Archives for February 2015

Radiation Protection During Mobile Exams

Do you wear a lead apron during portable exams?

I have found in my years of experience as a radiologic technologist that practices vary from one radiologic technologist to the next.  Of course, we utilize some form of radiation protection when it comes to using a c-arm for mobile fluoroscopy in the operating room.  Fewer people wear lead when performing plain film images during surgical procedures.  And most don’t seem to worry about radiation protection during routine portable exams like chest x-rays and abdomen films.

Why is this?  

We learn in school that lead shielding is required when performing these exams.  For those of you who do not wear radiation protection for mobile exams, I am about to show you something which may cause you to change the way you prioritize wearing radiation protection apparel.

For some context, I want to step back in time, when Computed Radiography (CR) was first implemented at a hospital I was a clinical instructor for.  My job was to accompany student technologists while they performed their exams and to educate and evaluate.  Having never been to the operating room at that facility, I was given the opportunity to tag along with one of the staff techs who had been observing my student for the day.  They were assigned to perform a cross-table lateral lumbar spine image during a discectomy.

I watched as the staff technologist carefully walked around the table, being mindful of the sterile field, and positioned the draped image receptor next to the patient.  My student used the portable x-ray machine to align a horizontal beam to include the lumbar spine for the prone patient.  When they were finished setting up, they indicated to the O.R. staff in the room that they were ready to expose the image.  All of them, including the physician left the room while the three of us from the radiology department stayed to make the exposure.

We had taken two CR image plates into the room with us.  One was positioned next to the patient, and the other had been placed against the wall behind us.  The student made the exposure, extending the full length of the cable that attached the exposure switch to the portable x-ray machine, which was about 12 feet.  The staff technologist and I backed up to the wall behind us – I would guess an additional 3 feet behind the student technologist who exposed the image.  We all wore lead aprons.

Upon returning to the radiology department to develop the image, the student made a mistake that every technologist has done in their career.  He was carrying both the exposed image plate of the lumbar spine image as well as the unexposed image plate that had been resting against the wall behind us, and he forgot which one was the exposed plate.  The logical solution was to process both image plates under the “lateral lumbar spine” algorithm and discard the image that was not exposed.

The first image was not the lumbar spine image we had hoped it would be.  Instead, something peculiar appeared on the monitor in front of us as the scanner slowly revealed more and more of the image during processing.  Once the entire image had been scanned and the processing the algorithm was applied, it was clear that this was an image of a lower leg (a portion of the tibia and fibula).

Thinking we had come across someone else’s image plate that had been exposed for a different patient (and thankful we did not use that plate to image the lumbar spine), we began asking around the department to see if anyone was missing a tib-fib image from any of their exams.  No one was missing an image.  I decided to examine the image further on a PACS monitor for larger viewing.  The image quality was poor, and the resolution was horrible.  The exposure indicator proved that the image was slightly over-exposed.  I then realized what I was looking at.  This was the cassette that was leaning against the wall in the operating room approximately 15 feet from the patient that was x-rayed.  If you recall, the staff technologist and I had backed up against the wall prior to the exposure being made for the lumbar spine.  This was an image of the staff technologist’s leg, which was positioned just a few inches in front of the image plate during the lumbar spine exposure.  This was purely created by scatter radiation from the exposure we took in surgery.

Here are some examples of images created solely from scatter radiation in an experiment based off of lessons learned from this experience:

S# was 1190 at 8 foot distance from lateral lumbar spine phantom, which indicates about 1/4 the exposure required to produce a diagnostic hand x-ray

S# was 980 at a 6 foot distance from lateral lumbar spine phantom

I also decided to x-ray a chest phantom to simulate a portable chest x-ray using 120 kVp and 5 mAs. The following image was created from scatter radiation from about 10 feet away from the chest phantom.

S# was 2780

Though the last image produced from the chest phantom didn’t receive nearly the exposure as the one from the lumbar spine phantom, it is still obvious that there is enough radiation to penetrate the fingers from 10 feet away.  Now that you’ve read this and seen evidence of the radiation we work with every day as a radiologic technologist, are you going to change your practices?  If you already use radiation protection for your mobile exams, will you encourage your co-workers and student technologists to adopt these habits?

Registered radiologic technologists vow to keep radiation dose “As Low as Reasonably Achievable” (ALARA).  It is our duty not only to protect patients from the harm that can be caused by radiation, but to protect yourself and your co-workers from it as well.  Let us not forget the three basic principles of radiation protection; time, distance and shielding.  Keep the amount of time you are exposed to radiation low.  Keep as much distance from a radiation source as possible.  And finally, use shielding, including during mobile examinations.  Consistent application of all three of these basic principles of radiation protection will keep you, your patients and your co-workers as safe as possible.

