A reader asked me this question:
In a follow-up progress note (soap note) for a hospitalized patient, if things are relatively stable with them BUT we have more than enough Physical Exam "bullets," and enough data points / diagnoses that we're watching.. does routine monitoring of the patient's PT INR testing (Coumadin dosing or warfarin dosing) or anticoagulation therapy qualify for the Medicare National Banks' criteria for the High Risk category of medical decision making, such as:
"Drugs requiring intensive monitoring for toxicity"
Here is my response (I'm not a certified coding expert with regards anticoagulation therapy so read this with that warning in mind. However I've been doing this for years and I could justify my answer till the cows come home to any judge or jury that would question my coding authority from my position as an expert in hospitalist medicine):
The reader is referring to the billing of a high level hospital follow up code
99233. I absolutely consider anticoagulation therapy (
coumadin dosing
or warfarin dosing) to be a high risk process requiring intensive monitoring. I would definitely consider ordering a daily protime or INR (International Normalized Ratio) as a form of intensive monitoring for toxicity. Intensive is a realitve word. I have never seen it defined. Weekly checks? Monthly checks? I have no idea what the government wants. Surely a daily INR would be considered intensive for a drug that can kill you if not prescribed with caution in sick hospitalized patients with multiple comorbidities.
Everyday I'm doing anticoagulation therapy patients who's INR has accelerated out of control due to the coumadin dosing or warfarin dosing interaction with Levaquin or Bactrim or amiodarone or Fluconazole. These patients are certainly at
high risk of complications from their disease process.
Everyday I'm adjusting my coumadin dose up or down trying to decide when it's safe to stop the full dose Lovenox or venous embolism prophylaxis dose of Arixtra being used for anticoagulant therapy. I see hospitalists and subspecialists everyday ordering bolus doses of coumadin. Published research suggests a bolus coumadin dosing does not improve outcomes but does increase the risk of bleeding complications by statistically significant amounts.
How do I initiate
coumadin dosing
or warfarin dosing as my anticoagulation therapy? After seven years of seeing the horrors of excess anticoagulation therapy on my hospitalized patients as well as my hospital admission patients with their spontaneous subdural hematomas and massive diverticular bleeds, I have adopted a highly conservative approach based on sound evidence and clinical experience when initiating this rat poison who's mechanism of action as a vitamin K antagonist interrupts the synthesis of clotting factors II, VII, IX, and X.
How do I initiate coumadin dosing? The standard starting dose I use is 6 mg for everyone under the age of 50. As far as I know, there is no randomized clinical trial that uses an age based scale for initiating coumadin dosing. All I have is seven years of experience treating thousands of patients. Here is my age based scale for coumadin dosing and warfarin dosing:
Less than 50 years old: 6 mg
Less than 65 years old 5 mg
Less than 70 years old 4 mg
Less than 75 years old 3.5 mg
Less than 80 years old 3 mg
Less than 85 years old 2.5 mg
Less than 90 years old 2 mg
Over 90 years old, I'm not starting it without a compelling reason.
I do not know the data or if there even is any data on prescribing short term or long term anticoagulation therapy in the 90+ year old population. Before I entered my medical school education, I worked as a lab technician for a year at a phase three clinical trial company. Prior to that in fact, I was a patient in a trial as an undergraduate college student. I quit that study because of the incredible amount of pain I experienced with 20 or more blood draws a day from the same site for over a week. And they didn't have a vein light to help the technicians. And I didn't need the money that badly.
It was very clear to me. The only people being studied were young healthy nonsmokers. That's how these drugs clear their clinical trials. There were no 90 year olds getting tested on the pharmacokinetics of warfarin dosing in their age group. All we have are clinical experience and post marketing data. That's as good as it's going to get. And my experience says coumadin dosing in a patient over 90 years old is a recipe for disaster. So I choose not to use it at all, if at all possible, even if the guidelines say I should. Because my experience says the guidelines were not made for the 90 year old body with twelve medical problems. Instead, if the patient had an immobilizing orthpaedic fracture or intervention of their lower extremities I would recommend a prolonged course of subcutaneous Lovenox or Arixtra for their anticoagulation therapy
After age, I next review the patients medication profile. Many medications will interact with warfarin dosing through the cytochrome P450 enzyme system. While recent genetic tests (the Amplichip CYP450 costs $500 and most insurance companies won't pay for it) have become available to check for individual patient response to warfarin dosing metabolism, they are not clinically useful as they are not widely available with quick turn around in a cost effective manner. In other words, by the time I get my patient's genetic coumadin profile, they will already be therapeutic from my clinically determined coumadin dose.
What effect does the cytochrome P450 enzyme system have on coumadin dosing metabolism? Some common drugs (quinolones such as Levaquin or levafloxacin, Cipro or ciprofolxacin, amiodarone, Bactrim, Diflucan or fluconazole, Biaxin or clarithromycin, Flagyl or metronidazole) are inhibitors of the P450 enzyme system (they make the patient require less coumadin dosing).
Some common drugs (Tegretol or carbamazepine, Dilantin or phenytoin, phenobarbitol, rifampin and even tobacco) are stimulators of the P450 enzyme system (they make the patient require more warfarin dosing). Once I have reviewed the patients age and medication profile, I make an approximate 30% adjustment in coumadin dosing (my own estimate) when drug interactions are obvious. I know of no published data other than clinical experience that can guide the clinician hospitalist towards dosing adjustment based on drug-drug interactions.
Once I have adjusted for age and drug interactions, I want to know what the patient's protein status is. Coumadin is highly bound to albumin. As you know, so is calcium, which is why a low calcium level is rarely critical if one had the education, motivation and inclination to calculate the scientifically proven and physiologically accurate corrected calcium level to prevent unnecessary interruptions through meaningless data-through-telephone-transfer-protocols.
Because coumadin is bound to albumin, a low albumin level will mean that the patient requires less coumadin dosing for long term anticoagulation therapy(ICD V58.61) to get to the therapeutic INR of 2-3 for most conditions (atrial fibrillation, DVT prophylaxis, deep venous thrombosis or pulmonary embolism treatment, arterial thrombus of any kind) or an INR 2.5-3.5 for mechanical valve anticoagulation therapy prophylaxis. If the patient's albumin level is really low (less than 2.5) I will cut my coumadin dose in half until I know how the patient responds to their initiating dose.
That means for a healthy 40 year old on no medications I will start the coumadin dosing at 6 mg a day with no bolus dosing. For an 85 year old on amiodarone and an albumin level of 2, I may chose to start warfarin dosing at 1 mg a day until I know how the patient responds.
With all that said, I reiterate that coumadin dosing is absolutely considered a high risk anticoagulation therapy requiring intensive monitoring for toxicity. And with that said, it would qualify as part of the ridiculous CPT® rules our Medicare National Bank has put into place for us to follow.
The same could be said for heparin. If you consider frequent checking of your partial thromboplastin time (PTT) when adjusting your heparin drip to be important, I would certainly consider coumadin dosing to be just as important. I would even consider an intravenous or subcutaneous insulin scale to be justified as intensive drug monitoring for the purposes of
CPT® medical coding. Glucose is the monitored parameter for toxicity and insulin is the drug. Are you checking Dilantin levels as well? That can get toxic real quick. Heck, even adjusting the lasix dose based on the creatinine could be justified as a high risk medication requiring intensive monitoring for toxicity (creatinine and potassium levels).
Coumadin dosing and anticoagulation therapy is one of the major coding tools I use when I accurately document my work performed in order to justify a high level complexity visit in a post operative orthopaedic surgical patient for which I am co-managing their anticoagulation therapy and other chronic diseases.
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