Q&A

Numerous questions to the Committee on Technology are individually and quickly answered each quarter by knowledgeable committee members. Many of those responses would be of value to the general readership, but are not suitable for the Dear SIRS column. Therefore, we have created this simple column to address the needs of our readership.


Q Dear Q&A,

Last year, the Executive Committee of the APSF considered whether or not it would be safe to re-use the syringe of medication within the syringe pump, if in fact the small-bore extension tubing was changed between patients. We did not know whether it would be possible for retrograde contamination to occur, if in fact the syringe was pressurized and the tubing was connected to a proximal intravenous port. Although there was variation in individual response, our opinion mostly, if not unanimously, opposed such practice. We knew that previous studies had demonstrated via Hemoccult® testing that invisible blood could migrate many inches retrograde up free-flowing IV tubing, at least. Does your committee have any opinion or facts in this matter?


A Dear Executive Committee,

Your question generated numerous emphatic responses that are listed here:

I would never use IV sets or infusions from patient to patient regardless of extension tubing or type of pressurized pump.

I am strongly against the practice of using a syringe for more than one patient. There are the infectious disease issues, which include both the theoretical retrograde contamination with bacteria, viruses, and prions and also the issue of having the medication drawn out of a sterile vial and remaining in a syringe for longer periods than if it were freshly drawn. Additionally, there is also the concern that a drug labeling error (though less likely with propofol) could now affect more than one patient.

I would think that a "multiple use" practice would be a legal problem as well.

As a former hospital administrator, I can't imagine such a practice being defensible. Therefore I would avoid it.

Reuse of a syringe with change of tubing between patients is totally unacceptable, although one type of tubing contains a one-way valve with a forward cracking pressure of approximately 100 mmHg and a reverse cracking pressure that is much, much higher. Nonetheless, reuse of syringes with a change of tubing between patients is totally unacceptable.

In my opinion, currently UN-controlled substances with potential for abuse might need internal control or at least internal audit capability. This is one more reason for not reusing a propofol syringe between patients, for example.

There is no possible justification for such practice, no matter how small the risk of cross-contamination.

I am in full agreement . . . absolutely no justification for re-using the syringe. Interestingly, I participate in providing anesthesia and medical leadership for surgical mission work (e.g., Guatemala) on a regular basis. We are always burdened with very limited resources, but would never support or condone such a practice.

I think providing opinion is helpful, but providing evidence is better. A short search of PubMed found several pertinent articles. A more detailed search would probably find more specific articles; however, the general consensus of these articles (from many countries and over many years) is that a tubing set should be used with only one patient. By extension, the suggested practice is wrong and very likely dangerous.

It seems that there is pretty uniform consensus against this. The professional societies should also be a resource, and here, for example, are relevant quotes from the AANA's infection control manual (available online at http://www.aana.com/resources.aspx?ucNavMenu_TSMenuTargetID=51&ucNavMenu_TSMenuTargetType=4&ucNavMenu_TSMenuID=6&id=732):

Administration of Drugs and Solutions

The potential for infection and transmission of microorganisms exists during the administration of drug therapy. Instructions for preparation, storage, and administration of all pharmaceutical agents provided by each manufacturer shall be read and followed. Drug administration by injection offers many opportunities for contamination. These include previously used needles, syringes, drug administration sets, intravenous tubing, and fluid containers.

#11. Do not reprocess for multiple use any intravenous fluids, tubing, or other intravascular infusions or connectors that are single-use disposable items. This includes transducers, tubing, and other items that make contact with the vascular system or other body compartments.

In our Clinical Engineering department we inspect syringe pumps for delivery accuracy. After multiple uses, we notice that the syringe integrity begins to degrade. This is manifested by the downstream occlusion pressure continuing to rise, secondary to increasing friction between plunger and barrel. We experienced some syringes causing false occlusion alarms during these tests. Such testing is performed using just water, and changing the fluid medium would undoubtedly have an impact. Many operators would not think the syringe is wearing out when it "looks" perfectly fine. You cannot determine the self-integrity of a multiple-used syringe unless you attach a pressure meter to it. Furthermore, fluid delivery rate can influence the friction; slower rates have more problems. These are just some technical things to consider if using a syringe multiple times.

