Friday Poll: Variable K+ Results

Bringing it Home

A recent report from the Centers for Disease Control (CDC) found that twenty-four laboratory workers were infected with a strain of Salmonella typhimurium, an enteric pathogen. The infections were reported in sixteen states across the country. Of those infected, six were hospitalized with symptoms such as diarrhea, fever, and severe abdominal cramps. Luckily, there were no deaths reported. These infections occurred in various teaching and clinical laboratories. The worst part? This could have been avoided.

When interviewed, some of those who became ill said they remembered specific exposure events. Many others who were unsure of how they became exposed described unsafe behaviors in the laboratory. Those victims admitted to working in the lab setting without lab coats or gloves, and many reported not washing their hands before leaving the department.

If you’re a laboratory leader, you very likely work during the day shift. Hopefully, when management is on site, staff is compliant with safety. If not, you may need to examine your safety program and leadership style. Do you enforce safety regulations in the lab? Do you lead by example? Do you don PPE when you pick up the phone or use a computer in the lab?

If safety seems to be good during the day, you may want to make a visit during the off-shifts. Depending on the level of safety culture, there may be anything happening from solid safe practices to open eating and drinking in the department. I know that was the norm in many labs 25 years ago, but those unsafe practices and safety violations should now be ancient history. Unfortunately, that is not the case, and that is one reason we have bacterial infection outbreaks in our laboratories.

An experienced lab auditor will tell you it is not difficult to assess the lab safety culture in a department, even on inspection day. I once entered a lab as part of an accreditation inspection team, and I watched as the lab staff struggled to find gloves. Even though they knew the inspection was imminent, they could not hide the fact that glove use was not the norm for them in that lab. A complete lab safety audit can reveal a number of inappropriate practices such as improper PPE use, gum chewing, cell phone use, and many others.

The National Institute for Occupational Safety and Health (NIOSH) has educated workers for years about hazard and exposure control. The “Hierarchy of Controls” is an excellent model to use in the laboratory setting, although certain facts about it may be surprising. The first and best two controls to remove hazards are elimination and substitution. Of course, these are not always possible in the lab setting. While there are substitutes for hazardous chemicals, the inherently dangerous specimens that are handled cannot be replaced or removed.

Engineering controls create physical barriers between the hazard and the employee. Biological Safety Cabinets (BSCs) and Chemical Fume Hoods are powerful engineering controls. Administrative and Work Practice controls are the safety policies and actual practices that help prevent infection. Written safety procedures are designed to change the way people work, and standard work practices include not eating or drinking in the lab setting and practicing hand hygiene when necessary.

The final control for infection prevention is Personal Protective Equipment (PPE). In the hierarchy, PPE is considered the last resort for staff protection. Since the lab hazard cannot be eliminated, and since humans commit errors with procedures, that final method of protection must be utilized. Lab coats, gloves and face protection need to be used at all times when working in the laboratory. Without it, the worker is at great risk for exposure- and that is what happened in the labs where the Salmonella infections occurred. Each of the controls that should be in effect in the lab were bypassed, and there were consequences.

It is always better to read about incidents that occur in other laboratories rather than have to report them about your own. When I hear of such stories, I always look at my own labs to see if such an event could occur there. What opportunities exist in my lab safety program? What about yours? Be sure to learn from these unfortunate events and keep your own staff safe.

The personal (and probably painful) part of the infection outbreak was that these laboratory workers were infected on the job, and then they brought it home. The CDC report says nothing about infections being spread to family members or friends, but it certainly could have happened. If there are weaknesses in your lab safety program, what could your staff be bringing home? What infections or diseases could be spread because of unsafe work practices? Now is the time to take the lead for your safety program before such an event can occur. Bring safety home for your staff. Teach them and lead them so that the unsafe practices of the past turn into practices that keep everyone healthy into the future.


Scungio 1

Dan Scungio, MT(ASCP), SLS, CQA (ASQ) has over 25 years experience as a certified medical technologist. Today he is the Laboratory Safety Officer for Sentara Healthcare, a system of seven hospitals and over 20 laboratories and draw sites in the Tidewater area of Virginia. He is also known as Dan the Lab Safety Man, a lab safety consultant, educator, and trainer.

