Fluid exchange is an area where more research is required, in particular the role of pore size and membrane osmotic pressure (MOP). The main objective of this study is to plot the MOP and Mean arterial pressure (MAP) of healthy participants onto a chart that has been created from previous work. This chart could act as a diagnostic tool to give individualised treatment to patients in shock. The secondary objectives are to see if it is possible to calculate MOP from biochemistry results and to create a chart plotting pore size against MOP.

This is an observational study looking to recruit 20 ‘healthy’ participants from staff employed at the RIE. Two blood samples will be taken. One sample will be sent to the labs for biochemistry testing. The second sample will be retained in order to measure MOP. Participant information taken would be minimal but include blood pressure reading and past medical history. No follow-up will be required.