Editor's Note:

Subsequent to the consideration of this question and the answers provided above, the highly publicized incident of actual cross-contamination in Nevada1 made national headline news, and in February 2008 the U.S. Department of Health and Human Services Centers for Disease Control and Prevention released a Fact Sheet, "A Patient Safety Threat-Syringe Reuse," online at http://www.cdc.gov/ncidod/dhqp/ PS_SyringeReuseFS.html, to patients who may have been exposed to multiple use vials/syringes/needles. That fact sheet, in addition to advising such patients, contains a link for health care providers:2 http://www.cdc.gov/ncidod/dhqp/gl_isolation_standard.html, regarding standard precautions for preventing transmission of infectious diseases, specifically including "Safe injection practices" under section IV.H. The precautions and practices state

Do not administer medications from a syringe to multiple patients, even if the needle or cannula on the syringe is changed. Needles, cannulae and syringes are sterile, single-use items; they should not be reused for another patient nor to access a medication or solution that might be used for a subsequent patient.

The following comment was opined after revelation of the Nevada event:

I think it is correct but insufficient to condemn such a practice without acknowledgement of the factors that could lead to syringe re-use. Addressing the symptoms without trying to cure the underlying "disease" would be but a short-term solution. Thus, we must investigate, understand, and eliminate the factors that predispose one to the practice of unsafe medicine: as clinicians, we face severe production pressure and take "shortcuts" in the process of safe preparation of medication; we may give in to the financial importance that others, or we ourselves, place on speed and efficiency; or we may sincerely believe that we are preventing waste, thereby reducing the cost of medicine. An understanding of this complex environment may help to eliminate the root cause of such behaviors, which could then facilitate safer practices.

Dr. Olympio

  1. Wells A, Harasiim P. Exposure Feared: 40,000 LV clinic patients urged to be tested for viruses. Syringe reuse at Endoscopy Center of Southern Nevada "common practice." Las Vegas Review-Journal. Feb. 28, 2008.
  2. Siegel JD, Rhinehart E, Jackson M, Chiarello L, and the Healthcare Infection Control Practices Advisory Committee, 2007. Guideline for isolation precautions: preventing transmission of infectious agents in healthcare settings, June 2007.

Q Dear Q&A,

I am a private practice physician at a community hospital where the administration purchases and maintains our fleet of anesthesia machines. Several years ago they committed to replace all of our machines. Our understanding was that a single model of machine would be placed throughout the facility. Currently we have a blend of manufacturers and models, some of which will not be supported after next year. We are asking to expedite the purchase process at this time and make the fleet consistent within this facility. I have been asked to provide information justifying this move. Specifically, I was asked it there is an ASA standard (or equivalent) addressing the benefits of a single machine model within a facility. Or, asked another way, what are the drawbacks of having multiple types of anesthesia machines within a single group of users? Does such information exist or can you point me to any resources?

Michael G. Royce, MD
Tulsa, OK

A Dear Dr. Royce,

Thank you very much for your question to the Q&A column. We are unaware of any ASA standards or other recommendations regarding your situation, and, a similar question pertaining to an academic installation is also pertinent. Please allow us to categorize our responses to you.

Confusion. The range of currently available anesthesia delivery systems includes many different models and manufacturers, including machines for office-based practice, MRI, and Day Surgery centers. Having multiple models and manufacturers in a single operating room suite relies on the fact that each provider has been trained on, and maintains intimate familiarity with, a much larger spread of features, shortcomings, and quirks, than if a single anesthesia delivery system were deployed. Attention may be misdirected to the operation of the anesthesia machine and could have negative consequences for the patient.

Education. This immediately brings to mind the Dear SIRS article in the Winter 2004 Newsletter. Who will be the key individual or local "champion" for this endeavor, and does he or she meet the attributes outlined in the article? Will this individual have the time, desire, patience, and diligence to provide training on each machine for new anesthesiologists, nurse anesthetists, anesthesiologist assistants,anesthesia technicians and technologists, and biomedical equipment technicians? How will those responsible for training receive expensive manufacturer training on so many machines? The learning curve for competency on multiple machines will be far greater than the learning curve for one machine. Training alone sounds like a near full-time job for someone even with a modest turnover of anesthesia providers. For academic institutions, an in-depth approach to training residents cannot be met if the goal is to expose all residents to such a wide range of machines. How does one handle the first 6 months of anesthesia training, when students are facing a different machine each day while trying to learn so many aspects of anesthesia care?

Interchangeability. The multi-model/manufacturer selection is even less compelling given that every manufacturer and model available offers a unique range of solutions for the clinical problems that providers face. Objectively viewed, while there may be significant differences in operation and use, there probably are not sufficient differences in performance or features to have some of each available. Other issues, such as complexity of managing service arrangements, interchangeability of vaporizers and other components, familiarity of technical personnel with simple troubleshooting routines, etc., suggest that there are serious problems with this approach.

