Respiratory

Question 1

Helium dilution with spirometer

Answer 1

Measure reduction in helium concentrations to find functional residual capacity
%He1 x (STARTING volume of spirometer + volume of tubing) =
%He2 x (FINAL volume of spirometer + volume of tubing + FRC)

Question 2

Peak expiratory flow

Answer 2

Use peak flow meter to measure maximal breath in first fraction of a second.
Asses airway obstruction in COPD

Question 3

Ventilators repsonse to hypercapnea, hypoxia and asphyxia

Answer 3

Changes in ventilation, using spirometer, with or without CO2 absorber, and with or without oxygen or room air

Question 4

Anatomic dead space

Answer 4

Fowlers method

Inspiration of 100% O2, the N2 concentration rises during expiration to a plague, representing pure alveolar gas

Question 5

Regional differences in ventilation

Answer 5

Bottom greater ventilation than top (gravity)

Inhale 133Xe and use radiation counters off the back wall, shows higher xenon count at lower parts of the chest wall

Question 6

Spirometer

Answer 6

Meausure lung volumes: vital capacity, tidal volume, inspirations and expiration reserve volumes