Guest Post: Drone Transport of Specimens

On a hot afternoon in late September 2016 the Johns Hopkins Medical Drones team drove to a flight field in the Arizona desert with 40 vacutainer tubes filled with human blood obtained from volunteers. The individually wrapped tubes sat in two custom-designed white plastic cooler boxes which had wires coming out of one end, ventilation holes at the other, and ran off the drone’s battery power. We carefully placed one of the boxes on the drone, stood back, and flew the samples around for 260 kilometers in what seemed like an unending series of concentric circles. Great. But why would doctors be involved in this exercise?

For the last 3 years, the Johns Hopkins medical drones team has examined the stability of human samples transported via drone. Our approach has been similar for each study. Get two sets of samples, fly one on the drone, then take both sample sets back to laboratory for analysis to see if there are any changes. However, until this study in Arizona we had only flown these samples up to about 40km, in mild weather, and for up to 40 minutes at a time. A request to set up a drone network in a flood-prone area of a country in Southwestern Africa made us realize that we needed to repeat the stability tests in warmer weather and for longer flights. This drone network would serve clinics that were up to 50 km away from each other, therefore requiring round-trips of at least 100km. Once we received this request it became clear pretty quickly that our previous tests flying for to 40km were not good enough for an aircraft that would have to fly in a hot environment between several clinics that were each 50km away from each other.

After the 3-hour 260km flight, we took both sets of samples back to the Mayo Clinic laboratories in Scottsdale, Arizona and performed 19 different tests on the samples. Each pair of samples was compared to check for differences between the flown and not-flown sample sets. Although results from sample pairs were similar for 17 of the 19 tests, small differences were seen in Glucose and Potassium, which do also vary in other transport methods. We suspect the differences seen in this test arose because the not-flown samples were not as carefully temperature controlled as the flown samples in the temperature-controlled chamber. This study (which is the longest flight of human samples on a drone to date) shows that drones can be used for blood samples even for long flights in hot conditions. However, the temperature and other environmental variables must be well-controlled to keep the blood stable.



-Dr. Timothy Amukele is an Assistant professor in the Department of Pathology at the Johns Hopkins School of Medicine and the Director of Clinical Laboratories at Johns Hopkins Bayview Hospital. He is also the Medical Director of two international research laboratories in Uganda and Malawi. He has pioneered the use of unmanned aerial systems (colloquially known as drones) to move clinical laboratory samples.

Jeff Street-small

-Jeff Street is an unmanned systems engineer and pilot at the Johns Hopkins School of Medicine with more than 10 years of experience in the development of new and innovative vehicles. He is leading the Johns Hopkins aircraft development efforts for a wide range of medical cargo applications.




Will Anyone See This Test Result?

We are all aware that there is substantial waste in testing. The mantra of utilization management is “the right test for the right patient at the right time.” This month, I want to focus on the right time. It turns out that many test results are never seen because they arrive after the patient has been discharged. This occurs for both routine and send-out testing. I will examine both.

Turnaround times for send-out testing are generally longer than those for tests performed in house. This means that results for tests ordered toward the end of a hospital stay are likely to be received after the patient has been discharged. Sendout tests are often expensive and, unlike tests performed in house, reducing sendout testing saves the hospital the full charge of the test. The savings can be substantial.

How do you prevent this? A recent article by Fang et al. shows one approach.[1] In this study, conducted at Stanford University, researcher displayed the cost and turnaround time of sendout tests in the computerized provider order entry (CPOE) system and achieved a 26% reduction in orders. I am aware of another hospital that restricts orders of sendout tests when the expected turnaround time is close to the expected remaining length of stay. Consider the graph in Figure 1. The upper panel shows the expected length of stay for a particular patient. The lower panel shows the expected turnaround time for a sendout test. In this case, there is a 62% chance that the test result will arrive after the patient has left the hospital.  Expected discharge dates are routinely kept and it is relatively easy to maintain a database of turnaround times. A hospital could combine these data and set a threshold for orders based on the probability that the result will arrive in time.

