If at the beginning of inspiration, pulmonary compliance is 0.2 L/cm H2O and a trans-pulmonary pressure is 5 cm H2O .If a person inhales 600 mL of air,what shall be the value of transpulmonary pressure ?
The transpulmonary pressure would be 8 cm H2O when she inhales 600mL of air. Pulmonary compliance is 0.2 L/cm H2O or 200 mL/cm H2O To expand the lungs by 200 mL, one require an increase in trans-pulmonary pressure by 1 cm H2O If person inhales 600 mL of air, Transpulmonary pressure has to be increased by 3 x 1 cm = 3 cm of H2O. Hence, the transpulmonary pressure would be 5 + 3 = 8 cm H2O.
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Respiratory System Pa 1