Thursday, March 31, 2011

A Quick Way of Estimating a Normal QT Interval

This is an awesome tip that I learned from Dr. Ernestine Lee (who is also faculty here at Florida Hospital Family Medicine Residency). This tips was given as part of our "Learning Center" morning teaching which our faculty personally do for our residents. Enjoy!

 In a busy practice, calculating the QTc (if your EKG machines doesn't do it for you) can be a chore. A quick way of estimating the normal QT interval is this:

The QT interval should be less than ½ the RR interval

This tips only works if the QRS complex is not widened. I haven't gone through the formal calculations yet to see how accurate this method is compared to directly calculating the QTc. But if sound logical since the QTc is the "corrected" QT interval which takes into consideration the RR interval. If someone does the calculations, please let me know! Cool!
Friday, March 25, 2011


Let's say that you treat a patient for a urinary tract infection and the initial UA which showed the following:

1+ protein, 1+ blood, 3+ LE, and POS nitrite

Then, several days later, the urine culture comes back normal:


That result should not provoke rejoicing! It should cause some stress and worrying! Why? Because if the patient did not have a urinary tract infection, then what caused the 1+ blood in the initial UA? Could it be bladder cancer? Could it be renal cell carcinoma?

Whenever, I get a normal urine culture, the first thing that I do is to check the initial UA. If there is blood on the initial UA, I have the patient see me again to repeat another UA with a urine microscopy. If there are more than 3 RBC per high powered field, then I do a urology referral to work-up hematurea.
Wednesday, March 23, 2011

Direct Patient-Care Face Time (DPCFT)

Most doctors see one patient every 15 minutes. The economics of our medical system dictate this. In order to pay salaries, malpractice, benefits, rent, electricity, and general supplies, we needs to see patients at this pace. But what does that mean to us practically in terms of time management? Let's think about it... Because we all have responsibilities outside of our direct patient-care face time (DPCFT)—typing up a SOAP note, filling out prior authorization forms, reviewing home nursing orders, answering telephone messages from patients, refilling medications from pharmacies, reviewing notes from specialists, reviewing labs from the prior day, calling patients, doing referrals, and so on—those 15 minutes of DPCFT really get cut down to about 10 minutes. TEN MINUTES! That's all we get folks! No jibber-jabber here! No shooting the breeze about Mrs. Johnson's grandson. Although we want to spend more time talking about family, fishing, and fun with our patients, the truth is that we don't have much luxury to do so. And this can be stressful!

So here are three imperfect solutions that I have come up with:
  1. Just run late—Honestly, I'm not good at this one. My patients expect to see their doctor on time (since I'm usually on time). But every once in a while, it good to throw efficiency into the wind, take a deep breath, and truly enjoy looking at Mrs. Jone's photo album of her pet pig (true story). 
  2. Schedule 30 minute appointments—I judiciously set up 30 minute appointments. They offer a breather for me with complicated followup visits. But obviously, if I set up too many 30 minute appointments, I will not be able to pay for the overhead of our office. 
  3. Split up the visit—I do this especially if the patient has multiple complicated medical problems. I often feel like a heel for doing it. But patients are generally understanding. 
Other than those three tips, I can honestly say that I don't know how to increase my DPCFT. People are constantly complaining about how the U.S. medical system is broken. And from my perspective, the most broken aspect of medicine is that I have so little time with my patients. In a traditional practice, doctor who only see 2 patients an hour get themselves fired for being unproductive or bankrupt for not meeting their overhead. It's a strange predicament that we are in.
Tuesday, March 22, 2011

Iron Deficiency Anemia

Although the gold standard for diagnosing iron deficiency anemia is a bone marrow biopsy (which is understandably unpopular), serum ferritin has largely replaced this in day-to-day practice. In fact, a serum

Ferritin < 40

is about 98% specific and 95% sensitive in diagnosing iron deficiency anemia. The problem, however, is that ferritin acts as an acute phase reactant (like the sedimentation rate). So any inflammatory process can falsely elevate the ferritin and fool you into believing that your patient does not have iron deficiency anemia (when she really does).
Monday, March 21, 2011

The "Rule of 20" for Pediatric Amoxicillin Dosing

The Rule of 6 for dosing amoxicillin, which we discussed in a previous post, is probably outdated since amoxicillin is typically dosed 80 to 90 mg/kg/day instead of 40 mg/kg/day for children (max 1000 mg per dose). So lets update this rule. For 90 mg/kg/day of amoxicillin, use the following calculation:

   Weight in Pounds  x  20   =   mg dose of amoxicillin per dose

The other change is that this calculation is assuming 2x/day dosing (instead of 3x/day dosing). Let's go through an example. Assuming that you have a 10 pound child in your office, the calculation would look like this: 10 x 20 = 200. So this child would need 200 mg of amoxicillin 2x/day. Since amoxicillin comes in 400 mg per teaspoon, the child would need ½ teaspoon by mouth 2x/day.

The important thing to remember is that this calculation is PER DOSE (and NOT per day). Also, remember that this calculation only works for dosing amoxicillin 2x/day. Double check this calculation with your normal method of calculating the amoxicillin dose. I think you will find that they are pretty close!
Saturday, March 19, 2011

The Miracle of Insulin

Have you ever stopped to wonder what a miracle insulin is? Before 1922, the death rate from type I diabetes was 100%. It wasn't until 1922 when Frederick Banting discovered insulin that hope arrived. Can you imagine that? 1922! That was not that long ago!

As doctors, we take insulin for granted. Right now, I'm going through the book The Discovery of Insulin by Michael Bliss. It's a great read! Full of suspense and intrigue! It's amazing how far we have come since the early days of Frederick Banting's discovery.