Hypokalaemia+protocol

Last reviewed by CRGH Renal Department 2012 Link to [|SLD potassium guidelines] (Intranet)
 * DRAFT **

//Definition // Mild K+ < 3.5 mmol/L Severe K+ <2.5 mmol/L

//Common causes // Diuretics e.g. loop, thiazide Other drugs e.g. insulin, salbutamol Vomiting, diarrhoea Metabolic alkalosis Hyperaldosteronism Pseudohypokalaemia

//Clinical Features // Muscle weakness Paraesthesiae <span style="font-family: 'Arial','sans-serif'; font-size: 13px;">Cardiac arrhythmias <span style="font-family: 'Arial','sans-serif'; font-size: 13px;">ECG – flattened T waves, ST depression, U waves (after T)

//<span style="color: #ff87b9; font-family: 'Arial','sans-serif'; font-size: 13px;">Investigations // <span style="font-family: 'Arial','sans-serif'; font-size: 13px;">Serum EUC, Mg <span style="font-family: 'Arial','sans-serif'; font-size: 13px;">Urine Na, K, creatinine <span style="font-family: 'Arial','sans-serif'; font-size: 13px;">Urine K/Cr < 2 indicates extra renal loss with intact renal K+ handling. <span style="font-family: 'Arial','sans-serif'; font-size: 13px;">Digoxin level (if patient on digoxin): note digoxin toxicity can occur with drug levels that are not high in hypokalaemia.

//<span style="color: #ff87b9; font-family: 'Arial','sans-serif'; font-size: 13px;">Management //
 * 1) <span style="font-family: 'Arial','sans-serif'; font-size: 13px;">Assess cause, ECG for arrhythmias, check serum Mg2+
 * 2) <span style="font-family: 'Arial','sans-serif'; font-size: 13px;">If the patient has just had haemodialysis repeat the K 4h later as serum K is usually very low after dialysis and does not reflect total body potassium
 * 3) <span style="font-family: 'Arial','sans-serif'; font-size: 13px;">Administer KCl intravenously if K+ < 3.0 mmol/L – //always follow Sydney LHD guidelines//
 * <span style="font-family: Arial,sans-serif;">Maximum concentration in ward areas **40mmol per litre**
 * <span style="font-family: Arial,sans-serif;">Maximum rate in ward areas **10mmol per hour**
 * 1) <span style="font-family: 'Arial','sans-serif'; font-size: 13px;">Oral potassium replacement
 * <span style="font-family: Arial,sans-serif;">Slow K, Span K = 8mmol potassium per tablet
 * <span style="font-family: Arial,sans-serif;">Chlorvescent = 14mmol potassium per tablet
 * 1) <span style="font-family: 'Arial','sans-serif'; font-size: 13px;">Correct magnesium if low
 * <span style="font-family: Arial,sans-serif;">Hypokalaemia is often resistant to treatment until hypomagnesaemia is corrected
 * 1) <span style="font-family: 'Arial','sans-serif'; font-size: 13px;">Correct alkalosis: hypokalaemia is often resistent to treatment if alkalosis persists.
 * 2) <span style="font-family: 'Arial','sans-serif'; font-size: 13px;">Hypokalaemia will exacerbate digoxin toxicity, so correction of hypokalaemia should be expedited in the setting of digoxin use (even when digoxin levels are not especially elevated).
 * 3) <span style="font-family: 'Arial','sans-serif'; font-size: 13px;">Higher concentrations or rates of replacement require cardiac monitoring and central venous access and should always be discussed with a consultant