Sections View Full Chapter Figures Tables Videos Full Chapter Figures Tables Videos Supplementary Content ++Table Graphic Jump LocationFavorite Table | Download (.pdf) | PrintConventional unitsConversionSI unitsSodium (Na)136−144 mEq/LmEq/L × 1.0 = mmol/L136−144 mmol/LPotassium (K)3.3−5.0 mEq/LmEq/L × 1.0 = mmol/L3.3−5.0 mmol/LCalcium (Ca) serum8.5−10.5 mg/dL4.25−5.25 mEq/Lmg/dL × 0.25 = mmol/LmEq/L × 0.5 = mmol/L2.1−2.6 mmol/LCalcium (Cai) Ionized4.5−5.3 mg/dL2.25−2.8 mEq/Lmg/dL × 0.25 = mmol/LmEq/L × 0.5 = mmol/L1.12−1.4 mmol/LMagnesium (Mg)1.8−3.0 mg/dL1.5−2.4 mEq/Lmg/dL × 0.411 = mmol/LmEq/L × 0.5 = mmol/L0.74−1.23 mmol/LPhosphate (PO4)2.5−4.5 mg/dLmg/dL × 0.323 = mmol/L0.81−1.45 mmol/L ++Table Graphic Jump LocationFavorite Table | Download (.pdf) | PrintDelay and treatProceed and treatProceed and monitorElective caseEmergent or urgent caseAny case typeAcute changeAcute changeChronic abnormalitySymptomatic patientSymptomatic patientAsymptomatic patientAbnormal ECGAbnormal ECGNormal ECG +++ Perioperative Management ++ Hypernatremia: Na ≥145 mEq/LCritical value: Na ≥ 160 mEq/LCommon causes: Hyperaldosteronism (excess mineralocorticoid), Cushing syndrome (excess glucocorticoid), excessive hypertonic saline or sodium bicarbonate administration, gastrointestinal losses, renal excretion, osmotic diuresis, diabetes insipidusSigns and symptoms: Intense thirst, confusion, irritability, hyperreflexia, lethargy, coma, twitching, seizuresNotes: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 ponsAlways iatrogenicVery high mortalityEarliest symptom is difficulty speaking and swallowingMRI is diagnostic; however, most cases are diagnosed at autopsyGradual increases in Na, even to levels ≥160 mEq/L, are generally well toleratedTreatment: 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 monitoringIf treating acute central diabetes insipidus (DI):Begin vasopressin IV at 2 U/h and titrate to reduce urine output to ≤0.5 mL/kg/hAdminister 0.45% NaCl 1 mL IV for each 1 mL urine outputCaution: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 allIf the abnormality develops rapidly (over hours), the rate of correction can match the rate of acquisition even if it exceeds 0.5 mEq/L/hHyponatremia: Na ≤135 mEq/L:Critical value: Na ≤125 mEq/LCommon 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 ... GET ACCESS TO THIS RESOURCE Sign In Username Error: Please enter User Name Password Error: Please enter Password Forgot Username? Forgot Password? Sign in via OpenAthens Sign in via Shibboleth Get Free Access Through Your Institution Contact your institution's library to ask if they subscribe to McGraw-Hill Medical Products. Access My Subscription GET ACCESS TO THIS RESOURCE Subscription Options Pay Per View Timed Access to all of AccessAnesthesiology 24 Hour $34.95 (USD) Buy Now 48 Hour $54.95 (USD) Buy Now Best Value AccessAnesthesiology Full Site: One-Year Individual Subscription $995 USD Buy Now View All Subscription Options