Question

How does your body alter driving pressure? Do you think altering pressure is more or less effective at regulating blood flow than changing vessel radius?

Answer 1

Firstly, the driving pressure of the respiratory system is defined as the difference between plateau pressure and positive end-expiratory pressure. i.e, driving pressure is the plateau airway pressure minus PEEP.It can also be expressed as the ratio of tidal volume to respiratory compliance,indicating the decreased functional size of the lung observed in patients with ARDS.

• Driving pressure is associated with clinical outcomes in ARDS,normal-lung patientsand post-surgical.
• It measures the strain on respiratory system and risk of ventilator- induced lung injuries.
• optimum driving pressure is below 14 cmH20

when driving pressure is altered the heart has to respond to a different force it is much difficult to maintain this.

Altering blood vessel radius is much more effective that altering driving force in order to effectively regulated blood flow because blood vessel radius is easier for the body to change.

• smaller the radius much bigger the resistance and much more decline in pressure.
• smaller radius also increase the collisions between particles and vessel walls.
• the body usually changes blood vessel radius to attain homeostatis easily.