RESP- Clinical Evaluation of Respiratory Function

Question 1

what does FVC and FEV1 stand for

Answer 1

FVC- forced vital capacity

FEV1- Forced expiratory volume in 1 second

Question 2

how do you calculate the % of total lung capacity an individual can exhale in the first second

Answer 2

100 x FEV1/ FVC

Question 3

what % is indicative of airway obstruction

Answer 3

<70% - FEV1/FVC

Question 4

an FVC < 80% with and FEV1/FVC >70% is indicative of what

Answer 4

fibrosis - decreased lung compliance

Question 5

what is the difference between static compliance and dynamic compliance

Answer 5

static compliance is taken whilst the airflow is 0

dynamic compliance is then during the movement of air

Question 6

the graph of dynamic compliance forms a loop - what is the area of the loop a measure of

Answer 6

level of airway resistance

Question 7

it is useful to know alveolar oxygen pressure for determining the cause of respiratory failure - how is this calculated

Answer 7

PAO2 = F102 x (PB-PH20) - (PaCO2/RER)

Where:
PAO2 - alveolar pressure 
F102 = fraction of oxygen present in inspired gas
PB= barometric pressure
pH20= H20 Vapour pressure
PaCO2 = arterial CO2 pressure
RER- respiratory exchange ratio

Question 8

outline the differentiation of different acid / base disorders

Answer 8

acidosis:

CO2 high (respiratory acidosis) - with :
HCO3 high = metabolic compensation 
HCO3 low= mixed acidosis

HCO3 low (metabolic acidosis) - with:
CO2 high - mixed acidosis
CO2 low- respiratory compensation 

alkalosis:

CO2 low (respiratory alkalosis)- with:
HCO3 high - mixed alkalosis
HCO3 low- metabolic compensation

HCO3 high (metabolic alkalosis)- with:
CO2 high - respiratory compensation
CO2 low- mixed alkalosis