Definition : Acute Kidney Injury (AKI) is an abrupt decline in kidney function, leading to retention of waste products, electrolyte imbalance, and fluid dysregulation. It is classified based on etiology and severity. 1. Types of AKI by Etiology Pre-Renal AKI Cause: Decreased renal perfusion without intrinsic kidney damage. Examples: Hypovolemia (dehydration, hemorrhage). Hypotension/shock (sepsis, cardiogenic shock) Heart failure, liver failure Documentation Tip: Specify underlying cause (e.g., “AKI due to hypovolemia from GI bleed”). Intrinsic (Intra-Renal) AKI Cause: Direct damage to kidney tissue. Examples: Acute Tubular Necrosis (ATN\) – ischemia or nephrotoxins Acute Interstitial Nephritis (AIN) – drug-induced, autoimmune Glomerulonephritis Documentation Tip: If ATN or AIN is suspected, document specifically (e.g., “AKI secondary to ATN from contrast exposure”). Post-Renal AKI Cause: Obstruction of urine flow. Examples: Ureteral obstruction (stones, tumors) Bladder outlet obstruction (BPH, neurogenic bladder) Documentation Tip: State the obstructive cause (e.g., “AKI due to bilateral ureteral obstruction from stones”). 2. Diagnostic Criteria (KDIGO) Increase in serum creatinine by ≥ 0.3 mg/dL within 48 hrs, OR Increase in serum creatinine to ≥ 1.5 times baseline within 7 days, OR Urine output < 0.5 mL/kg/hr for 6 hrs 3. Severity Staging Stage 1: 1.5–1.9 × baseline creatinine or ≥ 0.3 mg/dL rise Stage 2: 2.0–2.9 × baseline Stage 3: ≥ 3 × baseline or creatinine ≥ 4.0 mg/dL or dialysis required 4. CDI and Current Coding Guidance Avoid vague terms like “renal insufficiency”; use “acute kidney injury” or “acute renal failure” (interchangeable per coding). Always link AKI to the underlying cause (e.g., sepsis, dehydration, obstruction). If ATN or AIN are present, document explicitly (these are MCCs). Do not abbreviate AKI without context; clarify in the first mention. Trend labs and urine output to support diagnosis before querying. Assign code N17.0, Acute kidney failure with tubular necrosis, with a POA of N for documentation of a patient with AKI on admission who then develops ATN after admission. For a case of acute kidney injury (AKI) due to acute tubular necrosis (ATN) secondary to contrast-induced nephropathy, the correct coding assignment is N17.0 for acute kidney failure with tubular necrosis, N14.11 for contrast-induced nephropathy, and T50.8X5A for adverse effect of diagnostic agents, initial encounter. This combination accurately reflects the underlying cause, the specific kidney injury type, and the adverse effect of the contrast agent. Pro Tip: AKI impacts severity of illness and quality metrics (e.g., PSI-10 Post-Op AKI). Accurate documentation ensures correct DRG assignment and patient safety. References: AHA Coding Clinic, Third Quarter 2025, p. 22 AHA Coding Clinic, Fourth Quarter 2022, p. 33 Centers for Medicare and Medicaid Services. (2025). Official Guidelines for Coding and Reporting. www.cms.gov. Fatehi, P., & Hsu, C-Y. (2024). Evaluation of acute kidney injury among hospitalized adult patients. UpToDate. Palevsky, P. M. (2025). Definition and staging criteria of acute kidney injury in adults. UpToDate. Prescott, L., Manz, J. (2025). The ACDIS Inpatient CDI Pocket Guide. www.acdis.org

CDI Tip: Capturing Firearm Injury Intent from Other Clinicians’ Documentation What’s New in FY 2026? CMS and ICD-10-CM guidelines now allow documentation by clinicians other than the patient’s provider (e.g., nurses, social workers, trauma team) to be used for assigning external cause codes, including firearm injury intent. This change supports more accurate public health reporting and injury surveillance Key Actions for CDI Specialists Review All Clinical Notes Check ED notes, nursing assessments, social work documentation, and EMS reports for statements about firearm injury intent (e.g., accidental, assault, self-harm, undetermined). Apply the New Intent Hierarchy If intent is clearly documented by any clinician, code accordingly: Accidental: W34 series Assault: X93–X95 series Self-harm: X72–X74 series Undetermined: Y22–Y24 series If no intent is documented, follow the updated guideline: default to undetermined intent for firearm injuries (Y24.9), unless otherwise specified. Query When Needed If conflicting documentation exists (e.g., ED note states “possible assault,” nursing note says “accidental”), query the provider for clarification. Document Source When coding based on another clinician’s note, ensure the documentation is clearly attributed in the record. Pro Tip: Incorporate firearm injury intent review into your trauma and ED CDI workflows. Educate providers that intent matters for coding, quality metrics, and injury prevention programs. Example Clinical Scenario with Query: Setting: ED, trauma bay Patient: 28-year-old male with a through and through gunshot wound of the left thigh; hemodynamically stable. Documentation in record: ED triage RN note: “Pt states he was shot by someone outside a bar.” EMS run sheet: “Bystanders report drive by shooting; single GSW to L thigh.” ED SW note: “Patient reports unknown assailant; denies self-harm.” ED provider note: “GSW L thigh; hemorrhage controlled; analgesia given.” Intent not specified in provider note or discharge summary Query: Documentation in the medical record shows that the patient was injured by a firearm. Please clarify the intent of the firearm injury for this encounter, based on your clinical judgment and the medical record. Assault (injury inflicted by another person) Accidental/unintentional Intentional self-harm Undetermined (unable to determine intent from available information) Other (please specify): _______________________

