-sealed rooms are used in order to prevent infiltration of air from outside the room that could allow entry of spores and hinder maintenance of proper pressure differential, with respect to: windows (in 70.6%), monolithic ceilings (in 35%), and all plumbing pipes in the room (in 51.4% of centers). In order to guarantee the continuous positive pressure, a monitoring system that will set off an alarm when the pressure differential between any protective environment room and adjacent hallway or anteroom falls to less than 2.5 Pa to alert staff to possible engineering failures is installed in 33.9% of centers, and self-closing doors to maintain constant pressure differentials are present in 37.3% of centers. (C) The sensor monitor in the patient room used to determine when the HEPA filters require changing is installed in 18.1% of centers. The nursing staff is able to observe the HSCT recipient by the windows that are installed in the door/wall of the HSCT recipient's room or by the monitoring system in 61.6% of centers.

CONCLUSIONS: Knowledge about the maintenance of protective environments in the HSCT setting was inadequate, reflecting a lacking information between health personnel working in the ward and hospital offices. Only 6 centers were able to meet all 10 recommendations listed by Tomblyn et al and few centers were able to meet all the relevant technical requirements.