Kidney Disease: Structures and Functions

Kidney Disease: Structures and Functions

• Healthy kidneys remove waste products from the body
• Healthy kidneys are responsible for waste excretion.
• Waste builds up in the body when the kidneys are not functioning correctly.
• Excess fluid retention may occur if kidneys are malfunctioning
• Uremia is the kidney's inability to filter waste products from the blood
• Normal kidney function involves excreting medications
• Medications can build up in the bloodstream, leading to toxicity if the kidneys don't work as they should.
• Medication adjustments might be needed
• Kidneys actively maintain potassium homeostasis
• Hyperkalemia occurs when the kidneys malfunction. This can lead to arrhythmias.
• Dialysis patients are at risk for hyperkalemia
• Erythropoietin which effects red blood cell production can be impacted in kidney malfuction causing anemia
• Erythropoietin is needed for RBC production
• Low erythropoietin results in low RBCs
• Kidneys that don't function properly cannot remove insulin
• Early signs and symptoms of kidney malfuction include hypoglycemia, followed by hyperglycemia
• Administering insulin to patients with low blood sugars, when malfunction is evident, will result in more adding up
• The RAAS system becomes activated when the kidneys need more renin support to balance BP and fluids
• The heart can become strained from pushing for more blood production with constant RAAS activation
• A kidney needing stable blood pressure and fluid balance doesn't care about the state of the heart
• The kidney is responsible for producing active vitamin D and if it malfunctions, there is no active vitamin D
• Active Vitamin D is needed for adequate calcium and phosphorus balance, and bone health.
• Hyperparathyroidism, bone pain, weak bones, hypocalcemia, and hyperphosphatemia can occur when the kidney is not able to produce active Vitamin D

Gerontological Considerations

• Reduced blood flow to the kidneys leads to a decreased baseline in renal function
• Younger adults have an expected GFR greater than or equal to 90
• Older adults have an expected GFR greater than or equal to 60
• There is a decrease in bladder capacity from 450mL to 350mL with aging
• Older patients typically have an urge to pee more frequently.
• Nocturia, while considered age-related, should prompt heart failure screening to r/o fluid volume overload

Acute Glomerulonephritis

• It is sudden inflammation (antigen-antibody reaction) of the glomeruli, which are responsible for removing waste.
• Acute Glomerulonephritis is caused by infection or autoimmune disease (Lupus)
• It can lead to end-stage renal disease (ESRD)
• Risk factors are beta-hemolytic streptococcal infection (strep throat) and autoimmune diseases, or IV drug use that leads to strep
• Beta-hemolytic streptococcal manifests at tonsillitis or pharyngitis
• Strep from IV drug use goes into the bloodstream, then the heart, and then the kidneys
• Autoimmune diseases like SLE (Lupus) and RA trigger it
• Clinical manifestations include hematuria, oliguria, or anorexia
• Hematuria means blood in urine
• Oliguria means decreased urine
• Anuria means no urine output and sign of kidneys shutting down
• Proteinuria means excess protein in the urine, and it will be foamy
• Other clinical manifestations are dysuria, bilateral lower extremity edema, nausea, fatigue, and weight gain
• Dysuria is painful urination.
• Azotemia occurs as BUN increases since kidneys can't get rid of urea
• Other clinical manifestations of Acute Glomerulonephritis include fatigue, headache, hypertension, low-grade fever, and lethargy
• Anemia occurs as erythropoietin decreases, resulting in decreased H&H
• Flank and or abdominal pain is assessed with blunt percussion.

Kidney Diagnostics

• Elevated labs include BUN, creatinine, ESR, serum lipids, potassium, and phosphate
• Decreased labs include GFR, albumin, and calcium
• A positive ANA (antinuclear antibodies) shows an increase with autoimmune flare-ups.
• A positive ASO (antistreptolysin-O) titer confirms strep throat
• Hematuria, proteinuria, and RBCs in the urine are elements found during testing.
• Sediment, which looks like fine sand, contains cells, casts, crystals, or bacteria and tells us if the patient has a UTI, kidney stones, or kidney disease
• Casts are cylindrical structures in kidney tubules, where presence means kidney disease or damage.
• A kidney biopsy shows kidney damage, inflammation, scarring, or glomerular disease

Collaborative Care

• Drug therapy includes PCN or erythromycin for streptococcal infection, corticosteroids for inflammation, and ACE inhibitors and ARBs for elevated blood pressure
• Nursing interventions include bed rest and monitoring for fluid and electrolyte imbalances
• Monitor for decreased calcium, indicative of arrhythmias
• Emphasize fluid restrictions and daily weights for patients with fluid volume overload
• A high-calorie, low-protein, low-sodium diet is recommended
• Low protein helps give the kidneys a break.
• Low sodium helps reduce fluid retention.

