Tuesday, February 17, 2009

Piped Medical Systems

Understanding the piped medical delivery systems in your facility is a great opportunity to familiarize yourself with all of the various components that create these "systems". Depending upon your frame of reference, the "start" and "end" of these systems will vary from the clinician's perspective and a contractors point of view. To a nurse, the system starts at the patient location. To an engineer or contractor, the mechanical room is the "starting" location.

As a rule, I try to organize my thinking around patient care being the driver of all needs. Therefore, I will discuss these systems as starting at the patient location and ending in the associated mechanical rooms or storage locations.

Piped Medical Systems Include:
Medical Gasses: Pressurized gasses distributed from a central location.
Vacuum/Suction: Centralized suction pump(s).

Depending upon the type of care and acuity level, the gas and suction requirements will vary from department to department and room to room. Some of these needs are driven by code, while others are staff preferences.

Medical Gasses:
Oxygen - Provides oxygen to patients.
Medical Air - Used to blend with oxygen or to power some devices.
Nitrous Oxide - Used in operating rooms to anesthetize a patient.
Nitrogen - Used in some rooms to power pneumatic instruments/brakes.
Compressed Air - Used to power pneumatic instruments/brakes or to clean instruments.

Medical Suction - Provides a vacuum to draw fluids away from the patient into a collection canister.
Dental Suction - Provides a vacuum to draw fluids away from the patient into a central collection point.
Waste Anesthesia Gas - Provides a vacuum to remove exhausted anesthetic agents by the patient from the room.

Most gasses and suction outlets are provided with a flowmeter or regulator to regulate the flow or strength. Others are simply turned on or off.

Post #1: Oxygen and Medical Air at the patient side

Oxygen is delivered to the patient with a flowmeter controlling the volume of oxygen delivered to the patient. This is measured in LPM or liters per minute. For adults, the most common flowmeters are adjustable from 0 - 15 LPM. For infants, they use "low-flow" flowmeters that allow the flow to be regulated in much smaller increments. These can be commonly found in 0-3 LMP or 0-8 LMP. It is important to note that the flowmeter is controlling the flow volume, so the exact same gas system can deliver the oxygen to both adult and infant areas. The mechanical engineer is responsible for sizing the system to ensure there is proper capacity to support all locations and any anticipated future growth.

The flowmeters look almost identical, except this low flow offers increments of 0 - 3 LPM. (Increments of measure vary by manufacturer and model)

The more common "adult" version offers 0-15 LMP adjustment indicators:

From both of these types of flowmeters, plastic tubing will connect to either a nasal cannula or oxygen mask to provide the oxygen to the patient. Oxygen is expensive and flammable, so for both financial and safety reasons, the delivery of oxygen must be as efficient as possible.

Nasal Cannula:

Oxygen Mask:

Medical Air:
The system for medical air is identical, except medical air is less common. Today medical air is only used to blend air with oxygen for infants or in ventilators. Therefore, most patient locations that offer oxygen do not offer air.

An air flowmeter looks identical to an Oxygen flowmeter, except the color is standardized for easy differentiation. Oxygen is green and Air is yellow.

As a recap, the air and oxygen from a piped medical system is regulated at the patient location with a flowmeter and delivered using a mask or nasal cannula. A hose connects from the patient (Using a mask or nasal cannula) to the flowmeter. THe flowmeter attaches directly to a medical gas outlet. (More on this in my next post)

The tubing, masks and cannula are disposable. Therefore another consideration when designing the room is the convenient storage of these disposable products. It is common to see additional sets of tubing and nasal cannula wedged behind the flowmeter as a storage method.

While this is convenient, it can be unattractive and lead to items falling on the floor. Using a drawer in a bedside cabinet or wall mounted baskets are a better option in my opinion.

Wall mounted Storage Basket Option:

Bedside Cabinet for storing disposable supplies:

Our next post will discuss the medical gas outlets and all of the various configurations available.

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