The Conundrum of Kidney Disease

The Conundrum of Kidney Disease


Assessing the cause and severity of renal abnormalities should be the initial approach to kidney disease for all clinical documentation integrity (CDI) professionals. Hypertension, edema, nausea, or hematuria may be early clinical indicators of kidney disease.

The assessment of kidney disease includes:

  • Determining the duration of the disease
  • Examination of the urine
  • Glomerular filtration rate (GFR) assessment

According to the Association of Clinical Documentation Integrity Specialists (ACDIS)1, “the H&P provides concise information regarding a patient’s history and exam findings at the time of admission, and it outlines the plan for addressing the issues that prompted the admission.”

Discussing specific symptoms and signs related to kidney disease found in the history and physical (H&P) is beneficial and vital when conducting a medical record review. Reviewing the H&P is essential in outlining the plan for addressing the issues that prompted this admission. CDI professionals need to see and compare how the chief complaint contrasts with the diagnosis or how it relates to the principal diagnosis.

Interpreting Underlying Kidney Disease

Conditions and diagnoses need to be supported clinically; if not, a validation query is warranted. Identifying causative factors and relationships among medical conditions is essential in supporting the identification of the principal diagnosis. Furthermore, there is relevant past medical history found in the H&P.

CDI professionals need to review the H&P thoroughly and capture chronic conditions not included in the documentation. Clarifying current symptoms against past medical conditions and determining the true baseline is essential in differentiating between acute kidney injury (AKI) and chronic kidney disease (CKD) or establishing the CKD level.

CDI specialists should place significant emphasis on conditions not supported or no longer supported clinically by making sure to check this information during follow-up reviews. Based on the information found in the record and H&P, some queries might be issued right away, and some might be postponed until further information is available. Diagnostic testing results are essential because queries can be written on them to help rule in or rule out a diagnosis.

Common signs and symptoms of kidney failure may include:

  • Lethargy, seizures, coma
  • Epistaxis
  • Anemia (mucosal pallor)
  • Sallow pigmentation
  • Pruritic excoriations
  • Bruising
  • Amenorrhea, impotence, infertility
  • Myopathy
  • Peripheral neuropathy
  • Frost
  • Red-eye
  • Anorexia, nausea, vomiting
  • Hypertension, pericarditis, heart failure
  • Pleurisy, dyspnea on exercise
  • Nail changes
  • Bone pain
  • Edema

Kidney disease can be acute or chronic. AKI is worsening of kidney function over hours to days, while CKD is the abnormal loss of kidney function over months to years. Clinically, AKI can be conveniently grouped into three primary etiologies: prerenal, renal, and postrenal. The most common causes of AKI include decreased renal blood flow, toxic injury of kidney cells, or extracellular volume depletion. Differentiating between AKI and CKD is important for CDI professionals, and different tests help in this process. For example, oliguria is often observed in AKI, while anemia (low kidney erythropoietin production) might suggest CKD. Small kidney size on ultrasound or other imaging is more consistent with CKD. That’s why it is essential for reviewing the radiology reports and other diagnostics.

Urinalysis or examination of the urine is essential in finding important clues to underlying kidney disease. Anytime there is an abnormal urinalysis that hasn’t been addressed by a provider, a query is warranted. Queries should not be leading in nature and include all the pertinent clinical findings. CDI specialists should look for clinical indicators such as pelvic pain, hematuria, burning sensation when urinating, bacteriuria, flank pain, or fever. Pigmented granular casts (also termed “muddy brown casts”) and renal tubular epithelial cells alone or in casts are hallmarks of acute tubular necrosis (ATN). ATN caused by ischemia is the most common cause of intrarenal AKI. It occurs most often after surgery (40 percent to 50 percent of cases) but is also associated with severe sepsis, obstetric complications, and severe trauma, including severe burns.