About the Author 

Jeremy Enfinger is an experienced Radiologic Technologist, Radiography Program Instructor, and published author. He has served in leadership roles in hospital, outpatient and academic settings. His experience includes writing examination questions for the national ARRT Radiography Exam and multiple – modality training. He continues to pursue excellence in education and patient care. An avid blogger, Jeremy strives to promote standards of excellence in imaging through his online community with the sharing of veteran tips and techniques for high-quality imaging.

Additional Reading Written by Jeremy Enfinger via Topics in Radiography Blog

Experiments with Scatter Radiation (original post from 2009 – with updated images and technical factors)

Reducing Radiation Dose in Diagnostic Radiography

Podcast: How To Communicate Radiation Risks To Patients

What Everyone Should Know About Digital Radiography

Gold Standard Cleaning For X-Ray Aprons & Lead Wearables

What Does Gold Standard Cleaning Look Like For X-Ray Aprons And Lead Wearables?

Thus far in this lead apron based blog series, we have examined the infection issues and concerns associated with contaminated lead x-ray aprons and the science behind how staff members can easily test such surfaces for contamination using ATP testing.

This third blog entry will examine methodologies and practices utilized by clinical staff and facilities in the “cleaning” and maintenance of these protective lead wearables, and also explore what “cleaning” such a surface really entails. In discussing bioburden levels in the previous blog, we addressed how one cannot judge cleanliness on a surface by appearance alone.  Let’s take a deeper dive into what it means to truly clean and sanitize these protective, lead garments.

Survey Says…

In researching the topic, speaking with professionals at symposiums and inquiring with colleagues and peers, there is little consistency across the continuum of care with how these garments are cleaned and/or serviced. Shockingly, a number of Radiology, Cath Lab and Operating Room staff have lamented that such surfaces “never” get cleaned, while other staff and administrators have shared that such surfaces are sometimes cleaned, “when the case load is light on a Friday” or “on the midnight shift by the environmental services department.” Both patient and staff safety are at risk due to lack of staff compliance and clinical efficacy issues posed through improper cleaning practices.

Online research lead to a few administrators sharing that they ran these lead aprons through a cart washer, which lead manufacturing companies clearly advise not to do. Clinicians have also shared that they try to use products such as Lysol or Febreeze to “eliminate the odors” yet admit the lead wearables still aren’t “clean.” One of the more popular concepts considered in attempting to clean and service these wearables entails the discussion of “using sanitizing wipes” on such high-touch surfaces.  Unfortunately, the use of these wipes alone does not properly clean and sanitize the garments.

Pesky Directions

There are a number of sanitizing/disinfecting wipes on the market that some clinicians claim to use on lead aprons and wearables. When taking a closer look at the labels on these products, one may very well discover that most wipes are actually not recommended for use on lead wearables. Additionally, some wipes contain bleach and corrosive agents, which are both advised not to be used on aprons, according to the companies that manufacture them. A majority of the wipes on the market today are indicated for use on “non-porous” surfaces such as tables, bed rails, door handles, etc. rather than a porous surface such as a nylon covering of a lead wearable. Though the use of wipes might afford convenience to the user, the real issue with doing so lies in their clinical inefficiency in successfully cleaning the surface, not to mention completely removing any bioburden.

Wax Then Wash?

If your car had dirt, road tar and bird droppings on it, would you attempt to wax it in that condition?

For best outcomes, you would first clean and remove those elements before attempting to wax the car.  The same is true for other surfaces, including lead wearables.  Professionals who routinely assess bioburden understand the importance of a proper cleaning before sanitizing or disinfecting an item.  If an item is not properly cleaned and organic matter remains, nutrients also  remain to better foster the growth of surviving bacteria or future bacterial contamination.  This is by definition a risk factor for increased hospital associated infections.

All You Can Eat Buffet

In watching the news of late, one can gather that the world of microbiology is ever changing.  Bacteria are highly adept at persisting.  Through changes in their DNA they can gain antibiotic and/or antiseptic resistance, and these changes can happen through mutations or through integration of foreign DNA, but where would they find foreign DNA?  When bacteria die and the cells break open, then the DNA is accessible to the remaining bacteria.

The Problem with Sanitizing and Disinfecting Wipes

When facilities only use wipes on a surface and don’t completely remove the debris, they are in essence creating an “all you can eat buffet” for the surviving bacteria to thrive upon. If the dead bacteria had antibiotic or antiseptic resistance markers, now that DNA is fair game for susceptible bacteria to gain resistance!   In fact, numerous studies have shown that certain bacteria can pick up various genes from different species that makes them more pathogenic (either by making it antibiotic resistant, antiseptic resistant, or by allowing it to survive in a host better).

Layers Of Bacteria? Gross?

As if that wasn’t scary enough, what if I told you that some bacteria could gain antibiotic and antiseptic tolerance simply by growing?  (IT IS TRUE!)

Some bacteria can attach to a surface (particularly porous or textured surfaces such as lead wearables) and as they grow and form groups of bacteria (colonies) that can then form a biofilm.  Biofilms are clusters of bacteria that have attached and produced an extracellular polymeric substance (EPS) which are essentially a protective coating.

