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

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

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

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

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

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

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

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)

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

Hyperkalemia -Treatment Moderate hyperkalemia (K 6 – 7 mmol/L) - 10 units regular insulin in 25 g glucose (50 ml D50) and give IV over 20-30 minutes.

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. - 10 units regular insulin in 25 g glucose(50 ml D50) and give IV over 20-30 minutes. - then Kayexalate enema 15-50 g plus sorbitol PO

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

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

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

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

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

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

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.

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.

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

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

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

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 15-30 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!

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

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

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.

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.

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.

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

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)

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

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

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.

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

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

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.

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.

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

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

Hypocalcaemia Treatment Calcium gluconate (10% solution) 10 – 20 mls IV over 10 minutes. Then infusion 60-70 ml of 10% Ca gluconate in 500 – 1000 ml D5W at 1mg/kg per hour. Monitor and treat abnormalities of Mg, K and pH.

Summary

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 10-20 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 20-30 minutes.

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 120-130mmol/L: fluid restrict Na < 120mmol/L slow infusion 50 ml 3% saline Na < 120 with seizures 100ml bolus 3% saline, then as above Na > 145-150 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

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 20-60 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 1500-3000mg IV

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 500-1000 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 300-500 mg/h to replace fluid deficit Monitor Mg and K