It’s important that CDI professionals understand the differences between AKI and ATN to prevent denials and effective appeals.2

CDI professionals should investigate the post-op diagnosis and see if it is different from the pre-op diagnosis. CDI review process should not only focus on the DRG optimization but other aspects as well, such as patient safety indicators, hospital-acquired conditions (HAC), and mortality risk (observed vs. expected metrics). Analyzing healthcare data during the CDI review process by payer, service line, primary diagnosis, or mortalities leads to performance improvement and better healthcare outcomes. Taking a holistic view of all aspects of patient comorbidities is essential in the reporting of quality measures. Furthermore, aligning record reviews to organizational goals is one of the greatest challenges, and that’s why CDI specialists should review all records, regardless of the payer, ensuring documentation integrity across all patient populations.

Impact of Kidney Disease on Reimbursement

Assessing the severity of each condition by assigning the right severity of illness (SOI) and risk of mortality (ROM) will impact the APR-DRG assignment and drive payment and related quality measures. Capturing the true severity of each condition will decrease the mortality risk because it will directly impact the expected cases (by increasing them). The Affordable Care Act included the development of quality reporting and pay for performance programs in all practice settings (including hospitals, outpatient facilities, physician practices, and post-acute care). The Centers for Medicare and Medicaid Services (CMS) hospital and physician Pay for Performance (P4P) programs are a major component of Medicare’s effort to shift healthcare away from fee-for-service reimbursement.

According to the Centers for Medicare and Medicaid Services, there are three Medicare hospital P4P programs and one physician P4P program. Thirty-day mortality rates for acute myocardial infarction (MI), heart failure, pneumonia, and elective total hip arthroplasty (THA)/total knee arthroplasty (TKA) complication rate is included in the clinical care domain of hospital value-based purchasing (VBP). Readmission is formally defined as a patient who is readmitted for any reason to the same or another acute care hospital within 30 days of discharge. The Hospital Readmissions Reduction Program (HRRP) imposes a monetary penalty on hospitals for excess readmissions of Medicare patients 65 years of age, or older admitted initially with any four diagnoses (acute myocardial infarction, heart failure, pneumonia, chronic obstructive pulmonary disorder) or two procedures (coronary artery bypass graft and elective hip or knee replacement).

Reviewing readmissions is one of the goals of the CDI review process, and it also requires understanding your organization’s overall mission and goals. Setting clear goals and merging organizational goals with CDI workflows can be difficult, as it requires access to leadership. Different programs review VBP quality measures by focusing on first diagnosis assignment and other diagnoses reported under the Uniform Hospital Discharge Data Set (UHDDS) that drive risk adjustment on these measures. Furthermore, appropriate reimbursement is dependent on the review’s capture of severity, clinical validation, coding accuracy, medical necessity, and quality outcomes.

The terms renal insufficiency, renal failure, uremia, and azotemia are associated with decreasing renal function but are not specific to kidney function. Furthermore, the term acute kidney injury is preferred to the term acute renal failure as it captures the diverse nature of this syndrome ranging from minimal changes in renal function to complete renal failure. The clinical progression of acute renal failure occurs in three phases: the initiation phase, maintenance phase, and recovery phase. Renal insufficiency is insufficient. Generally, renal insufficiency refers to a decline in renal function to about 25 percent of normal or a GFR of 25 to 30 ml/min. If acute renal insufficiency is documented when the patient is in acute renal failure, we will be missing the severity of illness. Documenting the stage of CKD per KDIGO Guidelines and considering RIFLE (risk, injury, failure, loss of kidney function, and end-stage kidney disease) or AKIN (Acute Kidney Injury Network) criteria for AKI is essential in documenting the condition to the highest accuracy and receiving the right reimbursement.

