Sweetening Your Success

     Arriving in the emergency department, you quickly give your report to the nurse and physician. Your patient, a 58-year-old female, was found unconscious under a tree in the local park. "Angela" is well-known to both you and the ED staff, as she is transported almost daily by your agency. Today's assessment was unremarkable, with no signs of trauma, equal and reactive pupils, and the strong smell of alcohol on her breath-basically, the normal findings for Angela. As you write your run sheet, the nurse walks up and says, "We checked her blood sugar, and it was 40." You shake your head and think, Why didn't I use the glucometer?

     One of the easiest ALS tools to use, but often one of the most neglected, is the glucometer. Gone are the days of putting drops of blood on a chemical test strip and staring at it intently, trying to figure out which color it had changed to. Today's provider has accurate test results in as little as five seconds. But three challenges are commonly faced by the ALS provider using a glucometer:

• Not using the glucometer on the correct type of patient;
• Poor use and maintenance of the glucometer;
• Inaccurate readings.

How Does It Work?
     There are first- and second-generation glucometers, the main difference being the method they use to determine glucose levels. First-generation glucometers have a chemical on the test strip that, when exposed to glucose from blood, changes color-the darker the color, the more glucose present. This color variation is measured photometrically or colorimetrically to give a glucose reading.

     Second-generation glucometers have reagents (glucose oxidase and potassium ferricyanide) on the test strip. When these are exposed to blood containing glucose, the reaction causes electrons to increase their electrical activity. The more glucose present, the more electrical activity is generated. This activity is measured and returns the glucometer reading.

     Other trends in glucose monitoring include the development of glucometers that measure glucose extracted from interstitial fluid in the skin (resulting in less painful testing) and continuous-monitoring systems that measure blood glucose at set intervals over a specific time frame (e.g., every five minutes for three days). Third-generation glucometers are also being developed that will allow glucose testing without an actual body fluid being used. Promising technologies include infrared light and radiation.

     Most glucometers used prehospitally will measure the glucose in whole blood. Hospital lab tests generally measure glucose in plasma. As a result of this difference, lab test results will be about 10-15% higher than glucometer readings. Providers should read the manual for the particular glucometer they use to determine if it gives results as "whole blood" or "plasma-equivalent." If your glucometer gives readings that are plasma-equivalent, they will be closer to lab test values. Regardless, the type of reading will not necessarily change your treatment; the plasma equivalent is just better for comparison with hospital lab tests of the same blood. Glucometers will return readings in either mg/dL or mmol/L. A reading of 50 mg/dL is equivalent to 2.8 mmol/L. Most healthcare providers use the readings in mg/dL, while most laboratories use the readings in mmol/L.

     Although some services have hospital-grade glucometers, the glucometers used by many EMS agencies are nothing more than personal devices a patient might buy at their local pharmacy. This is an important consideration if a patient has called EMS thinking it may have a better machine, especially if the patient has had abnormal readings. Although the EMS glucometer may be better maintained (see below), the patient's glucometer does not get jostled around in a jump kit all day, every day. Helping the patient troubleshoot their glucometer may resolve their concerns (see Troubleshooting).

When to Use It
     Too often we think of using the glucometer only on those patients in whom we elicit histories of diabetes or who present with the common initial findings of hypoglycemia (confusion/unconsciousness, diaphoresis, medical alert bracelets, etc.). The reality is that the glucometer can provide a quick check of any patient with an altered level of consciousness, unexplained fall or lethargy. As with many medical conditions, signs and symptoms can be indicative of more than one thing; hyper- and hypoglycemia are not limited to those who suffer from diabetes. I have yet to meet an experienced ALS provider who has not been fooled by this at some point in their career. Abnormal blood sugar levels can also be found in patients who:

• Are pregnant.
• Have hepatitis.
• Have head trauma.
• Are septic.
• Have diarrhea.
• Exercise strenuously.
• Consume large amounts of alcohol or are chronic drinkers.
• Are on medications (beta blockers, quinine, prednisone).
• Overdose on medications (lithium, acetaminophen, antihistamines).
• Have Addison's disease.
• Have taken someone else's diabetes medications.
• Have expired medications.

Troubleshooting
     If the machine is off:

• Try reinserting a test strip, as the device may have turned off to save battery life.
• Is there an on/off switch?
• Try replacing the battery.

     If the machine will not read the test strip:

• Is the strip inserted in the correct direction?
• Is there enough blood on the strip to test?
• Is the strip contaminated (dirt, water, etc.)?
• Are you using the correct strip for the machine?
• Is the test strip expired?

