Airborne Infectious Disease Management: Methods for ...

1 Airborne InfectiousDisease ManagementMethods for Temporary Negative Pressure IsolationMinnesota Department of HealthOffice of Emergency PreparednessHealthcare Systems Preparedness ProgramOffice of Emergency PreparednessHealthcare Systems Preparedness ProgramAirborne Infectious Disease ManagementMethods for Temporary Negative Pressure IsolationThis guide has been produced by:This user guide has been written by the Minnesota Department of Healthin conjunction with the University ofMinnesota to assist hospital personnel in the management of Airborne infection :Jeanne AndersonInfection Control Practitioner Office of Emergency PreparednessMinnesota Department of HealthAndrew GeeslinEngineering/Infection Control Inter n University of MinnesotaAndrew StreifelHospital Environmental Health SpecialistEnvironmental Health and SafetyUniversity of MinnesotaMinnesota Department of Health does not endorse particular brands amongcompeting products.

2 Examples shown in these materials are for illustration material in this document is in the publicdomain and may be used and reprintedwithout special authors gratefully acknowledge theMinnesota Emergency ReadinessEducation and Training (MERET)at theUniversity of Minnesota Centers forPublic Health Education and Outreachand the following individuals for theirparticipation, assistance, and support of this project: Keith CarlsonDirector of Facilities ManagementMercy Hospital and Health Care CenterMoose Lake, MNGary DavisPlant EngineerLakeWood Health CenterBaudette, MN Pete SwansonFacility Services ManagerPipestone County Medical CenterPipestone, MN The following individuals are gratefullyacknowledged for their invaluablesuggestions:Judene BartleyVice PresidentEpidemiology Consulting Services Hills, MIRick HermansSenior Project ManagerCenter for Energy and EnvironmentMinneapolis, MN Curtain TNPI photographs courtesy of Ken Meade, Research MechanicalEngineer, NIOSH/CDC, USPHS MERET photos provided by Paul BernhardtFor further Information, please contact:Office of Emergency PreparednessMinnesota Department of Health625 Robert Street Box 64975St.

3 Paul, MN 55164-0975 Phone: (651) 201-5701 Fax: (651) 201-5720 This user guide is available on theMinnesota Department of Health Web site: Infectious Disease Management Methods for Temporary Negative Pressure IsolationAcknowledgements1 IntroductionPrinciples of Airborne Infectious diseasemanagement2 Airborne Infectious Disease MANAGEMENT PREPARED BY THE MINNESOTA DEPARTMENT OF HEALTH TNPIT emporary NegativePressure Isolation5 Portable anteroom13 Environmentalcontrols3 Surgecapacity16 Appendix20 Audiencefor this GuideThe intended audience for this guideline includes health care: facility engineering and maintenance infection control environmental health and safety management personnelPurposeof this Guide Provide guidanceon environmentalcontrols for Airborne infectiousdisease management Provide a general guide fortemporary setup, installation,and operationof portable HEPA machines when used to createnegative pressure in a hospitalroom/area Provide instruction on the use of:Pressure gaugesParticle counters Outline of preventativemaintenanceschedule for HVAC equipment related to AIIRG oalof this GuideA timely response is crucial foridentification and containment of potentially Infectious goal is for facilities to develop a 12-hour responseto implementcontainment measures.

4 Temporarynegative pressure isolation methodsare a safe alternative for hospitals that lack engineered can be utilized in facilities tomeet increased surge capacity forpatient isolation. TNPI should also be used during hospital constructionprojects to reduce risks associatedwith Airborne Infectious diseases. These temporary measures should be incorporated into the facility sinfection control and emergencyresponse plans. Hospital preparednessforbioterrorism and other public healthemergencies such as emerging airborneinfectious diseases requires strategicplanning to ensure that all componentsof respiratory protection programs,including environmental controls, are in place forairborne infectionisolation rooms (AIIRs).Hospitalshave insufficient facilities to provideairborne infection isolation for largenumbers of patients with airborneinfectious diseases presenting in a short time , 2 However, AIIR shave been increased recently, due torequirements of National BioterrorismHospital Preparedness adequate environmentalcontrols, patients with airborneinfectious diseases will pose a risk to other patients and health , ventilation,and air conditioning (HVAC)expertise is essential for properenvironmental management whenplanning control of Airborne infectiousdisease outbreaks (natural orintentional).

5 Design manuals andguidelines provide direction forinfectious Disease to Appendix A, 2006 AIAC riteria on page guide will assist health care facilityplant maintenance and engineeringstaff, in coordination with infectioncontrol professionals, to prepare for a natural or terroristic event, involvingan Infectious agent transmitted byairborne droplet nuclei. Examples of such agents include measles,varicella, and Infectious Disease MANAGEMENT PREPARED BY THE MINNESOTA DEPARTMENT OF HEALTH Administrative(work practice) controls Managerial measures that reducethe risk for exposure to personswho might have an airborneinfectious Disease . Work practice controls includeusing infection control precautionswhile performing aerosol-generatingprocedures, closing doors to AIIRs,hand hygiene, and equipment (PPE) Equipment worn by health careworkers and others to reduceexposure to Physical or mechanical measures(as opposed to administrativecontrol measures) used to reducethe risk for transmission of airborneinfectious infection isolation is based on the following hierarchy of control measures.

