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UASI CDI Monthly Scenario Discussion – Clinical Validation of Acute Kidney Injury

Topic: Clinical Validation of Acute Kidney Injury
H&P: 79 y/o F presents with cloudy urine and labored breathing. Patient has suprapubic catheter draining to bedside bag which was last changed 10 days prior per daughter. Patient started on IV ceftriaxone, IV furosemide, and 1 liter NS bolus. Suprapubic catheter was changed during hospitalization.
PMH: chronic systolic CHF, stage 4/5 CKD, type 2 DM, hypothyroidism, dementia, lung cancer s/p remission s/p lobectomy, and recurrent UTIs with multi-drug resistance (ESBL and MRSA)
Home medications: atorvastatin, carvedilol, vitamin D, divalproex, famotidine, folic acid, glipizide, levothyroxine, mirtazapine, sodium bicarbonate, tramadol, furosemide
Vitals: 147/73, HR 80, RR 20, Temp 98.3 F, SpO2 94% on RA, BMI 19.9
PE: A&O x 1, cooperative with normal mood and affect, breath sounds diminished, + cough and SOB, + dysuria
Labs: WBC 10.6, H/H 9.9/32.0, PLT 244, Na 149, K 5.5, Cr 3.59, GFR 12.4, BNP 44,621, UA showing 1+ glucose, 2+ blood, positive nitrites, 3+ leukocytes, 2+ protein, 31 RBCs, WBCs greater than 182, WBCs clumps 3+, bacteria 4+, 40 squamous epithelial cells, occasional mucus; urine culture showing mixed gram negative and gram-positive flora; Cr trend over hospitalization 3.59, 3.50. 3.17, 3.13, 3.28; GFR 12.4, 11.0, 14.4, 14.6, 13.8
Rad Studies: CXR showing persistent right basilar pleural effusion, Echocardiogram showing systolic function severely reduced, EF estimated at 20-25%, grade 1 diastolic dysfunction
Consult: Cardiology documentation of acute on chronic systolic HFrEF, ID consulted for recurrent UTI, nephrology for CKD
Discharge Summary: Complicated UTI, pleural effusion, CHF exacerbation, AKI superimposed on CKD stage IV, hypernatremia, macrocytic anemia, Type 2 DM with hyperglycemia, dementia w/o behavioral disturbance
Discharge Medication: dronabinol, isosorbide mononitrate ER, pantoprazole, torsemide, and continue home meds

Question: Are there query opportunities based on the scenario stated above?

Discussion: Pt with CKD stage 4/5 admitted with complicated UTI with suprapubic catheter. No documentation of relationship between UTI and suprapubic catheter. There is no documented baseline creatinine/GFR with highest being 3.59/12.4 and lowest being 3.13/14.6.

UASI Recommends:

  • Query for clinical validation of acute kidney injury vs. CKD stage 5 vs acute kidney injury on CKD 5

  • Query for cause and effect relationship between the complicated UTI and the suprapubic catheter

Documentation without clarification:
Principal Diagnosis: Complicated UTI (N39.0)
Secondary Diagnosis: acute on chronic systolic HF (I50.23), hypertensive heart & CKD with HF and stage 1-4/unspecified CKD (I13.0), CKD stage 4 (N18.4), hypernatremia (E87.0), Type 2 DM w/ hyperglycemia (E11.65), macrocytic anemia (D53.9), dementia w/o behavioral disturbance (F03.90), multi drug resistance (Z16.35), and DM with CKD (E11.22) and Long-term use of oral hypoglycemic drugs (Z79.84)
Working DRG: 689 Kidney and urinary tract infections with MCC
RW: 1.1471 GMLOS: 4.8 SOI/ROM: 3/3

Documentation with clarification:
Principal Diagnosis: Infection and inflammatory reaction due to cystostomy catheter, initial encounter (T83.510A)
Secondary Diagnosis: acute on chronic systolic HF (I50.23), UTI (N39.0), AKI (N17.9), hypertensive heart & CKD with HF and stage 1-4/unspecified CKD (I13.0), CKD stage 5 (N18.5), hypernatremia (E87.0), Type 2 DM w/ hyperglycemia (E11.65), macrocytic anemia (D53.9), and dementia w/o behavioral disturbance (F03.90), multi drug resistance (Z16.35), DM with CKD (E11.22) and long-term use of oral hypoglycemic drugs (Z79.84)
Working DRG: 698 Other kidney and urinary tract diagnoses with MCC
RW: 1.6025 GMLOS: 6.1 SOI/ROM: 2/3

CDI Educational Tips:

  • KDIGO Criteria for AKI (criteria applied to patients with and without CKD)
    • Increase in creatinine to greater than or equal 1.5x baseline (historical or measured), which is known or presumed to have occurred within the prior 7 days; (retrospective determination) or
    • Increase in creatinine greater than or equal to 0.3 mg/dl within 48 hours; (prospective determination) or
    • Urine output less than 0.5 ml/kg/hr for 6 hours (urine output determination)
    • When baseline creatinine is unknown, KDIGO advises “The lowest SCr obtained during a hospitalization is usually equal to or greater than the baseline. This SCr should be used to diagnose (and stage) AKI.”
  • A retrospective determination (using 1.5x baseline) of creatinine is used in this case study rather than prospective determination (>0.3 mg/dl within 48 hrs).

Lowest SCr is 3.13, so 1.5 x 3.13 = 4.695. The highest SCr is 3.59 which is lower than 4.695 so the patient does not meet the criteria for AKI. This is demonstrating that this is most likely CKD stage 5 as the lowest SCr is 3.13 and the highest GFR is 14.6 which is under 15. CKD is staged on the stable baseline GFR.

This is a short synopsis of a possible patient record and is not intended to be all inclusive. This is for educational purposes only and not intended to replace your institutional guidelines.