As one example, an apparatus includes a dielectric microsensor comprising a microfluidic chamber that includes a capacitive sensing structure, the microfluidic chamber including a fluid input port to receive a volume of a blood sample. A bioactive agent is disposed within the chamber to interact with the volume of the blood sample received in the microfluidic chamber. A transmitter provides an input radio frequency (RF) signal to an RF input of the dielectric microsensor. A receiver receives an output RF signal from an RF output of the dielectric microsensor. A computing device that computes dielectric permittivity values of the sample that vary over a time interval based on the output RF signal, the computing device to provide an assessment of hemostatic dysfunction and associated coagulopathy based on the dielectric permittivity values.