Table 5 Open in new tab Electrolyte...

Table 5

Electrolyte disturbances—ECG, causes and management

	Hypokalaemia	Hyperkalaemia
ECG findings	T-wave flattening/inversion Widespread ST depression Prominent U wave Increased P-wave amplitude Prolongation of PR interval Long QU interval	Peaked T waves P-wave widening/flattening PR prolongation QRS widening Bradyarrhythmias: sinus bradycardia, high-grade AV block with slow junctional and ventricular escape rhythms, slow AF Conduction blocks (bundle branch block, fascicular blocks)
Causes	Abnormal losses: medications (diuretics, laxatives, corticosteroids), gastrointestinal losses, renal losses, hypomagnesaemia, dialysis Transcellular shifts: medications: (insulin overdose, B2-sympaticomimetics, decongestants), alkalosis, thyrotoxicosis, hypothermia, head injury, myocardial ischaemia Inadequate intake: anorexia, dementia, parenteral nutrition	Increased intake: potassium supplementation, red blood cell transfusion Impaired excretion: kidney disease, congestive heart failure, cirrhosis, medications (potassium-sparing diuretics, ACE inhibitors, ARBs, heparin), hypoaldosteronism Transcellular shifts: insulin deficiency, acidosis, medications (BBs, digoxin toxicity) Pseudo-hyperkalaemia: haemolysis, leucocytosis (>75 000 cells per mm³), erythrocytosis, thrombocytosis
Management	Oral potassium chloride: 40–100 mmol i.v. 20–40 mmol/L potassium chloride in 500 mL of saline (not exceed 20 mmol/h; higher rates in emergency situation via central venous catheter)	Potassium <6 mEq/L: stop potassium-elevating drugs, 15–30 g sodium polystyrene sulfonate orally or rectally Potassium >6 mEq/L: insulin with glucose (5–10 unit with 50 mL 50% glucose), calcium chloride 10 mL of 10% solution i.v. over 5–10 min or calcium gluconate 30 mL of 10% solution i.v. over 5–10 min, beta 2-antagonist (salbutamol 0.25–0.5 mg iv, repeated dose after 15 min), dialysis

	Hypokalaemia	Hyperkalaemia
ECG findings	T-wave flattening/inversion Widespread ST depression Prominent U wave Increased P-wave amplitude Prolongation of PR interval Long QU interval	Peaked T waves P-wave widening/flattening PR prolongation QRS widening Bradyarrhythmias: sinus bradycardia, high-grade AV block with slow junctional and ventricular escape rhythms, slow AF Conduction blocks (bundle branch block, fascicular blocks)
Causes	Abnormal losses: medications (diuretics, laxatives, corticosteroids), gastrointestinal losses, renal losses, hypomagnesaemia, dialysis Transcellular shifts: medications: (insulin overdose, B2-sympaticomimetics, decongestants), alkalosis, thyrotoxicosis, hypothermia, head injury, myocardial ischaemia Inadequate intake: anorexia, dementia, parenteral nutrition	Increased intake: potassium supplementation, red blood cell transfusion Impaired excretion: kidney disease, congestive heart failure, cirrhosis, medications (potassium-sparing diuretics, ACE inhibitors, ARBs, heparin), hypoaldosteronism Transcellular shifts: insulin deficiency, acidosis, medications (BBs, digoxin toxicity) Pseudo-hyperkalaemia: haemolysis, leucocytosis (>75 000 cells per mm³), erythrocytosis, thrombocytosis
Management	Oral potassium chloride: 40–100 mmol i.v. 20–40 mmol/L potassium chloride in 500 mL of saline (not exceed 20 mmol/h; higher rates in emergency situation via central venous catheter)	Potassium <6 mEq/L: stop potassium-elevating drugs, 15–30 g sodium polystyrene sulfonate orally or rectally Potassium >6 mEq/L: insulin with glucose (5–10 unit with 50 mL 50% glucose), calcium chloride 10 mL of 10% solution i.v. over 5–10 min or calcium gluconate 30 mL of 10% solution i.v. over 5–10 min, beta 2-antagonist (salbutamol 0.25–0.5 mg iv, repeated dose after 15 min), dialysis

