Acute Kidney Injury (AKI) Pathophysiology

Introduction

AKI is also known as acute renal failure.
It occurs when the kidneys are suddenly damaged, often reversibly if treated promptly.
Causes include medications, sepsis, or insufficient blood flow.

Pre-renal Causes:
- Occur before blood reaches the kidneys.
- Examples: sepsis, heart failure, infection, obstructions preventing blood flow.
- Sepsis is a commonly tested topic.
Intrarenal Causes:
- Occur within the kidneys.
- Examples: nephron-damaging medications, kidney infections, internal kidney obstructions.
Post-renal Causes:
- Occur after the kidneys in the urinary system.
- Examples: kidney stones (renal calculi), benign prostatic hypertrophy (BPH), bladder infections.

Onset Phase:
- Blood flow to kidneys decreases, reducing urine output.
- Duration: hours to days.
Oligarch Phase:
- Urine output less than 400 ml/day due to reduced kidney function.
- Waste products (creatinine, urea) increase.
- Duration: 1-2 weeks.
Diuretic Phase:
- Occurs if blood flow improves and damage ceases.
- Increased urine production (4-5 liters/day).
- Duration: 1-2 weeks.
Recovery Phase:
- Urine output normalizes as kidneys heal.
- Full recovery can take months to years.

Check out the Nursing School study checklist for detailed study guidance.
Explore additional resources on sepsis and renal issues through Nursing SOS courses and video series.

Understanding the causes and phases of AKI is crucial for nursing exams and effective patient care.
Continuous learning through available resources is encouraged.