     If the data seems incorrect:

• Check the test-strip expiration date.
• Has the machine been calibrated?
• Are the test strips the correct code for the machine?
• Is the battery failing?
• Is the environment (heat, cold) affecting the reading?

     Do you see, care for or transport any of the above kinds of patients? If the answer is yes, your complete patient assessment should include evaluation of the patient's glucose level.

Glucometer Use and Maintenance
     According to the FDA, there are currently more than 25 approved portable glucose testing devices available. Although these may have different buttons or steps to take, the procedure for using them is roughly the same. Prepare your equipment and, when possible, explain the procedure to the patient and gain consent for the test. Cleanse the site of the puncture to obtain your blood sample. Next, obtain a drop of blood (glucometers use minute amounts of blood for the test, measured in microliters) and apply it to the test strip. Some machines require the blood to be applied to the test strip before it's inserted into the device, while others have the test strip inserted first (which generally turns the machine on) and the blood then applied to the end. The machine will begin analyzing the sample while you apply a sterile adhesive bandage to the site (as it is a potential site of infection). Properly dispose of your supplies, and continue your treatment and assessment of the patient.

     The glucometer is a sensitive laboratory device but unfortunately tends to be tossed into the jump kit or IV tray carelessly. Your device should be stored in a protective case (hopefully with the supplies needed to use it) and in the correct environment. The Ascensia Elite XL glucometer from Bayer, for example, has an operating range of 50°F-104°F, but test strips must be stored in temperatures between 59°F-86°F. The manufacturer also recommends keeping it out of high humidity and excessive dust or dirt. In our world of EMS, this may be a difficult goal.

     Glucometers may require calibration with "code strips," which calibrate the machines to match their reactivity. Packaged with each set of test strips, they require the user to insert the code strip before using that particular set of test strips. Again using the Ascensia Elite XL as an example, this device requires the user to insert a code strip labeled as an F strip (F-1, F-3, etc.). The code strip must match the code listed on each test strip when it is used (the current calibrated code strip will appear on the screen when the machine is turned on). Although it will still work without changing the code strips, the accuracy of the reading on the test strip will be questionable. With this in mind, realize it is important to understand the specific model(s) in use by your agency. If you can't find the instruction manual, check the manufacturer's website; it will often have a copy available to print.

     Services that perform glucose testing during patient care fall under the federal Clinical Laboratory Improvement Act (CLIA). This statute defines a laboratory as "any facility which performs laboratory testing on specimens derived from humans for the purpose of providing information for the diagnosis, prevention, treatment of disease, or impairment of, or assessment of health." The CLIA standard provides for waivers for many home tests, such as pregnancy tests and home glucometer tests, but any professional use of these devices is not waived. Because glucometer use is considered a lab test for licensing and billing purposes (Medicare and state healthcare aid programs require CLIA certification to bill for glucose testing), services may also need to meet state guidelines. State health departments are generally the contact points when applying for CLIA waivers.

Street Tips

• Glucose test strips can be handled by either end. As long as your hands are clean, your touch, with or without gloves, will not cause erroneous readings.
• Food, sugar or hand-cleaning gel on your or your patient's hands may alter the reading.
• Be cautious with lancets. Although most now have safety covers built in, be sure to dispose of them in sharps containers, as they are easy to sit or kneel on.
• Prepare the test strip and machine prior to inserting an IV.
• Retest, especially on extended transports, extrications or delayed transports. Glucose levels can change very quickly.
• Some machines can return readings of low or high. These usually indicate levels beyond the measurement capabilities of the machine.
• "Milking" the finger to get a better blood flow may result in lower readings. If the site doesn't flow, retest in another site.
• FDA guidelines for glucometer readings have a target accuracy of +/- 5%. The FDA notes that "No company that manufacturers glucose meters has developed a cost-effective system to meet these goals." Keep this in mind when treating patients: The glucometer, no matter how useful, is only one piece of the patient assessment. Use your training, assessment tools and experience.

Inaccurate Readings
     Providers may at times have difficulty obtaining accurate readings with their glucometers. As mentioned earlier, an incorrect operating environment and/or poor maintenance can affect readings. Not correctly coding the test strips can do this as well. Test strips may also have expiration dates.