	Hypocalcaemia	Hypercalcaemia
ECG findings	QTc prolongation (ST-segment prolonged) The T-wave unchanged Dysrhythmias uncommon TdP may occur	Shortening of the QT interval Osborn waves (J waves) PVCs/PVT/VF
Causes	Hypoparathyroidism Pseudo-hypoparathyroidism Renal disease Vitamin D deficiency and dependency Acute pancreatitis Drugs: phenytoin, phenobarbital Infusion of gadolinium Magnesium depletion Septic shock	Primary hyperparathyroidism Cancers (lung, breast, multiple myeloma, renal cell carcinoma, prostate, ovarian, lymphoma, sarcoma) Drugs: hydrochlorothiazide, lithium, calcium supplements, vitamin D toxicity Sarcoidosis Renal disease Thyrotoxicosis
Management	i.v. calcium gluconate 10 mL of 10% solution over 10 min 1–2 g of oral calcium for post-operative hypoparathyroidism 1–2 g of oral calcium and vitamin D for chronic hypocalcaemia	Serum calcium <11.5 mg/dL (< 2.9 mmol/L): oral phosphate 250–500 mg 4 times a day serum calcium <18 mg/dL (<4.5 mmol/L): iv 500–1000 mL of saline and furosemide 20–40 mg every 2–4 h serum calcium 11.5 to 18 mg/dL (3.7 to 5.8 mmol/L) and/or moderate symptoms: iv 500–1000 mL of isotonic saline and furosemide 20–40 mg every 2–4 h, bisphosphonates (zoledronate 4–8 mg iv) or other calcium-lowering drugs serum calcium >18 mg/dL (>5.8 mmol/L): haemodialysis

	Hypocalcaemia	Hypercalcaemia
ECG findings	QTc prolongation (ST-segment prolonged) The T-wave unchanged Dysrhythmias uncommon TdP may occur	Shortening of the QT interval Osborn waves (J waves) PVCs/PVT/VF
Causes	Hypoparathyroidism Pseudo-hypoparathyroidism Renal disease Vitamin D deficiency and dependency Acute pancreatitis Drugs: phenytoin, phenobarbital Infusion of gadolinium Magnesium depletion Septic shock	Primary hyperparathyroidism Cancers (lung, breast, multiple myeloma, renal cell carcinoma, prostate, ovarian, lymphoma, sarcoma) Drugs: hydrochlorothiazide, lithium, calcium supplements, vitamin D toxicity Sarcoidosis Renal disease Thyrotoxicosis
Management	i.v. calcium gluconate 10 mL of 10% solution over 10 min 1–2 g of oral calcium for post-operative hypoparathyroidism 1–2 g of oral calcium and vitamin D for chronic hypocalcaemia	Serum calcium <11.5 mg/dL (< 2.9 mmol/L): oral phosphate 250–500 mg 4 times a day serum calcium <18 mg/dL (<4.5 mmol/L): iv 500–1000 mL of saline and furosemide 20–40 mg every 2–4 h serum calcium 11.5 to 18 mg/dL (3.7 to 5.8 mmol/L) and/or moderate symptoms: iv 500–1000 mL of isotonic saline and furosemide 20–40 mg every 2–4 h, bisphosphonates (zoledronate 4–8 mg iv) or other calcium-lowering drugs serum calcium >18 mg/dL (>5.8 mmol/L): haemodialysis

	Hypomagnesaemia	Hypermagnesaemia
ECG findings	Prolonged QT interval Prolonged PR interval Atrial and ventricular ectopy VT and TdP	Flat P wave Prolonged PR interval Widened QRS complex Tall T wave
Causes	Gastrointestinal: reduced intake, reduced absorption, increased losses (diarrhoea, laxative abuse) Increase renal excretion: drug-induced (loop diuretics, thiazides, proton pump inhibitors), hypercalcaemic states, hyperaldosteronism	Impaired renal excretion: renal failure, hypothyroidism, adrenal insufficiency, lithium therapy Excessive intake: as treatment for peptic ulcer disease Excessive absorption: gastric or intestinal inflammatory
Management	Oral magnesium salts In severe cases [magnesium <1.25 mg/dL (<0.5 mmol/L)] and life-threatening arrhythmia: magnesium sulfate 1–2 g i.v. over 30–60 s and repeat in 5–15 min if necessary In asymptomatic patients and magnesium <1.25 mg/dL (<0.5 mmol/L): magnesium sulfate 1–2 g/h i.v. for up to 10 h	Ca2+ in as 10–20 mL of 10% calcium gluconate i.v. i.v. administration of 1000–2000 mL of 0.9% NaCl and furosemide 20–40 mg Haemodialysis using magnesium-free or low-magnesium dialysate

