1. Critical Electrolyte problems in the Er
LMHER
Prepared by Dr. Shane Barclay

2. Goals
Learn the signs and symptoms of critical electrolyte problems in the ER.
Know how to treat critical electrolyte values.

3. Why worry about electrolytes?
Many cardiac emergencies are related to or associated with electrolyte abnormalities.
These abnormalities can lead to cardiac arrest.

4. Topics
Potassium (K)
Sodium (Na)
Magnesium (Mg)
Calcium (Ca)

5. Topics
Potassium (K)
Sodium (Na)
Magnesium (Mg)
Calcium (Ca)

6. Potassium
The potassium gradient across cell membranes determines nerve and muscle excitability. Thus K levels can have devastating consequences if not recognized and treated.

7. Hyperkalemia
Hyperkalemia is defined as K > 5 mmol Critical Hyperkalemia is defined as K > 7 mmol/L

8. Hyperkalemia - Causes
Chronic Renal Failure – the most common cause. Diabetic Ketoacidosis Chemotherapy causing tumor lysis Rhabdomyolysis Hemolysis Hypoaldosteronism (Addison’s) Medications (diuretics, ACEI, NSAIDS, K supplements, beta-blockers)

9. Hyperkalemia - signs and symptoms
Weakness
Respiratory failure,
ECG – peaked T waves, Wide QRS, flattened P waves (these are not always present!)

10. Hyperkalemia -Treatment
Moderate hyperkalemia (K 6 – 7 mmol/L) - 10 units regular insulin in 25 g glucose (50 ml D50) and give IV over minutes.

11. Hyperkalemia -Treatment
Severe hyperkalemia (K > 7 mmol/L) - Calcium Gluconate 1000 mg (10 ml of 10%solution) IV over 10 – 20 minutes - Sodium Bicarbonate 50 mEq IV over 5 minutes units regular insulin in 25 g glucose(50 ml D50) and give IV over minutes. - then Kayexalate enema g plus sorbitol PO

12. Hypokalemia
Hypokalemia is defined as K < 3.5 mmol/L Critical Hypokalemia is defined as K < 2.5 mmol/L or Arrhythmias are present

13. Hypokalemia - causes
Gastrointestinal loss – diarrhea. The most common cause. Renal loss – K depleting diuretics, severe hyperglycemia… Malnutrition.

14. Hypokalemia – signs and symptoms
Weakness, fatigue Paralysis Respiratory distress Constipation Leg cramps ECG – T wave flattening, Ventricular arrhythmias, PEA.

15. Hypokalemia – treatment
For Critical Hypokalemia: Potassium 10 – 20 mEq/hour with ECG monitoring If cardiac arrest due to hypokalemia: Potassium 10 mEq IV over 5 minutes

16. Topics
Potassium (K)
Sodium (Na)
Magnesium (Mg)
Calcium (Ca)

17. Sodium - N a
Sodium controls serum osmolality. Sodium concentration and osmolality equilibrate across the vascular membrane in both the intravascular and interstitial spaces. Thus an acute rise in Na will produce a shift of free water from the interstitium to the vascular space. An acute fall in Na will shift free water from the vascular space into the interstitium. This may cause cerebral edema

18. Sodium - N a
Rapid correction of Hyponatremia has been associated with development of pontine myelinolysis and cerebral bleeding. Thus careful neurological monitoring is needed when correcting both hypo and hypernatremia.

19. Hypernatremia
Hypernatremia is defined as Na > 145 – 150 mmol/L (Normal 135 – 150 mmol/L) Causes: Increase Na (Cushing’s syndrome, hyperaldosteronism, excess hypertonic saline or Na Bicarb administration) Loss of free water – GI loss, renal excretion. Symptoms: altered mental status, weakness, irritability, focal neurological deficits, coma or seizures.