Standing orders are another source of waste.  I recently performed an analysis of the test rate as a function of the time until discharge (Figure 2). The test rate was 249 tests per hour for patients who were within 12 hours of discharge and 349 tests per hour for all other patients. It seems odd to me the testing rate in the final 12 hours is 70% of the “normal” testing rate. Further, the distribution of tests in both groups (those about to be discharged vs. all other patients) is very similar (Table 1). The main tests are basic metabolic panels and complete blood counts.  I suspect the majority of the testing within 12 hours of discharge is due to standing orders and the results were not needed for patient care.  The best intervention is less clear in this case because some peri-discharge testing is appropriate and it is difficult to distinguish the appropriate testing from the inappropriate testing. Education is one option. Perhaps the CPOE could raise a flag on orders for patients who are about to be discharged; however, this could be cumbersome and clinicians object to flags and popups that interfere with their workflow. I would be interested in readers’ thoughts on methods to reduce inappropriate peri-discharge testing.

In summary, some results do not reach clinicians in time to affect patient care. This is a source of waste. It is relatively easy to create an intervention to reduce inappropriate sendout testing but more difficult to reduce unnecessary peri-discharge testing.



  1. Fang DZ, Sran G, Gessner D, Loftus PD, Folkins A, Christopher JY, III, Shieh L: Cost and turn-around time display decreases inpatient ordering of reference laboratory tests: A time series. BMJ Quality and Safety 2014, 23(12):994-1000.


Figure 1: Comparison of expected length of stay (upper) and turnaround time (lower) for a sendout test.
Figure 2: Peri-discharge testing
Table 1: Test patterns stratified by time to discharge. The table shows the percentage of total testing accounted for each group. For example, BMP represents 15% of the total test volume among patients who are within 12 hours of discharge.


-Robert Schmidt, MD, PhD, MBA, MS is a clinical pathologist who specializes in the economic evaluation of medical tests. He is currently an Associate Professor at the University of Utah where he is Medical Director of the clinical laboratory at the Huntsman Cancer Institute and Director of the Center for Effective Medical Testing at ARUP Laboratories.


Planning Lab Testing for Medical Missions, Part 2

Last month I blogged about key points to consider when preparing to do lab testing in the field. Here I will expand on using point of care testing in medical missions. Point of care testing is easy to use and relatively easy to access, making it very attractive for use in the field or on medical missions. In fact, it is tempting to take these tests and go rogue – it’s not uncommon for point of care diagnostics to be obtained by non-laboratory professionals and tossed in luggage to be used by short-term medical teams. However, this is not in the best interest of the patients or the community. Helping establish point of care testing for medical missions is one very important way that a laboratory professional can get involved in this kind of outreach.

Proper utilization and quality assurance practices are just as critical in the outreach situation as at home in a large lab. Perhaps even more so; for example, in areas with high disease prevalence, false positives and negatives can significantly affect patient care and population health. Under-diagnosis due to false negatives means that those who need treatment might not get it, just as over-diagnosis due to false positives may cause patients to get unnecessary treatment. Unnecessary treatment, especially for infectious diseases, harms the community by contributing to drug resistance.

Most point of care tests, especially lateral flow tests, have built-in controls which lessens the need to run QCs with patient testing. However, it is important to know the limitations of the testing. Sometimes point of care testing systems that are not available in the United States are selected for use in outreach in foreign countries. It’s more likely that an American medical team would be unfamiliar with the tests. A laboratory professional can help establish or at least verify the validity of the tests, including limits of detection and accuracy, before they are deployed. Also, it is often helpful to have the results interpreted for the end user. Little interpretation is needed for the more straightforward qualitative tests that simply give a positive or negative result. Even with these tests, the limit of detection should be available to the provider, especially if this is significantly different from that which the provider is accustomed. Tests that involve titration, such as some of the rapid typhoid and syphilis testing, benefit from having an explanation of what the titers mean clinically available to the end user.

Other tests with results that are prone to confusion are point of care versions of assays more commonly performed in clinical laboratories. Difference in reference intervals for the POCT compared to a conventional test can be particularly confusing. For example, the results of a lateral flow point of care C-reactive protein assay have a different reference interval than results from high-sensitivity C-reactive protein assays used in clinical labs. Using the incorrect reference interval to determine whether a result is normal can lead to over- or under-treatment, which is contrary to the purpose of diagnostic testing. Yet, when using point of care tests in the field, there is not a neat little interpretive comment accompanying the result.

So, how can this be remedied? If the laboratory professional is also on the team, they can be available to provide information as needed. However, if the team is not so fortunate as to have their own laboratory professional, another way to provide the information is to provide a short guide to cheat sheet that briefly explains how to use test results.

