5 Common Medical Gases Used in Hospitals

Posted by Jason Di Marco on December 08, 2021
Jason Di Marco


Medical gas is critical to the function of hospitals and many other healthcare facilities. Knowing the most common types of gases, understanding how each is used, and then maintaining your systems for each gas will ensure your facility's success.

At CHT, we understand it's essential to keep your medical gas running smoothly, so you have no unexpected failures, and you have the proper equipment to do your job competently and worry-free. 

In this article, we discuss five types of medical gas used in hospitals: 

  1. Medical Air - Used in the ICU and NICU areas, medical air is supplied by a specific air compressor to patient care areas.
  2. Oxygen - Oxygen is medical gas required in every healthcare setting and is used for resuscitation and inhalation therapy. 
  3. Nitrous Oxide - A medical gas is used in numerous surgical procedures as both an anesthetic and analgesic.
  4. Nitrogen - A medical support gas primarily used for powering surgical tools and other equipment.
  5. Carbon Dioxide - Used for less invasive surgeries.

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Gases that are used during medical procedures are considered medical gases. In medical facilities, each gas is supplied by a separate system that is gas-specific designed. 

The gases are delivered from their central supply source through a piping network. Some gases may be supplied either in cylinders or via pipeline. 

While vacuum, WAGD, Medical air, and Instrument air are generated locally in most hospitals, lower volume gases may come through a piped system from cylinders connected to a manifold. Commonly hospitals will have nitrogen, nitrous oxide, and maybe carbon dioxide produced through a manifold. 

The infographic below shows most of the requirements for a manifold room as described by NFPA 99 - 2012. 


Medical gas systems in hospitals are lifesaving and are regulated as a drug. This means multiple layers of restrictions and instruction on the proper, safe and legal way to do things.

Let's look at the five most common types of gas used in medical gas systems in hospitals... 

1. Medical Air

Medical Air refers to a clean supply of compressed air used in hospitals and healthcare facilities for patient respiration. It is free of contamination and particles, has no oil or odors, and is dry to prevent water buildup in your facility's pipeline.

When a patient is in the operating room, whether it's an emergency or not, a surgeon relies on medical air to keep the patient comfortable and breathing. Medical air sources are connected to the medical air distribution system only. They are used only for air in applying human respiration and calibration of medical devices for respiratory application.

What is Instrument Air?

Medical Instrument Air is compressed air purified to meet the requirements of the Instrument Society of America and NFPA as an alternative to Nitrogen. Instrument Air can support multiple medical applications, including driving surgical tools, operating pneumatic brakes and tables, central sterile supply, and laboratory air.  

Smaller operations that do not want to have a separate compressor and piping line use pure nitrogen out of cylinders for this purpose.

Compressor Technologies

Three different compressors are strongly favored for the distribution of medical or instrument air: Scroll, Oil-Less Reciprocating, and Oil-Free Tooth Machines. Oil-free and oil-less technology is the preferred method to distribute medical air because it is the simplest and most cost-effective solution.

A scroll compressor works by using one stationary scroll and one moving scroll. The moving one orbits the stationary one to compress the air. The space for the trapped air gets smaller and smaller, decreasing the volume and thereby increasing the pressure.

This compressor type is used in distributing medical gas because required maintenance is minimal, and they operate well in all duty cycles. Scroll compressors are also very clean, quiet, and small, making them ideal for distributing med gas in your hospital or clinic setting.

Scroll compressors are commonly used to carry medical gas for anesthesia, calibrate surgical tools, and power incubators and ventilators.

Oil-less reciprocating compressors are used to distribute air when an intermittent cycle is needed. Installation is inexpensive, the noise level is low, and maintenance is cost-effective. It is designed to keep oil out of the compression chamber and air stream and does not add any flammable or toxic contaminants to the air. The medical gas typically travels through clean copper piping, leading to your surgical suites and patient rooms to supply medical outlets for ventilators and respirators.

Oil-free tooth compressors, such as Atlas Copco's ZT-MED, prevent oil contamination and the expenses that go with it. There is no risk to your patients or risk of damage to your expensive hospital equipment. They operate quietly, are self-regulating, and are easy to maintain.

In addition, Atlas Copco offers a state-of-the-art software tool that assists your hospital engineers, medical specialists, and developers. This tool helps to determine the size and quantity of compressors needed, along with the necessary purifiers and vessels to meet your medical gas flow requirements.

