What does PPD/BCG/TB mean?

Clinical scenario:
In the Hawaii HOME project, we had a series of patients who were being screened for TB with PPDs.  Three of them had a history of (+)PPDs.  Two of them claimed to have a history of (+) chest x-ray without follow-up of medications.  One of them came in with fever and cough.

Definitions:

• TB: Tuberculosis
  • Caused by Mycobacterium tuberculosis
  • Tubercles are warty, cheesy lesions
  • Respiratory infection characterized by:
    • Cough
    • Hemoptysis (bloody sputum)
    • Fever/Chills/Night sweats
    • Weight loss
  • DIFFICULT: to catch, to culture, to get rid of
• BCG: Bacillus Calmette-Guerin
  • Calmette (French bacteriologist) and Guerin (assistant) cultured a cow-version of the TB bacteria and created a TB vaccine
  • Similar theory to the smallpox vaccine
    • Jenner made a vaccine from cowpox
  • Causes a false-positive PPD skin test
• PPD: purified protein derivative aka Mantoux test
  • Sterilized tuberculin glycerol extract from the tubercle bacillus
  • Injected subcutaneously (right under skin)
  • Read 2-3 days later (delayed type IV hypersensitivity reaction)
    • (+) if induration (hardness) forms >5/10/15mm depending on situation
    • (-) if no reaction is present
• Chest x-ray
  • Test of choice in non-active TB for determining clinical status
  • (+) indicates that lesions suspicious for TB are observable
  • (-) indicates that the patient is at risk for secondary TB activation in the future, but currently does not have active TB assuming the patient is asymptomatic

Why is this important?
Swaziland has the highest prevalence of TB in Africa (1,198:100,000), shortly followed by South Africa (948:100,000). In the Pacific Islands, Cambodia, Kiribati and the Philippines have high rates as well (495, 365 and 290:100,000 respectively.) In Southeast Asia, DPR Korea, Timor-Leste and Bhutan have high rates; also places of conflict.
Many immigrants pass through Hawaii to the mainland US and the immigrant homeless population has a significantly higher risk of exposure to TB and subsequent infection.

Treatment
Active TB Standard recommended regimen:
2 months of RIPE: rifampicin, isoniazid, pyrazinamide, ethambutol
4 months of RI: rifampicin, isoniazid
Latent TB infection:
6 months of isoniazid, or 3 months of RI
-Advise patients about side effects of isoniazid:
GI upset (loss of appetite, nausea, vomiting, stomach pains)
Weakness, peripheral neuropathy (prevented by vitamin B6 intake)
Liver damage
-Do Cr and LFTs monthly for monitoring

Resolution of clinical scenario:
The two patients with (+)PPDs and (+)chest x-rays were questioned further.
The one with fever and cough was confused and through a translator, thought that the word "positive" meant "good."  In the context of the tests, both were negative.
The other patient had a card with a record locator number.  The main office for TB screening was contacted for confirmation: the chest x-ray was reportedly normal.  This patient had unintentional weight loss of 35 lb over the past year (since becoming homeless.)
The patient was warned about the possibility of "reactivation TB" and was advised to start isoniazid.  The patient agreed to prophylactic treatment and routine testing.

Take home lesson:
Always question your patients about what they mean!  Positive in terms of disease is may not mean the same thing to a patient as it does to a clinician.

References:
WHO estimates of TB incidence by country, 2007
NICE 2006 guidelines: Clinical diagnosis and management of TB and measures for its prevention and control by the UK's National Institute for Health and Clinical Excellence

Traumatic rhabdomyolysis

In recent news, a survivor of the 7.0 earthquake in Haiti have been found after 10 days -- including a 22 year old, Jean-Pierre.  In the rubble of the collapsed hotel he fed on cola, beer and cookies to stave off dehydration and malnutrition until his timely rescue.

He was lucky enough to dive underneath a desk as the earthquake hit, avoiding major trauma.  What if his legs were pinned under tons of rock and timber?  What if he were held immobile for the better part of a week?

Jean-Pierre was spared the fate of acute renal failure/acute tubular necrosis by traumatic rhabdomyolysis.  It would start as dark red urine, that eventually lessens until there is no urine being produced at all.