Proper utility is also important, especially in areas with high burden of disease or in areas where there is no confirmatory testing. Consider rapid tests for H. pylori. These typically detect antibody to H. pylori, which can be found in up to 70% of asymptomatic populations. The rapid test is of little utility since positive results only indicate the presence of antibody and not necessarily an active infection. Consider using rapid screening tests, such as for HIV, when confirmatory testing is not available. Sometimes a second screening test that employs a different method than the first can be used as a confirmatory test if nothing else is available.

Consider environmental limitations of the testing when selecting tests for use in the field. Many tests are unreliable at extremes of temperature and humidity. This might not always be obvious even when quality controls are used properly. For example, Tang et al (1) showed that the effect of temperatures and humidity similar to what was experienced in Louisiana after Hurricane Katrina on quality control material for a POCT glucose meter system caused significantly depressed results. Also keep in mind that exposure to environmental extremes can reduce the shelf life of POCT and related reagents. If using POCT long term, it is good practice to routinely test a known standard – even on tests with built in quality controls such as the test line on lateral flow tests – to ensure there has not been degradation in quality due to the environment.

Preparing POCT for medical missions is a great way for a laboratory professional to get involved in global health and outreach. From helping to select appropriate tests, to verifying test validity, to teaching proper utilization of testing and providing interpretive guideline, the laboratory professional is a vital part of a medical mission – even if they never leave their lab!

  1. Tang CS, Ferguson WJ, Louie RF, Vy JH, Sumner SL, Kost GJ. Ensuring quality control of point-of-care technologies: effects of dynamic temperature and humidity stresses on glucose quality control solutions. Point of Care 2012;11:147-51.


Sarah Brown Headshot_small

Sarah Riley, PhD, DABCC, is an Assistant Professor of Pediatrics and Pathology and Immunology at Washington University in St. Louis School of Medicine. She is passionate about bringing the lab out of the basement and into the forefront of global health.  

Owning Safety in the Autopsy Suite

The hospital security guard placed the deceased patient into the morgue refrigerator while chatting with his co-worker. They walked away without realizing the door did not close completely. Within the hour the automated temperature recording system sent an alert to the lab on the third floor.

The body had been unclaimed, and it stayed on the bottom shelf in the morgue. No one in the hospital wanted to take ownership of it. After a couple of months, fluids began to fill the shelf where the body was. The environmental services staff refused to clean up the mess since some staff were afraid.

The pathologist wanted to finish the autopsy quickly, so he started before the complete patient chart arrived. When the phone rang in the morgue, the physician on the other end of the phone said he believed the patient may have Creutzfeldt-Jakob Disease (CJD).

Managing safety in the autopsy suite can be difficult, but as these case studies show, it is important. One reason for the struggle is that clear ownership of the area is often not defined. Multiple internal departments and even external agencies may work in the morgue and autopsy suite. Pathologists, medical examiners, research physicians, security personnel, nurses, and organ procurement staff are just some of the various people that may perform tasks in the autopsy suite. This can create some unique and unwanted problems. The laboratory should take the lead in making sure all safety regulations are followed and that other users of the suite comply to avoid any unfortunate mishaps.

The morgue should be treated as a laboratory space, and it should be designed similarly to a BSL-3 laboratory space which includes an anteroom. Warning signs indicating the presence of biological and chemical materials should be placed on entry doors. Whenever work is performed in the area, proper personal protective equipment should be utilized. This PPE may include lab coats, gowns, gloves, respirators, and face protection. Make sure PPE is available in the area at all times. The autopsy space should be adequate, such that procedures may be performed effectively and that items such as knives and saws can be stored and used safely. Ventilation should be adequate (with a recommended minimum 12 air exchanges per hour), and the ambient temperature should be monitored as well.

While other personnel may access the morgue body storage refrigerator, it is often the lab or security departments who monitor the temperature. Since CAP inspectors set specific morgue refrigerator temperature ranges (1.1 to 4.4° Celsius), it can be important to communicate with the people who utilize the unit often. If placing or removing a body takes longer than expected, make sure there is adequate communication so that proper documentation of the temperature outages can be made. If a department other than the lab is responsible for temperature monitoring, make sure it is done correctly so there are no citations during an inspection.

