Pathophysiology of respiratory system

Question 1

COPD : what it stands for, curable ?, characteristics

Answer 1

chronic obstructive pulmonary disease.
Uncurable.
- breathing difficulties
- limitations of inspiratory flow
- changes in airways/alveoli
- triggered by inhalation of harmful particles / gases

Question 2

3 main symptoms and 3 main risk factors

Answer 2

• dyspnea
• cough
• secretions
• smoking
• environmental factors
• genetic factors

Question 3

what machine used to establish diagnosis ?

Answer 3

Spirometer.
COPD = non reversible obstruction = FEV1/FVC <0.7 post bronchodilator

Question 4

name another assessment that can be done for COPD diagnosis

Answer 4

CAT : 8 questions about quality of life asked every couple months

Question 5

what is the refined ABCD assessment ?

Answer 5

first the FEV1 test.
Then look at exacerbation history and symptoms (CAT, MRC) -> classify in states A, B, C or D

Question 6

what are some COPD etiotypes

Answer 6

genetic, early life events, infection, smoking, environmental

abnormal lung development, COPD-asthma overlap, unknown

Question 7

2 main aims of therapy, explain inhalation therapy and self-management

Answer 7

Reduce symptoms + risk !

Inhalation :
- bronchodilators (relaxes muscles in airways)
- cortisone : inflammation

Self :
- healthier lifestyle (stop smoking, …)
- monitor symptoms and contact with physician

Question 8

what is an exacerbation ? most common cause ? duration ?

Answer 8

acute breathing deterioration leading to additional therapy. Mostly due to viral airway infections. 7-10 days.

Question 9

what test can be done to assess the performance of patients with underlying diseases ? 2 things you can measure

Answer 9

6 minute walking test.
-> baseline CO and peak oxygen uptake

Question 10

how can you enhance the 6MWT ?

Answer 10

mobile telemetry -> able to identify factors limiting exercise in patients (real time monitoring)

Question 11

what is the mean response time ?

Answer 11

time needed for a 63% increase in O2 uptake

Question 12

oxygen kinetics : non linear regression model with 6 parameters

Answer 12

1, 2, 3) VO2 rest, steady state and recovery
4) tau1 : growth rate of the mono exponential VO2 during 6MWT
5) tau2 : steepness of exponential decay during recovery
6) T0.5 VO2 : half decrease time of VO2 during recovery

Question 13

what does the incline of VO2 during exercise phase tell us about ?

Answer 13

Info about oxygen delivery and muscle metabolism -> delayed in patients with chronic pulmonary diseases

Question 14

how can you model batches of curves ?

Answer 14

non linear mixed models

Question 15

what do VO2 on-kinetics during 6MWT and recovery kinetics reflect ?

Answer 15

1) oxygen delivery -> functional capacity in patients with COPD

2) ability to recover from exercise, under investigated until now

Question 16

4 parameters for non linear mixed model of oxygen recovery, what are the 3 plausible regression models ?

Answer 16

tau, VO2 steady state, VO2 rec, T0.5 VO2

1) symmetrical sigmoid (log-logistic)
asymmetrical sigmoids :
2) inflection point at beginning (weibull I)
3) inflection point at the end (weibull II)

Question 17

which model fits better the COPD stage II ?

Answer 17

weibull 1 : steeper decrease at beginning of recovery