     Other impacts can be a result of infection control. The current preferred method of cleaning a testing site is with a chlorhexidine wipe. If a provider uses an alcohol wipe to cleanse the skin in preparation, he must allow the alcohol to dry before testing. This prevents alcohol from being absorbed into the test strip, which can lead to a false reading. Additionally, hands (either the patient's or the provider's) that have recently been cleaned with a waterless hand cleaner may also react with the test strip, so it is best to thoroughly clean them with soap and water if possible.

     One common concern is the source of the blood tested. There is limited literature on this, but it is generally accepted that, mainly due to oxygen content in the blood, arterial blood gives the highest reading, capillary blood gives an average reading, and venous blood gives the lowest reading. That being said, the difference has been reported to be as low as 5mg/dL between these sources.

Conclusion
     Providers should consider the variety of potential causes of abnormal glucose readings and utilize their glucometers to help formulate overall patient assessment pictures. To do this, providers must take the time to understand the value and limitations of the glucometer, ensuring their complete understanding of the particular model in use by their agency.

Adding an Advanced Skill: Glucometry for the BLS Provider
     By Michael W. Dailey, MD, FACEP, & Francis "Skip" Nerney

     Blood glucose monitoring, while an advanced skill, is listed under the NHTSA National Scope of Practice Model for Basic Life Support providers. In 2003, it was being done by BLS providers in several states; however, in New York State, glucometry was a skill reserved for advanced providers only. Albany Fire Department Medical Director Bruce Ushkow and Captain Kris Madsen, supervised by the Deputy Chief for EMS, Bill Davis, saw that there was a significant potential within the two-tiered EMS response of Albany for the BLS companies to perform glucometry and improve the delivery of care to the more than 14,000 patients treated per year in the capital of New York.

     With 12 BLS companies and four ALS companies serving an area of 26 square miles, these leaders saw this as an opportunity to allow a team-based approach to care, giving the BLS providers skills that would interface more with the paramedic, rather than awaiting ALS for all diagnostic care. It would also decrease the on-scene disparity between the ALS and BLS providers. This operational efficiency would improve both objective and subjective patient care, better meeting the needs of patients.

     The process of changing the BLS scope of practice in New York involved developing a training program, an implementation phase and a quality assurance model. The Bureau of EMS and the regional and state Medical Advisory Committees, were responsible for initial approval and oversight. As part of a demonstration project, Albany Fire Department EMT-Basics were trained to perform glucometry in accordance with regional paramedic protocols. Basic EMTs independently used the glucometer 778 times during the study period. Protocol adherence was 776/778 (99.7%) and, in the two protocol violations, there were no adverse patient outcomes.

     All told, 27% of the patients who had their glucose levels checked under the protocols were found to be abnormal.

     No patients or providers were injured in the course of the project. The demonstration project has now been converted into a regional option for BLS glucometry in New York State. The BLS companies of the Albany Fire Department continue to successfully implement glucometry on a daily basis.

     What should you do if there is a new skill or piece of equipment that you believe would assist you in the care of your patients? Research it. Is the skill used elsewhere? Is there a record of success? How will it benefit your patients and your providers? Make the case to your medical director and together, create a program. Will it always be easy? Of course not. But the results are worth it for the providers and, most important, for the patients.

Bibliography
Dungan K, et al. Glucose measurement: Confounding issues in setting targets for inpatient management. Diab Care 30(2): 403-09, Feb 2007.
Grazaitis DM, Sexson WR. Erroneously high dextrostix values caused by isopropyl alcohol. Pediatrics 66(2): 221-23, Aug 1980.
Maki DG, Ringer M, Alvarado CJ. Prospective randomised trial of povidone-iodine, alcohol, and chlorhexidine for prevention of infection associated with central venous and arterial catheters. Lancet 338(8,763): 339-43, Aug 10,1991.
Mehta M, et al. Emerging technologies in diabetes care. U.S. Pharmacist 27:11, Nov 2002.
U.S. Food and Drug Administration. CLIA-Clinical Laboratory Improvement Amendments. www.fda.gov/cdrh/clia.
U.S. Food and Drug Administration. Glucose Meters and Diabetes Management. www.fda.gov/diabetes/glucose.html.

Marc A. Minkler, NREMT-P, CCEMT-P, is a paramedic/firefighter with the Portland (ME) Fire Department and has been an EMS provider for more than 19 years. He is the author of several internationally published EMS instructor programs. Reach him at pfd225@adelphia.net.

Michael W. Dailey, MD, FACEP, is medical director for the Albany (NY) Fire Department.

Francis "Skip" Nerney is a captain with the Albany (NY) Fire Department.