Prepare your physicians for the new renal disease stages, coordinating codes

As of October 1, 2005, an important ICD-9-CM code will be replaced by a bunch of unfamiliar intruders that will be unwelcome and threatening to some, but a delight and a boon to others.

ICD-9-CM code 585, which has been around since ICD-1, will no longer be an option. There will be no code, as we know it, for chronic renal failure (CRF). In fact, chronic renal insufficiency (CRI) will be hard to find anymore.

Understand the difference
Here’s the issue: The National Kidney Foundation and the physicians who deal with medical kidney disease have proposed a standardized approach to staging of progressive kidney disease. Chronic renal disease, from insufficiency to failure, will hereafter be referred to as chronic kidney disease (CKD).

We’ve struggled to reach all physicians about the difference between CRF and CRI—one is a major condition associated with mortality and morbidity and the other is not even a comorbid condition (CC). Physicians seem to use the terms interchangeably, even on the same patient during the same admission. A nephrologist may even describe a patient with obvious CRF with the term “CRI” until the patient goes on dialysis. Then the nephrologist calls it end-stage renal disease (ESRD).

Coding Clinic has written definitions of the codes 593.9 and 585, stating that the disease is a progression from insufficiency with no or very mild clinical implications, to failure with considerable clinical implications. Consultants have had trouble with this concept.

Set the stage
The changes to ICD-9-CM for 2006 relieve us of this burden by devising a staging system for CKD (see chart below).

CKD is defined as kidney damage, either as confirmed by kidney biopsy or markers of damage, or by glomerular filtration rate (GFR) < 60 mL/min/1.73 m2 for = three months with or without kidney damage.

Yet they consider patients in Stages 1 and 2 as having CKD even if their GFR is higher than 60 mL/minute. GFR is defined as the amount of blood going through all of the nephrons—the tiny units of the cortex of the kidneys that filter the blood and take out water and electrolytes and nitrogenous wastes—per minute.

The greater the amount of exposure of the blood to functioning nephrons, the better the clearing of wastes. If there is inadequate flow through the nephrons, there is a rise in nitrogenous waste levels, as measured by blood urea nitrogen and creatinine.

This is different from acute renal failure. That code (584.9) will remain the same. This is a transient disease caused by a specific disease process, unless there is so much damage to a functioning kidney that it becomes chronic and never heals.

We know that there are five stages of CKD. However, the cooperating parties of ICD-9-CM along with the National Kidney Foundation advisers added a sixth stage by dividing the existing Stage 5 into two segments. They are ESRD patients being treated without dialysis (now 585.5) and those being treated with dialysis (585.6).

There are specific codes for each of the stages, as follows:

• 585.1—CKD, Stage 1
• 585.2—CKD, Stage 2 (mild)
• 585.3—CKD, Stage 3 (moderate)
• 585.4—CKD, Stage 4 (severe)
• 585.5—CKD, Stage 5 (ESRD without dialysis)
• 585.6—CKD, Stage 6 (ESRD on dialysis)
• 585.9—CKD, unspecified

Despite the earlier reference to six stages, there are seven codes on this list. All references to words that have been used describe any stage of chronic renal disease in the past (other than ESRD) will default to 585.9. Yes, CRI is 585.9, and CRF is 585.9. And all seven of these stages are now comorbid conditions.

Great for the hospital, but what about the physicians? We’ve been talking about severity adjustments for years. One physician writes “CRF” and gets 585.9, and another physician writes “CRI” and also gets 585.9. There’s no difference anymore. There’s no way to tell that one patient is sicker than another patient in the absence of a major change in physicians’ documentation routine.

Look at the GFR
There is hope, however. Most authorities consider that the cut-off point to differentiate CRF has been a GFR under 30 mL/min. And a GFR between 30 mL/min. and 60 mL/min. should be consistent with CRI:

• Stage 4 CKD is defined as GFR less than 30 mL/min.—equal to chronic renal failure
• Stage 5 is ESRD not on dialysis
• Stage 6 is ESRD on dialysis

If the patient is on dialysis, coding accurately is a breeze—Stage 6. The problem is telling the difference between Stage 4 and Stage 5 if a nonnephrologist doesn’t know whether to call the patient’s condition ESRD or only CRF.

So if a GFR between 30 mL/min. and 60 mL/min. is CRI, why can’t coders assign 585.3 for documentation of CRI? Because coders will not have access to these GFR limits associated with the codes for coding purposes. We are not supposed to second-guess the physician’s autonomy on these issues.

To address the problem, meet with a nephrologist or an internist who knows about the stages of CKD.

Present the codes and the limitations that documentation has regarding code assignment. Discuss the profiles of the hospitals, the medical staff in general, and the surgeons, intensivists, and infectious disease docs in particular. If there is no coding distinction between CRI and CRF, we have to do something—train the medical staff.

Look online for a GFR calculator. There are several ways to access the free program that has the support of the National Kidney Foundation. This is a program that allows medical personnel to provide the patient’s age, sex, race, and creatinine level. Plug in these factors and you get the GFR. Support staff can do this task as well.

To download the calculator to a hand-held device, go to http://nkdep.nih.gov/professionals/gfr_calculators/gfr_application.htm.

Once the practitioner calculates the GFR, the physician should enter the patient’s precise stage of kidney disease into the chart. It costs nothing, and it’s good medical practice. Anyone with a GFR under 60 mL/min. should receive treatment, anyhow. Those with GFR under 30 mL/min. should be on a comprehensive treatment program.

The codes for hypertensive renal disease are changing as well (403.xx and 404.xx). The descriptions now say with and without CKD, rather than with and without renal failure. But if a patient has hypertensive renal disease, the patient by definition has one of the levels of CKD, so coders should never use the codes for “without CKD.” The “without” codes will probably be deleted in 2006.

Take a look at the poster on p. 11. Discuss this information with the medical staff to start the ball rolling to ensure an easy conversion to CKD stages in October.