 

--------------------------------

Myoglobin is a heme-binding molecule present in skeletal and cardiac muscle. It makes our muscles red, especially the slow-twitch (Type I) muscles. It is similar to hemoglobin but greedier -- it's affinity for oxygen is much stronger.  Underwater mammals like seals and whales are able to hold their breath much longer than us due to their higher concentration of myoglobin in muscle.

For reasons that are not entirely clear to us, when muscle tissue breaks down from trauma and immobility, myoglobin is released into the bloodstream and subsequently filtered by the kidneys where it can cause major damage -- nephrotoxicity by iron-dependent and -independent mechanisms.
1) Ferrous oxide (Fe2+) is oxidized into Ferric oxide (Fe3+) and leads to free radical damage in the kidneys.
2) Tubule obstruction and direct toxic effects are thought to occur as well.

Aggressive saline infusions with possible addition of sodium bicarbonate to alkalinize the urine (and prevent conversion of myoglobin into its more toxic metabolites) are the sole treatment of this kidney condition.  This makes sense, since you're clogging up the filtration system with this muscular gunk, you vigorously flush the whole system out!

We're talking about boluses of 20cc/kg (or ~1.5 L of NS for the typical person) initially, with maintenance IVF of 200-300cc/hr thereafter!

This is expected to go on until the urine output hits 2-3cc/kg/hr (or 150-200cc/hr for the typical person) and the urine clears up.

 

Hopefully you find this topical and interesting as well.

 

References

Photo by simminch via flickr

BurnDoc ICU Rounds:
-Traumatic rhabdomyolysis/Crush Syndrome
-Acute Renal Failure

Myoglobinuria - Medscape

"Nonreassuring" Vocabulary

The word "nonreassuring" is a curious phenomenon of OB/GYN.  Nowhere else is this particular word used in a professional context... which is embarrassing that the word is cited in literature when it doesn't exist.

 

Reassuring is defined thusly:

tr.v. re·as·sured, re·as·sur·ing, re·as·sures

1. To restore confidence to.

2. To assure again.

3. To reinsure.

The implication is that "nonreassuring" means the opposite -- worrisome, vexing.  Of course, to a pregnant mother about to deliver, that's some of the scariest news to hear about her unborn child!

 

In an effort to further obscure the assessment in Fetal Heart Tone monitoring, in April of 2008 the "National Institute of Child Health and Human Development Workshop Report on Electronic Fetal Monitoring" issued a new statement to categorize it in a "Three-Tier Fetal Heart Rate System:

Category I
Category I fetal heart rate (FHR) tracings include all of the following:
• Baseline rate: 110–160 beats per minute (bpm)
• Baseline FHR variability: moderate
• Late or variable decelerations: absent
• Early decelerations: present or absent
• Accelerations: present or absent

Category II
Category II FHR tracings include all FHR tracings not categorized as Category I or Category III. Category II
tracings may represent an appreciable fraction of those encountered in clinical care. Examples of Category II
FHR tracings include any of the following:
Baseline rate
• Bradycardia not accompanied by absent baseline variability
• Tachycardia
Baseline FHR variability
• Minimal baseline variability
• Absent baseline variability not accompanied by recurrent decelerations
• Marked baseline variability
Accelerations
• Absence of induced accelerations after fetal stimulation
Periodic or episodic decelerations
• Recurrent variable decelerations accompanied by minimal or moderate baseline variability
• Prolonged deceleration 2 minutes but 10 minutes
• Recurrent late decelerations with moderate baseline variability
• Variable decelerations with other characteristics, such as slow return to baseline, “overshoots,”
or “shoulders”

Category III
Category III FHR tracings include either:
• Absent baseline FHR variability and any of the following:
- Recurrent late decelerations
- Recurrent variable decelerations
- Bradycardia
• Sinusoidal pattern

Basically, Category I is "reassuring", Category III is "Nonreassuring" (ugh) and Category II is somewhere in between.

 

Personally, I don't like it when the assessment of a patient needs to be translated for the patient's benefit -- why is there a deliberate effort to make something difficult to understand even harder to explain to patients?!?  We don't need to tell someone what they already know, but in a completely different language.

 

It's doubtful, but in the future it could be categorized as "good," "hmm" and "uh oh."

