Korean J Clin Pharm.  2023 Sep;33(3):195-201. 10.24304/kjcp.2023.33.3.195.

Hematocrit Determination using a Volumetric Absorptive Microsampling Technique in Patients with Pancreatic Cancer

• Jung Y
• Yoo S
• Kang M
• Lim H
• Lee MH
• Ryu JK
• Lee J

• KMID: 2553153
• DOI: http://doi.org/10.24304/kjcp.2023.33.3.195

Abstract

Background
Hematocrit is usually measured from venous blood collected by invasive venipuncture. This study was performed to determine hematocrit accurately and precisely using minimally invasive volumetric absorptive microsampling (VAMS) technique. Such technique is to be applied to determining hematocrit in various clinical settings for the care, including therapeutic drug monitoring, of neonatal or epileptic patients, or patients with high risk of infection or bleeding.
Methods
The study was performed using 31 VAMS samples obtained from 21 pancreatic cancer patients. Hematocrit was determined using the values of potassium concentrations obtained from blood in VAMS tips (Hct_VAMS ). Hct_VAMS was compared with hematocrit measured from blood collected by venipuncture (Hct_VP ). The accuracy and precision of Hct_VAMS in comparison to Hct_VP were evaluated using BlandAltman plot, Deming regression and mountain plot.
Results
Bland-Altman plot displayed a random scattering pattern of the differences between Hct_VAMS and Hct_VP with the mean bias of −0.010 and the 95% limit of agreement ranging from −0.063 to 0.044. Deming regression for Hct_VAMS and Hct_VP line demonstrated very small proportional and constant biases of 1.04 and −0.003, respectively. Mountain plot exhibited a narrow and symmetrical distribution of the differences with their median of −0.011 and central 95% range from −0.049 to 0.033.
Conclusion
Hematocrit was accurately and precisely determined using less invasive VAMS technique. Such technique appears to be applicable to determining hematocrit in situations that venipuncture is not favorable or possible.

Keyword

Hematocrit determination; pancreatic cancer; potassium concentration; venous blood sampling; volumetric absorptive microsampling