Chronic Glomerulonephritis

• Progressive destruction of the glomeruli with eventual sclerosis in the kidneys
• It is seen with a kidney biopsy, and damage is permanent
• Clinical manifestations include persistent N/V, changes in mentation, pruritis, fatigue, and muscle cramps
• Fluid volume overload s/s: SOB, peripheral edema, and ascites are other manifestations

Drug Therapy

• Loop diuretics (Furosemide) are used and change position slowly
• Corticosteroids reduce swelling and suppress the immune system, avoid large crowds, and practice hand hygiene
• Hydralazine, Calcium Channel Blockers, and ACE Inhibitors are used for hypertension and arrhythmias

Urinary Diversion

• Is performed with patients who have bladder cancer
• It is a restructuring of the bladder and surrounding GU components to reroute urinary flow through a stoma and into a pouch

Ileal Conduit

• Uses a small intestine section to make a tube that connects ureters to a stoma or the intestines and directs urine out of the rectum
• Can be done without a stoma and provides relatively good urine flow
• Disadvantages include incontinence and needing a bag if a stoma is created
• Special considerations include postoperative complications; reabsorption of urea by the ileum and needing meticulous stoma care

Cutaneous Ureterostomy

• Brings the ureters to the abdomen's surface to form a stoma, and urine is collected in a pouch
• Isn't a major surgery; however, a stoma is made, therefore, needing a bag
• Periodic catheterizations may be needed to dilate stomas for patency

Nephrostomy

• Two thin, flexible tubes are placed into each kidney to drain urine directly into collection bags outside the body
• Not a major surgery, but is at high risk for renal infection, with a predisposition to calculus due to the catheter
• The nurse needs to empty and flush the tubes and monitor for flank pain; the nephrostomy tube may need to be changed every month
• Never clamp the tube
• Collaborative care and post-op care is level of comfort with stoma
• Assess stoma color: Pink=good, pale/white/ purple/ black= strangulation
• Consult with wound ostomy and continence nurses [WOCN]
• Encourage fluid intake to establish output
• Person should report cloudy or foul-smelling output= urine infection.
• Abdominal discomfort, pain, or pressure
• Never clamp nephrostomy tube: it needs to be open to gravity or the urine will back up. We need to flush the nephrostomy tube

Acute Kidney Injury

• It is an abrupt decrease in renal function that is reversible, and the underlying cause is treated and the AKI resolves
• Baseline kidney function can be restored with treatment.
• Never the primary dx, it is always caused by something else: E.g.
  • Vancomycin toxicity: Intrarenal
  • Rhabdomyolysis: Intrarenal
  • Heart Failure exacerbation: Prerenal
  • Severe dehydration: Prerenal
  • Hydroureter and hydronephrosis: Postrenal
  • Prerenal AKI causes Definition and cause
  • Def: Is volume depletion and reduction of blood flow to the kidneys
  • Cause: d/t ischemia and Injury e.g. stabbed/shot, blood loss, or atherosclerosis of renal artery.
• Intrarenal AKI (aka intrinsic AKI) causes Definition and cause
  • Results from direct damage to the kidneys when substances or pathogens get inside the kidney
  • Causes include Methotrexate, Vancomycin, Ketorolac, Strep throat infection, Autoimmune system
• Postrenal AKI causes Definition and cause
  • Results from the mechanical obstruction of urine outflow
  • Causes are kidney stones that get into the ureter and scar tissue obstructing ureters
• Clinical manifestations
  • There are two phases include Oliguric phase:
    • First there is a decrease in urine output, Urine output of 100-400 mL/24 hrs, and fluid volume overload
    • Generalized edema
    • Metabolic acidosis
    • Presence of casts, RBCs, WBCs in Urine
    • Increased Urine Specific gravity: how heavy the urine is.
    • Confusion, fatigue, agitation, coma

Labs

• Increased: K+ (Hyperkalemia), Mg2+ (hypermagnesemia), PO43- (hyperphosphatemia), BUN, Creatinine, and WBC
• Decreased: Na+ (hyponatremia), Ca2+ (hypocalcemia), and Hematocrit

Diuretic Phase:

• Up to 5L/day of urine output which is an insane amount of output, pt. is reestablishing kidney function. Normal Kidney function is reestablished
• Loss of electrolytes K+, Mg2+, Ca2+
• Low BUN, which then goes back to normal
• Low specific gravity: less Casts, RBCs, WBCs in urine

Recovery Phase:

• Baseline urine output; Complete recovery may take up to 12 months according to ATI. In real life: 2-6 weeks +

Diagnostics Studies:

• Urinalysis: positive for crystalluria with renal calculi and crystals/chips are seen in urinalysis
• KUB: abdominal X-Ray
• Kidney Ultrasound
• Kidney CT scan without contrast: REMEMBER contrast is nephrotoxic.
• MRI
• Cystoscopy: The camera goes from the bladder to the ureters to visualize where the stone is.

