Skip to Main Content

++
Table Graphic Jump Location
Favorite Table | Download (.pdf) | Print
Conventional unitsConversionSI units
Sodium (Na)136−144 mEq/LmEq/L × 1.0 = mmol/L136−144 mmol/L
Potassium (K)3.3−5.0 mEq/LmEq/L × 1.0 = mmol/L3.3−5.0 mmol/L
Calcium (Ca) serum
  • 8.5−10.5 mg/dL
  • 4.25−5.25 mEq/L
  • mg/dL × 0.25 = mmol/L
  • mEq/L × 0.5 = mmol/L
2.1−2.6 mmol/L
Calcium (Cai) Ionized
  • 4.5−5.3 mg/dL
  • 2.25−2.8 mEq/L
  • mg/dL × 0.25 = mmol/L
  • mEq/L × 0.5 = mmol/L
1.12−1.4 mmol/L
Magnesium (Mg)
  • 1.8−3.0 mg/dL
  • 1.5−2.4 mEq/L
  • mg/dL × 0.411 = mmol/L
  • mEq/L × 0.5 = mmol/L
0.74−1.23 mmol/L
Phosphate (PO4)2.5−4.5 mg/dLmg/dL × 0.323 = mmol/L0.81−1.45 mmol/L
++
Table Graphic Jump Location
Favorite Table | Download (.pdf) | Print
Delay and treatProceed and treatProceed and monitor
Elective caseEmergent or urgent caseAny case type
Acute changeAcute changeChronic abnormality
Symptomatic patientSymptomatic patientAsymptomatic patient
Abnormal ECGAbnormal ECGNormal ECG
++

Perioperative Management

++

  • Hypernatremia: Na ≥145 mEq/L
    • Critical value: Na ≥ 160 mEq/L
    • Common causes: Hyperaldosteronism (excess mineralocorticoid), Cushing syndrome (excess glucocorticoid), excessive hypertonic saline or sodium bicarbonate administration, gastrointestinal losses, renal excretion, osmotic diuresis, diabetes insipidus
    • Signs and symptoms: Intense thirst, confusion, irritability, hyperreflexia, lethargy, coma, twitching, seizures
    • Notes:
      • Hypernatremia is always associated with a primary gain in Na or excess loss of water. Diagnosing the etiology hinges on assessment of the patient’s volume status (see Figure 36-1)
      • A rapid rate of rise in Na is associated with worse neurologic outcomes (central pontine myelinolysis):
        • Myelin sheath destruction in pons
        • Always iatrogenic
        • Very high mortality
        • Earliest symptom is difficulty speaking and swallowing
        • MRI is diagnostic; however, most cases are diagnosed at autopsy
      • Gradual increases in Na, even to levels ≥160 mEq/L, are generally well tolerated
    • Treatment: Calculate free water deficit (L) = {([measured Na] − 140)/140} × body weight (in kg) × 0.6 (men) or 0.5 (women)
      • If Na is moderately elevated:
        • Administer H2O enterally provided the gut is functional; otherwise judiciously infuse isosmotic, hyponatremic IV solution (D5W) with close monitoring
      • If treating acute central diabetes insipidus (DI):
        • Begin vasopressin IV at 2 U/h and titrate to reduce urine output to ≤0.5 mL/kg/h
        • Administer 0.45% NaCl 1 mL IV for each 1 mL urine output
    • Caution:
      • A decrease in serum sodium of >0.5 mEq/L/h can lead to cerebral edema. If the patient has elevated ICP, correct hyponatremia very slowly if at all
      • If the abnormality develops rapidly (over hours), the rate of correction can match the rate of acquisition even if it exceeds 0.5 mEq/L/h
  • Hyponatremia: Na ≤135 mEq/L:
    • Critical value: Na ≤125 mEq/L
    • Common causes: Burns, sweating, vomiting, diarrhea, pancreatitis, diuretics, salt-wasting nephropathy, cerebral salt wasting, mineralocorticoid deficiency (Addison’s disease), congestive cardiac failure, cirrhosis with ascites, nephrotic syndrome, chronic renal failure, syndrome of inappropriate antidiuretic hormone secretion (SIADH), hypothyroidism, hypopituitarism (glucocorticoid deficiency), primary polydipsia, iatrogenic (excessive administration of parenteral hypotonic ...

Want remote access to your institution's subscription?

Sign in to your MyAccess profile while you are actively authenticated on this site via your institution (you will be able to verify this by looking at the top right corner of the screen - if you see your institution's name, you are authenticated). Once logged in to your MyAccess profile, you will be able to access your institution's subscription for 90 days from any location. You must be logged in while authenticated at least once every 90 days to maintain this remote access.

Ok

About MyAccess

If your institution subscribes to this resource, and you don't have a MyAccess profile, please contact your library's reference desk for information on how to gain access to this resource from off-campus.

Subscription Options

AccessAnesthesiology Full Site: One-Year Subscription

Connect to the full suite of AccessAnesthesiology content and resources including procedural videos, interactive self-assessment, real-life cases, 20+ textbooks, and more

$995 USD
Buy Now

Pay Per View: Timed Access to all of AccessAnesthesiology

24 Hour Subscription $34.95

Buy Now

48 Hour Subscription $54.95

Buy Now

Pop-up div Successfully Displayed

This div only appears when the trigger link is hovered over. Otherwise it is hidden from view.