Acute Kidney Injury

  1. Glomerular Filtration
    the movement of fluid and solutes from teh vascular system to the tubular system of the nephron
  2. Glomerular Filtration Rate
    the volume of plasma that can be cleared of a substance within a set time frame
  3. Functions of the kidney
    • Maintain fluid and electrolyte balance
    • Maintains acid-base balance
    • Excretes nitrogeneous end products of protein
    • Activates vitamin D
    • Secretes erythropoietin
    • ESRD pts: chronically anemic bc kidneys and bone marrow can't make more RBCs
  4. 2 types of vitamin D
    • 25, OH (supplements): inactive, used by kidneys; unusable by body
    • 125, OH: active and usable for cells
    • Conversion takes place in kidneys
  5. AKI results in...
    (characteristics)
    • azotemia: retention of BUN and Cr
    • imbalances in fluids and electrolytes
    • acid-base disorders
    • decreased urine output
  6. Prerenal failure
    • a decrease in effective renal perfusion resulting in a decreased GFR and kidney function
    • MAP >70-75 mmHg should be maintained to perfuse kidneys
    • Urine output of at least 25-30ml/hr
  7. Prerenal failure causes
    • Excessive fluid loss: hemorrhage, burns, vomiting, diarrhea, acities
    • Decreased renal perfusion: HF, decreased CO, MI, shock, tumor, vascular obstruction; kidneys one of last organs to get perfusion in emergencies
    • Glomerular arteriole vasodilation or constriction: ACE-inhibitors, NSAIDS, cyclosporine
  8. Intrinsic (intrarenal) renal failure cause
    • Most common: ATN: from ischemia, sepsis, drugs (big)
    • Renal tubular ischemia
    • Nephrotoxicity: from contrast dye (big), antibiotics, NSAIDS, chemicals
    • Rhabdomyolysis: muscle breakdown w/ myoglobin release (urine is dark red, toxic to kidneys)
    • Intratubular obstruction
  9. End result of Intrarenal failure
    • Permanent injury
    • Only thing can do is fix cause and keep from getting worse
  10. Postrenal failure causes
    • Calculi
    • Clots
    • Prostatic hypertrophy
    • Strictures
    • Edema
    • Tumors
    • Obstructed catheter (kinks/clots)
    • Diabetic neuropathy
    • Pregnancy
    • Drugs (narcotics, PCA)
    • Spinal cord injury
  11. Systemic complications of AKI
    • Neuro: decreased alertness (buildup of nitrogeneous wastes, ph issues), drowsiness, seizures (f/e imbalances), coma
    • Cardiac: HTN, dysrythmias, edema
    • Pulmonary: decreased cough reflex (decreased LOC, RR), crackles, infiltrates
    • GI: weight loss (will stop eating bc vomiting), anorexia, N/V, constipation (phosphorus imbalances), diarrhea
  12. Systemic complications of AKI cont.
    • Hematopoietic: anemia (decreased erythropoietin production), fatigue, weakness, platelet function impaired (presence of uremic toxins)
    • Skin: pale, dry, dull, yellow skin, bruising (impaired platelets), pruritis, thin hair, brittle nails
    • Skeletal: disorders r/t decreased calcium absorption, fractures
  13. 2 Principle features of AKI
    Azotemia Oliguria/AnuriaCould be compensatory mechanisms to decreased intravascular blood flow
  14. Lab Trends: BUN
    Increased
  15. Lab Trends: Cr
    Increased
  16. Lad Trends: K+
    Increased
  17. Lab Trends: Ca
    Decreased
  18. Lab Trends: Chloride
    Increased
  19. Lab Trends: Phosphorus
    Increased
  20. Lab Trends: Albumin
    Decreased
  21. Lab Trends: Protein
    Increased
  22. Lab Trends: Creatinine/Urea Clearence
    Decreased
  23. AKI Managment: FVE
    • Diuretic therapy
    • Dialysis
    • Fluid restriction (may allow 1L/day)
    • Monitor for: imbalanced I&O, edema, pulmonary crackles, HTN, weight gain
  24. AKI Management: Catabolic process
    • Protien, Na, K+, and fluid restircted diet
    • High carb, fat, and amino acid diet
    • Dialysis to decrease BUN & Cr
    • Monitor for: weight gain, neuro changes, GI dysfunction, decreased serum protein levels
  25. AKI Management: Electrolyte Imbalance (elevated K+)
    • Administer Kayexylate via oral, gastric, or rectal routes (if doesn't have BM in 4-6hrs, K+ will not be removed)
    • Administer IV sodium bicarb, insulin followed by D5 (prevent hypoglycemia), then hypertonic glucose to move K+ into cells
    • Hemodialysis
    • ECG changes: prolonged QRS, tall, peaked T waves
  26. AKI Management: Electrolyte Imbalance (Met. Acidosis)
    • Sodium bicarb (severe cases)
    • IV or dialysate additive
  27. AKI Management: Electrolyte Imbalance (Na)
    • Limit oral and IV Na
    • Diuretics for hypernatremia (use cautiously)
  28. AKI Management: Infection
    • Strict medical asepsis w/ all invasive lines
    • Antibiotics
    • Monitor for: elecated WBC, fever, positive blood cultures
  29. Intermittent Hemodialysis
    • Filter toxins and excess water from blood
    • Toxins removed by diffusion
    • Fluid removed by ultrafiltration by pressure gradient across semipermeable membrane
