Hematocrit prediction in volumetric absorptive microsamples.

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Clinical Diagnostics

Background:

• Volumetric absorptive microsampling (VAMS) is a novel blood collection technique offering an alternative to traditional dried blood spot (DBS) sampling.
• VAMS collects a fixed blood volume, mitigating hematocrit (HT)-related biases seen in DBS analysis.
• However, HT remains crucial for converting VAMS whole blood results to serum or plasma concentrations for clinical interpretation.

Purpose of the Study:

• To develop and validate methods for determining hematocrit (HT) from volumetric absorptive microsampling (VAMS) devices.
• To enable accurate conversion of VAMS blood analyte concentrations to plasma values, facilitating comparison with therapeutic drug monitoring intervals.
• To integrate HT determination seamlessly into existing VAMS workflows.

Main Methods:

• Two novel methods were developed to derive HT from VAMS samples by analyzing their potassium content.
• Method 1 involved an aqueous extraction procedure.
• Method 2 utilized an organic extraction procedure.

Main Results:

• Both developed methods successfully derived HT values from VAMS samples.
• The methods are compatible with existing VAMS analysis techniques.
• These approaches allow for simultaneous quantification of target analytes and HT determination from a single VAMS extract.

Conclusions:

• The developed potassium-based methods provide a straightforward way to determine HT from VAMS samples.
• Accurate HT measurement from VAMS is essential for reliable conversion to plasma concentrations.
• These integrated methods enhance the utility of VAMS for clinical and pharmacokinetic studies.