Burn Unit Electrolyte Replacement

Original Date: 01/2022
Purpose: To standardize the electrolyte monitoring and replacement of patients in the burn unit.

Exclusions

  • Renal failure (acute or chronic)
    • Ongoing continuous renal replacement therapy (CRRT) or intermittent hemodialysis (iHD)
    • Creatinine clearance <20 mL/minute
  • Patients with cardiac arrhythmias who need more aggressive electrolyte repletion
  • Patients at risk for acute kidney injury
    • Rhabdomyolysis with ongoing resuscitation

Frequency of Phosphorous, Magnesium, and Ionized Calcium Labs

  • Burn intensive care unit
    • Active resuscitation – check all with each scheduled lab draw and replete as needed
    • Stable ICU patients – check Monday, Wednesday, and Friday
  • Burn intermediate unit
    • Check Monday, Wednesday, and Friday
  • Burn floor
    • Check Monday and Friday

*If a patient has required consistent replacement of one, check daily as needed until levels are stable.*

Potassium Replacement

  • Review serum phosphorus level prior to potassium replacement.
  • If serum phosphorous level is greater than 2.5 mg/dL, replete potassium with potassium chloride (KCl):
    Potassium level Replacement Re-check level
    3.4-3.5 mEq/L 40 mEq KCl PO/IV (PO preferred)

    • 40 mEq KCL PO x 1
    • 20 mEq KCL IV x 2 doses
    		 With next set of morning labs
    3.0-3.3 mEq/L 60 mEq KCl PO/IV (PO preferred)

    • 20 mEq KCL PO x 3 doses
    • 20 mEq KCL IV x 3 doses
    		 With next set of morning labs
    <3.0 mEq/L 80 mEq KCL PO/IV (PO preferred)

    • 40 mEq KCL PO x 2 doses
    • 20 mEq KCL IV x 4 doses
    		 Immediately and with next set of AM labs
  • If serum phosphorous level is less than 2.5 mg/dL, replete serum potassium with potassium phosphate (KPhos)
    • Intravenous KCl:
      • Central venous access: infuse at 20 mEq/hour
      • Peripheral venous access: infuse at 10 mEq/hour

Phosphorous Replacement

  • Review serum potassium level prior to phosphorous replacement.
  • If serum potassium is <4.0 mEq/L, use potassium phosphate
  • If serum potassium is ≥4.0 mEq/L, use sodium phosphate
    Formulations Phosphorous Potassium Sodium
    Potassium phosphate (Kphos) (IV) 3 mmol/mL 4.4 mEq/mL –
    Phos-Nak packet (PO) 8 mmol 7.1 mEq 6.9 mEq
    Sodium phosphate (NaPhos) (IV) 3 mmol/mL – 4 mEq/mL
    Serum phosphorous level Replacement Re-check level
    2.0-2.5 mg/dL If potassium <4.0 mEq/L:

    – Phos-Nak 2 packets PO q4 hours x 3 doses (48 mmol phosphorous, 42.6 mEq potassium), or

    – 15 mmol KPhos (has 22 mEq potassium)

    If potassium ≥ 4.0 mEq/L:

    – 15 mmol NaPhos

    		 With next set of morning labs
    1.6-1.9 mg/dL If potassium <4.0 mEq/L:

    – Phos-NaK 2 packets PO q4 hours x 4 doses (64 mmol phosphorous, 56.8 mEq potassium), or

    – 30 mmol KPhos (has 44 mEq potassium)

    If potassium ≥ 4.0 mEq/L:

    – 30 mmol NaPhos

    		 With next set of morning labs
    <1.6 mg/dL If potassium <4.0 mEq/L:

    – 45 mmol KPhos (has 66 mEq potassium)

    If potassium ≥ 4.0 mEq/L:

    – 45 mmol NaPhos

    		 6 hours after replacement and with next set of morning labs
  • IV phosphorous replacement are diluted in normal saline by default; they can be ordered in D5W if desired

Magnesium Replacement

  • Magnesium replacement is done with magnesium sulfate
    Magnesium level Replacement Re-check level
    1.5-1.9 mg/dL -2 grams IV q2 hours times 2 doses

    -Each 2 gram dose is infused over 2 hours

    		 No indication to re-check
    1.0-1.4 mg/dL -2 grams IV q2 hours times 3 doses

    -Each 2 gram dose is infused over 2 hours

    		 No indication to re-check
    <1.0 mg/dL -2 grams IV q2 hours times 4 doses

    -Each 2 gram dose is infused over 2 hours

    		 With next set of morning labs

Calcium Replacement

  • Replete calcium based upon an ionized calcium level using intravenous calcium gluconate.
    Ionized Calcium level Replacement Re-check level
    0.8-0.9 mmol/L 1 gram calcium gluconate IV No indication to re-check
    <0.8 mmol/L 2 grams calcium gluconate IV With next set of morning labs