Throughout the United States, engineers are trained to design patient life-supporting piped medical gas distribution systems according to requirements of NFPA 99 consensus standard (2005). Installers, inspectors, verifiers, maintenance personnel and instructors are third-party certified to requirements of their applicable American Society of Sanitary Engineering Series 6000 consensus standard. Series 6000 is revised to parallel the current edition of NFPA 99.
In most healthcare facilities, piping is needed for conveying oxygen, medical air, nitrous oxide, medical vacuum, waste anesthesia gas disposal, nitrogen, carbon dioxide and other medical gases to wall outlets/ inlets at the points of patient use.
This training emphasizes the proper design, installation and operation of these systems that are used by healthcare patients of all ages - ranging from premature infants to adults. However, this training usually implies that the grouping of medical gas piping systems is just another piping system category used by the patient. This grouping seems to be classified on only the same level of importance as the healthcare facility's other piping systems.
In regards to patient outcomes, I feel that this extensive training must place much more emphasis on the direct, real-time patient life supporting roles that piped medical gas distribution systems play.
It should also underline the major patient safety advocate role that all piped medical gas system professionals must envision while performing all procedures regarding these systems.
Ironically, throughout their history, these complex piping systems have, on occasion, caused accidental catastrophic patient consequences.
Today's all-encompassing regulations mandate continually improving professionals' training, equipment design and gas manufacturing, thus serious accidents rarely happen. However, the occurrence of any catastrophic healthcare patient medical gas event is totally unacceptable.
Because of this, medical gas installations have effectively placed medical gas professionals directly into the loop of patient care. To guarantee patient safety, these professionals must become knowledgeable about exactly how each of these systems influences the total care of the patient - just as the hospital's medical staff must.
Upgraded Levels
Since the administration of various gases is directly prescribed by physicians, these gases have been upgraded to the level of pharmaceuticals. All medical gases must meet requirements that qualify them to be designated as either a USP (United States Pharmacopoeia) or NF (National Formulary) purity grade. They must also comply with Food and Drug Administration regulations.Properly certified professionals design, install and operate all facets of medical gas piped distribution systems. All must, therefore, consider themselves to be of equal rank, and perform with the same level of intensity regarding knowledge, alertness and care, as the hospital's pharmacists.
As an example, 100 percent Oxygen (O2) USP, manufactured and delivered by FDA-compliant suppliers, is usually placed on the pedestal of being considered the exclusive indispensable medical gas. Most professionals involved in healthcare recognize the role that O2 plays in:
- assisting patient breathing using the low-flow nasal cannula;
- providing life support in combating hypoxic (too low) blood O2 levels during the use of ventilator; and
- anesthesia needs during the use of either the anesthesia or the heart-lung machine.
In hospitals, the normal source of Medical Air USP is a complex system of compressors, dryers, alarms and other equipment. In lower demand applications, the medical air source is cylinders connected to NFPA 99-compliant automatic changeover manifold assemblies.
Normally Diluted
Contrary to many people's beliefs, in life-critical situations, 100 percent O2 is seldom administered to patients. It is normally “diluted” with medical air.The treatment of hypoxemia (seriously deficient concentration of O2 level in the patient's blood) is an example. Hypoxic patients develop individual needs regarding the specific amount of O2 needed to be added to their blood. To raise O2 levels to normal, ventilators attached to the facility's piped O2 and medical air systems are used to provide highly oxygenated breathing air.
Before initiating use of the ventilator, each patient's O2 blood percentage needs must first be determined by blood gas testing. After testing is evaluated, each patient's precise ventilator O2 breathing percentage requirement is prescribed.
For the respiratory therapist to be able to “fill” this prescription, a reliable piped medical air system, that supplies USP grade breathing air that is blended inside the ventilator to accurately dilute 100 percent O2, is required. To battle the hypoxemia, this patient-specific O2/medical air “blend” is then continuously delivered to the patient's trachea tube.
A continuous and reliable supply of O2 and Medical Air USP is absolutely critical. Depending on patient needs, sudden and unplanned termination of either, especially O2, could result, in just five minutes, in permanent patient injury or even death.
During anesthesia, each patient's oxygen needs also vary. For anesthesia purposes a precise O2/Medical Air USP “blend” is required for each individual patient. Piped O2 and Medical Air USP are blended in either the anesthesia or heart-lung machines. Other piped medical gases are also connected to these machines.
During open heart or heart transplant surgery, this process becomes more complicated. This is because the initial phase of anesthesia is performed by the anesthesiologist using the anesthesia machine. While the anesthesia machine is used, O2 and medical air are blended and then inhaled by the patient.
As the procedure continues, the patient's life-supporting blood circulation and anesthesia needs are switched to a heart-lung machine. The heart's beating is stopped and the patient's blood is circulated through the machine by the perfusionist. While the heart-lung machine is used, piped O2 and medical air are blended and added directly to the patient's blood.