	Hypomagnesaemia	Hypermagnesaemia
ECG findings	Prolonged QT interval Prolonged PR interval Atrial and ventricular ectopy VT and TdP	Flat P wave Prolonged PR interval Widened QRS complex Tall T wave
Causes	Gastrointestinal: reduced intake, reduced absorption, increased losses (diarrhoea, laxative abuse) Increase renal excretion: drug-induced (loop diuretics, thiazides, proton pump inhibitors), hypercalcaemic states, hyperaldosteronism	Impaired renal excretion: renal failure, hypothyroidism, adrenal insufficiency, lithium therapy Excessive intake: as treatment for peptic ulcer disease Excessive absorption: gastric or intestinal inflammatory
Management	Oral magnesium salts In severe cases [magnesium <1.25 mg/dL (<0.5 mmol/L)] and life-threatening arrhythmia: magnesium sulfate 1–2 g i.v. over 30–60 s and repeat in 5–15 min if necessary In asymptomatic patients and magnesium <1.25 mg/dL (<0.5 mmol/L): magnesium sulfate 1–2 g/h i.v. for up to 10 h	Ca2+ in as 10–20 mL of 10% calcium gluconate i.v. i.v. administration of 1000–2000 mL of 0.9% NaCl and furosemide 20–40 mg Haemodialysis using magnesium-free or low-magnesium dialysate

ACE, angiotensin-converting enzyme; AF, atrial firbrillation; ARB, angiotensin receptor blocker; AV, atrioventricular; BB, beta-blocker; ECG, electrocardiogram; PVC, premature ventricular complex; PVT, polymorphic ventricular tachycardia; TdP, torsade de pointes; VF, ventricular fibrillation; VT, ventricular tachycardia.

Table 5

Open in new tab

Electrolyte disturbances—ECG, causes and management

	Hypokalaemia	Hyperkalaemia
ECG findings	T-wave flattening/inversion Widespread ST depression Prominent U wave Increased P-wave amplitude Prolongation of PR interval Long QU interval	Peaked T waves P-wave widening/flattening PR prolongation QRS widening Bradyarrhythmias: sinus bradycardia, high-grade AV block with slow junctional and ventricular escape rhythms, slow AF Conduction blocks (bundle branch block, fascicular blocks)
Causes	Abnormal losses: medications (diuretics, laxatives, corticosteroids), gastrointestinal losses, renal losses, hypomagnesaemia, dialysis Transcellular shifts: medications: (insulin overdose, B2-sympaticomimetics, decongestants), alkalosis, thyrotoxicosis, hypothermia, head injury, myocardial ischaemia Inadequate intake: anorexia, dementia, parenteral nutrition	Increased intake: potassium supplementation, red blood cell transfusion Impaired excretion: kidney disease, congestive heart failure, cirrhosis, medications (potassium-sparing diuretics, ACE inhibitors, ARBs, heparin), hypoaldosteronism Transcellular shifts: insulin deficiency, acidosis, medications (BBs, digoxin toxicity) Pseudo-hyperkalaemia: haemolysis, leucocytosis (>75 000 cells per mm³), erythrocytosis, thrombocytosis
Management	Oral potassium chloride: 40–100 mmol i.v. 20–40 mmol/L potassium chloride in 500 mL of saline (not exceed 20 mmol/h; higher rates in emergency situation via central venous catheter)	Potassium <6 mEq/L: stop potassium-elevating drugs, 15–30 g sodium polystyrene sulfonate orally or rectally Potassium >6 mEq/L: insulin with glucose (5–10 unit with 50 mL 50% glucose), calcium chloride 10 mL of 10% solution i.v. over 5–10 min or calcium gluconate 30 mL of 10% solution i.v. over 5–10 min, beta 2-antagonist (salbutamol 0.25–0.5 mg iv, repeated dose after 15 min), dialysis

