How much saline should be used for small animal pressure-volume saline calibrations?

The goal of a saline bolus is to achieve a sudden increase in measured volume while maintaining a stable pressure signal. This provides the data required by the software to eliminate the parallel volume of the myocardium. The response to the bolus should look like below:

A mixture of 15-30% hypertonic saline solution is typically injected through the jugular vein. The left jugular is suggested for ease of surgery when collecting PV data from the left ventricle.

  • Typical injection ranges for mice are 5-10 µL
  • Typical injection ranges for rats are 20-40 µL

Depending on injection site, animal size and strain bolus volume and strength of solution may vary. It may be necessary to increase/decrease the amount of saline injected, speed of injection, and the percent of salt within the saline.