  30. When is IHD used?
    • Pts w/ renal failure who were on peritoneal dialysis and got an infection
    • When PD cannot adequately remove wastes
    • More efficient in clearing blood, but more destabilizing
  31. IHD Indications
    • BUN >100
    • Cr >10
    • Hyperkalemia, drug toxicity, met. acidosis, fluid overload, pulmonary edema
    • S/S of uremia: pericarditis, GI bleeding, encephalopathy
    • Contraindications to other forms of dialysis
    • Transfusion rx
  32. Contraindications for IHD
    • Hemodynamic instability (biggest)
    • Coagulopathies
    • Lack of access to circulation
    • Age extremes (children and elderly)
  33. Temporary vascular access
    Dual lumen subclavian or femoral vein catheter (Udall, Quinton, or Tesio)
  34. Permanent vascular access
    Internal arteriovenous (AV) fistula
  35. Continuous Renal therapy indications
    • Need for fluid volume removal in a hemodynacially unstable pt
    • Hypervolemia unresponsive to diuretics
    • MODS
    • Coagulapathies
    • Ease of fluid management
    • PD/HD contraindications
  36. Continuous Renal therapy contraindications
    • Hct >45%
    • Lack of arterial/venous access
  37. Continuous Arteriovenous Hemofiltration (CAVH)
    • Venous and arterial access obtained, fluid and moderate solute removal
    • Driven by pt's BP
  38. Continous Arteriovenous Hemofiltration (CAVH-D)
    • Venous and arterial access obtained
    • Allows for fluid removal plus maximum solute removal
    • Driven by pt's BP
    • Dialysate bag used
  39. Continous Venovenous Hemofiltration (CVVH)
    • Double lumen catheter placed in vein
    • Blood pumped through filter
    • Removes solutes and fluid
  40. Continous Venovenous Hemofiltration Dialysis (CVVH-D)
    • Double lumen catheter placed in vien
    • Blood pumped though a filter
    • Removes solutes and fluid
    • Dialysate bag used
  41. Graft AV fistula
    • Used when surgeon blieves standard AV fistula will not work
    • An artery and vein are joined w/ an artificial substance (bovine graft) or w/ the saphenous or umbilical veins
  42. IHD Nursing Care
    • Monitor of increased risk for bleeding 6hr post HD (on heparin and anticoags)
    • BP q 5-15min
    • HR q 5-15min
    • PCWP q 1-2hrs
    • Respiratory pattern q 1hr
    • Neuro status q 1hr
    • Continous cardiac monitoring
  43. IHD Complications
    • Hypotension: lower HOB, raise feet, slow rate of ultrafiltration, IV volume expanders, vasopressors, blood products
    • Dysrythmias
    • Bleeding
  44. PD Nursing Care
    • Dialyste instilled at body temp
    • Weight pt before 1st and after last exhange
    • Document I&O
    • Restrict fluid intake
    • Monitor, assess, and report changes in VS, LOC
    • Watch and prevent peritonitis
    • Drain if SOB occurs
    • Small feedings to prevent nausea
    • Skin care
    • Tenchoff catheter care: sterile dressing
    • Prevent infection
  45. Peritonitis
    • Rebound tenderness
    • Severe abdominal pain
    • Guarding
    • Distention
    • Cloudy drainage
    • Fever
    • Leukocytosis
    • Change in LOC
Author
chell668
ID
104609
Card Set
Acute Kidney Injury
Description
AKI
Updated