Asthma attacks result in reversible blockage of respiratory pathways, leading to difficulties in breathing, reduced FEV1, and decreased maximal voluntary ventilation (MVV) due to bronchoconstriction and inadequate air sac capacity. The pathophysiology is characterized by lower oxygen availability and higher carbon dioxide levels, which worsen during apnea. Apnea can also follow hyperventilation, with impaired pulmonary exchange causing further decreases in oxygen and increases in carbon dioxide levels.

1. Ques-1. how and why would an asthma attack attack have an impact on the FEV and MVV?
Answer:
Asthma is the reversible blockade of respiratory pathways, which causes difficulty in breathing
out. This causes tightness in the chest region, dyspnea, and expiratory wheezing. Asthma
pathophysiology includes the constriction of bronchiolar smooth muscles result in low alveolar
PO2 due to lower oxygen availability for respiration. PO2 is decreased and Pco2 is increased.
Lesser ratio of V/Q leading to reduced partial pressure of O2 (due impairment of the pulmonary
air exchange) and reduced excretion of CO2 leading to more PCO2 usually happens in apnea or
asthma.
Maximal voluntary ventilation (MVV): it is the total volume of air expired within a specific time
when repetitive maximal voluntary effort. In asthma MVV, is reduced due to allergic histamine
secretion in the air sacs (alveoli) & due to bronchoconstriction. This is due to inadequate space
availability to fill the air sacs during respiration process
The variables such as FEV1 (expiratory volume) will be decreased in “asthma- lung disease due
to narrowing of bronchioles” however, FVC (F vital capacity) is approximately normal therefore,
finally FEV1/FVC ration will be decreased with time.
Peak Expiratory Flow Rate (PEFR): also referred as FEV (forced expiratory volume). In the
above case, spirometry performed to assess the function of lungs and it depends on age and sex,
height. Given, 60% predicted PEFR means severe and obstruction of airways lungs due to
asthma.
Ques-2. What causes apnea that sometimes occurs after hyperventilation?
Answer:
Apnea usually reduced rate of breathing thereby volume of breathing is less. Hyperventilation
induces higher incidence of pulmonary edema or fluid accumulation in the lungs as a result
"apnea" is going to develop. PO2 is decreased and Pco2 is increased. Lesser ratio of V/Q
leading to reduced partial pressure of O2 (due to impairment of the pulmonary air exchange) and
reduced excretion of CO2 leading to more PCO2 usually happens in apnea
Solution
Ques-1. how and why would an asthma attack attack have an impact on the FEV and MVV?
Answer:
Asthma is the reversible blockade of respiratory pathways, which causes difficulty in breathing
out. This causes tightness in the chest region, dyspnea, and expiratory wheezing. Asthma
pathophysiology includes the constriction of bronchiolar smooth muscles result in low alveolar

2. PO2 due to lower oxygen availability for respiration. PO2 is decreased and Pco2 is increased.
Lesser ratio of V/Q leading to reduced partial pressure of O2 (due impairment of the pulmonary
air exchange) and reduced excretion of CO2 leading to more PCO2 usually happens in apnea or
asthma.
Maximal voluntary ventilation (MVV): it is the total volume of air expired within a specific time
when repetitive maximal voluntary effort. In asthma MVV, is reduced due to allergic histamine
secretion in the air sacs (alveoli) & due to bronchoconstriction. This is due to inadequate space
availability to fill the air sacs during respiration process
The variables such as FEV1 (expiratory volume) will be decreased in “asthma- lung disease due
to narrowing of bronchioles” however, FVC (F vital capacity) is approximately normal therefore,
finally FEV1/FVC ration will be decreased with time.
Peak Expiratory Flow Rate (PEFR): also referred as FEV (forced expiratory volume). In the
above case, spirometry performed to assess the function of lungs and it depends on age and sex,
height. Given, 60% predicted PEFR means severe and obstruction of airways lungs due to
asthma.
Ques-2. What causes apnea that sometimes occurs after hyperventilation?
Answer:
Apnea usually reduced rate of breathing thereby volume of breathing is less. Hyperventilation
induces higher incidence of pulmonary edema or fluid accumulation in the lungs as a result
"apnea" is going to develop. PO2 is decreased and Pco2 is increased. Lesser ratio of V/Q
leading to reduced partial pressure of O2 (due to impairment of the pulmonary air exchange) and
reduced excretion of CO2 leading to more PCO2 usually happens in apnea