	Hypokalaemia	Hyperkalaemia
ECG findings	T-wave flattening/inversion Widespread ST depression Prominent U wave Increased P-wave amplitude Prolongation of PR interval Long QU interval	Peaked T waves P-wave widening/flattening PR prolongation QRS widening Bradyarrhythmias: sinus bradycardia, high-grade AV block with slow junctional and ventricular escape rhythms, slow AF Conduction blocks (bundle branch block, fascicular blocks)
Causes	Abnormal losses: medications (diuretics, laxatives, corticosteroids), gastrointestinal losses, renal losses, hypomagnesaemia, dialysis Transcellular shifts: medications: (insulin overdose, B2-sympaticomimetics, decongestants), alkalosis, thyrotoxicosis, hypothermia, head injury, myocardial ischaemia Inadequate intake: anorexia, dementia, parenteral nutrition	Increased intake: potassium supplementation, red blood cell transfusion Impaired excretion: kidney disease, congestive heart failure, cirrhosis, medications (potassium-sparing diuretics, ACE inhibitors, ARBs, heparin), hypoaldosteronism Transcellular shifts: insulin deficiency, acidosis, medications (BBs, digoxin toxicity) Pseudo-hyperkalaemia: haemolysis, leucocytosis (>75 000 cells per mm³), erythrocytosis, thrombocytosis
Management	Oral potassium chloride: 40–100 mmol i.v. 20–40 mmol/L potassium chloride in 500 mL of saline (not exceed 20 mmol/h; higher rates in emergency situation via central venous catheter)	Potassium <6 mEq/L: stop potassium-elevating drugs, 15–30 g sodium polystyrene sulfonate orally or rectally Potassium >6 mEq/L: insulin with glucose (5–10 unit with 50 mL 50% glucose), calcium chloride 10 mL of 10% solution i.v. over 5–10 min or calcium gluconate 30 mL of 10% solution i.v. over 5–10 min, beta 2-antagonist (salbutamol 0.25–0.5 mg iv, repeated dose after 15 min), dialysis

	Hypocalcaemia	Hypercalcaemia
ECG findings	QTc prolongation (ST-segment prolonged) The T-wave unchanged Dysrhythmias uncommon TdP may occur	Shortening of the QT interval Osborn waves (J waves) PVCs/PVT/VF
Causes	Hypoparathyroidism Pseudo-hypoparathyroidism Renal disease Vitamin D deficiency and dependency Acute pancreatitis Drugs: phenytoin, phenobarbital Infusion of gadolinium Magnesium depletion Septic shock	Primary hyperparathyroidism Cancers (lung, breast, multiple myeloma, renal cell carcinoma, prostate, ovarian, lymphoma, sarcoma) Drugs: hydrochlorothiazide, lithium, calcium supplements, vitamin D toxicity Sarcoidosis Renal disease Thyrotoxicosis
Management	i.v. calcium gluconate 10 mL of 10% solution over 10 min 1–2 g of oral calcium for post-operative hypoparathyroidism 1–2 g of oral calcium and vitamin D for chronic hypocalcaemia	Serum calcium <11.5 mg/dL (< 2.9 mmol/L): oral phosphate 250–500 mg 4 times a day serum calcium <18 mg/dL (<4.5 mmol/L): iv 500–1000 mL of saline and furosemide 20–40 mg every 2–4 h serum calcium 11.5 to 18 mg/dL (3.7 to 5.8 mmol/L) and/or moderate symptoms: iv 500–1000 mL of isotonic saline and furosemide 20–40 mg every 2–4 h, bisphosphonates (zoledronate 4–8 mg iv) or other calcium-lowering drugs serum calcium >18 mg/dL (>5.8 mmol/L): haemodialysis