 

DR C BRaVADO: mnemonic for Fetal Heart Monitoring

Define Risk (low/high)
Contractions (freq)
Baseline Rate (110-160)
Variability (10-15bpm)
Accelerations (2, >20 over 20s)
Decelerations (early/variable/late)
Overall assessment (reassuring vs "nonreassuring" ugh!)

 

References:

Advanced Life Support in Obstetrics (ALSO)

AAFP website

AAFP Mnemonics brochure

National Institute of Child Health and Human Development Workshop Report on Electronic Fetal Monitoring

The Match.

I submitted my Rank-Order List for Family Medicine programs on Friday. I updated it again today to double-check that my top program numbers were inputted appropriately. Whew!

There's a lot of factors that go into the decision-making process for residency program selection -- geography, work-hours, resident/faculty support, curriculum, monetary factors, etc.

When I looked at Family Medicine programs on the Mainland, I must say, I had NO idea what to look for -- being a medical student from Hawaii, almost all of the faculty in our Family Medicine department trained in the Family Med program here as well! So, I took a shortcut of investigating the P4 programs because I figured that they were excellent programs already, looking for fresh new ideas to integrate into their curriculum. My other choices were based on good things I heard from people, as well as my discussions with them at the Kansas City AAFP National Conference (if you're looking for the perfect family medicine program for YOU, I'd highly recommend visiting in your first month as a fourth year!)

Despite the "4", in the name, not all P4 programs are four year programs, although I found some of the ones that were to be of particular interest. Innovations are a great topic to discuss, but I want to share something else on my mind.


-----------------

Now that the rank-order list is out of my hands, I have nothing to do but wait and see what the final outcome will be, come March 18th. The National Resident Matching Program "matches" me with my #1 choice, putting me in the queue of their program according to their ranking for me -- if I happen to be in their top 10 (or so,) then I get matched there. If someone higher on their list ranks the program highly as well, then I would get bumped down (and possibly off) their list and when all the slots are filled, I would move on to my #2 choice or my #3, until I get placed.

Naturally, I feel a sense of relief.
I've gone through the grueling process of medical school (for the most part.) The countless hours of mind-numbing study in the first two years, culminating in the Step 1 exam. The thrill and terror of third year, suddenly exposed to the organic, living, breathing patient that we've heard so much about. The uncertainty and anxiety of the interviews and the ever-expanding hole of debt traveling across the country far and wide for the perfect place to spend the next three+ years of my life. Now it is time to relax and breathe. It is out of my hands.

I also feel a sense of dread and underlying anxiety.
Questions of self-doubt and second-guessing arise.
Should I have applied to X program?
What if the people at Y didn't like me?
Would I really be happy at Z program?
Can I handle the responsibilities to come?
Will medical school be enough preparation for the next harrowing experience known as INTERN YEAR?

This lack of control is both comforting and anxiety-provoking.
I have no choice but to have faith that my interviews went as well as I felt they did and just keep my brain active in the mean-time. I am tutoring a small group of incredibly fun second year med students and I'm touching on all sorts of issues that I know will be important in the future. More to come on this. :)

*Picture by 96dpi, courtesy of flickr.

Anathem Review

On my interview trail, I purchased this book for my Kindle DX -- and boy, am I glad that I got it electronically, since it clocks in at 960 pages and nearly 3 pounds in the hardcover edition!

It is a work of Science Fiction in the classic sense, inventing a whole world of "compossibility." A world where concents (monasteries) outlive surrounding civilizations by millenia, watching them rise and fall. The Avout (monks) revere Science, Reason, Logic and Physics instead of religion. Indeed, orders of the avout are called "maths." They strive to preserve the world's knowledge and seek out new discoveries, even though a Saunt (Saint) Lora of the 16th century proposed that all possible ideas had already been thought of, which includes Saunt Lora's own Proposition as well.

Stephenson dreamed up this world after participating in the 10,000 Year Clock of the Long Now project, where he thought of the idea of a church that had a clock with a set of individual gates, each programmed to open only at a set time: everyday, every year, every decade, every century and every millenia. A group of monks tended to the clock and were cloistered until such time that their specific gates opened.

The story follows a young "Tenner" who was collected at age 9 and finds himself released back out into the Saecular world shortly after completing his ten-year term. World-altering events call upon young Fraa Erasmus and his fellow clock-winders to solve a great mystery and save Arbre.