6 Administrative (work practice) controlsEnvironmental controlsPersonal protective equipment (PPE)These measures are intended toreduce the risk for exposure toairborne Infectious Disease agents by uninfected persons. AIIRs andhospital systems in general must be monitored to provide continualprotective measures. Refer toAppendixes B and C, AIIR and HVAC System MaintenanceSchedules, on pages 22 and of Airborne Infectious Disease managementEXAMPLES gownsglovesmasksrespiratorseye protection EXAMPLES ventilationfiltrationultraviolet germicidalirradiationAIIRs local exhaustventilation devicesEXAMPLES written policies andprotocols to ensurethe rapid identification,isolation, diagnosticevaluation, andtreatment of personslikely to have anairborne infectiousdisease 2 Introduction1 Principles of Airborne Infectious Disease managementTNPIT emporary NegativePressure Isolation5 Portable anteroom13 Environmentalcontrols3 Surgecapacity16 Appendix20 References373 Introduction1 EnvironmentalcontrolsTNPIT emporary NegativePressure Isolation5 Principles of Airborne Infectious diseasemanagement2 Portable anteroom13 Surgecapacity16 Appendix20 Airborne Infectious Disease MANAGEMENT PREPARED BY THE MINNESOTA DEPARTMENT OF HEALTH Pressure managementFor the purposes of this guide,pressure refers to the differentialpressure between two spaces(FIGURE 1).

7 In health care settings, the two spacesare typically the isolation room and thecorridor. For AIIR, the roomshouldbe negatively pressurizedin relation to the corridor. This helps to preventinfectious particles from escaping theroom envelope. If an anteroom is present between theAIIR and the corridor, the AIIR may benegatively or positively pressurized tothe anteroom. However, if the AIIR ispositively pressurized to the anteroom,the anteroom must be negativelypressurized to the corridor. A difference in pressurecauses movement of air from areas at higher pressure to those at lowerpressure. The greater the pressuredifference, the greater the resultingair velocity. The movement of air isused to help provide containment ofinfectious particles by providing cleanto dirty airflow. Refer to Appendix D, Using a Pressure Gauge toMeasure Relative PressurizationBetween Two Spaces on page 24for instructions on using a pressuregauge to determine differentialpressure.

8 The differential pressure orpressure offset is established bymechanically adjusting the supplyand exhaust a negativepressure room, the sum of themechanically exhausted air mustexceed the sum of the mechanicallysupplied air. This offset forces air toenter the room under the door andthrough other leakages and preventsinfectious particles from In order to maintain consistentoffset airflow, the difference betweenexhaust and supply should create a pressure differential of about inch water gauge (in. ) or Pascals (Pa).9 Pressure in this application is used to induceairflow from adjacent spaces into the isolation room. EnvironmentalcontrolsThis user guide will focus on theenvironmental controls necessaryfor Airborne infection isolation. The ventilation parameters essential for Airborne infection isolationrooms/areas include: Pressure managementforappropriate airflow direction; Room air changes for dilution ventilation; and Filtrationto remove Infectious 1 Illustrations used to identify Negatively (top) and Positively (bottom)pressurized air Infectious Disease MANAGEMENT PREPARED BY THE MINNESOTA DEPARTMENT OF HEALTH Dilution ventilationMechanical ventilation is used to exchange the air in a space.

9 The time required for removing a given percentage of airborneparticles from a room or spacedepends on the number of air changes per hour (ACH), location of the ventilation inlet and outlet, and the physicalconfiguration of the room or space(FIGURE 2). Refer to Appendix E, Using a HEPA Filter for DilutionVentilation on page 26. FiltrationFor the purposes of this guide,filtrationrefers to the process ofpassing air through a filter. Hospitalbuildings have some of the highestfiltration requirements. Without filtration,particle concentrations accumulate inindoor environments. This can causetoxic effects even in healthy people. Filtration reduces the risk fortransmitting Airborne Infectious upon their size, particlesmay be deposited in the upperrespiratory tract or the lower respiratorytract of humans. Particles can also bedeposited in open wounds duringdressing changes or invasiveprocedures.

10 See Appendix F, Microorganisms Associated withAirborne Transmission on page used correctly, portable HEPA filters prove to be an effective method for achieving an Airborne properly installedand maintained, filters for clinicalspaces should be able to remove atleast 90% of particles ( microns in size and larger)9from outside andinside evaluation of hospital HVAC systemsand HEPA filters refer to Appendix G, Using a Particle Counter to AssessIndoor Air Quality and Filter Efficiency on page information on filter selection and performance, see Appendix H, Data Interpretation on page Appendix I, Sample Log forMeasuring Particle Counts on page 36. AIR CHANGES PER HOUR (ACH)21020304050607080901001101201301401 501601701801902002104 6 8 1012152090% EFFICIENCY99% EFFICIENCY50 MINUTESM odified from Table , CDC Guidelines forEnvironmental Infection Control in Health-Care Facilities, 2:ACH AND TIME REQUIRED FOR REMOVAL EFFICIENCIESTime (minutes) required for removal of 90%, 99%, and of mixing of air is assumed.