Maximum vital capacity decreased in
C i.e. Trendelenberg Trendelenburg (head down) position causes cephalad shift of abdominal viscera and diaphragm leading to marked decrease in lung capacities (i.e. vital capacity, functional residual capacity, total lung volume, lung compliance) Q Respiratory rate is not affected in any position.Q Physiological effects of patient position Trendelenburg Horizontal Lithotomy Prone Lateral decubitus * Cardiac : Activation of * Cardiac * Cardiac * Cardiac * Cardiac baroreceptors produce - Decreased hea rate - Increase in - Decrease - Cardiac output unchanged decrease in - Decreased peripheral circulating preload, cardiac unless venous return - Cardiac output resistance blood volume output, blood obstructed. - Hea output - Equalization of and preload. pressure due to - Aerial blood pressure - B.P. pressure through out - Effect on peripheral may fall as a result of - Peripheral vascular resistance the aerial system blood pooling of blood. decreased vascular * Respiratory : Cephalad shift of - Increased right sided pressure and * Respiratory resistance. abdominal viscera produces filling & cardiac cardiac - Decreases total * Respiratory - Marked decrease in lung output. output lung compliance - Decreased volume of capacities (VC, FRC, Total * Respiratory depends on and increases dependent lung. lung volume, lung - Diaphragm is volume work of - Increased perfusion of compliance)Q displaced cephalad status. breathing. dependent lung. - Atelactasis by abdominal viscus * Respiratory - Increased ventilation of - Increase ventilation perfusion - Increase perfusion of - Decreased dependent lung in awake mismatch dependent vital capacity. patient (No v/q mismatch) - Increase likelihood of (posterior) segment - Increase - Decreased ventilation of regurgitation - Functional residual likelihood of dependent lung in * Others - Increase intraocular pressure in glaucoma - Increase in intracranial Pressure & decrease in cerebral blood flow. capacity decreases aspiration anaesthetized patient (v/q mismatch) - Fuher decrease in dependent lung ventilation with paralysis and open chest.
Prone
Supine
Trendelenberg
Left lateral