×
MedSchool: Ace Your OSCEsThe Medical Company
 
 
 
 
 
GET - On the App Store
View
Electrolyte Abnormalities
 
 

Hypomagnesaemia

 
 
 
Bookmark

Pathogenesis

  • Causes of Hypomagnesaemia

  • Reduced intake - malnutrition, TPN
  • Urinary loss - acute tubular necrosis (polyuric phase), postobstructive diuresis, loop / thiazide diuretics, ACE inhibitors, renal tubular acidosis, aminoglycoside toxicity, hypercalcaemia, genetic tubular defects
  • GI loss - diarrhoea, laxative abuse, malabsorption, vomiting, NG aspirates, GI fistula, short bowel syndrome, long-term PPI use
  • Compartmental shift - refeeding syndrome, hyperparathyroidism, hyperthyroidism, acute pancreatitis, hungry bone syndrome

Manifestations

  • Clinical Features

    Only occur in the presence of resultant biochemical abnormalities
  • Hypocalcaemia - hyperreflexia, tetany, seizures, heart failure
  • Hypokalaemia - weakness, hypotonicity, depression, constipation, ileus
  • Associated Lab Abnormalities

  • Hypokalaemia
  • Hypocalcaemia

Diagnosis

  • Bloods

  • Serum magnesium <0.7 mmol/L.
  • ECG Findings

  • Long QTc → torsade de pointes
  • Atrial or ventricular ectopics
  • Atrial fibrillation
  • Ventricular arrhythmias
  • Hypokalaemia - ST depression, prolonged QT interval, T wave flattening or inversion, prominent U wave
Next Page
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Want more info like this?
  • Your electronic clinical medicine handbook
  • Guides to help pass your exams
  • Tools every medical student needs
  • Quick diagrams to have the answers, fast
  • Quizzes to test your knowledge
Sign Up Now
   
 
 

Snapshot: Initialising...