1 / 74

Electrolyte Abnormalities

Electrolyte Abnormalities. Teresa Lianne Beck, MD Assistant Professor Emory Family Medicine August 4, 2011. Goals. Review of common electrolyte abnormalities Normal ranges Clinical manifestations of hypo- or hyper- states Causes Treatment options. Goals. What will spend time on today…

wesley-doyle
Télécharger la présentation

Electrolyte Abnormalities

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Electrolyte Abnormalities Teresa Lianne Beck, MD Assistant Professor Emory Family Medicine August 4, 2011

  2. Goals • Review of common electrolyte abnormalities • Normal ranges • Clinical manifestations of hypo- or hyper- states • Causes • Treatment options

  3. Goals • What will spend time on today… • Sodium • Potassium • Calcium • Magnesium • Phosphorus

  4. Hyponatremia • Sodium: Normal 135 – 145 mg / dl • Symptoms usually begin <120 mg /dl • Nausea • Lethargy • Muscle cramps • Psychosis • Seizure • Coma • Death

  5. Hyponatremia • Diagnosis based on assessment of serum osmolality and volume status

  6. Hyponatremia • Serum Osmolality • Osmolality (calculated) = 2 (Na) + Gluc / 18 + BUN /2.8

  7. Hyponatremia • Normal Osmolality (280 – 295 mOsm / kg) Isotonic pseudohyponatremia Hyperproteinemia (>10 mg / dl) Hyperlipidemia (severe)

  8. Hyponatremia • High Osmolality (>295 mosm / kg) Hypertonic hyponatremia Hyperglycemia Na: 1.6 mEq / liter decrease per 100 mg/dl increase in glucose Mannitol excess Glycerol therapy Am J Med 1999 Apr;106(4):399-403

  9. Hyponatremia • Low serum osmolality (<280 mOsm / kg) Hypotonic hyponatremia Need to assess volume status next in these patients.

  10. Hypotonic hyponatremia • Hypovolemia • GI losses • Renal losses plus excess water ingestion • Third space losses Tx: Isotonic saline

  11. Hypotonic Hyponatremia • Hypervolemia • CHF • Liver disease • Nephrotic syndrome • CKD Urine Na: < 20 mEq /liter except in CKD Tx: Salt restriction / water restriction / diuretics

  12. Hypotonic Hyponatremia • Isovolemia • Glucocorticoid insufficiency • Hypothyroidism • Psychogenic polydipsia • Medications (amitriptyline / cyclophosphamide / carbamazepine / morphine) • SIADH • Nausea / pain / emotional stress • Diuretic use with potassium depletion

  13. Isovolemic Hypotonic Hyponatremia • SIADH • Syndrome of inappropriate antidiuretic hormone • Hypotonic hyponatremia • Clinical euvolemia • Inappropriately elevated urine osmolality (>200) in face of low serum osmolality • Urine Na >20 mEq / liter • Normal renal function / TSH / cortisol

  14. SIADH • Acute tx • Severe hyponatremia (<110 mEq / liter) • IV lasix • NS with 20 – 40 mEq / liter KCL • Rarely 3% saline will be needed • Chronic tx • Mild hyponatremia • Water restriction to approx 1000 ml / day • Demeclocycline 300 mg PO bid if water restriction not working (contraindicated in liver disease)

  15. SIADH • Chronic treatment (cont) • Vasopressin receptor antagonists • Conivaptan (Vaprisol) IV prep • 20 mg infusion over 30 min, then gtt of 20 mg/24 hrs • Maximum dose 40 mg/24 hrs gtt • Maximum duration is 4 days

  16. Hyponatremia • How fast do we correct it?

  17. Hyponatremia • Treatment principles • Not too fast (pontine myelinolysis) • Symptomatic • Initial 1 - 2 mEq / L / hr x two hours, then • 0.5 mEq / L / hr • Asymptomatic • 0.5 mEq / L / hr • Max in 24 hours: 10 meq total rise • Max in 48 hours: 18 meq total rise Am J Med. 2007 Nov;120(11 Suppl 1):S1-21.

