Electrolyte Imbalances:

Hydration is the key to keeping the body's fluid and electrolytes balanced. When electrolytes are imbalanced, symptoms such as tachycardia, muscle cramping or arrhythmia may occur. Electrolytes include sodium, potassium, magnesium, calcium and phosphorus. Normal electrolyte values:

  • Sodium (Na): 135 – 145 mEg/L

  • Potassium (K): 3.5 – 5.0 mEg/L

  • Magnesium (Mg): 1.5 – 2.6 mg/dL

  • Phosphorus (P): 2.7 – 4.5 mg/dL

  • Calcium (Ca): 8.6 – 10.4 mg/dL


Dehydration/ hypovolemia: is a loss of fluid volume. Causes of dehydration are poor nutrition or fluid intake, surgery, diarrhoea, renal disease, vomiting, NGT suctioning, and diuretics. Patients may present with symptoms of increased HR, decreased BP, poor skin turgor, weight loss, low urine output, dizziness, and weakness. Treatment for dehydration is to increase oral intake and administer IVF. Monitor intake and urine output.

Fluid overload/ hypervolemia: an excess of fluid; too much fluid can cause oedema (swelling in the intravascular space). It can be caused by renal disease or congestive heart failure. Symptoms include lung crackles, oedema, bounding pulse, weight gain, increased BP, and SOB. Treatment consists of administering a diuretic, discontinuing IVF, decreasing fluid intake, monitoring daily weights and cardiac monitoring.

Potassium imbalances:

  • Hypokalaemia: potassium level below 3.5 mEq/L. can be caused by vomiting, diarrhoea, gastric suctioning, kidney disease, and diuretics. Symptoms include irregular pulse, heart arrhythmias, muscle weakness and muscle cramping. Treatment includes administering oral potassium and IVF with potassium. Patients with hypokalaemia usually have an ECG with a depressed U wave.

  • Hyperkalaemia: potassium levels above 5.0 mEq/L. caused by kidney disease and medications such as ACE inhibitors. Symptoms include slow HR, weakness, cardiac arrhythmias, abdominal cramping and muscle twitching.

Patients may have an ECG with a peaked T wave – this can be fatal and must be treated immediately.

Treatment includes decreasing potassium in the diet and administering sodium polystyrene, which decreases potassium in the blood.


Sodium imbalances:

  • Hyponatremia: sodium levels below 135 mEg/L. caused by fluid overload, oedema, diuretics, burns/ wounds and administration of an excess amount of D5W. Symptoms include headache, confusion, abdominal cramping, muscle cramps, nausea, dry mucous membranes, and clammy skin.

Treatment involves IV fluids with sodium.

  • Hypernatremia: sodium levels above 145 mEg/L. hypernatremia is caused by dehydration and an increased salt intake. Symptoms include oedema, weight gain, thirst, weakness, and fatigue.

Treatment involves monitoring sodium intake, administering diuretics, and monitoring daily weights.