Hyperkalemia

Hyperkalemia – Mengyao Tang, Amanda Morrison

Background

  • Causes: excessive intake (iatrogenic, supplementation), insufficient loss (CKD, AKI, type IV RTA, adrenal insufficiency, intracellular release or shifts (rhabdo, TLS, acidosis)
  • Medication-related: ACEi, ARB, MRA, NSAIDs, TMP/SMX, digoxin, heparin
  • “Pseudo”: hemolysis, severe leukocytosis, hand exercises w/ tourniquet on during labdraw
  • Can be asymptomatic, or develop parasthesias, hyporeflexia, muscle weakness, GI upset

 

Evaluation

  • Confirm it is real: check for hemolysis, repeat BMP
  • Check EKG for hyperkalemic changes
      • K+ 5.5-6.5:  peaked T waves, prolonged PR interval
      • K+ 6.5-8: prolonged QRS, loss of P wave, ST elevation, ectopic beats
      • K+ >8: sine wave pattern, asystole, PEA, VF
  • To establish cause once confirmed:
      • Labs: CBC with diff, UA, urine electrolytes, Mg, VBG
        • Also consider LDH, haptoglobin, uric acid, CK
      • Imaging: bladder scan, renal ultrasound

 

Management

  • If there are EKG changes
      • Calcium gluconate 1g IV (effective within 3-5 min)
        • Stabilizes cardiac membrane for ~60mins
        • SHOULD BE REPEATED HOURLY while Hyperkalemic
  • Correct acidosis: Can use NaHCO3 dosed based on bicarb deficit
  • Shift K+ Intracellularly
      • D50 w/ regular insulin 10 units (can order using Adult Hyperkalemia order set in epic)
        • Consider using 5 units if there is renal impairment
        • Lasts for 4-6hrs (can be longer in renal impairment)
      • Beta Agonists (e.g. high-dose albuterol nebulizer); lasts 2-4 hrs
  • Increase K+ Excretion
      • Loop diuretic (e.g. lasix)
        • If there is AKI or a volume deficit can administer with IVF (Don’t dry out an already dry patient! Sometimes a dry patient only needs fluids to start kaliuresis)
        • Kayexalate 60g PO q2h until bowel movement (If using oral, ensure patient is having bowel movements and is not obstructed, could cause bowel injury/ necrosis)
          • PO can take up to 2hrs to work
          • Strongly consider per rectal administration for quicker onset of action or if unable to tolerate PO
            • DO NOT GIVE WITH SORBITOL per rectum
  • Hemodialysis
      • Can correct K+ rapidly but will take time to set up, especially if pt does not have access
      • Consult nephrology early if severe hyper K+ or concerned that pt will not respond