Safety. The safety issue is serious, since the "new provider danger period" is significantly extended, and affected not only by time-on-machine, but now by incidence of exposure to EACH machine. Providers who work intermittently (part-time or PRN), are going to be in the position of working with equipment with which they are only marginally familiar. New systems will incorporate more sophisticated modes of ventilation and monitoring, requiring the operator to be proficient on multiple machines that they may work with infrequently. Proficiency must include topics ranging from basic operation and understanding to the design features and troubleshooting. Proliferating anesthesia machines from multiple vendors, and perhaps multiple models from the same vendor, could potentially become a breeding ground for human error, especially in stressful situations. And, if this is a teaching OR, the safety issue is even more serious, since residents and students are trying to learn many diverse aspects of anesthesia care and should not have their attention diverted from patient care to learn the setup, machine checkout, nuances of operation, and troubleshooting of many different machines.

Technical Support. Issues related to the ownership and support of multiple anesthesia machines from numerous vendors would present significant challenges to any hospital. The issues include training of technologists and support staff with documentation of competency, spare machines, spare parts, a variety of disposables, as well as introducing interface complexities to patient monitors and record-keeping systems, and monitoring and maintaining multiple service contracts.

Economics. There are economic reasons to use only one type of machine, such as volume purchase discount, smaller stock of disposables, and lower training costs. For example, oxygen fuel cells and CO2 absorbent cartridges may not be universally compatible and would need to be stocked for each of the machine types. Recordkeeping would also vary from machine to machine and could cause patient record problems. If a patient problem results, the cost to deal with the problem would most likely be at least the cost differential of buying one brand of machine over another.

Compromise. If there are multiple machines in a large institution, perhaps the best approach would be to populate different surgical sites with different types of machines. For example, the main operating room suite could have a single type of machine; the outpatient surgery center could have another type of machine, and the pediatric hospital yet another type. For the providers who live in each one of these single environments, there would be no issue with using a different machine each day. This might fit best for academic training programs that typically follow monthly rotations. The anesthesia providers at each site would only have to learn a single machine, thereby increasing patient safety and greatly reducing the learning curve for attaining proficiency.

Summary. Multiple models and manufacturers of anesthesia machines represent a number of potential hazards with additional liability, and will ultimately cost the hospital a great deal more money to support. Is it appropriate to make that milieu even more complex to new providers by adding the difficulties of learning how to operate and effectively use multiple potentially very different anesthesia machines?

Additionally, new microprocessor-based anesthesia machines come with the potential for undiscovered catastrophic failure modes. With multiple new machines the likelihood of discovering some of these modes at an inopportune moment in a given suite of operating rooms will increase. Our consensus is that the concept of placing multiple different anesthesia machines in a single suite of operating rooms is seriously flawed.


Machine Obsolescence

Response to Q&A:

In response to the Q&A article on older machines (APSF Newsletter 2008;22(4):78), I would like to report that we are replacing our 2 Narkomen 2B machines in 2008 after 24 years of service. The "near" 100% non-failure rate involved only 2 in-flight failures. One was a sticky valve, replaced in flight, and the other an electronic display failure easily remedied with a replacement board.

Our greatest safety issue over these 24 years was certainly not the machine hut the primitive agent level gauge on the vaporizers. An exception to this statement is the Ohmeda Tec 6 plus vaporizer, with its light and squawk alarm before the vaporizer is empty.

In evaluating the new machine choices available, it is discouraging to still see vaporizers with a 10¢ glass tube for an agent level gauge.

My question is, in light of unwanted patient movement or patient awareness from an empty vaporizer, why do we continue to utilize such a poor agent level gauge? Is it a patent restriction that allows only the Ohmeda Tec 6 vaporizer to have a safe agent level alarm? Or is it because we clinicians are requesting the machine engineers to provide larger drawers, a writing shelf, or a better cockpit light instead?

I welcome any response.

Robert R. Jirgl, CRNA
Dowagiac, MI


The information provided is for safety-related educational purposes only, and does not constitute medical or legal advice. Individual or group responses are only commentary, provided for purposes of education or discussion, and are neither statements of advice nor the opinions of APSF. It is not the intention of APSF to provide specific medical or legal advice or to endorse any specific views or recommendations in response to the inquiries posted. In no event shall APSF be responsible or liable, directly or indirectly, for any damage or loss caused or alleged to be caused by or in connection with the reliance on any such information.