Kidneys

KIDNEYS: WHAT DO THEY DO?

• Filters waste and excess substances such as urea, uric acid, and toxins from the blood

• Controls how much water is excreted in the urine

• Regulates the body’s fluid balance

• Regulates body’s pH by excreting acids or bases in urine

• Filters electrolytes from the blood to retain or excrete them

WHAT LABS DO WE LOOK AT?

• Blood Urea Nitrogen (BUN)

• Serum Creatinine: 0.6-1.2

• Glomerular Filtration Rate (GFR)

• Urinalysis

• Electrolytes: sodium, potassium, chloride, bicarbonate

• Arterial Blood Gas (ABG)

DIAGNOSTICS

• Ultrasonography: obstruction, size of ureters

• CT scan / MRI

• X-ray

• MAG3 Renal Scan

GLOMERULONEPHRITIS

What is it?

• GLOMERULONEPHRITIS: Inflammation of glomerulus

  • Proteins, WBCs, RBCs can spill into urine

  • Can lead to nephrotic syndrome

• Causes

  • Infections

  • Autoimmune

  • Chronic illnesses

  • Toxins or vascular disease

SYMPTOMS

• Blood in the urine

• Protein in the urine

• Edema

• Hypertension

• Flank pain

• Decreased urine output

Complications

• Acute Kidney Injury (AKI)

• Chronic Kidney Disease (CKD)

• Rapid progression can lead to requiring dialysis

TREATMENT

• Rest

• Sodium and fluid restrictions

• Diuretics

• Hypertensive medications

• Antibiotics

• Dialysis if severe

ACUTE KIDNEY INJURY (AKI)

• Kidneys suddenly lose their ability to filter blood, causing waste products to build up in the body

  • Sudden = few hours to days

  • Affects many body systems

  • Potentially reversible

  • AKI = Acute Kidney Injury

PHASES OF AKI

• Initiating Phase: Injury occurs; phase ends when symptoms start

• Oliguric Phase: Very little urine produced (<400\ \mathrm{mL/day}); swelling and electrolyte problems occur

• Diuretic Phase: Lots of dilute urine; risk of dehydration and electrolyte loss

• Recovery Phase: Kidney slowly heals; may take up to 1\ \mathrm{year}

WHAT CAUSES AKI?

• PRE-RENAL: Indirect damage before the kidneys

• INTRARENAL: Damage to structures inside the kidneys

• POST-RENAL: Damage after the kidneys

AKI SIGNS AND SYMPTOMS

• Oliguria or anuria

• Azotemia: the accumulation of nitrogenous waste products in the blood, which can indicate impaired kidney function.

• Fluid volume overload: Crackles, dependent or generalized edema, decreased oxygenation, confusion, increased respiratory rate, dyspnea

• Hypoperfusion and hypoxemia: 90/40\ \mathrm{mmHg}

TREATMENT OF AKI

• Treat the cause!

• Assess patient fluid status: intake and output; daily weights

• IV fluids or diuretics (depends on the cause)

• Avoid exposure to nephrotoxic agents

• Nutritionist will establish a diet with specified amounts of protein

• Balance out electrolytes, particularly potassium

• Dialysis

CHRONIC KIDNEY DISEASE (CKD)

• Kidneys gradually lose their ability to filter blood, causing waste products to build up in the body

  • Gradual = months to years

  • Affects every body system

  • Progressive, irreversible

• Major causes:

  • Hypertension

  • Diabetes mellitus

  • Autoimmune disease

  • Glomerulonephritis

CKD SIGNS AND SYMPTOMS

• Oliguria or anuria

• Azotemia

• Uremia

• Uremic syndrome

• Anemia

• Fluid volume overload: Crackles, dependent or generalized edema, decreased oxygenation, confusion, increased respiratory rate, dyspnea

• Cardiac changes

• Bone problems

• 180/120\ \mathrm{mmHg} (severe hypertension)

TREATMENT OF CKD

• Lifestyle modifications:

  • Dietary changes

  • Maintain a healthy weight

  • Exercise

  • Avoid smoking and alcohol

• Controlling diabetes and hypertension

• Other medications:

  • Diuretics

  • Phosphate binders

  • Calcium and Vitamin D

• Dialysis to remove toxins and excess fluid from the blood

• Kidney Transplant

RENAL REPLACEMENT THERAPY (RRT)

• Purpose: Acts as the kidneys when the kidneys are not working properly; Removes waste and extra fluid from the blood to correct electrolyte imbalances

• Indications:

  • Symptomatic uremia

  • Increased potassium levels

  • Severe metabolic acidosis

  • Fluid overload

  • Drug or alcohol intoxication

• Forms of dialysis:

  • Intermittent

  • Continuous

RRT ACCESS

• AV fistula

• AV graft

• Central venous catheter

• Mixed arteriovenous blood flow concepts (illustrative diagram elements show connections between fistula, graft, and dialysis machines)

• Synthetic bridge graft

• From dialysis machine to dialysis machine (diagrammatic language)

• Vein and artery connections; Right atrium involvement in some configurations

AV ACCESS COMPLICATIONS

• Blood clots

• Infection

• Aneurysms

• Ischemia

• Heart failure

PERITONEAL DIALYSIS

• Types: Continuous ambulatory PD; Automated PD

• Completed at home

• Diffusion and osmosis: Fill, dwell, drain

• Complications:

  • Peritonitis

  • Pain

  • Insufficient outflow

  • Changes in outflow

HEMODIALYSIS

• Intermittent

• Delivered over 4 hours, 3 days a week

• Completed at the bedside or dialysis unit

• Uses diffusion to remove waste and fluid

• Creates shifts of fluid and electrolytes

CONTINUOUS (CRRT)

• Continuous

• Delivered over 24\ \mathrm{hours}

• Completed in the ICU

• Uses ultrafiltration via a filter: Blood is passed through a filter to remove waste and fluid

HD & CRRT COMPLICATIONS & CARE

• Complications:

  • Hypotension

  • Dialysis disequilibrium syndrome

  • Cardiac events

  • Reactions to dialyzers

  • Bleeding

  • Hypoglycemia

• Care:

  • Closely monitor patient

  • Vital signs

  • Daily weights

  • Bleeding

KIDNEY TRANSPLANTATION

• Treats end-stage kidney disease

• Various donors

• Preoperative Care:

  • Immunologic studies

  • Dialysis and Blood transfusion required within 24 hours of surgery

• Procedure:

  • New kidney placed in the right or left anterior iliac fossa

  • Easier connection of ureter and renal artery/vein

  • Failed kidney is not removed

POSTOPERATIVE CARE

• Daily weights

• Frequent assessment of vital signs

• Assess intake and output

COMPLICATIONS

• Rejection

• Ischemia

• Thrombosis

• Renal artery stenosis

• Infection

NOTE

• NSAIDS, antibiotics, contrast, chemo - nephrotoxicity