	Hypocalcaemia	Hypercalcaemia
ECG findings	QTc prolongation (ST-segment prolonged) The T-wave unchanged Dysrhythmias uncommon TdP may occur	Shortening of the QT interval Osborn waves (J waves) PVCs/PVT/VF
Causes	Hypoparathyroidism Pseudo-hypoparathyroidism Renal disease Vitamin D deficiency and dependency Acute pancreatitis Drugs: phenytoin, phenobarbital Infusion of gadolinium Magnesium depletion Septic shock	Primary hyperparathyroidism Cancers (lung, breast, multiple myeloma, renal cell carcinoma, prostate, ovarian, lymphoma, sarcoma) Drugs: hydrochlorothiazide, lithium, calcium supplements, vitamin D toxicity Sarcoidosis Renal disease Thyrotoxicosis
Management	i.v. calcium gluconate 10 mL of 10% solution over 10 min 1–2 g of oral calcium for post-operative hypoparathyroidism 1–2 g of oral calcium and vitamin D for chronic hypocalcaemia	Serum calcium <11.5 mg/dL (< 2.9 mmol/L): oral phosphate 250–500 mg 4 times a day serum calcium <18 mg/dL (<4.5 mmol/L): iv 500–1000 mL of saline and furosemide 20–40 mg every 2–4 h serum calcium 11.5 to 18 mg/dL (3.7 to 5.8 mmol/L) and/or moderate symptoms: iv 500–1000 mL of isotonic saline and furosemide 20–40 mg every 2–4 h, bisphosphonates (zoledronate 4–8 mg iv) or other calcium-lowering drugs serum calcium >18 mg/dL (>5.8 mmol/L): haemodialysis

	Hypomagnesaemia	Hypermagnesaemia
ECG findings	Prolonged QT interval Prolonged PR interval Atrial and ventricular ectopy VT and TdP	Flat P wave Prolonged PR interval Widened QRS complex Tall T wave
Causes	Gastrointestinal: reduced intake, reduced absorption, increased losses (diarrhoea, laxative abuse) Increase renal excretion: drug-induced (loop diuretics, thiazides, proton pump inhibitors), hypercalcaemic states, hyperaldosteronism	Impaired renal excretion: renal failure, hypothyroidism, adrenal insufficiency, lithium therapy Excessive intake: as treatment for peptic ulcer disease Excessive absorption: gastric or intestinal inflammatory
Management	Oral magnesium salts In severe cases [magnesium <1.25 mg/dL (<0.5 mmol/L)] and life-threatening arrhythmia: magnesium sulfate 1–2 g i.v. over 30–60 s and repeat in 5–15 min if necessary In asymptomatic patients and magnesium <1.25 mg/dL (<0.5 mmol/L): magnesium sulfate 1–2 g/h i.v. for up to 10 h	Ca2+ in as 10–20 mL of 10% calcium gluconate i.v. i.v. administration of 1000–2000 mL of 0.9% NaCl and furosemide 20–40 mg Haemodialysis using magnesium-free or low-magnesium dialysate

	Hypomagnesaemia	Hypermagnesaemia
ECG findings	Prolonged QT interval Prolonged PR interval Atrial and ventricular ectopy VT and TdP	Flat P wave Prolonged PR interval Widened QRS complex Tall T wave
Causes	Gastrointestinal: reduced intake, reduced absorption, increased losses (diarrhoea, laxative abuse) Increase renal excretion: drug-induced (loop diuretics, thiazides, proton pump inhibitors), hypercalcaemic states, hyperaldosteronism	Impaired renal excretion: renal failure, hypothyroidism, adrenal insufficiency, lithium therapy Excessive intake: as treatment for peptic ulcer disease Excessive absorption: gastric or intestinal inflammatory
Management	Oral magnesium salts In severe cases [magnesium <1.25 mg/dL (<0.5 mmol/L)] and life-threatening arrhythmia: magnesium sulfate 1–2 g i.v. over 30–60 s and repeat in 5–15 min if necessary In asymptomatic patients and magnesium <1.25 mg/dL (<0.5 mmol/L): magnesium sulfate 1–2 g/h i.v. for up to 10 h	Ca2+ in as 10–20 mL of 10% calcium gluconate i.v. i.v. administration of 1000–2000 mL of 0.9% NaCl and furosemide 20–40 mg Haemodialysis using magnesium-free or low-magnesium dialysate

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