Patients with acute kidney injury, most recently treated solely in the hospital environment, are now making their way back into freestanding dialysis clinics.

But the clinical transition is still a work in progress. Renal associations made a point at their annual meetings this year to include talks on the transition of an AKI patient from the hospital to treatment in an outpatient setting. Questions were raised about ongoing treatment and recovery, as well as payment issues and regulations.

A better approach to acute kidney injury

Legislation was approved in 2015, initially tagged on as a rider to the trade agreement (Section 808 of the Trade Preferences Extension Act of 2015), and the law took effect  January 1, 2017.  This new law allows outpatient dialysis providers to treat Medicare patients with AKI and to bill for this care.

While there is as yet no change to the ESRD regulations used by state surveyors, the reimbursement side of CMS has indicated that dialysis providers will be allowed to bill for more than three treatments per week if needed, without medical justification.  The reimbursement side has also made it clear that additional laboratory tests or pharmaceuticals necessary for the care of an AKI patient may be billed outside the dialysis composite rate, as well as other treatment-related expenses AKI patients may incur.

As for physicians, because these patients do not have end-stage renal disease, nephrologists will use hospital codes for billing instead of receiving the monthly capitated rate (the Renal Physicians Association recommends E&M codes 90935/90937 for nephrology services provided during dialysis. Code 90935 is used to report inpatient HD or outpatient HD performed on non-ESRD patients; 90937 can be used to cover two visits during the same dialysis session).

CMS defines an AKI patient in these regulations as “an individual who has acute loss of renal function and does not receive renal dialysis services for which payment is made under (the ESRD program).” The new benefit does not provide Medicare coverage for any patient diagnosed with AKI.  This benefit only applies to those AKI patients who are already Medicare eligible (e.g., due to age or disability).

The new law, which had been sought by the kidney community for a number of years, can be characterized as a win-win for CMS and dialysis providers: the government will be able to reduce the high cost of keeping AKI patients in the hospital, and outpatient clinics can offer more expertise in kidney treatment.

But providers must be aware that AKI patients on dialysis need special care. As noted by the Renal Physicians Association in a statement released last year:

“AKI-D (AKI requiring dialysis) patients are by definition in a transitory state, heading toward either renal recovery or ESRD, with weak predictive markers and no finite time frame to a decision point,” noted the Renal Physicians Association in a statement about the condition. “In addition, many AKI-D patients are recovering from critical illness and multi-organ system failure; the functioning of various non-renal organs is also in transition, and their overall clinical care needs are substantial.

“They require close monitoring to determine if renal recovery is developing, to avoid nephrotoxic medications and diagnostic studies, and to assure that as renal and other organ functions change, the necessary adjustments in medications, nutrition and clinical care are continuously implemented,” the RPA wrote in the statement.

It is also true that issues important for quality care among ESRD patients may not be the same for AKI patients.

“Clinical quality-of-care measures that are well vetted for the ESRD population (e.g. avoiding dialysis catheters) may not be applicable to the AKI-D population,” the RPA wrote. “A reassessment of clinical, regulatory and economic aspects of outpatient dialysis services for AKI-D patients may be valuable to assure that these critical services are tailored to the unique characteristics and needs of this special population.”

In 2015, the Acute Disease Quality Initiative of the Kidney Disease—Improving Global Outcomes (KDIGO) released a consensus statement on defining and treating AKI. The report authors estimated that AKI, defined as “an abrupt decrease in kidney function that occurs over a period of 7 days or less,” occurs in about 20–200 per million population in the community, impacting 7-18% of patients in the hospital, and approximately 50% of patients admitted to the intensive care unit.

An estimated two million people worldwide die of AKI every year, the authors reported.

Understanding acute kidney injury

Causes for AKI can vary; not all patients will be good candidates for outpatient care because of the intensity of the illness. Acute kidney injury has three main causes:

  • Sepsis
  • Hypovolemia, hypoperfusion
  • Nephrotoxic injury

“It’s rarely a single event or etiology,” noted Mary Schira, PhD, RN, ACNP-BC, during a panel discussion on AKI patients at the Annual Dialysis Conference earlier this year. “Think of AKI as a syndrome. Understanding the cause can matter.”

Type, frequency of acute kidney injury

Schira gave ADC attendees a picture of when AKI occurs and statistics regarding recovery (see graphic).

There are several types of AKI, Schira noted.

  • Pre-renal (about 35% of patients) signaled by a loss of perfusion
  • Intra-renal (about 50% of patients), known as acute interstitial nephritis, or kidney poisoning
  • Post-renal (about 10%), from obstruction between the kidney and the urethra

Determining recovery can be difficult. “There is ‘no magic wand’ to determine how/when/if kidney function will return,” said Schira. “The only biomarker we really have is creatinine.”

Promoting renal recovery in acute kidney injury patients

The majority of people with AKI  recover in about three months.

To promote renal recovery, the dialysis team should:

  • avoid nephrotoxins
  • avoid hypotension
  • frequently reassess dry weight (don’t “over dry” the patient and hurt renal recovery)
  • monitor urine output
  • check labs frequently
  • adjust medications based on improvement in renal function

Even with such guidelines, the outpatient dialysis staff will have a learning curve when treating AKI patients. What most renal teams focus on with outpatient care––anemia management, metabolic bone disease, and vascular access management–– don’t apply to these AKI patients, said Schira. The key is not to look at AKI as another definition of chronic kidney disease.

“AKI and CKD patients are not the same,” noted Schria. “You cannot treat them the same.”

Reimbursement, monitoring for acute kidney injury

Here are basic payment rules and CPT codes for billing AKI services on an outpatient basis.

  • Applied base payment rate: $231.55 (after adjusted for wage index)
  • ESRD network payment share: not applicable for AKI patients
  • Allowed “exceptional” charges, including non-routine medications and no limit on the number of treatments/week.
  • Physician services can be billed separately
  • Additional lab tests are expected for monitoring kidney health
  • Immunizations are covered
  • Patients are not included in performance scoring for the Quality Incentive Program

AKI billing codes that will be accepted by CMS include the following:

  • A specific condition code (TOB 72X, Condition Code 84 (dialysis for AKI)
  • An AKI diagnosis
  • An appropriate revenue code
  • An appropriate Common Procedural Terminology code

Diagnosis codes for acute kidney injury

  • N17.0 Acute kidney failure with tubular necrosis
  • N17.1 Acute kidney failure acute cortical necrosis
  • N17.2 Acute kidney failure with medullary necrosis
  • N17.8 Other acute kidney failure
  • N17.9 Acute kidney failure, unspecified
  • T79.5XXa Traumatic anuria, initial encounter
  • T79.5XXD Traumatic anuria, subsequent encounter
  • T79.5XXS Traumatic anuria, sequela
  • N99.0 Post procedural (acute) (chronic) renal failure

Revenue codes for acute kidney injury

Code for modality of dialysis furnished:

  • 082X: In-center HD
  • 083X: PD: outpatient or home (in-center PD allowed only for AKI patients)
  • 084X: CAPD
  • 085X: CCPD
  • G0491: “Dialysis procedure at a Medicare certified ESRD facility for AKI without ESRD”
  • G0491: “Dialysis Acute Kidney Injury with no ESRD”