Stephenson definitely does not cut you any slack in the novel as you are introduced to the "Orth" language of the people Arbre on the first page and he never lets up. Slowly, the definitions for all of these words unfold in the novel. The payoff is rich in the form of contemplative prose in classic Plato and Socrates style dialoging that encompasses the physics of geometric coordinate phase space, the philosophy of consciousness, the existence/non-existence of time, the power of observation, and the exciting possibilities of science fiction (yes, there are parts of the book that include classic sci-fi space-opera elements to make geeks and nerds glomph and squeal and huggle and hurr.)

If you enjoy xkcd comics, Snow Crash, His Dark Materials, or anything along this vein where education itself is a form of entertainment for you, then this book is a definite buy.

It is quite a struggle for me to describe how this book has affected me, save to say that I have some upsight into the possible tracings of my own Narrative along multiple Worldtracks as they progress along a Directed Acyclic Graph in a Wick fashion, leaking in from the Hylean Theoric World. Complete nonsense to most, but I could put it best in no other way.

And that's Not My Second Opinion.

Further Blogging Musings

I started off one of my Family Medicine interviews in a very interesting way.

"I noticed you were a blogger and I must say, I was disappointed." He paused to drink in my reaction and his eyebrows furrowed as he continued in a very somber tone. "You haven't blogged in a few months!"

"Well, I have been busy interviewing," I confessed. "Plus, I would not want to blog about a specific program only to have it come back to me in a bad way."

"Exactly. I thought that I could comment on your thoughts about interviews in the hopes of bringing up a point of awkwardness."

I thought to congratulate him on doing just that, but we moved forward from that point... but he did make me think more about the frequency of my posts as well as the content itself.

One of the things that has made blogging difficult for me has been the way I have spent my free time.
My blogging dropped off precipitously when I started a relationship with a special someone (with a p-value of <0.0001! I like to joke) and when I decided to blog, it quite often turned out to be "catching up on blogs" rather than "writing cool and fun content for my own blog." Sadly, my comments on other blogs dropped off with the exclusive use of Google Reader for my blogging needs. It does a splendid job of offering me text content, but a terrible job in helping me reach out and become a part of a virtual community. I put myself in the position of observer alone, having all of these amazing bloggers teach me about fascinating clinical cases.

I have been afraid to post things of personal interest.
My posts of late have adopted more of a neutral tone and lacked personality. Tossing back the curtain of "pseudoanonymity" by attaching my Real Name to this blog and revealing its presence to ALL of my potential residency programs made me meek. I have been afraid to say anything that may offend, provoke or be of any real interest, to be quite frank. This has made me think of the Happy Hospitalist and his "crap or not, here it comes" attitude to posting. Despite the fact that I often disagree with his philosophy and politics, he does occasionally have an excellent pearl or two to share... the rest are just his opinions.

And I certainly do not live up to my pseudonym if I am afraid to offer up opinions of my own, as ill-informed, naive, idealistic, fluffy bulshytt as they may be.

Writings and Ramblings

January 1st is a time of reflection on the past year as well as a time to resolve to make changes.

There's a few things that I want to do differently in the year 2010 and beyond.

I want to complete the 100 pushups workout. This is something that I think will be achievable by March.

I want to Blog more. Technically, this is something that I have accomplished with the simple exercise of writing this post! More specifically, I want to blog daily. There are a lot of things that go unwritten that I might find of relevance at a later date.

Recently, during a resident dinner, I found myself making two quite random non-sequitors on the subjects of urushiol and polydactyly -- subjects I fancied enough to blog about in the past. I found it quite striking that these topics bubbled up from my subconscious and became somewhat relevant!

One of my favorite interviews (at my favorite residency program) included a discussion on blogging. Indeed, said interviewer encouraged resident blogging as a way of reflecting on issues that came up!
There was a suggestion to ask yourself three questions:

What?
So what?
Now what?

What: Subject of discussion
So What: WHY is this of importance to you (the writer) and me (the reader?)
Now What: Conclude with something of significance.

So there. I've come up with a new method for generating blogging content that hopefully will me more entertaining and engaging than recent posts (that have been so dry that I bored myself writing them) and hopefully I can find a way to blog more often.

Cheers!