What is ventricular standstill? SA node is functioning, and P waves are present on EKG. There is no ventricular response, no contractions of the muscle. The presence of complete heart block with no escape rhythm. No cardiac output with the patient in full arrest. May be paroxysmal or prolonged.

With the FY 2026 update, ICD-10-CM adds more specificity for egg allergies and reactions — especially distinguishing tolerance vs reactivity to baked egg. Here are the key new (or revised) codes: T-codes (for adverse reactions / anaphylaxis) - These go in Chapter 19: Injury, Poisoning and Certain Other Consequences of External Causes (T66–T78 etc.):

New ICD-10 Codes for Inflammatory Breast Cancer (IBC) – Effective October 1, 2025 As of October 1, 2025, three new ICD-10 codes are now available for use to improve accuracy in reporting Inflammatory Breast Cancer (IBC). Coders should begin applying these codes to ensure precise documentation and compliance with current coding standards. C50.A0 – Malignant inflammatory neoplasm of unspecified breast Used when documentation confirms inflammatory breast cancer (IBC) but does not specify which breast is affected; supports accurate reporting when laterality is not documented. C50.A1 – Malignant inflammatory neoplasm of left breast Identifies confirmed inflammatory breast cancer involving the left breast, allowing precise coding that reflects the disease’s location and aids in treatment tracking. C50.A2 – Malignant inflammatory neoplasm of right breast Used to report inflammatory breast cancer of the right breast, improving data accuracy for diagnosis, outcomes monitoring, and research purposes. IBC is a rare but aggressive form of breast cancer, accounting for approximately 1–5% of cases in the U.S. Unlike typical breast cancers, IBC often presents without a detectable lump. Instead, symptoms include: Skin changes such as redness, swelling, or bruising “Peau d’orange” texture (pitted skin resembling an orange peel) Tenderness or burning sensation Due to its atypical presentation, IBC is frequently misdiagnosed as mastitis and often detected at advanced stages (III or IV). It disproportionately affects women under 40, particularly African American and Black women, and is associated with excess body weight. Previously, providers had limited options for coding IBC, often defaulting to malignancy by site breast cancer codes without specifying type. These new codes will enhance clinical documentation, support better tracking of disease progression, and improve access to appropriate treatment. Thanks to advocacy efforts by the IBC Research Foundation and Susan G. Komen, these updates aim to improve data collection and advance research. Resources for Providers: IBC Scoring System Tool https://www.komen.org/ibc-calculatory-intro/ IBC Provider Guide (PDF) https://www.komen.org/wp-content/uploads/IBC_Guide_082824.pdf

With many states legalizing marijuana, “recreational marijuana use” has been appearing in physician documentation more frequently. Is this coded regularly in the same way that drug abuse and dependence is? The answer is in the coding guidelines for Chapter 5 in Section II.5.b.3 “the codes for unspecified psychoactive substance use (F10.9-, F11.9-, F12.9-, F13.9-, F14.9-,F15.9-, F16.9-, F18.9-, F19.9-)… are to be used only when the psychoactive substance use is associated with a substance related disorder (chapter 5 disorders such as sexual dysfunction, sleep disorder, or a mental or behavioral disorder) or medical condition, and such a relationship is documented by the provider.” This guideline means that merely the documentation of drug/alcohol use alone is not enough to require coding. A good example of when alcohol use would be coded is if a patient has alcoholic cirrhosis and only alcohol use is documented. The alcohol use would be coded since there is an associated medical condition as described in the guideline. Coding clinic 2nd quarter 2018 pg 11 provides further guidance on recreational marijuana use. Coding drug use in a pregnant patient, however, requires different guidelines: Per coding clinic 2nd quarter 2018 pgs 10-11 the drug use complicating pregnancy is coded for any drug use during pregnancy. Per the coding guidelines “It is the provider’s responsibility to state that the condition being treat is not affecting the pregnancy”. Drug use DISORDER is a different diagnosis and is coded differently: Per coding guideline Section II.5.b.1 “mild substance use disorders… are classified to the appropriate codes for substance abuse…and moderate or severe substance use disorders…. are classified to the appropriate codes for substance dependence.” Therefore, we have guidance that if mild drug use disorder is documented we code this as drug abuse, and if moderate or severe drug use disorder is documented we code this as drug dependence. The same applies to alcohol. If drug use disorder is documented without a severity, we cannot assume the severity and a query must be placed. Sources: AHA Coding Clinic for ICD-9-CM and ICD-10-PCS ICD-10-CM Official Guidelines for Coding and Reporting FY 2025