Test questions Flashcards
(17 cards)
Women has absent sounds over right lung fields. Her Po2 = 60
PCO2 = 50
HCO3- = 25
What is the first likely thing to be increased
Shunt fraction
What would happen to someone’s arterial PO2 and PCO2 while awake in high altitudes.
Both arterial PO2 and PCO2 would go down. The hypoxemia drives ventilation which will lower PCO2 as well.
Patient has HCO3- = 26
PO2 = 80
and pH 7.33
WHat is the driving force for the patients hyperventilation?
You should conclude that PaCO2 is high and its a respiratory acidosis considering that the HCO3 is elevated.
The oxygen is not low enough to trigger hypoxic drive.
That means the driving force is hypercapnea
A patient has really high blood glucose and low bicarb. What does this mean about his oxygen Hb affinity?
It’s lowered due to metabolic acidosis with ketoacidosis. Low pH lowers the binding affinity of hemoglobin to oxygen
Difference between hypoxia and hypoxemia
Hypoxia leads to hypoxic drive which is driven by PaO2 levels. It is not affected by carbon monoxide. Hypoxia is the driving force for ventilation at high altitudes.
Hypoxemia is lowered CaO2 levels and is affected by carbon monoxide.
What is the affect on pulmonary vascular resistance adn alveolar diffusing capacity during exercise?
During exercise pulmonary vascular resistance goes down. This is because of the increased cardiac ouput supplies enough blood pressure to overcome the cirtical opening pressure for previously underperfused lungs. This lowers the pulmonary vascular resistance. This increases alveolar diffusing capacity due to increased ventilation and perfusion.
What increases FRC?
Decreased lung recoil - COPD
What is the main driving force for ventilation always
PaCO2
What happens to FEV1, TLC, RV, DLCO in restrictive disease?
all go down by definition.
A patient is cyanotic and his trachea deviates to the right, what is the likely diagnosis?
Tension pneumothorax on the left side.
A 26 year old has cellular destruction at the distal portions of his respiratory system. He makes full recovery, why?
He has type II pneumocytes which serve as stem cells to repair the alveoli.
What are the relative positions of the pulmonary arteries, veins and bronchi?
Pulmonary veins - anterior and inferior
Pulmonary arteries - posterior and superior
bronchi - most posterior and is also superior
At what level does the trachea bifurcate?
What level is the sternal angle (ribs)?
Trachea bifurcates T4-T5
Sternal angle is at second intercostal rib/space and where the trachea bifurcates, T4-T5/
What is the function of pneumocyte II and more specifically the effect of surfactant?
What about clara cells
- Surfactant reduces surface tension which reduces surface tension
- Surfactant helps the elastic recoil of the lungs
- Surfactant coats bacteria/viruses so they are more readily phagocytosed by alveolar macrophages
- serve as stem cells which can produce type i and type II pneumocytes.
Clara cells are in smal bronchioles, secrete lipoprotein which reduces surface tension in air ways, metabolize foreign materials and serve as stem cells.
What is the composition of the respiratory epithelium
30% goblet cells
30% ciliated cells - move layer of mucous, much faster in large airways
30% basal cells - stem cells to replace goblet and ciliated cells.
3-5% DNES cells - secrete neuropeptides and vasoactive substances into the lamina propria
Bowman glands in lamina propria
Histology -
1. mucosa: pseudostratified ciliated epithelium with goblet cells + lamina propria with lymphatic ducts
(BALT): bronchus associated lymphatic tissue)
lamnia propria is highly vascular and periodically becomes engorged with blood obstructing passage of air. (aka swell body)
3. Submucosa with mucous and serous glands
4. (adventitia with cartilage if trachea)
A person has normal glucose levels, normal perfusion (blood pressure with normal oxygen saturation). But low pH, low HCO3-. AG of 30. What likely condition lead to these blood work results?
Methanol ingestion
Can’t be ketoacidosis nor lactic acidosis (normal glucose and normal perfussion)
Not GI fluid loss nor pulmonary edema because we are dealing with a metabolic acidosis.
A baby has a low pH, really high PCO2 (75) and extremely low PO2 (10). What can account for this?
Pulmonary dysfunction.