  18. Hypernatremia • Sodium: Normal 135 – 145 mg / dl • Clinical manifestations • Tremors • Irritability • Ataxia • Spasticity • Mental confusion • Seizures • Coma • Death

  19. Hypernatremia • Cause: • Net sodium gain • Net water loss

  20. Hypernatremia • Volume expansion (net sodium gain) • Cause • Hypertonic saline / NaHCO3 administration • Primary hyperaldosteronism • Cushing’s syndrome Tx: Diuretics D5W to replace fluid loss after diuretics

  21. Hypernatremia • Water depletion • Hypotonic fluid losses

  22. Hypovolemic hypernatremia • Treatment • Calculate free water deficit • TBW (liters) = 0.6 x current total body weight (kg) • Desired TBW (liters) = Measured Na (mEq/l) x current TBW / Normal Na • Body water deficit (liters) = Desired TBW – current TBW

  23. Hypovolemic hypernatremia • If hemodynamic compromise, then replace initially with NS • Otherwise use ½ NS or D5W • Aim to decrease Na by 0.5 mEq / liter / hr • Correct one half of the water deficit in 24 hrs • Correct other half over next 24-48 hours

  24. Hypovolemic hypernatremia • Diabetes insipidus Sxs: Polyuria / Polydipsia / Low urine osm • Central • Tumor / Granuloma / Trauma / Surgery • Nephrogenic • Severe hypokalemia / hypercalcemia / CKD / Drugs (lithium / demeclocycline / amphotericin)

  25. Hypovolemic hypernatremia • DI • Differentiation of central and nephrogenic • Trial of water deprivation • Failure to concentrate urine confirms DI • Subsequently given arginine vasopressin • Central DI (urine concentration increases) • Nephrogenic DI (no increase)

  26. Hypovolemic hypernatremia • DI • Treatment • Central • DDAVPP 5-10 mcg intranasally q day / bid • Nephrogenic • Correction of underlying cause if possible • Genetic abnl / lithium / hypercalcemia • Thiazide diuretic / salt restriction can help

  27. Hypokalemia • Normal K level: 3.5 – 5.0 • Clinical manifestations • Fatigue • Cramps • Constipation • Weakness / Paralysis • Paraesthesias • Arrhythmias

  28. Hypokalemia • EKG abnormalites • Flattened T waves • ST depressions • Prominent U waves http://www.merck.com/media/mmpe/figures/MMPE_12END_156_02_eps.gif

  29. Hypokalemia • Causes • Inadequate intake • GI losses • Renal losses • Acid-base shifts • Hypomagnesemia • Hyperaldosterone • Medications (diuretics)

  30. Hypokalemia Treatment • Oral therapy • Mild hypokalemia • Ability to tolerate oral replacement • Increase dietary intake • Potatoes / Bananas • KCl preps (i.e. KDur) • Preps can be used in range 8 – 20 mEq • Monitor K level and adjust dose as needed • Correct cause

  31. Hypokalemia Treatment • IV repletion • Severe hypokalemia • Inability to tolerate oral repletion Max Concentration: 60 mEq / liter Note pain is common at > 40 mEq /liter Rate: 10 mEq / hr (20 mEq / hr with tele) Monitor response and decrease conc / rate as appropriate.

  32. Hyperkalemia • Potassium Normal 3.5 – 5.0 • Elevated potassium level should be evaluated as to the following: • What is the cause? • Is the cause an acute or chronic issue? • Are there accompanying EKG changes?

