Blood pressure (BP) measurement is one of the basic procedures in biomedical research. Three methods are most widely used for recording the BP in a rat: tail cuff plethysmography (noninvasive), intra-arterial catheters (invasive), and radio telemetry.
Intra-arterial catheters yield the most precise values, and surgery is required to use them. Most of our physiological and pharmacological knowledge related to BP, and its regulation has been derived from acutely prepared, anesthetized, or immobilized laboratory animals.
Invasive blood pressure (IBP) is the gold standard against which the accuracy of noninvasive blood pressure method (NIBP) is compared. IBP is the arterial pressure directly measured in any artery such as the radial, femoral, or brachial artery using a saline-filled catheter/cannula.
Invasive blood pressure can be done with 3 different types of catheters:
- Fluid Filled
- Solid State
- Fiber Optic.
The response of solid state and fiberoptic catheters is similar.