This slide summarize all the ways to measure the blood pressure in an very easy manner.This slide specially explains all invasive methods of blood pressure measurement with real world images and examples.
• This technique involves direct
measurement of arterial pressure
by inserting a catheter (thin,
hollow, and flexible tube).
• Invasive (intra-arterial) blood
pressure (IBP) monitoring is a
commonly used technique in the
Intensive Care Unit (ICU) and
in the operating theatre.
• IBP technique also allows accurate blood
pressure readings specially the very low
pressures, for example in shocked patients.
• It allows continuous ‘beat-to-beat’ blood
• Its complex procedure involves many risks.
The first invasive blood
• The first invasive
attempt to measure
blood pressure was
made by Stephen
Hales in 1733.
• He inserted a glass
tube directly into the
artery of a horse
Catheterization method types
• Generally, this Invasive technique can be divided
into two division:
Extravascular Sensor System
Intravascular Sensor System
Extravascular Sensor System
• The sensor is located behind the catheter and
the vascular pressure is transmitted by
Steps to: Percutaneous radial artery
(A) The wrist is positioned and the artery identified by
(B) The catheter-over-needle assembly is introduced through
the skin and advanced toward the artery.
(C) Entry of the needle tip into the artery is identified by the
flash of arterial blood in the needle hub reservoir.
(D) Needle-catheter assembly is advanced at a lower angle to
assure entry of the catheter tip into the vessel.
(E) If blood flow continues into the needle reservoir, the
catheter is advanced gently over the needle into the artery.
(F) The catheter is attached to pressure monitoring tubing
while maintaining proximal occlusive pressure on the
• Anesthetic solution (typically 1% lidocaine) is
injected intradermally and subcutaneously
alongside the artery, using a 25- or 26- gauge
• A 3-mL syringe with the plunger removed should
be used as a blood reservoir
• Teflon catheter is the most common one used for
radial artery cannulation
• The size (20- or 18-gauge) of the catheter
• The catheter is advanced at an angle of 30 to 45
degree and lowering with each advance to ensure
that catheter enters the vessel lumen
Advantages of direct arterial blood
• Arterial blood sampling
• Continuous real-time monitoring
• Intentional pharmacologic or mechanical
• Failure of indirect blood pressure
• Supplementary diagnostic clues.
Implantation technique for blood
• A novel less-invasive blood pressure
monitoring system involve the principle:
if a blood vessel is pressed against a flat
surface of a pressure sensor diaphragm until
vessel flattening occurs, according to
Laplace’s law the pressure measured by the
sensor will be approximately equal to the
pressure inside the vessel