Management of Prolonged Ventilation in ICU

Abstract

The primary function of the lung is gas exchange between alveolar gas and the blood flowing through the nearby capillaries. Ventilation is the process of movement of air into and out of the lungs to be available for gas exchange. Similar to other physiological systems, this process includes sensors (central and peripheral receptors) and effectors (muscles of respiration) working and interacting together to maintain respiratory homeostasis. The movement of gas in and out of the lungs is a mechanical process which depends upon: Respiratory muscles, Compliance of the lungs and chest wall and Gas flow in the airways. The lung behaves as an elastic body. Factors involved in this include the surface tension developed by the very large air–water surface area of the fluid lining the alveoli and the elasticity of the lung tissues. Flow is defined as the volume of gas passing a fixed point per unit of time. Resistance is a measure of the pressure required to generate flow through a tube.