Extracellular Polymeric Substance (EPS)

EPS consists of DNA, proteins, lipids (fats) and polysaccharides (sugars).  This coating protects the bacteria inside the human body from cells that can either tag the bacteria for destruction or destroy the bacteria outright.  Externally (on a surface) it can protect the bacteria from anti-microbial drugs or antiseptic agents.  In fact, bacterial biofilms are 10 – 1,000 times more resistant to antibiotics than there standalone bacterial counterparts.  Their EPS is essentially a bacterial Teflon coating.  This Teflon coating only gets stronger when multiple species of bacteria co-inhabit the same biofilm, and if these attributes weren’t scary enough, bacteria in a biofilm can sense their microenvironment and may even produce toxins while in a biofilm that they wouldn’t normally produce.

Biofilm Life Cycle

Like all living things, biofilms have a life cycle, and a part of that life cycle involves dispersion of some bacteria that are then free to go and attach elsewhere, including in a human host. In 2007, the National Institutes of Health estimated that approximately 80% of chronic infections were biofilm related; thus, biofilms remain a serious problem in many facilities. When surfaces such as the nylon covering of a lead wearable are not cleaned properly, it allows different bacteria to begin to congregate.

Layers of Bacteria

Thinking this all sounds like something from a fictional book or movie, as if biofilms can only exist in some weird lab conditions or in some rare disease?  Nope!!!!

The most common example of a biofilm is one that everyone is probably familiar with, but may not realize is a biofilm, is dental plaque!  Biofilms are so hard to remove from surfaces that companies have spent millions of dollars trying to prevent their formation.  If you think about dental plaque, it makes sense.  We brush our teeth twice a day to best prevent plaque.  Unfortunately, when it comes to medical devices or any surface (particularly a porous or textured surface) in a medical treatment facility (such as lead wearables), biofilms can form once the surface is exposed to organic matter such as blood.  Now with the mental picture of layers of bacteria (such as plaque) on surfaces in medical treatment facilities, consider that some high-touch surfaces, such as radiological shields and aprons have not been properly cleaned for years (if ever!)

Elbow Grease Helps Break Up Biofilms

Biofilms are so tolerant of antimicrobials and antiseptics, that even the CDC positions the best way to remove a biofilm is to disrupt it physically, and they have included the ‘use of friction’ in their definition for proper cleaning.  Studies have been done that show that physically disrupting the biofilm by using friction is the primary means for destruction of the layers and thus removal of the biofilm.  (In the example of dental plaque, this would be equivalent of one going to the dentist and having them scrape the teeth in order to remove the plaque.)  The procedural process and outcomes are different when looking at the process of “cleaning” and “sanitizing” and it takes both of these separate processes to eradicate biofilms from porous, high touch surfaces. The surface on a lead wearable first needs to be cleaned before it can then be sanitized.

  • Cleaning – According to the CDC, cleaning entails the use of EPA registered products, coupled with the use of friction to physically remove dirt, microorganisms and bioburden and then removing/rinsing them away from the surface. Though a vast majority of the bioburden is removed during this process, the cleaning process does not always remove 100% of all bioburden & microorganisms.
  • Sanitizing – This process then “inactivates” 99.9% of all remaining microorganisms on environmental surfaces if allowed to sit visibly wet or “dwell” on the surface for the recommended amount of “dwell time” as per manufacturer instructions and guidelines.

Cleaning and Sanitizing really can’t be done in one-step, let alone with just a wipe. When you go to the dentist, the first step in the process is to scrape the plaque from the teeth before they are polished, just like your car needs to be adequately washed and dried, before it can be then waxed. Cleaning and sanitizing of a neglected surface such as a lead apron cannot be accomplished in one step either. In an effort to address such biofilms “head on” X-Ray apron servicing companies, such as Radiological Care Services (IN) are implementing multi-step, cleaning and sanitization programs for X-ray aprons and lead wearables. These programs are built in accordance with governing bodies, such as the CDC, JCAHO, AORN and HFAP, which position that surfaces should first be cleaned, before attempting to sanitize or disinfect them.

Stay Tuned For The Next Post

Stay tuned for the next follow up blog post, as we look specifically at what policies, regulations and expectations these governing bodies have of high touch surfaces, such as X-ray aprons and lead wearables. Between now and then, go brush your teeth and think about the layers of bacteria building up on lead wearables and aprons as they continue to invite bacteria to the biofilm party!

About The Author:

Kathleen R. Jones received her BS from Purdue University (West Lafayette) in Biology specializing in Genetics and Microbiology.   After working for five years in Quality Control she then completed her MS at Purdue University in Indianapolis.  Her growing interest in Infectious Diseases lead her to the Uniformed Services University of the Health Sciences where she obtained a Doctorate in Emerging Infectious Diseases.  Kathleen has a passion for progressive sciences and initiatives, and employs her keen understanding of the biofilm formation and elimination processes into her research and work.