Proper decontamination in the morgue is crucial. Instruments, tables, and counters must be disinfected to remove contamination of bloodborne pathogens. Use a chemical germicide for instrument and surface decontamination such as a 10-percent solution of sodium hypochlorite (or bleach). This intermediate-level disinfection will eliminate most bacteria (including Mycobacterium tuberculosis), and all fungi, and it inactivates viruses such as the hepatitis B virus. Rinsing with water or ethanol after disinfecting will help prevent the pitting of any stainless-steel surfaces.

Dealing with Creutzfeldt-Jakob Disease (CJD) in the autopsy suite requires special safety measures. Procedures should be posted in the area directing staff how to handle tissue and clean up in cases where patients are infected with CJD. The intact brain should be fixed in formaldehyde for one to two weeks before handling or cutting in order to reduce the prion activity. Non-disposable implements used with such patients should be immersed in 1N sodium hypochlorite (NaOH) for one hour before reuse. Surfaces on which autopsies occurred should also be immersed in NaOH for one hour for disinfection purposes.

Chemicals are stored and used in the autopsy suite, and standard safe lab practices should be used. Make sure staff is trained in proper the handling, labeling, and storage of chemicals as well as prepared to handle spills. Spill kits should be available and suitable to the chemicals used in the area. If formaldehyde is used, be sure an appropriate neutralizer is available for spill incidents.

As the most involved and best educated about its dangers, laboratory personnel should take the lead in making sure safety is a priority in the morgue, and educate all who may enter the area. Make sure communication is clear about who will use the suite and when- it’s never good to have someone walk in during an autopsy or organ removal. Use signage when necessary, and be willing to help in any unusual situations, because with a morgue, they definitely will arise. Work together as a team with all who utilize the area, and that ownership of safety will translate into safety for all.


Scungio 1

Dan Scungio, MT(ASCP), SLS, CQA (ASQ) has over 25 years experience as a certified medical technologist. Today he is the Laboratory Safety Officer for Sentara Healthcare, a system of seven hospitals and over 20 laboratories and draw sites in the Tidewater area of Virginia. He is also known as Dan the Lab Safety Man, a lab safety consultant, educator, and trainer.

Chemistry Case Study: Falsely Elevated Methotrexate

High dose methotrexate infusion is widely used in the treatment of malignancies such as leukemia, high risk lymphoma, and osteosarcoma. It can be associated with multiple adverse effects, especially renal toxicity, which could leads to acute kidney injury (AKI), delaying drug elimination and worsening its toxicity. Leucovorin, a reduce folic acid, is commonly used with methotrexate treatment to lessen its toxicity. After administration of methotrexate, serum creatinine and methotrexate concentration should be closely monitored. The levels of serum methotrexate to be associated with a high risk for nephrotoxicity are: 24 h, > 10 μmol/L; 48 h, > 1 μmol/L; 72 h, > 0.1 μmol/L.

In this case, the patient is a 33-yo old male with T-lymphoblastic leukemia in complete remission. He was given consolidation therapy with high dose methotrexate. Leucovorin rescue was given 24 hours after methotrexate administration. Patient’s methotrexate level was at 4.7 μmol/L 3 days postinfusion due to AKI and poor methotrexate clearance. An alternative rescue, glucarpidase (Garboxypeptidase G2), was then given to patient to rapidly lower serum methotrexate level. Glucarpidase cleaves methotrexate molecule to inactive metabolite, DAMPA (2,4-diamino-N-methylpteroic acid). After glucarpidase rescue, patient’s methotrexate level were still remained above the toxic level on the following two days (1.02 μmol/L and 0.68 μmol/L).

In most clinical laboratories, serum methotrexate is measured by immunoassays, and the inactive metabolite of methotrexate after glucarpidase rescue, DAMPA, cross-reacts with immunoassays and interferes the measurement of methotrexate. After glucarpidase treatment, patient’s methotrexate level can be falsely high for 5-7 days, before accurate measurement can be obtained using immunoassays. In this case, the concentrations of methotrexate after glucarpidase rescue were falsely high results due to DAMPA interference. There are laboratory-developed LC-MS methods to detect methotrexate. LC-MS methods are more specific and have no interference from the metabolite, can be used for accurate methotrexate measurement in the case of glucarpidase rescue.



-Xin Yi, PhD, DABCC, FACB, is a board-certified clinical chemist, currently serving as the Co-director of Clinical Chemistry at Houston Methodist Hospital in Houston, TX and an Assistant Professor of Clinical Pathology and Laboratory Medicine at Weill Cornell Medical College.