2. Oxygen

Oxygen is a medical gas present in virtually every healthcare setting and is used for resuscitation and inhalation therapy. It was introduced in the early 1900s. You can use it for medical conditions such as COPD, cyanosis, shock, severe hemorrhage, carbon monoxide poisoning, trauma, cardiovascular and respiratory arrest, resuscitation, and life support.

Cylinders of oxygen are defined by their color, green label, and their unique gas-specific connection fitting. They may be connected to a manifold and then to a master alarm and control valves and gauges. Some organizations use small liquid oxygen tanks, commonly referred to as dewars, or larger bulk cyrogenic tanks.

3. Nitrous Oxide

Nitrous oxide is a variant of nitrogen—when mixed with oxygen, it acts as an anesthetic agent. 

Nitrous Oxide is a medical gas commonly known as "laughing gas," and dentists began using it as an analgesic in 1812. Since then, this medical gas has been used in numerous surgical procedures as both an anesthetic and analgesic.

There are certain times when this medical gas is contraindicated. Patients undergoing those types of procedures are provided with a medical gas warning wristband that alerts your facility's staff not to administer it.

As a medical gas, it is still used in operating rooms.

4. Nitrogen 

Nitrogen as gas is used to power tools in places where they do not have instrument air. In fact, it is more commonly used to support gas in a facility. It can come from a manifold of cylinders and is piped at pressure with an alarm system at the source and at the use site.

5. Carbon Dioxide

Carbon Dioxide is used for insufflating patients—blowing into the body cavity for less invasive surgeries like laparoscopy, arthroscopy, endoscopy, and cryotherapy. It is used to enlarge and stabilize the body cavity for greater visibility and access to surgical areas.  

Carbon dioxide can also provide respiratory stimulation when mixed with oxygen, during and after the administration of anesthesia.

Carbon Dioxide can also be used for cryotherapy, where temperatures of -76° C can be achieved. Using this technique, body cells are destroyed by the process of crystallization. [source]

Carbon dioxide (CO2) is an odorless, colorless gas. CO2 may be piped in large hospitals but more likely comes from a tank.

In addition, helium gas is used in critical operations.

Helium gas is an alternative to carbon dioxide surgeons are exploring to insufflate a patient's abdomen undergoing laparoscopic abdominal procedures.

It is a gas that can help prevent respiratory acidosis—a condition that can occur when the lungs cannot remove all of the carbon dioxides the body produces.  

Helium gas, when combined with oxygen, can also be to aid the treatment of asthma, emphysema, and other respiratory conditions. 

Inspecting Your Medical Gas Systems

Your medical gas systems need to be inspected regularly, not only because they are critical to your patient's well-being but also because those inspections can make the difference between financial success or failure. You must supply your facility's technicians with repair, maintenance, and operational information to keep your medical gas systems safe and cost-effective.

Like other medical products, medical gas must have a Marketing Authorization (product license) to be sold. Equipment must have a CE marking to indicate that it complies with the Medical Devices Directive.

Annual inspections of the following medical gas systems are required:

  • Bulk oxygen system
  • All central supply systems
  • Carbon Monoxide monitor (more often than annually if the manufacturer recommends it)

Periodic inspections are also required for the inlets and outlets, the alarm warning system, and maintenance programs for all central supply systems.

Additionally, the Joint Commission requires all accredited facilities to inspect, test, and maintain the following:

  • Piping
  • Master and area alarms
  • Outlets
  • Flexible connectors
  • Automatic pressure switches
  • Shut-off valves

Closing Thoughts

Knowing the various types of gases and compressors and understanding their maintenance requirements is critical for facility managers and other staff.

Adhering to proper maintenance standards will allow your facility to avoid unnecessary risks and delays. Plus, understanding the types of gases you are using and how to use them properly will maintain top patient safety.

Medical gas systems must be built by certified installers and then verified by a specially trained verifier before being used. Once the system is up and running, annual inspections ensure the patients and staff are protected and served well by the system.

CHT offers medical gas services to help you reach your compliance goals. To help you navigate through these challenges, we offer a free 30-minute discovery call.

Get a Quote



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Topics: Medical Gas Compliance

Jason Di Marco

Jason Di Marco

President and CEO at Compliant Healthcare Technologies, LLC
Jason Di Marco has been intimately involved with helping hospitals protect and improve their medical piped gas systems from CHT's beginnings. He is certified by ASSE, NITC, and NFPA as an inspector and installer and has worked with major institutions from construction to risk assessment planning.