Collaborative Care:

• Therapeutic procedure: Dialysis is a treatment that cleans your blood when your kidneys are not able to function.

Drug therapy:

• IV insulin and IV Glucose Treats Hyperkalemia. The process is to D50 into IV w/ IV insulin to push the K+ back into the cells and drop K+.
• IV sodium bicarbonate
• IV calcium gluconate
• PO or PR sodium polystyrene sulfonate
• Give D/T low calcium, this replaces it. Remember to push slowly
  • When K+ is not too high but should go back down. It takes time to work.
  • Binds to phosphate so it comes out.
  • Give subQ to stimulate RBC production and elevate H&H

Chronic Kidney Disease (CKD)

• Progressive irreversible loss of kidney function: GFR
• GFR60 mL/min - Leading causes of Diabetes, Uncontrolled or unmanaged HTN
• Clinical Manifestations: Uremic Frost: urea crystal accumulation. s/s of end-stage renal disease
  • Collaborative Care:
    • Therapeutic Procedures includes Dialysis and kidney transplants.
  • Drug Therapy: to Manage hyperkalemia with dialysis

Therapeutic Procedures

• Dialysis and Kidney transplant

Drug Therapy:

• Manage hyperkalemia with dialysis
• Manage hypertension and hyperlipidemia with hydralazine
• Phosphate binders
• Calcium supplementation with TUMS
• Vitamin D supplementation
• Iron and folic acid supplementation
• Epoetin alfa: for RBC production via subQ injection

Nursing Interventions:

• Avoid nephrotoxic drugs: NSAIDs, vanco, methotrexate, digoxin, cyclosporine, and memormin.
• Monitor for digoxin toxicity
• Monitor BP when taking sodium polystyrene (kayexalate). Can elevate BP
• Avoid administering antacids with magnesium due to compromised renal clearance of this electrolyte (risk for hypermagnesemia).

Renal Replacement Therapy (RRT)

• Decreased deep tendon reflex
• Renal replacement therapy (RRT): Dialysis
  • Peritoneal dialysis (PD)
  • Intermittent hemodialysis (HD)
    • Continuous renal replacement therapy (CRRT)
      • Is carried out in critical care settings do to the risk of severe hemodynamic instability and hypovolemic shock and is done over 24 hr period (SLOWLY). - Movement of fluid and molecules across a semi-permeable membrane Hemodialysis
• Is required for vascular access: AV fistula is created to accommodate higher volume flow: - AV Fistula: Artery and vein are combined for flow. - AV Graft:

Vessels:

• Catheter brings flow together with external vessel. Cath Types:
• Tunneling Hickman:* Is under the skin
• Non-Tunneling Quinton:* No subQ Tunnel, not under skin Assess and hold medications Assess for bruit and thrill of fistula/graf catheter patency; Hold medications like anithypertensives and and anithypertensives and anibiotics The anibiotics, if given, should be redosed post the dialysis

Continually monitor pts BP for:

• Hypovolemic shock pts; report the persons volume output and electrolyte K
• Be mindful of know K , since it can kill the patient and we want to know know the volume: 3L is a general and ideal volume to aim for

Peritoneal Dialysis

• Is performed by The catheter inserted through the anterior abdominal wall. Dialysis is suspended above the pt. and goes into the peritoneum
• Average time spent spent in dialysis is roughly 4 hours

Patient considerations:

• The abdomen will swell and as a result, gets bigger since fluid is getting added. Then, there is pull it out, or the patients should reposition to relieve pressure and the abdomen. At this time, if there, is an increased resistance, reposiions may be needed.
  • The expected average for output should be greater than what was put in.
• The patients oumlow should be clear and yellow. NEVER anything pink/red (blood), green (bile), Brown/ black (stool), or cloudy (infection) - Dialysis is perfoemd every night

Knowns with Dialysis

• PRO: longer life expectancy than hemodialysis pts at (15-20 years). Hemodialysis pts usually die from sepsis Phases include
  • Inflow-
  • Dwell Time (4-6 hrs)-
  • Drain-

Complications include Exit Site infection, Hypotension, Bleeding, Hernias or lower back pain pts, increased in abdominal pressure, Dyspnea and/or increased respiratory effort and Bowel and Bladder Perforation

• Supplies for dialysis: consist of a new dressing, a new anchor, and new tubes