Page 1871 - Saunders Comprehensive Review For NCLEX-RN

Acute Kidney Injury: Phases and Laboratory
Findings

Onset

▪ Begins with precipitating event

Oliguric Phase

▪ Elevated blood urea nitrogen (BUN) and serum creatinine levels
▪ Decreased urine specific gravity (prerenal causes) or normal (intrarenal causes)
▪ Decreased glomerular filtration rate (GFR) and creatinine clearance
▪ Hyperkalemia
▪ Normal or decreased serum sodium level
▪ Hypervolemia
▪ Hypocalcemia
▪ Hyperphosphatemia

Diuretic Phase

▪ Gradual decline in BUN and serum creatinine levels, but still elevated
▪ Continued low creatinine clearance with improving GFR
▪ Hypokalemia

▪ Hyponatremia
▪ Hypovolemia

Recovery Phase (Convalescent)

▪ Increased GFR
▪ Stabilization or continual decline in BUN and serum creatinine levels toward
normal
▪ Complete recovery (may take 1 to 2 years)

Table 54-2

Progression of Chronic Kidney Disease
Stage of CKD Estimated GFR
At risk; normal kidney function (early kidney disease may or may not be present) > 90 mL/min
Mild CKD 60-89 mL/min
Moderate CKD 30-59 mL/min
Severe CKD 15-29 mL/min
ESRD < 15 mL/min
CKD, Chronic kidney disease; ESRD, end-stage renal disease; GFR, glomerular filtration rate.

Data from Ignatavicius D, Workman ML: Medical-surgical nursing: patient-centered

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