AKI note 2 24

Definition

  • KDIGO criteria
  • creatinine can be affected by medication, secretion, muscle mass
  • generation of creatinine lower in septic states
  • volume resuscitation can dull change in GFR

Causes

  • Sepsis: most common cause in ICU
  • cardiac surgery: 2nd most common cause
  • acute liver failure, acetaminophen toxicity
  • intra-abdominal HTN: decreased perfusion
  • hepatorenal syndrome
  • malignancy
  • cardiorenal syndrome

Indications for dialysis

  • urea > 150
  • iHD: mostly does not require heparin during iHD inpatient unless at risk of clotting
    • outpatient: IV heparin during dialysis due to micro clots
  • dialysis disequilibrium syndrome: urea removal too quickly
  • CRRT: not good for ingestions because slower
  • hybrid treatment
    • SLED: intermittent HD 6 hour treatment. Slower iHD
    • prolonged intermittent renal replacement therapy: a longer dialysis 8-12 hours treatment
  • PD can be acute by surgically place PD catheter

Hyponatremia

  1. is it dangerous: give 3% Na
  2. know if it's true hyponatremia (serum osm)
    • hypo-osmolar: true
    • isoosmolar: interfering substance such as TG, IVIG, protein. Check whole blood Na
    • hyper-osmolar (osm > 310): mannitol, hyperglycemia
  3. decide volume status

SIADH

  • rule out hypothyroidism, adrenal insufficiency
  • causes:
    • uncontrolled pain, nausea
    • SSRI, AED's, anti neoplastics
    • ecstasy: increase ADH secretion
    • SCC
    • COPD
    • diuretics (thiazides)
  • diagnosis: low serum Na, high urine Na, high urine osm
  • treatment: fluid restriction
    • 1L very little fluid
    • how much urine is water vs electrolytes
    • 3% if severe or pt NPO
    • salt tabs
    • Ure-Na, palatable urea: makes BUN go up and kidney have osmotic diuresis

Osmotic demylelination syndrome

  • over correct Na
  • quadriplegia, mentation changes, dysphagia/dysarthria
  • diagnose with MRI
  • correction: 6-10 mEq/day is ok, more 6
  • potassium repletion contributes to increase in Na
  • pt very dehydrated will have high ADH and will self correct when ADH stimulus shut off, easy to over correct (when urine output starts to go up)
  • If over correction: re under correct
    • DDAVP (1-2 mcg subq/IV q8h)
    • D5
    • vaptans
    • sometimes give DDAVP/3% together

Hypernatremia

  • most common cause is pt not able to communicate free water loss
  • vent/trach: high insensible loss
  • hyperglycemia: (glucose - 100) x 1.6 + measured Na
  • correction: replace free water + urinary loss + insensible loss

DI

  • central, nephrogenic
  • drug induced (lithium)
  • gestational (degrade vasopressin by vasopressinase by placenta)
  • diagnosis

    • 4L output per day

    • low urine osm, ± hypernatremia
    • water deprivation test
      • complete: doesn't change urine osm
      • partial: changes some
    • trial of DDAVP