Kidney Disorders: Overview and Management

Kidney Disorders Overview

• Kidney Function: Essential for eliminating metabolic wastes, regulating fluids and electrolytes, and maintaining homeostasis. Dysfunction leads to fluid, electrolyte, and acid-base disturbances.

Chronic Kidney Disease (CKD)

• Definition: Enduring kidney damage or decreased glomerular filtration rate (GFR) for ≥3 months.

• Stages:

  • Stage 1: GFR > 90 (kidney damage, normal)

  • Stage 2: GFR 60-89 (mild decrease)

  • Stage 3: GFR 30-59 (moderate decrease)

  • Stage 4: GFR 15-29 (severe decrease)

  • Stage 5: ESKD (GFR < 15)

• Risk Factors: Diabetes, hypertension, cardiovascular disease, obesity, and certain kidney diseases.

• Complications: Cardiovascular disease is the leading cause of morbidity/mortality.

Acute Kidney Injury (AKI)

• Definition: Rapid loss of renal function, often reversible, but can lead to CKD.

• Classification: RIFLE criteria (Risk, Injury, Failure, Loss, and ESKD).

  • Types:

  • Prerenal: Blood flow issues (e.g., dehydration).

    • result of impaired blood flow that leads to hypoperfusion of the kidney commonly caused by volume depletion (burns, hemorrhage, GI losses), hypotension (sepsis, shock), and obstruction of renal vessels, ultimately leading to a decrease in the GFR.

  • Intrarenal: Damage to kidney tissue (e.g., acute tubular necrosis).

    • This type of damage can result from various factors including nephrotoxic medications, ischemia from prolonged hypotension, or severe infections that affect renal function.

  • Postrenal: Obstruction of urine flow.

    • Postrenal AKI usually results from obstruction distal to the kidney by conditions such as renal calculi, strictures, blood clots, benign prostatic hyperplasia, malignancies, and pregnancy-related anatomical changes, which can all impede urinary excretion and lead to increased pressure within the renal system.

Nephrotic Syndrome

• Characteristics: Increased glomerular permeability resulting in proteinuria, edema, and hyperlipidemia.

• Typical Symptoms: Massive proteinuria (>3.5g/day), hypoalbuminemia, diffuse edema.

• Complications: Increased risk for infections and thromboembolic events.

Treatment & Management

• CKD: Control hypertension, hyperglycemia, and proteinuria; engage patients in self-management.

• AKI: Fluid management, electrolyte monitoring, and possible renal replacement therapy (RRT) if necessary.

• Diuretics and dietary adjustments: For fluid overload and electrolyte imbalances.

• Nutritional Support: High-quality protein, caloric intake, and vitamin supplementation.

Renal Replacement Therapy (RRT)

• Choices: Hemodialysis (HD), Peritoneal Dialysis (PD), and kidney transplantation.

• HD: Removes toxins, fluids; performed thrice weekly.

• PD: Uses peritoneal membrane; suitable for patients intolerant to HD.

Kidney Transplantation

• Indications: Choice for patients with ESKD, offering improved quality of life.

• Post-Transplant Care: Monitor for rejection (e.g., oliguria, edema, weight gain); educate on immunosuppressive therapy.

• Complications: Infections, malignancies, cardiovascular issues.