Lewis ch. 51: acute and chronic kidney disease

acute kidney injury (AKI)

rapid loss of kidney function with increase in creatinine, BUN, and K and decreased urine output, potentially reversible

azotemia

accumulation of nitrogenous waste products in blood

prerenal AKI

type of AKI caused by decreased blood flow to kidneys, leads to oliguria, caused by shock, severe dehydration, heart failure, low cardiac output, and hypovolemia

intrarenal AKI

type of AKI caused by direct damage to kidney tissue, caused by acute tubular necrosis, prolonged ischemia, nephrotoxins (drugs, contrast media), increased Hgb from hemolyzed cells, increased myoglobin, and kidney diseases

postrenal AKI

type of AKI that deals with mechanical obstruction of urine outflow, causes reflux of urine into renal pelvis which can lead to hydronephrosis, caused by BPH, prostate cancer, calculi, trauma, and extrarenal tumors

risk, injury, failure, loss, end stage renal disease

RIFLE

creatinine

what is the best indicator of AKI?

GFR

what is the best indicator of CKD?

oliguric phase

first phase of AKI where urine output is <400mL/day, lasts 10-14 days, 50% of patients have normal urine output making diagnosis difficult

manifestations: retention→ fluid volume excess (distended neck veins, bounding pulse, edema, HTN), metabolic acidosis, hyponatremia, hyperkalemia, anemia due to decreased EPO, high BUN and creatinine level, seizures, coma, difficulty concentrating

diuretic phase

2nd phase of AKI where urine output is 1-3L/day (can be up to 5 L), lasts 1-3 weeks, monitor for hypovolemia, hypokalemia, hypotension, hyponatremia, and dehydration

recovery phase

last phase of AKI that begins when GFR increases, lasts up to 12 months, can progress to ESRD if it continues to progress

chronic kidney disease (CKD)

progressive, irreversible loss of kidney function, risk factors include old age, HTN, obesity, and diabetes, diagnosed when GFR <60 for 3+ months, has 5 stages

<15

GFR for ESRD

manifestations of CKD

uremia, fluid retention as disease progresses, increased BUN and creatinine, hyperkalemia, Na imbalance, hypocalcemia, low vitamin D, hypermagnesemia, hyperphosphatemia, metabolic acidosis, anemia, increased bleeding, increased risk of infection CV disease, HTN, dysrhythmias, Kussmauls (compensatory), CKD-BMD, pruritus, uremic frost, uremic fetor, n/v, gastroparesis, constipation, stomatitis, dyslipidemia