  33. Hyperkalemia • Symptoms • Usually asymptomatic • Muscle weakness / paralysis • EKG abnormalities • Peaked T waves • ST depression • 1st degree AVB • QRS widening • “Sine wave sign”

  34. Hyperkalemia • EKG changes

  35. Hyperkalemia • Think about the cause • 1. Too much total potassium • Renal disease • Intake increased (rare outside of renal disease) • 2. Shift of potassium from intracellular space to extracellular space • DKA

  36. Hyperkalemia • Does the potassium level make sense in the patient? Pseudohyperkalemia (hemolysis)

  37. Hyperkalemia • When do we treat • Patient assessment • Cause • Chronicity • Degree of potassium elevation • <6.0 Does not need acute invasive tx • >6.0- 6.5 Kayexalate +/- other modalities • >6.5 Consider more acute modalities

  38. Hyperkalemia • Treatment options • Calcium gluconate • NaHCO3 • Regular insulin • Albuterol nebulizer treatment • Kayexalate • Dialysis

  39. Hyperkalemia • Calcium gluconate • IV formulation is 1000 mg / 10 ml (10% soln) • Dose: 10 ml over 2-5 minutes IV with EKG monitoring • Action: Stabilization of cardiac cells. Does not lower potassium. Used for hyperkalemia with EKG changes. • If EKG changes do not immediately resolve, dose can be repeated in 5 minutes.

  40. Hyperkalemia • Calcium gluconate • Precautions • Do not infuse with bicarbonate (precipitation of calcium carbonate) • Do not use routinely with digitalis as hypercalcemia can augment digitalis toxicity. Limit use to patients with widened QRS.

  41. Hyperkalemia • Beta agonist • Albuterol nebulizer treatment • 2-4 ml of 0.5% soln (10-20 mg dose) • Note a usual nebulizer tx for RAD is 2.5 mg • Peak effect in 90 minutes • Epinephrine IV infusion • 0.05 mcg / kg / min IV infusion • Peak effect in 30 minutes • I would be hesitant to use this when an albuterol neb is easy and less risky.

  42. Hyperkalemia • Insulin • Regular insulin 10 units IV plus one D50 Amp over 5 minutes. This will give patient 25 grams of glucose. • Follow this with a D 5 containing IV maintenance fluid for several hours. • Effect within 15 minutes. Peak effect 60 min. Duration 3-4 hours.

  43. Hyperkalemia • NaHCO3 • 1 Amp (44.6 meq) IV over 5 minutes. • Onset: 30 minutes • Duration: 60-120 minutes

  44. Hyperkalemia • Alternate approach to NaHCO3 / Insulin: • Put 2 Amps NaHCO3 in 1 liter D10 W. • Give 300 ml over first 30 minutes, then change to 250 ml / hr until finished. • Give Regular insulin 25 units SQ with starting the IVF.

  45. Hyperkalemia • Kayexalate (Na – K exchange resin) • PO dosing: 15 -30 gram • Can be used as a dry powder • Can be mixed with 60-120 ml of a 20% sorbitol soln to avoid constipation • PR dosing: 50 grams • Mix with 50 ml of 70% sorbitol and 100 ml tap H20 • Retain in rectum x 30 minutes minimum but ideally 2+ hours

  46. Hypocalcemia • Normal Calcium: 8.9 – 10.3 mg/dl • Calcium • 40% bound to albumin • 15% bound to other serum anions • 45% is ionized in serum

  47. Hypocalcemia • Correct for low albumin • 0.8 mg / dl drop in Calcium for every 1 g / dl drop in Albumin • Corr Ca = Meas Ca + (0.8 * (4.5 – Meas Alb))

  48. Hypocalcemia • Clinical signs of low calcium: • Tetany / Carpopedal spasm • Trousseau’s sign • Chvostek’s sign • Lethargy / confusion • Seizures • Heart failure • EKG: Prolonged QT

  49. Hypocalcemia • Treatment of symptomatic cases • Calcium gluconate (10% soln) which contains 100 mg elem calcium / 10 ml. 1. Give two ampules IV over 10 minutes then 2. Add six ampules to 500 ml D5W and infuse at 1 mg / kg / hr

More Related