Dr. Henochowicz (Associate Clinical Professor at Georgetown University School of Medicine) of Medviews hosts this week’s Grand Rounds. The entries are divided into three categories: 1) Medical Thoughts; 2) Sociological, Observational and Personal Thoughts; and, 3) Policy Thoughts

The submission from On The Wards is featured in “Medical Thoughts” as follows:

On the Wards talks of the case of the false positive alcohol test that is sure to become a favorite with medical folks being pulled over for a potential DWI citation (but officer, I am on a very low calorie diet!).

Good job to Dr. Henochowicz for this week’s work!

Imagine this far-fetched hypothetical scenario where an overworked, sleep-deprived, and hypoglycemic post-call resident is driving home (unbelievable, huh?). During a brief moment of weakness, he drifts to the right, but rapidly corrects his driving trajectory. However, a highway patrolman, Officer Poelis, is sitting along the shoulder of the road and notices the momentary lapse in the driver’s control. Sirens blare and the resident stops his car. Given the circumstances, the resident’s erratic driving behavior probably resulted from his prolonged lack of food and sleep. Officer Poelis, however, suspects that alcohol is involved and asks the resident to take a breath test. To the resident’s shock and surprise, he tests positive for alcohol despite not having had any alcoholic beverages since the last Residents Night Out party two weeks earlier.

Although a seemingly stretched hypothetical scenario, it is not beyond the realm of possibility. A Swedish group recently published a case report of a 59 year-old non-drinker who was unable to start a motor vehicle equipped with an alcohol ignition interlock device. A second breath-alcohol test revealed a blood alcohol level of 0.01-0.02 g/dL. These results were shocking, considering the gentleman has remained abstinent from alcohol his entire life.

There is nevertheless a biochemical explanation for the false alcohol reading. In an attempt to lose weight, the patient was on a very low calorie diet (VLCD). People on such diets or prolonged fasting states depend on fat metabolism for energy. Three forms of ketone bodies (acetone, acetoacetate, beta-hydroxybutyrate) subsequently accumulate in the body. The acetone can be metabolized by the liver to form isopropanol. A drawback of the breath-alcohol analyzer is that it cannot differentiate isopropanol from ethanol (the form of alcohol found in liquor). Consequently, despite the lack of substance use, he was recorded to have had an elevated concentration of alcohol in his breath.

Fortunately, blood alcohol tests utilize gas chromatography, which generate more specific results. This method could be used to verify false positives, but I doubt we will see bulky gas chromatograms in squad cars anytime in the near future.

Since this is the first case report of its kind, it is still unclear whether prolonged fasting states relate to a false positive reading. Besides the obvious warning to not drink and drive, I would strongly discourage the use of this excuse if caught. It would be much easier and safer to just find a designated driver. In the case of a resident on q4 call, finding a willing volunteer may be more difficult to accomplish.

• Source
• Jones AW, Rossner S. False-positive breath-alcohol test after a ketogenic diet. Int J Obes 2007;31:559-61.

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Congratulations to all the medical students who matched today! I hope you matched to the residency program and specialty of choice. Different medical schools have their unique ways of commemorating this occasion, but I gather from others that most Match Day ceremonies involve public humiliation celebration. That is, the student is called on stage, opens a mystery envelope, and proclaims his or her match results before a sea of onlookers. Some schools are more discreet, permitting the student to discover their destiny via e-mail. The next step from here involves preparation for the big move: paperwork galore, moving sales, housing searches, etc. But for now, bask in the excitement surrounding the Match.

For those who went through the Scramble, I sympathize for the added hurdle you had to jump to locate a residency position. I hope that, in the midst of the chaos, you were able to find a good fit.

For everyone else who may not have the slightest clue what I am talking about, here is a super brief summary of the residency match process.

