PHTY205 Lecture Notes - Lecture 16: Shortness Of Breath, Central Chemoreceptors, Lung Volumes
Document Summary
Describe the pathophysiology (cause) of dyspnoea: perception of uncomfortable/unpleasant respiratory sensations, mechanism, mismatch between motor output and incoming afferent signals, peripheral and central chemoreceptors that monitor co2 movement. Feedback from chest wall about how much movement there is. Supported positioning/relaxation: reduces use of postural muscles -> reduces amount of o2 needed, exercise training (phty300, o2 therapy. Lean forward position: alter perception, desensitise, coping strategies. Discuss the rationale for the use of the lean forward position to manage dyspnoea. Stabilising the arms results in accessory muscles being able to work more efficiently: changes origin and insertion of postural/accessory muscles. Supine: during inspiration drop in oesophageal pressure, as the diaphragm descends -> increase in gastric/intra-abdominal pressure. Inspiration abdominal wall moves out, reverse happens when you breathe out. Standing and sitting erect: a lot more emg activity in all muscles involved to generate the negative inter-thoracic pressure, also a negative gastric pressure, abdominal wall moves in opposite direction.
