In health plasma potassium concentration is maintained within the approximate reference range of 3.5-5.2 mmol/L, so that hypokalemia (reduced plasma potassium) is defined as plasma potassium < 3.5 mmol/L.  Mild hypokalemia (plasma potassium in the range of 3.0-3.5 mmol/L) is a common electrolyte disturbance that may or ...

It is commonplace for clinical staff tasked with blood sample collection to ask patients to make a fist before venipuncture; it reportedly helps by making veins more visible. Patients may also be asked to maintain a clenched fist during the procedure. This practice of ”fist clenching” is sanctioned in phlebotomy...

Plasma ionized calcium (iCa) concentration is normally maintained within the approximate range of 1.15-1.33 mmol/L, so that hypocalcemia (reduced plasma ionized calcium concentration) is widely defined as iCa <1.15 mmol/L. Massive blood transfusion is a relatively rare cause of hypocalcemia that is highlighted by this...

In health serum sodium concentration is maintained within the approximate range of 135-145 mmol/L, so that hyponatremia (reduced plasma sodium concentration) is defined as serum sodium Hyponatremia is a frequent complicating feature of common chronic conditions such as heart failure, chronic kidney disease and...

Serum sodium concentration is normally maintained within the approximate reference range of 135-145 mmol/L.Abnormal sodium concentration (dysnatremia), which is a relatively common feature of critical illness – affecting 10-20 % of intensive care patients – is associated with adverse outcome for this patient group....

Practically all victims of significant trauma will have blood sampled for plasma potassium estimation soon after admission to hospital emergency departments. But what is the frequency and significance of abnormal potassium results at admission for these trauma patients?  That was the question addressed in design of a...

In health serum total calcium concentration is maintained within the approximate reference range of 2.15-2.60 mmol/L largely by the synergistic action of two hormones: parathyroid hormone (PTH) and the vitamin-D-derived hormone, calcitriol. These two hormones control absorption of dietary calcium from the gut, renal...

In health plasma sodium concentration is maintained within the approximate reference range, 135-145 mmol/L (mEq/L). Hyponatremia (defined as plasma sodium The vast majority of affected patients have mild to moderate hyponatremia (plasma sodium in the range of 120-134 mmol/L), which is usually asymptomatic, especially ...

Potassium, the most frequently measured electrolyte in clinical practice is, in health, maintained at a blood serum concentration within the approximate reference range of 3.5 to 5.2 mmol/L. Physiological control of this potassium concentration depends crucially on the ability of the healthy kidney to regulate...

Plasma sodium concentration is measured with an ion-specific electrode (ISE) using either an undiluted sample (direct ISE) or diluted sample (indirect ISE).  This is the second of two linked articles highlighting the spurious sodium values that can occur if an indirect ISE method is used to analyze plasma samples with ...