What makes open heart surgical procedures unique and much more complicated is that to reduce the patient's O2 blood level needs during most procedures, the patient's blood temperature is cooled to as low as 50 degrees F. The blood is chilled, and re-heated, in the heart-lung machine. At this lower temperature, hypothermia is initiated and the patient needs much less O2 to be sustained - sometimes as much as 85 percent less.
The heart's beating is then restarted and the patient's anesthesia needs are switched back to the anesthesia machine.
During these cardiac procedures, especially involving blood chilling/ warming, the patient's O2 blood percentage levels require continual adjustment. An extremely reliable Medical Air USP supply is mandatory.
Small emergency back-up O2 and medical air cylinders, along with other gases, are attached to the anesthesia machine. If the normal wall outlet source gases are suddenly interrupted, these back-up cylinders will immediately supply anesthesia gases. However, during these highly complex cases, the sudden distraction that an unnecessary loss of source anesthesia gases might initiate to the surgeon and operating room staff could still trigger a catastrophic patient injury.
Another critical use for Medical Air USP is in neonatal intensive care units (NICU's). A possibly permanent neonatal eyesight complication, which requires medical air utilization to address, is retinopathy of prematurity (ROP). ROP is a potentially serious blinding condition that could permanently affect the retina of premature newborns. Today, if detected in time, ROP can almost always be cured.
One cause was set in motion in the early 1950s by the newly initiated and unknowledgeable administration of extremely high levels of supplemental O2 to neonatal infants. This practice was a major cause of this disease. Infants receiving highly elevated levels of supplemental O2 were more likely to develop undetected ROP, but the same infants receiving lower levels of O2 were also more likely to die, or have permanent complications, from too-low levels of O2.
With today's precise blood gas monitoring, the level of supplemental O2 now can be carefully supervised. To regulate the neonate's oxygen needs to minimize the risk of either excessive, or inadequate, O2 levels, a reliable Medical Air USP manufacturing and distribution system is required.
Because elevated O2 ROP usually develops over a period of time, with symptoms that do not reveal themselves immediately, not only a reliable supply of medical air but also reliable area alarms are necessities in NICU's.
There are many other examples why Medical Air USP is considered to be, and must be treated as, a pharmaceutical.
Medical Vacuum
Another taken-for-granted medical gas-type rated piping system is medical vacuum. Most professionals think that medical vacuum is used only to suction blood from wounds, or fluids during invasive procedures.However, for certain patients in intensive care units, a reliable source of medical vacuum is crucial for their survival.
In hospitals, the source of medical vacuum consists of a complex system of pumps, alarms and other equipment.
During situations where the entire chest cavity is filled with fluid, chest tubes are inserted into the patient and connected directly to the medical vacuum system to drain this fluid. Without negative pressure provided by a reliable medical vacuum system, this fluid will eventually collapse the patient's lungs and the patient will surely suffocate to death within minutes.
When a heart-lung machine is attached to a surgical patient's circulatory system, medical vacuum is introduced directly into the machine. This causes the patient's blood to be initially drawn out of the body to begin its flow through the heart-lung machine.
Medical Air USP and medical vacuum systems may be the most critical systems for the facility. This is because other gases are manufactured, purchased from and delivered by an FDA compliant supplier in high-pressure cylinders or cryogenic liquid containers. They are simply connected to the facility's piped distribution systems.
However, life-supporting Medical Air USP and vacuum are manufactured by the facility using its own equipment that must be installed and maintained correctly. The facility's vigilance regarding proper installation and maintenance of these systems is absolutely compulsory.
These are just a few examples emphasizing the critical role that piped medical gas systems directly play in the role of patient care and safety.
Upcoming Revision
To facilitate the sharing of this knowledge, the upcoming revision of ASSE Series 6000 will include a new standard. Standard 6005 will provide general knowledge of medical gas and vacuum systems. The purpose is to provide continuing education to all individuals who have an “interest” in piped medical gas distribution systems, but do not meet the requirements of any current Series 6000 standards.It will include a valuable third-party certification opportunity that, to reflect the revisions of NFPA 99 and ASSE Standard Series 6000, will be updated every three years. Standard 6005 will pertain to healthcare design and facilities engineers, construction managers and other interested parties. This revision will be available the beginning of 2006.
I hope that I have raised the level of awareness of the magnitude that all piped medical gas distribution systems play in directly influencing patient outcomes.
Of far greater importance, I hope that I have fully emphasized the concept that, to be able to stay ahead of and to avoid future negative healthcare patient consequences, all piped medical gas professionals must envision themselves not only as extremely capable designers, installers, inspectors, verifiers, maintenance personnel or instructors, but also as extremely committed patient safety advocates.