2.1 Medical Gas

Everything that a respiratory therapist does is in some way tied to the delivery or titration of medical gasses. The storage, transport, and delivery of gasses both in the hospital and in the homes of patients are essential to the field of respiratory therapy.

Oxygen therapy supports life and supports combustion; however, it is not flammable. While there are many benefits to inhaled oxygen, there are also hazards and side effects. Anyone involved in the administration of oxygen should be aware of potential hazards and side effects of this medication. Oxygen should be administered cautiously and according to the safety guidelines.

Oxygen Guidelines

When helping patients with oxygen, you should follow these guidelines:

• Remind patients that oxygen is a medication and should not be adjusted without consultation with a physician or respiratory therapist.
• When using oxygen cylinders, store them upright, chained, or in appropriate holders so that they will not fall over. (See Figure 3^[1])
  

  

• Do not smoke around any oxygen delivery devices in the hospital or home environment because oxygen supports combustion.
• Keep oxygen delivery systems away from any heat source.
• Check for electrical hazards in the home or hospital prior to use. Determine that electrical equipment in the room or home is in safe working condition. A small electrical spark in the presence of oxygen will result in a serious fire. The use of a gas stove, kerosene space heater, or smoker is unsafe in the presence of oxygen. Avoid items that may create a spark (e.g., electrical razor, hair dryer, synthetic fabrics that cause static electricity, or mechanical toys) with nasal cannula in use.
• Check oxygen levels of portable tanks before transporting a patient to ensure that there is enough oxygen in the tank.
• Closely monitor high concentrations of oxygen therapy with formal assessment such as pulse oximetry and arterial blood gasses (ABGs)^[2].

Oxygen Cylinder Facts

• O2 concentration: Varies depending on the type and the quality of the source (e.g., 99.9% if filled from liquid oxygen (LOX); 94% if filled from low-quality source).
• Distribution: Can be placed at the bedside (secured) or connected to a manifold pipeline distribution system.
• Capacity: Wide range of sizes, ranging from 100-10,000L (gaseous) capacity. (See Figure 4)
• Costs: Moderate cost (e.g., $60-$250) for the “E” cylinder but also requires regulator, flowmeter, and delivery; ongoing costs can be high, including cylinder deposit or leasing fee, refill costs, and transport costs.
• All cylinders come with a standard oxygen label, which includes items such as manufacturer, size, weight, filling pressure, etc.  (See Figure 4^[3])
• Advantages: Portable, common, can be used at facilities without O2 piping systems, do not require power, easy to use.
• Disadvantages: Large cylinders are heavy, require special facilities to refill (often not available at hospitals), exhaustible supply, easy to be placed in areas that cylinders are not intended to be stored, can be safety hazard if not properly secured and maintained.

Valves, Regulators, and Accessories

Cylinders require several accessories for safe use in clinical settings. Each cylinder has a valve that must be opened with a specialized key, hand wheel, or toggle. For valves that require a key, it is recommended to secure these to the cylinders.

Once oxygen leaves the cylinder valve at high pressure, it must be lowered to a pressure safe for administration to a patient or an oxygen delivery device. Regulators are specialized devices used for the purpose of lowering pressure to a level where a device can be used to further control flow to the patient. (See Figure 5^[5] explaining more about a Bourdon Guage: Bourdon Gauge (Medical definition) | Quick Explainer Video