Analyzing Kidney Function

The GFR provides a useful measure of kidney function at the level of the glomerulus and is important for CDI professionals when reviewing the medical record. Any process that causes loss of nephron (and thus glomerular) mass can cause decreased GFR in patients with kidney disease. GFR is generally accepted as the best overall index of kidney function. Even if it’s not a complication or comorbidity or a major complication or comorbidity, you still need to specify if the patient has CKD because that’s a comorbid condition that does affect morbidity and mortality statistics and risk adjustments. According to National Kidney Foundation, CKD is classified based on the presence or absence of systemic disease and the location within the kidney of observed or presumed pathologic-anatomic findings on kidney biopsy or imaging.

There is no specific treatment for acute renal failure and management principles include:

  • Correcting fluid and electrolyte disturbances
  • Managing blood pressure
  • Treating infections
  • Maintaining nutrition
  • Remembering that drugs or their metabolites are not excreted

The general term dialysis means to separate substances using a permeable membrane. Dialysis is used in the treatment of chronic, end-stage renal failure, as well as in acute renal failure (ARF). Most cases of ARF resolve without requiring dialysis. However, intensively ill patients with ARF have high mortality. Hemofiltration and hemodiafiltration employ extremely high-porosity dialyzers that permit transmembrane filtration of large volumes of plasma ultrafiltrate. Peritoneal dialysis, like hemodialysis, affords gradient-driven solute clearance. The ICD-10-PCS procedure codes for the hemodialysis would be assigned based on the duration of the session or individual sessions of hemodialysis received. Cardiovascular complications occur more frequently with hemodialysis than with other blood purification techniques. Hypotension is the most common complication and its pathology is multifactorial. Hypotension of hemodialysis can be controlled or prevented by the cooling of dialysate, which promotes vasoconstriction and improved myocardial contractility and careful volumetric control of ultrafiltration. Providing care for patients with chronic kidney disease, end-stage renal disease, and for those on dialysis can be complicated. It is important to document Z99.2 (dependence on renal dialysis) for patients on dialysis after also documenting N18.6 (end-stage renal disease). These conditions must be documented together in the medical record.

Renal transplantation is the procedure of choice and the most cost-effective strategy for the management of patients with end-stage renal disease. The great advantage of transplantation is the re-establishment of nearly normal constant body physiology and chemistry. The disadvantage includes bone marrow suppression, susceptibility to infection, cushingoid body habitus, and the physiologic uncertainty of the homograft’s future. Most of the disadvantages of transplantation are related to the medicines given to counteract the rejection. Later problems with transplantation include recurrent disease in the transplanted kidney and an increased incidence of cancer. Code T86.1- should be assigned for documented complications of a kidney transplant, such as transplant failure or rejection or another transplant complication.

The medical review process usually starts with the emergency department documentation and continues to the history and physical, progress notes, query, and follow-up. Many CDI programs began with a goal of DRG optimization. But, this approach could lead to busy clinicians missing comorbidities in the documentation, resulting in an accurate patient classification in the DRG system.

In recent years CDI has evolved, taking a holistic view of all aspects of patient comorbidities, including the impact on reporting of quality measures. Clinical documentation specialists should be focusing on capturing the medical diagnosis to the highest specificity and educating providers on the importance of linking AKI with the underlying etiology. Staging CKD is essential as well because it impacts the severity of illness.

  1. Association of Clinical Documentation Improvement Specialists. “How to Conduct a Medical Record Review.” October 2018.
  2. Wilson, Denise and Karla Hiravi. “Guest post: Understanding the common denial rationale for AKI and ATN.” March, 12, 2019.

National Kidney Foundation. “How to Classify CKD.”

Centers for Medicare and Medicaid Services. Hospital Quality Initiatives Outcomes Measures.


Alba Kuqi, MD, CCS, CDIP, CCDS, CRCR, CICA, is the CDI supervisor at Prime Healthcare. She is an ACDIS Leadership Council member, PHIMA member, and AHIMA Foundation Research Network Volunteer.

Continuing Education Quiz

Review quiz questions and take the quiz based on this article, available online.

  • Quiz ID: Q2039105
  • Expiration Date: May 1, 2021
  • HIM Domain Area: Clinical Data Management