see: [RCH - hypokalaemia](https://www.rch.org.au/clinicalguide/guideline_index/Hypokalaemia/), [Marino ICU - Potassium](x-devonthink-item://82A334A0-2166-466B-B59F-64C76CCF073F?page=619) ![[Pasted image 20240208090641.png]] - if K > 3.0, 10mEq K → 0.1 increase in serum K - K 2.5-3, need 15 mEq K for each 0.1 increase - K 2-2.5 need 20 mEq for each 0.1 increase ![[Pasted image 20240208121945.png]] > note that correlation btwn serum and intracellular K is **often poor** > more reliable when HCO3 is normal, Cr normal, no diuretics or digoxin, and Mg2+ is normal # causes - [[Blood gas#assess NAGMA|NAGMA]] - Adrenergic excess - coffee - theophylline - salbutamol - pain - insulin - aldosterone - alkalosis -- each 0.1 increase in pH causes a 0.6 mmol/L decrease in K - [[thyrotoxicosis]] - GI losses - renal losses - [[Hyperaldosteronism]] -- a/w metabolic alkalosis - [[Renal tubular acidosis|RTA]] type 1 - [[Hypomagnesemia]] -- usually only when Mg < 0.5 - gentamycin - leukemia - cisplatnin > - Renal losses: Diuretic use, drugs, steroid use, metabolic acidosis, hyper- aldosteronism, renal tubular acidosis, diabetic ketoacidosis (DKA), alcohol consumption > - Increased nonrenal losses: Sweating, diarrhea, vomiting, laxative use > - Decreased intake: Ethanol, malnutrition > - Intracellular shift: Hyperventilation, metabolic alkalosis, drugs > - Endocrine: Cushing disease, Bartter syndrome, insulin therapy # symptoms - 50% of pts with K 2.5 are asymptomatic - muscular - weakness, pain, tetany - paralysis may be present if K <2 - ileus - vasoconstruction - can cause [[rhabdomyolysis]] - nephropathy - some risks of first and second degree heart block, **ventricular tachycardias/fibrillation** atrial tachycardias eg AF, and asystole ## hypokalemia in [[ACS|myocardial infarction]] - ==can precipitate VF arrest!== - K 3.6-4 - 7.5% risk - 3-3.5 - 17% risk - <3.0 - 33% risk ## hypokalaemic periodic paralysis - more common in south east asian pts - males > women - autosomal dominant in 2/3 of pt - exacerbation: - high carbs - EtOH - hot weather - strenuous exercise - insulin - emotional stress - flaccid paralysis, absent deep tendon reflexes, usually symmetrical - lower > upper - lasts hours -days - usually a/w hypokalemia - normal between attacks DDx: thyrotocic periodic paralysis adrenergic drug related hypokalemic paralysis # ECG changes [example](x-devonthink-item://642FA0DE-2080-4EB1-BA8C-1A71C3092929) > - T wave flattening > - prominent U waves > - U wave T wave fusion > - QT interval appears prolonged if T and U waves merge (the real Q-T interval is not prlonged) > - prolonged QT interval > - ectopic beats > - ocasional late T wave inversion or STD in precordial leads > > ![[Pasted image 20240208124631.png]] # treatment - 750mg = 10 mEq K - Span K 600mg = 8 mmol - correct any [[Hypomagnesemia|hypo-mg]] - **max rate 40 mmol/h** - 0.5 mmol/kg/h in children - cardiac monitoring requred if > 15 mmol/h | treatment | dose | K amount | rate | | ------------ | ----------- | -------------- | -------------------------------------------------------------------------------------- | | chlorvescent | 1-2 tablets | 14 mmol/tablet | if K 2.5-3, give 2x TDS<br>+ 4 hour bag with 40 mmol K<br>if severe, 3 tablets W 2-4 H | | span K | 1 tablet | 8 mmol | not appropriate for rapid | | mini-bag | 10mmol | | 30 min-1h if peripheral | ## paediatric hypokalaemia treatment see: [RCH - hypokalaemia](https://www.rch.org.au/clinicalguide/guideline_index/Hypokalaemia/) > note that [[DKA#RCH DKA guidelines|paeds DKA]] has its own protocol to add 40 mmol KCl to resus fluids replace if K < 3.0; severe is < 2.4 - oral: 1-2 mmol/kg/dose po max 20 mmol/dose. can be repeated after checking serum K to max of 5 mmol/kg/day (max 50 mmol/day) - IV: 0.4 mmol/kg/hour for 1-2 hours (max 20 mmol/hour) WITH ECG monitoring (rate for ED or ICU) - re-check 1 hour after replacement commenced and 1 hour after replacement completed - 0.2 mmol/kg/hour for 3 hours is the "ward" rate" # backlinks and tags ```dataview LIST WHERE (contains(file.tags, this.file.name) OR contains(this.file.inlinks, file.link)) SORT file.name ASC ```