Hypokalemia. INTRODUCTION. Potassium is one of the body's major ions. Nearly 98% of the body ’ s potassium is intracellular. The ratio of intracellular to extracellular potassium is important in determining the cellular membrane potential.
The reference range for serum potassium level is 3.5-5 mEq/L
chronic inadequate intake,
long-term diuretic or laxative use,
chronic diarrhea, hypomagnesemia & hyperhidrosis
Total body deficit
severe GI losses : vomiting / diarrhea,
dialysis, and diuretic therapy
from the EC
to IC space
Alkalosis & hypothermia
Distal RTA & Bartter syndrome,
Periodic hypokalemic paralysis,
Hyperaldosteronism & hyperthyroid.
Gennari FJ. Hypokalemia. N Engl J Med 1998; 339: 451-458
The ECG findings in hypokalemia: described clinical features
Ventricular dysrhythmia, Prolongation of QT interval, ST segment depression, T wave flattening& U waves.
left adrenal adenoma described clinical features
There is no direct correlation between the serum potassium and the total body potassium deficit, but a rough estimate is to assume a total body deficit of ~ 200 - 400 meq of potassium for every 1 meq/L the serum potassium is below 4 meq/L
consider the possibility of associated magnesium deficiency
cardiac monitoring is necessary in patients with
IV potassium should normally be diluted in saline solution so that the maximum concentration is 40 meq/L (peripheral lines) or 60 meq/L (central lines) and IV potassium.
Medical Decision-Making and Treatment described clinical features
The patient should be transferred to ICU for severe or symptomatic hypokalemia for:
what is the next step? described clinical features
The cause of hypokalemia
Certain simple combinations of clinical features and abnormal laboratory values could suggest a particular diagnosis
Q.1. abnormal laboratory values could suggest a particular diagnosis Hypertension + High Serum Renin + High Serum Aldosterone.
Q.2. abnormal laboratory values could suggest a particular diagnosis Hypertension + Low Serum Renin + High Serum Aldosterone.
Q.3. abnormal laboratory values could suggest a particular diagnosisHypertension + Low Serum Renin + Low Serum Aldosterone.
Q.4. abnormal laboratory values could suggest a particular diagnosisHypertension + Normal/high Serum Renin + Normal Serum Aldosterone
Q.5. abnormal laboratory values could suggest a particular diagnosis Hypotension/normotension + High Serum Renin + High Serum Aldosterone.
Q.6. abnormal laboratory values could suggest a particular diagnosis Normotension + metabolic acidosis + hyperchloremia + urine ph > 6.
Increased serum renin
Increased urinary chloride (> 100 meq/l)
Q.8. abnormal laboratory values could suggest a particular diagnosis Normotension/hypotension + metabolic alkalosis + low urinary chloride
The following consultations may be appropriate, depending on the clinical findings:
The low-sodium diet limits the amount of sodium reabsorbed at the cortical collecting tubule, thus limiting the amount of potassium secreted.