Negative Pressure Rooms

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Negative Pressure Rooms

Normal results
Morbidity and mortality rates


A negative pressure room is a volumetric space in which the internal atmospheric pressure is lower than the spaces into which it opens.


An infectious disease or emergency physician usually admits patients to negative pressure rooms in hospitals or other healthcare facilities.


The purpose of a negative pressure room is to confine pathogens to sa single closed environment and to prevent the release of pathogens into other adjacent spaces.


Official counts of negative pressure rooms do not exist. Experts estimate that approximately 4000-5000 negative pressure rooms exist in hospitals throughout the United States.


A negative pressure room is designed to confine pathogens to a small volume of space. It is also intended to prevent the accidental release of pathogens into a greater space thereby protecting workers and employees in a hospital or other healthcare facility.

All communications between a negative pressure room and adjacent spaces are controlled. Communications include doors and ventilations ducts. These are sealed. Air flow is controlled by airlocks for human travel and vacuum pumps for ventilation systems.


Negative pressure rooms require special construction. All points if entrance or egress must be able to be tightly sealed so that air cannot pass by the seals. The room ventilation system must be equipped with a vacuum pump that must create a constant but relatively low level vacuum. This creates the negative pressure.

In operation, the vacuum created stops the outflow of air, thus containing

Two doors, separated by at least 6 feet, must be installed to create an airlock. Only one door is opened at a time. This preserves the vacuum, maintains the negative pressure and prevents pathogens from escaping.


  • Why am I being confined in a negative pressure room?
  • What treatment options do I have?

All air exhausted from the room is routed through special filters that are designed to trap and contain pathogens.

Negative pressure rooms are used when the presence of an airborne pathogen such as tuberculosis is suspected.


Entrance and egress protocols must be followed by all people that enter or leave a negative pressure room.

Seals on vents and airlocks must be checked on a regular basis.

Negative pressure rooms must be decontaminated before being cleaned after being occupied.


Seal, pump or protocol failure destroys the negative pressure and increases the chances that pathogens will be released.

Inadequate cleaning after occupancy puts subsequent occupants at risk of exposure to a potentially dangerous pathogen.

Normal results

In a properly operating negative pressure room, the expected and normal result is containment of a potentially dangerous pathogen.

Morbidity and mortality rates

Data on morbidity and mortality related to negative pressure rooms is not available.


The only feasible alternative to a negative pressure room is quarantine and isolation. This practice is very difficult to enforce. Even when enforced, it is not as microbiologically efficient.


Anthrax— A dangerous pathogen that should contained in a negative pressure room.

Ebola virus A dangerous pathogen that should contained in a negative pressure room.

Tuberculosis— A dangerous pathogen that should contained in a negative pressure room.



Fischbach, F. T. and M. B. Dunning. A Manual of Laboratory and Diagnostic Tests. 8th ed. Philadelphia: Lippincott Williams & Wilkins, 2008.

McGhee, M. A Guide to Laboratory Investigations. 5th ed. Oxford, UK: Radcliffe Publishing Ltd, 2008.

Price, C. P. Evidence-Based Laboratory Medicine: Principles Practice, and Outcomes. 2nd ed. Washington, DC: AACC Press, 2007.

Scott, M.G., A. M. Gronowski, and C. S. Eby. Tietz’s Applied Laboratory Medicine. 2nd ed. New York: Wiley-Liss, 2007.

Springhouse, A. M. Diagnostic Tests Made Incredibly Easy!. 2nd ed. Philadelphia: Lippincott Williams & Wilkins, 2008.


Chow, T. T., A. Kwan, Z. Lin, and W. Bai. “A computer evaluation of ventilation performance in a negative-pressure operating theater.” Anesthesia and Analgesia 103, no. 4 (2006): 913–918.

Humphreys, H. “Control and prevention of healthcare-associated tuberculosis: the role of respiratory isolation and personal respiratory protection.” Journal of Hospital Infection 66, no. 1 (2007): 1–5.

NIska, R. W., and C. W. Burt. “Emergency response planing in hospitals, United States: 2003–2004.” Advance Data 391 (2007): 1–13.

Rydock, J. P. “On the need for a separate standard for performance testing of negative-pressure isolation rooms.” Infection Control and Hospital Epidemiology 27, no. 5 (2006): 531–532.

Walker, J. T., P. Hoffman, A. M. Bennett, M. C. Vos, M. Thomas, and N. Tomlinson. “Hospital and community acquired infection and the built environment-design and testing of infection control rooms.” Journal of Hospital Infection 65, Supplement 2 (2007): 43–49.


American Academy of Family Physicians. 11400 Tomahawk Creek Parkway, Leawood, KS 66211-2672. (913) 906-6000. E-mail: [email protected].

American Academy of Pediatrics. 141 Northwest Point Boulevard, Elk Grove Village, IL 60007-1098. (847) 434-4000, Fax: (847) 434-8000. E-mail: [email protected].

American College of Physicians. 190 N. Independence Mall West, Philadelphia, PA 19106-1572. (800) 523-1546, x2600, or (215) 351-2600.

American Medical Association. 515 N. State Street, Chicago, IL 60610. (312) 464-5000.


Centers for Disease Control and Prevention. Information about negative pressure rooms. 2008 [cited February 25, 2008].

Scientific American. Information about negative pressure rooms. 2008 [cited February 22, 2008].

University of Pennsylvania Medical Center. Information about negative pressure rooms. 2008 [cited February 24, 2008].

Yale-New Haven Hospital. Information about negative pressure rooms. 2008 [cited February 24, 2008].

L. Fleming Fallon, Jr, MD, DrPH