Grand Rounds 3.25 is held this week at Scienceroll, a blog created by Hungarian medical student Bertalan Meskó. Bertalan has done a magnificent job categorizing the entries, while interspersing them with humorous yet relevant Monty Python video clips. On The Wards was present with the article on mobile phone use in hospitals.

I forgot to mention that On The Wards also had an article in last week’s Grand Rounds. That iteration was Grunt Doc’s fourth time hosting the weekly blog carnival. A new record!

Last year in February, I reported on a Singaporean hospital’s conclusion that mobile phones posed no significant risk to medical equipment. That same month, clinical and telecommunications researchers at the Mayo Clinic (Rochester, Minnesota) began a four-month study to evaluate for interference by cellular phones on medical equipment. After 300 tests on 192 medical devices, the researchers published their conclusions in the Mayo Clinic Proceedings (March 2007):

Although cellular telephone use in general has been prohibited in hospitals because of concerns that these telephones would interfere with medical devices, this study revealed that when cellular telephones are used in a normal way no noticeable interference or interactions occurred with the medical devices (emphasis added).

Interestingly, the same group published two similar studies in 2001 and 2005. Their earlier conclusions were less direct, noting possible interference from mobile phone use. In the 2001 study, they discovered that cell phones caused interference in 55% of the tests, affecting 41% (7/17) of the medical devices. The interference was considered clinically relevant 7.4% of the time, comprising “interference that may hinder interpretation of the data or cause the equipment to malfunction.” The 2005 study showed more promising results. While the number of devices affected remained constant at 44% (7/16), the incidence of clinically important interference dropped to 1.2%. This year, the incidence is reported at 0%.

Newer cell phone models presumably emit less electromagnetic interference (EMI), explaining the progressive decline in interference found among the three studies. The results are not novel, but they bolster the current belief that cell phone use is acceptable in hospitals. In fact, I have noticed a higher density of newfangled Motorola Razrs^® and Palm Treos^® in hospitals than in any community setting. I also know several physicians who have traded their antiquated pagers for the PDA-pager-phone-Batman buckle combos.

• Sources
• Tri JL, Severson RP, Firl AR, Hayes DL, Abenstein JP. Cellular telephone interference with medical equipment. Mayo Clin Proc 2005;80:1286-90.
• Tri JL, Severson RP, Hyberger LK, Hayes DL. Use of cellular telephones in the hospital environment. Mayo Clin Proc 2007;82:282-285.
• Tri JL, Hayes DL, Smith TT, Severson RP. Cellular phone interference with external cardiopulmonary monitoring devices. Mayo Clin Proc 2001;76:11-5.

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It is interesting what you can find while browsing your hard drive archives. As I pored through my mountain of blog drafts (okay, it’s more like a hill or even a knoll), I bumped into an article I had intended to use in February 2006, before the NRMP rank list deadline last year.

What is the NRMP and how is it like a dating service?

The NRMP (National Resident Matching Program) is an organization that oversees the residency matching process for all but a few medical specialties in the United States. Among a myriad others, these include anesthesiology, dermatology, emergency medicine, family medicine, general surgery, internal medicine, neurology, obstetrics and gynecology, pediatrics, psychiatry, radiology, … you get the picture. There are a few exceptions, such as urology, ophthalmology, plastic surgery, neurology, and neurological surgery, which are part of the San Francisco Matching Program.

The NRMP can be compared to an online dating service. Medical students apply to different residency programs in their desired area of specialty. After the interview process (a series of “big dates”), the students and residency programs submit their respective “rank order lists” (ROL). As the term implies, the applicant’s rank list is an ordered list of residency programs from most to least desired. The program’s rank list is, as you guessed correctly, a list of applicants in order of preference. There can only be one #1, one #2, one #3, and so forth.