20. Hypernatremia treatment
Reduce ongoing water losses.
Normal saline or D5 ½ normal saline.

21. Hyponatremia
Defined as Na < 130 mmol/L Causes: Reduced excretion of water by kidney with continued water intake or Loss of sodium caused by: Thiazide diuretics Renal Failure Vomiting SIADH CHF, Cirrhosis with ascites Hypothyroidism Adrenal insufficiency

22. Hyponatremia
Unless hyponatremia is acute or severe, it is usually asymptomatic. If acute or Na < 120 mmol/L nausea, vomiting headache irritability lethargy seizures coma

23. Hyponatremia Treatment
If asymptomatic – fluid restriction by 50-60% maintenance fluid requirement. Can add loop diuretics. If severe chronic hyponatremia with mild/moderate symptoms: - slow infusion of 50 ml 3% saline at ml/hour often with desmopressin 1 -2 mcg iv or sc every 8 hours. Do not use desmopressin in psychotic patients, CHF, cirrhosis or SIADH Worth calling Internal medicine or nephrology!

24. Hyponatremia Treatment
If neurological compromise/symptomatic (ie seizure) 100 ml bolus of 3% hypertonic saline IV immediately. This will usually raise Na by 2 -3 mmol/L If neurological symptoms (ie seizure) continue, bolus again. Then treat as prior slide for severe, asymptomatic hyponatremia

25. Topics
Potassium (K)
Sodium (Na)
Magnesium (Mg)
Calcium (Ca)

26. Magnesium
Mg is involved in movement of sodium, potassium and calcium into and out of cells. It also stabilizes excitable membranes. Mg balance is closely tied to potassium, calcium and sodium levels in the body.

27. Hypermagnesemia
Defined as Mg > 1.05 mmol/L (Normal 0.65 – 1.05 mmol/L) Causes: Renal failure Symptoms: Mild/Mod: Muscle weakness, paralysis, ataxia, drowsiness Severe: lowered consciousness, bradycardia, arrhythmia, hypoventilation, cardiorespiratory arrest.

28. Hypermagnesemia Treatment
Calcium: this removes Mg from the serum. Calcium Chloride 500 – 1000 mg IV (prefer central line) or Calcium gluconate 1500 – 3000 mg IV Dialysis is the treatment of choice for severe hyperMg.

29. Hypomagnesemia
Much more common than hypermagnesemia Defined as Mg < 0.65 mmol/L (normal0.65 – 1.05 mmol/L) Causes: decreased absorption increased loss via kidneys or GI tract. medications/other: diuretics, alcohol

30. Hypomagnesemia
HypoMg interferes with parathyroid hormone, thus causing hypocalcemia (and sometimes hypokalemia) Symptoms: muscular tremors, ocular nystagmus, tetany, | altered mental status, ataxia, vertigo, seizures and arrhythmia (torsade de pointes)

31. Hypomagnesemia Treatment
Severe or symptomatic: MgSO4 1-2 g IV over 5 – 60 minutes. For Torsade de pointes/cardiac arrest: MgSO4 1-2 g IV push over 5 minutes. For Seizures: MgSO4 2 g IV over 10 minutes Administer Calcium as most HypoMg patients are hypocalcemic

32. Topics
Potassium (K)
Sodium (Na)
Magnesium (Mg)
Calcium (Ca)

33. Calcium
Most abundant mineral in the body. Essential in enzymatic reactions, muscle contraction, cardiac contractility and platelet aggregation. Calcium concentration is normally regulated by parathyroid hormone and vitamin D. Half of Ca is bound to serum albumin.

34. Calcium
Calcium antagonizes both potassium and magnesium at the cell membranes. Thus calcium is extremely useful for treating both hyperkalemia and hypermagnesemia.

35. Hypercalcemia
Defined as Ca+ > 3 mmol/L (normal 2.1 – 2.5 mmol/L) Causes: 90% causes are primary hyperparathyroidism and malignancy.

36. Hypercalcemia
Symptoms: usually develop when Ca > 3.1 mmol/L (Normal 2.1 – 2.5 mmol/L) Depression, weakness, fatigue, confusion Hallucinations, hypotonicity, seizures and coma. GI: dysphagia, constipation, peptic ulcer, pancreatitis. Cardiac: (Ca > 3.1 mmol/L) – QT shortens, PR & QRS prolonged. (Ca > 3.6 mmol/L) – AV block, cardiac arrest.

