Heartfelt with Dr Melissa Walton-ShirleyView all posts »
The DOSE trial: The Carnac-the-Magnificent approach to diuretic dosing still works!Mar 16, 2010 18:18 EDT
Remember the good old days of late-night television when Johnny Carson and Ed McMahon used to own the airways? The DOSE trial reminded me of the "Carnac the Magnificent" routine, where Carson, decked out in a purple robe and hat, used to give an answer to an unknown question contained in an envelope he held to his forehead.
It's the same approach we take to dosing diuretics in patients with acutely decompensated congestive heart failure. I imagine myself standing at the foot of the patient's bed, purple hat in place with feathery plume tickling my nose and a crimson robe draped off my shoulders. I have an envelope pressed to my forehead. I close my eyes and say the answer to the unknown question: "Whatever I feel like giving." Ed laughs in the background and repeats with a loud guffaw, "Whatever she feels like giving." I take the envelope, blow it open Carson style, and reveal the question: "What dose of furosemide does Ms Smith, who's drowning in CHF today, require?" Except in this situation, neither the question nor the answer are particularly amusing, and interestingly, even though we have no idea how to duplicate what we're doing or specifically how we do it, it seems to work amazingly well.
The DOSE trial had the ambitious task of trying to pin down exactly what goes into the thinking of a physician who is treating heart failure. But even now, as I remember trying to explain to a fourth-year med student how I arrive at a furosemide dose, it's extremely difficult. I look at the patient's home dose first, then their BUN/creatinine and potassium. I take a quick glance at their blood pressure. I am subconsciously aware of their respiratory rate and how much acute distress they are in. For the most severely decompensated, I've rarely not been able to turn the patient around with a 4-mg dose of morphine chased with 4 mg Zofran and shaken and stirred with nitroglycerin sublingual and 40-mg Lasix IV stat! Explaining my CHF cocktail and diuretic dose is like the answer my mom used to give me when I'd inquire about her recipe for those wonderful fluffy homemade biscuits that literally "melt in your mouth." She would always say, "Well, you take some flour, mix in a little shortening, add some milk, knead it a while, if it's too dry you add some milk, if it's too moist, add some flour," after which I 'd try to duplicate her instruction and wind up with something that was more the consistency of a hockey puck. My family jokes that you could "win a war" with my biscuits.
I probably won't change much after today's presentation, but after talking with Dr Ileana Piña, I'll probably revisit continuous furosemide infusion. Although there was nothing to suggest that this population of patients responded any differently to bolus vs continuous infusion of diuretic, she thinks her population of patients with predominantly chronic CHF might have less renal insufficiency after the continuous-infusion method. It might be worth it just to get familiar with the regimen again.
What I find most interesting about this trial is just exactly why it is that in the history of medicine the utilization of furosemide in the acutely decompensated patient has never been formally studied. I guess some things are just so obvious that they seemingly don't even merit a question. Have you ever wondered about a placebo-vs-sublingual-nitro trial for unstable-angina patients? What about CPR vs no CPR for patients dying of sudden arrest? Then again, thinking like this could be dangerous because without questioning the obvious, we'd still be using leaches for the treatment of infection and other maladies.
For now, I'll continue my "Carnac-the-Magnificent" diuretic dose-finding routine, because like Carson and McMahon, we've all kept on doing it because it keeps on working.