Soon after the submission deadline for the rank lists, a computer performs the “matching” process, based on a time-tested algorithm. The computerized process supposedly takes a mere few minutes, but applicants must wait three weeks before hearing where they have matched. A reason given for the delay is that the results need to be re-checked to the nth degree. The match is a binding contract. In essence, this is a marriage that follows a series of dates, but determined by the matchmaker. And just like in the dating world, there is an unfortunate minority who do not match. They enter the “Scramble” to find a position somewhere somehow.

One week from now, over 20 000 residency applicants (and roughly 6000 who enter the Scramble) will discover where they are destined to train and live for at least the next few years. There will be many tears shed, both of joy and of pain.

A Turkish study, published in the British Journal of Sports Medicine, recently reported the presence of occult hepatitis B virus (HBV) infection in 13% of Turkish Olympic wrestlers. Occult HBV infection is the detectable presence of virus through PCR (polymerase chain reaction), despite the lack of a viral protein called HBsAg (hepatitis B surface antigen) in the blood. The current standard for evaluating hepatitis B infection or immunity relies on measuring hepatitis antibody and antigen markers. By definition, the standard tests used in hospitals did not reveal hepatitis B in these wrestlers even though they were infected. Interestingly, 11% of the wrestlers also secreted HBV in their sweat.

Several studies estimate the HBsAg positivity (indicator for acute or chronic hepatitis B) to be roughly 7% in Turkey. This figure is less than the prevalence of occult HBV found in the wrestlers. For comparison, low-risk regions, such as the United States and Western Europe, have an HBV prevalence of <2%.

Although more studies are needed, it is interesting to speculate the significance of the recent findings. For one, there may be a higher prevalence of hepatitis B infection than earlier believed. It is not standard of care to test individuals for HBV DNA. The occult HBV category may comprise a large yet underdiagnosed group. On the other hand, by nature of their profession, wrestlers sweat copiously and engage in prolonged bodily contact. Their increased risk for exposure could have contributed to the increased prevalence in this population.

Hepatitis B possesses several modes of transmission: maternal-fetal, mucous membranes, exposure to blood via needlestick injuries or contaminated transfusions, and transplantation. Excessive bodily contact has been suggested before as a form of transmission, particularly in children, but the data are unclear. With the finding of HBV DNA in the sweat, we wonder whether this supports transmission through bodily contact and fomites. Should we be concerned about it? Our knowledge in this area of study is still superficial. I am only aware of a few groups engaged in epidemiologic and laboratory-based research of occult HBV. It is nevertheless possible that wrestlers in endemic areas may someday need to get vaccinated prior to participation in sports.

• Sources
• Bereket-Yücel S. Risk of hepatitis B infections in Olympic wrestling. Br J Sports Med 2007.
• Maynard JE. Hepatitis B: global importance and need for control. Vaccine 1990;8 Suppl:S18-20.
• Mehmet D, Meliksah E, Serif Y, Gunay S, Tuncer O, Zeynep S. Prevalence of hepatitis B infection in the southeastern region of Turkey: comparison of risk factors for HBV infection in rural and urban areas. Jpn J Infect Dis 2005;58:15-9.

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You may have noticed a few subtle changes in the appearance of On The Wards. They superficially reflect an array of server-side modifications and upgrades to the entire blog. I recently opted to move the site to another server. The past server was great; they were reliable and offered many features. Unfortunately, since it was a blog-hosting site with pre-loaded software, I did not have the flexibility to upgrade the WordPress blog engine or upload plug-ins. More importantly, I did not have access to the blog database and was unable to maintain back-ups. Besides resolving the aforementioned issues, an added benefit to the recent move is the new custom site address (http://onthewards.com). [For the computer geeks: I would prefer to avoid domain name forwarding, as I did with the previous host.]

There are drawbacks, too. I have had to invest two weeks researching web hosts, rewriting the bulk of code, manually transferring blog entries, and dealing with server issues. I am sure there are bugs yet to be discovered. Since the web address has changed, I have also had to sacrifice links from search engines and sites that recognize the previous version of On The Wards. So, please don’t forget to update your bookmarks.