Volume 8, No. 4 • Winter 1993

New Standards Focus on Piped Medical Gas Systems Part of a Series on “Out of Sight, Out of Mind: Behind the Wall”

Thomas A. Nagle, M.B.A.

Historically, anesthesiologists’ primary equipment concerns have been with the operation and reliability of their increasingly sophisticated anesthesia delivery system. Anesthesia systems usually undergo rigorous planned maintenance several times a year as well as daily user pre-operative checkouts. These are safeguards for patient safety and equipment reliability. There is, however, a critical equipment system used by anesthesia personnel which typically does not receive as much attention: the piped medical gas distribution system.

Without a doubt, piped medical gas systems are life support utilities which play key roles in the treatment of patients, especially during anesthesia delivery. Administration of pure, particulate-free gases at proper flows and pressures is vital for the proper operation of anesthesia system components (ventilators, vaporizers, pressure regulators, flow controls, etc.). A properly operating medical gas distribution system which meets or exceeds the various industry standards is important to the anesthesia practitioner.

For many institutions the medical gas system is viewed as ‘out of sight, out of mind’ until problems arise. In the current economic environment, funds are often focused toward revenue production, while operating costs are closely scrutinized. Together, these factors can result in very few resources being invested in the maintenance and testing of the piped gas systems.

Agencies that set the standards for the construction and operation of health care facilities have recognized the need for more attention directed toward piped medical gas systems. In 1993, the National Fire Protection Agency (NFPA) and the joint Commission on Accreditation of Healthcare Organizations UCAHO) adopted new requirements designed to ensure that medical gas systems are properly installed, maintained, and understood.

The NFPA makes very specific recommendations concerning the installation, maintenance, and testing of medical gas systems. When a medical gas pipeline is installed, renovated, or expanded, it must be certified to meet the current NFPA-99 Standard for Healthcare Facilities code adopted for that locale. This code is generally updated by the NFPA every three years, most recently in 1993. Older existing systems need not be updated to the current code unless there is a clearly hazardous condition in the existing system. The NFPA also makes very specific recommendations concerning the retesting of existing systems to ensure continued quality.

The NFPA is stressing these new standards because the certification and retesting of piped medical gas systems can prevent or eliminate problemts with system performance and can enhance user understanding.

The following are some common problems which may be avoided through piped gas system testing per NFPA recommendations:

* Improper plumbing/installation techniques.

* Improper use of construction materials.

* Improper location and filtration of medical air intakes.

* Presence of particulate matter.

* Inadequate pressure or flow

* Improper safety keying of gas outlets. s Leaking or broken gas outlets. , Cross connection of gases.

* Improperly connected or not functioning system alarms.

* Incorrectly located emergency shut-off.

* Improper labeling.

* Contaminants

(1) Dewpoint standing water in lines and

equipment (natural by-product from the manufacture of medical air which has not been sufficiently dried possibly due to undersized or faulty dryers).

(2) Presence of gaseous contaminants such as CO, C02, gaseous hydrocarbons (possibly entrained through air intakes from vehicle exhaust or introduced by faulty air compressors).

(3) Halogenated hydrocarbons (cleaning agents).

The need of testing for microorganisms is not outlined by the NFPA, but reports of gram negative bacteria are said to have been found in some systems.

New JCAHO Recommendations

Because of the importance of piped medical gas systems and their impact on patient safety and equipment performance, the JCAHO has also elevated the status of the piped gas system in the survey process. While the NFPA makes very specific technical recommendations, the JCAHO has more open ended requirements focused on maintenance of the piped gas system and the education of those who use it.

New 1993 survey standards adopted by the JCAHO require OR staff to be knowledgeable on various aspects of the system. They also place heightened focus on the hospital’s responsibilities. “Where we’ve seen slippage (in medical gas performance), we’ve responded. The JCAHO (this year) has added new questions to the survey process to emphasize the need for improved maintenance and training,” says Ode R. Keil, the JCAHO’s director of plant, technology and safety management.,

The following are some excerpts taken from the JCAHO publication Plant, Technology & Safety Management Series (the 1993 KIPS hospital accreditation program [on] how to prepare for a PTSM survey) which draws specific attention to piped medical gas systems:

PL.4.3. A current, accurate, unique inventory is kept of all equipment for utility systems included in the program. It is further stated that, ‘…the inventory for piped medical gas systems must include alarms, valves, automatic pressure switches, flexible connectors, and outlets.’

PL.4.4. Utility systems operational plans are written to help assure reliability, control risks, reduce fatigue, and train users and operators of the systems.

PL.4.4.1. The hospital develops procedures and establishes intervals for the testing and maintenance of equipment for utility systems included in the program. It is further stated that, ‘…written procedures for testing and maintaining piped medical gas systems must include cross-connection, contamination, and pressure testing when the system is installed, modified, or repaired.” It is further stated that, ‘…established intervals for testing and maintaining piped medical gas systems must include alarms, valves, automatic pressure switches, flexible connectors, and outlets.’

PL.4.4.3. Orientation and education is provided in accordance with SE.1 through SE.4.4. for individuals who use and/or maintain utility systems are documented.

PL.4.5. There is a current, complete set of documents that indicate the distribution of each utility system, including controls for a partial or complete shutdown. It is further stated that, ‘…must include piped medical gas system.’

PL.4.5.1. Where provided, emergency shutoff controls are labeled. It is further stated that, ‘…zone and area shutoff valves for piped medical gas system must be accessible and clearly identified.’ It is stated that, ‘…random sample of personnel who use or maintain the piped medical gas system must be able to describe the location and function of normal and emergency controls for the system.’

Hospital staff should be especially aware of PL.4.5.1. which permits surveyors to randomly approach staff members and question them on the location and function of the system’s alarms, shutoff valves, and so on.

Respiratory therapy departments also have a role in managing piped medical gas systems. This role is particularly important to clinicians who have patients supported by the respiratory therapy department and to those medical directors who oversee this department. As outlined in the ‘Intent’ section of RP.3.3 of JCAHO Accreditation Manual for Hospitals, 1993: ‘The respiratory care department/service should have a mechanism for managing respiratory equipment and medical gas systems so that therapeutic gases are administered safely. This requires developing and implementing policies and procedures for testing, maintaining, and operating the system and for verifying the integrity of the equipment and the system.’

The responsibility to comply with most of He above maintenance issues usually rests with the institution’s plant engineering department. However, the extent to which institutions adhere to industry recommendations concerning piped gas systems can have an impact on patients, clinicians, and equipment.


Piped medical gas systems network through multiple clinical areas of most hospitals. New standards have been implemented to encourage the support of these systems which have traditionally been ‘out of sight, out of mind.” As a primary user group, the anesthesia staff should play a key role in communicating the need to guarantee that this fife support utility system is properly understood and maintained.

Thomas A. Nagle, M.B.A., is the service marketing manager for Ohmeda, Madison, M. Ohmeda manufactures and provides field testing services for piped medical gas delivery systems.


1. Weisman Ellen, NFPA and JCAHO Look at Medical Gas Systems, Health Facilities Management Vol. 5, No. 8 (August 1992):28.