Acute Kidney Injury Flashcards
Definition of AKI
Abrupt loss of kidney function that results in the retention of BUN, creatinine, and metabolic wastes normally excreted (Replaces acute renal insufficiency)
Classification of AKI & UOP: Anuric
<50mL urine/24 hours
-Patients with CKD, shock, bilateral urinary tract obstruction, bilateral renal artery obstruction
Classification of AKI & UOP: Oliguric
-<500mL/24 hours
-More likely to have acute tubular necrosis
Classification of AKI & UOP: Non-oliguric
> 500ml/24 hours
AKI Hx & ROS
-Fatigue, infectious symptoms
-oral/nasal ulcers, vision changes
-edema, weight gain/loss, HF hx, recent hypotension, chest pain
-SOB, Cough, sputum production
-intake amount, n/v, appetite, diarrhea, liver disease hx
-urine color, output amount, dysuria, stone hx, urgency/hesitancy, frequency
-Itching
-cramping, myalgia, arthralgia, trauma
-Confusion, asterixis, mental status changes, LOC changes, headaches, seizures
-Anemia, bleeding
–Rashes, fevers.
-Ask about any new OTC and prescribed meds?
-Any contrast administration?
-any chronic comorbid conditions-DM, HTN, stones, recurrent UTIs, vascular disease, cancer?
AKI Physical Exam
-Htn or HOtn
-ulcerations: ent
-Elevated JVP, S3 or S4 sounds, pericardial friction rub, peripheral edema
-Crackles, signs of pleural effusions, o2 requirements, pink frothy sputum
-ascites
-enlarged prostate, bladder distention,
-Rashes, poor skin turgor, itch marks,
-cramping, weakness
-asterixis, altered LOC,
-signs of bleeding, petechial rash
Prerenal AKI
-Sudden and severe drop in BP (shock), or interruption of blood flow to the kidneys from severe injury or illness
Intrarenal AKI
Direct damage to the kidneys by inflammation, toxins, drugs, infection, or reduced blood supply
-Medication induced (abx, nsaids, PPI)-fever, rash, athralgia, hematuria-allergic interstitial nephritis
-ATN
-Acute glomerulonephritis
Post renal AKI
-Sudden obstruction of urine flow due to enlarged prostate, kidney stones, bladder, tumor, or injury
Types of acute renal failure
-ATN-Leading
-prerenal
-Acute renal failure, chronic renal failure
-Urinary tract obstruction
-glomerulonephritis or vasculitis
-atheroemboli
-acute interstitial nephritis
Acute Tubular Necrosis
-intrarenal or intrinsic causes
-nephrotic exposure
-Abx, contrast, chemo, myeloma, uric acid, tumor lysis syndrome
Acute Glomerulonephritis
-Intrarenal
-inflammation and damage to glomeruli
-autoimmune causes (lupus, IGA, goodpasture, nephropathy)
-vasculitis (polyarteritis, wegners)
-infectious causes (strep, endocarditis, HIV, HEP B/C
Initial eval & dx
-Electrolytes-mag, phos, Ca
-ABG
-CXR-Volume overload
-Baseline creatinine level, BUN, bicarbonate
-+/- ultrasound
-Post void residual
Creatinine
-Byproduct derived from the metabolism of creatine in skeletal muscle and from dietary meat
-Affected by age, gender, race, muscle mass, protein intake
-12–24-hour lag behind of kidney damage
-Small increase in creatinine level may represent larger decrease in GFR
Cystatin C
-Measurement of kidney function
-less influenced by muscle mass or diet
-results affected by inflammation and atherosclerosis
-Expensive
-Estimates still being studied on age, race, and gender
Stage 1 of AKI
-Increase in SCr by by ≥0.3 mg/dL
-or ≥1.5 - <2.0 x baseline
-UOP: Less than 0.5 mL/kg per hour for more than 6 hours
Stage 2 of AKI
-Increase in SCr by ≥2.0 - <3.0 times baseline
-UOP: Less than 0.5 mL/kg per hour for more than 12 hours
Stage 3 AKI
-Increase in SCr by ≥3.0 times baseline
-Less than 0.3 mL/kg per hour for 24 hours or anuria for 12 hours
GFR in CKD
-Normal kidney function – GFR above 90mL/min/1.73m2 without proteinuria
1) CKD1 – GFR above 90mL/min/1.73m2 with evidence of kidney damage
2) CKD2 (Mild) – GFR of 60 to 89 mL/min/1.73m2 with evidence of kidney damage
3) CKD3 (Moderate) – GFR of 30 to 59 mL/min/1.73m2
4) CKD4 (Severe) – GFR of 15 to 29 mL/min/1.73m2
5) CKD5 Kidney failure - GFR less than 15 mL/min/1.73m2 or on dialysis, however many patients in CKD5 are not yet on dialysis.
