Lange and Laws Flashcards
Final Exam content (21 cards)
Which of the following would decrease a patient’s FRC?
3rd trimester in pregnancy
pulmonary fibrosis
obesity
What are the changes you would expect in lung volumes and capacities going from supine to an upright position?
Increased: FRC, ERV
Decreased: IRV, IC
Same: RV, TLC, Vt, VC
How would standard lung volumes and capacities differ in an elderly person from a young healthy 20 year old?
Increased: RV, FRC
Decreased: ERV, IRV, IC, VC
Same: Vt, TLC
What decreases PVR?
moderate exercise (increased CO and BP) (leads to more Zone 2 conditions and increases the boundary between Zones 2 and 3)
What increases Zone 1 conditions of the lungs?
blood loss secondary to trauma, PPV and PEEP
What causes pulmonary edema?
-over-transfusion of saline
-occlusion of lung lymphatics
-left ventricular failure
-low concentration of plasma proteins
-destruction of pulmonary capillary endothelium by toxins
If pulmonary partial pressure of a gas equilibrates with the alveolus before the blood leaves the capillary what is true about that gas?
- It is perfusion limited
- increasing CO WILL increase the amount of gas that diffuses
- increasing alveolar partial pressure of a gas WILL increase the amount of gas diffused
- recruiting additional pulmonary capillaries WILL increase the amount of the gas diffusion
… Fick’s Law
A patient has lost enough blood for their Hb to go from 15g/dL to 12g/dL. What would you expect to decrease?
oxygen carrying capacity and arterial oxygen content would decrease
what conditions would be expected to stimulate arterial chemoreceptors?
strenuous exercise, hypoxia at high elevations, acute airway obstruction, and large intrapulmonary shunts
stimulation of which receptors leads to a decrease in ventilation?
Hering-Breuer stretch receptors
What would decrease the ventilatory response to CO2, shifting the CO2 response curve to the right?
barbiturates, slow wave sleep, metabolic acidosis, deep anesthesia
What would you expect to occur in an untrained person who begins exercise?
decreased PVR
increased CO
more homogenous V/Q ratios throughout the lung
increased Dclo (diffusing capacity of the lung)
What would you expect to occur in the blood gas of a trained athlete undergoing strenuous exercise?
no changes in PO2, PCO2 or pH
What responses would you expect in a person after 6 days of residence at high altitude?
elevated mPAP
increase VA (from sea level)
increased Hct
decreased plasma bicarb
What would you expect to see change w/r to lung volumes and capacities in neck-deep submersion in water?
increased work of breathing (more pressure on the chest wall)
decreased FRC (passive forces are impacted but volumes and capacities involving active expiration and inspiration are not changed as we can overcome these with an increase in work of breathing)
What would you expect to be increased in a patient with OSA?
inspiratory airway resistance (d/t extra thoracic obstruction)
PVR (d/t HPV)
right ventricular afterload
arterial Hb concentration
What is Dalton’s Law?
in a gas mixture, the pressure exerted by each individual gas in the space is independent of the pressures of other gasses in the mixture. Basically explains partial pressures
What is Boyle’s Law?
As the volume of a gas increases, it’s pressure decreases (they are inversely related) at a constant temperature
What is Henry’s Law?
states that the amount of gas absorbed by a liquid is directly proportional to the pressure of the gas to which the liquid is exposed to. Ex. alveolar PO2 is 100mmHg. and arterial PO2 is also 100mmHg
What is Graham’s Law?
The rate of diffusion of a gas is inversely proportional to the square root of it’s molecular weight.
What is Fick’s Law of Diffusion?
the amount of gas diffused is directly proportional to: surface area, solubility, pressure gradient
and inversely proportional to the thickness of the barrier and the molecular weight of the gas
