Osmolality: using automation to enhance this powerful screening tool

Here is a typical, and overmodest, definition for osmolality: It “indicates the concentration of all the particles dissolved in body fluid”.¹ What’s hiding behind this dry description is that osmolality is a powerful tool: It delivers crucial information for making accurate diagnoses and establishing proper treatment plans for patients with disorders involving water and electrolyte imbalances. In fact, osmolality testing by freezing-point depression osmometry is essential for getting extremely accurate, and even fast, insights into the pathophysiology of disorders such as hyponatraemia, metabolic acidosis and different types of intoxication.

A high-value, low-cost test

Acute intoxication with alcohol or other substances is frequently seen in emergency departments and constitutes a significant burden on emergency health services.^2,3 Metabolic acidosis⁴ and electrolyte disorders⁵ such as hypo- and hyponatraemia are also common issues in both emergency medicine and intensive care medicine. In the latter two cases, there can be dozens of possible causes for their conditions. As a result, it would be very expensive and time consuming to test each laboratory analyte for all possibilities.