Anesthesia Safety: Medical Gas Distribution in Anesthetizing Locations

Posted by Tim Richards on July 30, 2020
Tim Richards
It may come as no surprise that of all the various care spaces within a healthcare facility, the surgical suite can be considered one of the most important. It is not only because of the critical life-saving procedures that occur but also because of the organization's overall financial health. 
It is paramount that the operating rooms' medical gas systems are designed and installed correctly. The individuals working within the department need to be aware of their function and responsibilities in an emergency.
At CHT, we understand you want your medical gas systems to be compliant, pass inspections, and are safe for your facility. In this article, we discuss the different levels of anesthesia, the importance of its safety, and the distribution of your medical gas systems for areas designated for the administration of general anesthesia. 


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Different Levels of Anesthesia in Healthcare Facility

It is essential to understand the different levels of sedation that may be administered. Although it is considered a sliding scale in most hospital OR’s, there are four distinct levels of anesthesia, based upon the patient’s physical response to the drug-induced state. 

1. General Anesthesia

A loss of consciousness in which the patient is not arousable, even with
painful stimulation

2. Deep Sedation/Analgesia 

A depression of consciousness in which the patient cannot be easily
aroused, but will respond to repeated or painful stimulation
3. Moderate Sedation/Analgesia or Conscious Sedation
Depression of consciousness in which the patient responds to verbal commands, either alone or with light tactile stimulation
4. Minimal Sedation or Anxiolysis
A state in which the patient responds typically to verbal commands, but cognitive function or coordination may be impaired.
According to NFPA 99-2012, an anesthetizing location is defined as:
"Any area of a facility that has been designated to be used for the administration of general anesthesia."

In the 2018 edition of NFPA 99, this definition is no longer included, but as it relates to the design requirements of zone valves and area alarm panels, anesthetizing locations for moderate or deep sedation or general anesthesia are grouped into the same category.

Yet, it is important to note that NFPA 99 is a risk-based document, and the determination of an anesthetizing location is up to the facility, as stated in NFPA 99:
“It shall be the responsibility of the health care facility’s governing body to designate anesthetizing locations.”

Anesthesia Safety: Requirements for Zone Valves and Area Alarm Locations 

Now that the anesthetizing location has adequately been determined, the appropriate codes and regulations can be applied. The Joint Commission Hospital Accreditation Standards, EC.02.05.01, EP 25 lists the requirements for zone valves and area alarm locations for accredited facilities.
These requirements closely mirror those found in NFPA 99. Specifically, for areas designated for the administration of general anesthesia, the following shall apply:
  • Zone valves shall be located outside each anesthetizing location
  • The zone valves shall be readily accessible
  • Shutting off one zone valve shall not affect others
  • Area alarm panels shall monitor all gas systems and provide surveillance of pressure variations of +/- 20% from normal operating pressure and vacuum decreases of 12in HgV
  • The sensor locations for the area alarm panels may be installed on either the source side of individual room zone valve box assemblies or the patient side of each of the individual zone valve box assemblies
In addition to the installation requirements for the valves and alarms, proper labeling is required on all assets. It can be critical in the event of providing safe and effective shutdowns or modifications to existing systems.
Again, the requirements of both NFPA 99 and TJC are in unison. From a Joint Commission perspective, Standard EC.02.05.09, EP 11 indicates that all valves are accessible and identify what the valve's control, both in terms of gas content and area of control. Additionally, all piping shall be identified by the name or chemical symbol of the gas system at intervals of no more than 20 feet.
For area alarm panels, NFPA 99 requires labeling, indicating the name or chemical symbol of the system being monitored and the area(s) monitored by the alarm panel. Furthermore, it is recommended that emergency labeling also be applied to area alarm panels to ensure staff is trained and aware of the proper protocols to respond to an alarm condition within the anesthetizing location.
While not a requirement of NFPA 99...
EC.03.01.01, EP1 requires that staff responsible for the maintenance, inspection, testing, and use of medical equipment, utility systems and equipment, fire safety systems and equipment, and safe handling of hazardous materials and waste are competent and receive continuing education and training.
EC.03.01.01, EP2 requires that staff and licensed independent practitioners can describe or demonstrate actions to take in the event of an environment of care incident. A simple label indicating what actions staff are to take in the event of a medical gas emergency would be the best practice for facilities to incorporate into their medical gas management plan. 


Medical gases are found throughout healthcare facilities, especially in anesthetizing locations such as operating rooms. Anesthetizing areas require a few special considerations during the planning and design stages. When completed correctly, the setting can provide an environment maximized for safety and the well-being of patients and staff.

Healthcare facilities need to confirm that all the equipment and devices that affect life safety are trustworthy. Managing your medical gas equipment with risk assessment can be a complicated situation. Consult with your CHT representative to have the confidence your facility is safe and will pass your next survey.
Tim Richards

Tim Richards

Technical Director at CHT Healthcare
Tim has been working in the medical gas industry since 2002, and is dedicated to establishing long-term relationships by surpassing the needs of his clients. Tim holds a BS in Biology from Concordia University Wisconsin, maintains ASSE Medical Gas certifications as an Installer, Verifier, and Instructor.