Page 52 - Read Online

Page 20 of 33 Berardi et al. J Cancer Metastasis Treat 2019;5:79 I http://dx.doi.org/10.20517/2394-4722.2019.008

Figure 5. Algorithm of hypokalemia management [48,129-139] . In the case of hypokalemia, it is useful to consider oral or intravenous
supplementation based on the degree and symptoms. It is always useful to associate the identification and correction of the underlying
cause. For a correct differential diagnosis, it is essential to evaluate UK and UCr. UK: urinary potassium; Ucr: urinary creatinine

muscular, neurological, or cardiac dysfunction. The most common clinical manifestation is characterized
by weakness, fatigue, myalgia, muscle cramps, and constipation. In the case of moderate or severe
hypokalemia, neurological and psychiatric symptoms (e.g., psychosis, delirium, hallucinations, and
depression), or cardiac signs (bradycardia) until acute respiratory failure with cardiovascular collapse,
secondary to muscle paralysis, might occur. In particular, cardiac arrhythmias represent life-threatening
complications requiring immediate diagnosis and adequate treatment. Therefore, ECG monitoring should
be performed in patients with hypokalemia (typical alterations are inverted T waves, appearance of U wave,
ST depression, and enlarged PR interval) [130] .

Diagnosis of hypokalemia is based on detection of low serum potassium levels. For a correct management
of hypokalemia, it is important to understand the underlying causes. For a correct differential diagnosis,
it is important investigate the patient’s medical history, evaluating the concomitant therapies and clinical
conditions that might cause potassium losses or intracellular redistribution (insulin, diuretics, nephrotoxic
agents, anticancer agents, diarrhea, and vomiting). Presence of pseudo-hypokalemia should be excluded in
patients with marked leukocytosis.

Furthermore, other laboratory exams should be performed for a correct differential diagnosis. Blood sugar,
acid-base balance, creatinine, magnesium levels, and urine electrolytes concentration should be evaluated
[Figure 5] [131] . In particular, 24-h renal potassium concentration is useful to establish renal or extra-renal
potassium losses.

When urinary potassium is > 30 mEq/L there is a renal potassium loss, while a urinary potassium
concentration of < 25 mEq/L might be related to an extra-renal potassium loss. Another useful evaluation
to distinguish between renal and extra-renal potassium losses is the urinary potassium concentration and
urinary creatinine concentration ratio. Values > 15 are suggestive for renal potassium losses [131] .