37. Hypercalcemia Treatment
Required if symptomatic or if Ca level > 3 mmol/L Treatment is to restore intravascular volume and promote Ca excretion. Infuse 0.9% saline at 300 – 500 ml/h until any fluid deficit is replaced. Monitor Mg and K as diuresis can reduce these electrolytes.

38. Hypocalcemia
Defined as Ca < 2.1 mmol/L Causes: toxic shock syndrome, abnormalities of Mg, after thyroid surgery and tumor lysis syndrome.

39. Hypocalcemia
Symptoms: paresthesia, muscle cramps, stridor, tetany, seizures, hyperreflexia. heart failure.

40. Hypocalcaemia Treatment
Calcium gluconate (10% solution) 10 – 20 mls IV over 10 minutes. Then infusion ml of 10% Ca gluconate in 500 – 1000 ml D5W at 1mg/kg per hour. Monitor and treat abnormalities of Mg, K and pH.

41. Summary

42. Potassium Hyper K Hypo K
K < 3.5 mmol/L Critical = K < 2.5 mmol/L Causes: GI loss, renal loss, malnutrition S/S: weakness, paralysis, leg cramps, resp. distress, ECG flat T waves, Vent arrhythmia, PEA K < 2.5 mmol/L: K mEq/hr Cardiac arrest due to hypoK: K 10 mEq IV over 5 min.
K > 5 mmol/L Causes: CRF, DKA, hemolysis, rhabdo S/S: weakness, resp. failure, ECG peaked T, wide QRS K 6-7mmol/L: 10 u reg insulin in 25 g glucose (50 ml D50) IV over 20 minutes K > 7mmol/L: CaGluconate 1 gm (10 ml 10% sol’n) IV over 10 min. NaHCO3 50 mEq IV over 5 min 10 units reg insulin in 25 g glucose (50 ml D50) IV over minutes.

43. Sodium
Hypo Na
Hyper Na
Na < 130 mmol/L, Critical < 120 mmol/L Causes: reduced excretion water by kidneys, diuretics, renal failure, vomiting, SIADH, CHR, cirrhosis S/S nausea, irritable, lethargy, seizures, coma Na mmol/L: fluid restrict Na < 120mmol/L slow infusion 50 ml 3% saline Na < 120 with seizures 100ml bolus 3% saline, then as above
Na > mmol/L Causes: Increase Na, Cushing’s, Free water loss (GI, renal) S/S: altered mentation, weakness, neuro deficits, seizure Trt: reduce ongoing water loss, N/S or D5 ½ NS

44. Magnesium Hyper Mg Hypo Mg Mg > 1.05 mmol/L Causes: renal failure
Mg < 0.65 mmol/L Causes: decreased absorption, loss via GI and renal. Meds – diuretics, Alcohol S/S: tremors, nystagmus, tetany, altered mentation, ataxia, seizures, torsade de pointes. Mg < 0.65mmol/L MgSO4 1-2 g IV over min Torsade de Pointes: MgSO4 1-2 g IV over 5 min Seizures: MgSO4 2 g IV over 10 minutes. May need to also give Calcium.
Mg > 1.05 mmol/L
Causes: renal failure
S/S muscle weakness, paralysis, ataxia, lowered LOC, hypoventilation, cardiorespiratory arrest.
Mg > 1.05 mmol/L: CaGluconate mg IV

45. Calcium Hyper Ca Hypo Ca
Ca < 2.1 mmol/LCauses: toxic shock, Mg abnormalities, tumor lysis S/S: paresthesia, cramps, stridor, seizures, hyperreflexia, heart failure Ca < 2.1 mmol/L with symptoms: Ca gluconate 10 – 20 mls of 10% sol’n IV over 10 minutes Then infuse 60 ml of 10% Ca gluconate in ml of D5W at 1 mg/kg per hour Monitor Mg, K and pH.
Ca > 3 mmol/L Causes: primary hyperparathyroidism, malignancy S/S: depression, weakness, confusion, hallucinations, seizures, coma, constipation, ECG QT shortening, PR & QRS prolonged, AV block, cardiac arrest Ca > 3 mmol/L: N/S mg/h to replace fluid deficit Monitor Mg and K