Problem 6: Management of Hypokalaemia Flashcards
How hypokalemia is SAFELY managed with potassium?
Potassium overdose can be fatal and so ready-mixed infusion bags are regularly used and should be used where possible. Ready-mixed bags are stored in the CD cupboard. When using potassium bags they should be thoroughly mixed before use.
Plasma potassium concentration measured atleast once a day. ECG used to monitor arrhythmic disturbances in difficult cases. Check magnesium levels; repletion of Mg stores will facilitate more rapid correction of hypokalaemia.
Potassium is replaced with caution in patients with renal impairment (renal team contacted if severe or on dialysis).
How much potassium is to be given to Peter i.e. how is it safely prescribed?
Initial therapy should not involve glucose as can further decrease the plasma potassium concentration and may cause a trans-cellular shift of potassium into cells.
Follow BNF advice: Potassium Chloride Concentrate should be diluted with not less than 50 times the volume of sodium chloride infusion 0.9% or other suitable diluent and mixed well.
Why is potassium IV infusion to be used? Explain the possible causes for the low K level
Oral potassium is not sufficient in the treatment of hypokalaemia; onset not quick enough in metabolic acidosis case.
Causes of hypokalaemia: diuretics such as furosemide (often used in the treatment of cor pulmonale)
Vomiting, diarrhoea
Hyperaldosteronism (disorders of the adrenal gland)
Explain what central and peripheral lines are, how they are used and the need for hospital pharmacists to understand them
Peripheral lines: inserted into the hand or arm, can become blocked or dislodged easily as the veins are narrow. Not used for irritant drugs such as amiodarone, concentrated drugs in fluid restricted patients (e.g. potassium) or vasoconstriction drugs (such as adrenaline).
Central lines: inserted into larger veins such as the superior vena cava. Can be used to give any IV medicine.
Choice of line depends on the drugs (i.e. indication, rate, volume, irritancy, pharmacokinetics) and patient factors such as age, availability of IV access, concurrent disease. Some drugs may cause pain on injection because of their tonicity, pH, irritance (e.g. erythromycin). The vein may become red or inflamed, this is known as phlebitis.
Explain the storage requirements for K
Patient Safety Alert: Minimise overdose with potassium IV
CD storage cupboard in pre-mixed bags (thoroughly mixed before administration). So that they are kept separate from other premixed bags such as saline and not administered in error.m
Explain what monitoring is required for administering potassium IV infusion?
Potassium can cause arrhythmic disturbances so ECG used to monitor HR in severe / difficult cases (flat T waves, prominent U waves, ST depression.
Magnesium levels often monitored to ensure not depleted also.
General bloods (bicarbonate, glucose creatinine etc)
Plasma-potassium concentration monitored atleast once a day
