anesth 4 thoracic surg 1/3 (pgs 1-28) Flashcards
section 1: anatomy of respiration
what is pao2 at the lips?
160mmhg (.21 x 760)
section 1: anatomy of respiration
- what is the moisture content of air in the nasopharynx?
- what is it by the time it reaches the carina
- 70-80% relative humidity
2. 100% humidified by the time it reaches the carina
section 1: anatomy of respiration
what is pao2 by the time it leaves the nasal turbinates?
150 (760-40=720… 720 x .21=150)
section 1: anatomy of respiration
how much of the Dead space anatomy does the upper airway constitute?
30-50% of VD anat.
section 1: anatomy of respiration
- what can a NT tube block/ cause?
- how long might it take for symptoms to emerge?
1a) eustachian tube
b) frontal and maxillary sinuses (causing sinusitis)
c) otitis media
d) mastoiditis
2. may occur several days later
section 1: anatomy of respiration
lower airway:
what are bronchi and bronchioles sometines called?
- bronchi= central or large airways
2. bronchioles= peripheral or small airways
section 1: anatomy of respiration
what type of respiration is the lower airway responsible for?
external respiration (the transfer of gasses from and to the atmosphere)
section 1: anatomy of respiration
- what generation is the trachea?
- what is its length and diameter?
- what vertebral level is the carina at?
- what forms the trachea?
- where are the cords?
- trachea is generation “0”
- length is 10-13 cm; diameter is 1.5-2.5 cm
- carina is at level of T4-T6
- formed by 16-20 “C” shaped cartilaginous rings
- cords at C4-5
section 1: anatomy of respiration
- what generation is mainstem bronchi?
- what angle for right and for left?
- how far down mainstem is RUL bronchi?
- bronchi are generation 1
- right is 25 degrees; left is 40-60 degrees
- RUL is 2.5 cm past the carina
section 1: anatomy of respiration
- what airways are generation 2?
- how many do you have?
- lobar bronchi are generation 2
2. you have 3 right and 2 left (one for each lobe)
section 1: anatomy of respiration
- generation 3 are?
- how many are there?
- segmental bronchi
2. 18
section 1: anatomy of respiration
- generations 4-9
- what happens to the size and cartilage?
- how much airway resistance below the glottis normally occurs here?
- what begins to emerge here?
- subsegmental bronchi #4-9
- size from 4 mm to 1 mm with decreasing amounts of cartilage
- 80% of RAW (airway resistance) below the glottis occurs here
- emergence of goblet cells and mucosal glands
section 1: anatomy of respiration
- broncioles are generation #?
- tube diameter is how big? (what is that the same size as?)
- what happens to the walls? How is patency maintained?
- how much of the RAW is found in these airways (2 mm or less)?
- how is this possible?
- broncioles are generation #s 10-15
- tube diameter is 1mm (same diameter as a period “.”).
- no cartilage in walls. patency is maintained by elasticy of surrounding parynchyma
- less than 20% (in airways
section 1: anatomy of respiration
- what is the last portion of the airways to only conduct (and not exchange gasses)? what generation are they?
- what is their diameter?
- what cells start here? what do they produce?
- terminal bronchioles (generation 16)
- diameter is 0.5 mm
- contains surfactant producing Clara cells
section 1: anatomy of respiration
- what is the name of the respiratory pathways of generations 17-19?
- what is this the beginning of?
- what factors influence airway patency here?
- respiratory bronchioles
- beginning of lung parenchyma (gas exchange units of the lung)
- airway patency factors are same that influence alveolar patency
section 1: anatomy of respiration
- alveolar ducts…what generation?
- how many of these?
- alvolar ducts arise from?
- generation 20-24
- 9 million of these
- ducts arise from walls of respiratory bronchioles
section 1: anatomy of respiration
- what is generation 25?
- what percentage of alveoli arise from what 2 origins?
- alveolar sacs
2. 65% arise from sacs; 35% arise from ducts
section 1: anatomy of respiration
- generation 26…?
- what is the surface area?
- how are alveoli connected?
- why have so many (how many)?
- alveoli
- 9m x 9m (80 m squared or 29 ft x 29 ft)
- connected by “pores of Kohn”
- by having 300,000,000 single alveoli, surface area for gas exchange is increased
section 1: anatomy of respiration
- how much of lung volume is alveolated?
- how much of total lung volume is dead space?
- 3L
2. 150 ml
section 1: anatomy of respiration
- what is TLC (total lung capacity) in Liters?
- what is FRC (functional residual capacity) in liters?
- what is
- TLC=6L
- FRC=2.5L
3.
section 1: anatomy of respiration
where is blood distributed in the body at any one momemt?
a) veins= 65%
b) arteries= 15%
c) pulmonary vessels= 9%
d) heart= 7%
e) capillaries= 5%
section 1: anatomy of respiration
how much distending pressure does it require to take a 500 mL breath
3 cmH2O
section 1: anatomy of respiration
- Where does most of the RAW is below the glottis occur?
- where does the rest occur?
- 80% of the RAW below the glottis occurs at the subsegmental bronchi (generations 4-9)
- the other 20% occurs at the bronchioles (generations 10-15)
section 2: regulation of respiration:
- inspiration is always ____?
- exhalation is always ____ except for ____?
regulation of respiration:
- inspiration is always -active?
- exhalation is always -passive except for -with active expiration?
section 2: regulation of respiration:
what muscle groups are used in inspiration?
- diaphragm
- external intercostals
- accessory muscle group
section 2: regulation of respiration:
how do the external intercostals work?
- elevate anterior end of each rib
- increases AP and transverse diameter by bucket handle
section 2: regulation of respiration:
- what innervates the diaphragm
2a. how much excursion does the diaphragm cause with normal excursion ?
2b. with effort?
- controlled by phrenic nerve c3,4,5
2a. 1.5 cm
2b. 7-8 cm
section 2: regulation of respiration:
What are the layers of alveolar epithelium (that we need to know)?
- type I, type II, type III
section 2: regulation of respiration:
what is type I alveolar epithelium?
specialized for gas exchange, form the thin alveolar walls
section 2: regulation of respiration:
what are type II epithelium (what do they do)?
- cover 10% of the alveolar surface
- produce surfactant
- regenerate type I cells
section 2: regulation of respiration:
what are type III cells (what do they do)?
phagocytic macrophages which aid in cleaning debris
section 2: regulation of respiration:
- what are the major accessory muscles used in inspiration?
- what type of respiration are accessory muscles active in?
- sternocleidomastoid, scalenes (anterior, middle, posterior), pec major & pec minor
- not used during resting ventilation (used during exercise, strenuous breathing)
section 2: regulation of respiration: central chemoreceptors: 1. how do they work? 2. where are they located? 3. what are the effects of stimulating central chemoreceptors?
- sense changes in pH of CSF (monitor arterial CO2 concentration)
- located in medulla of brain
- increase ventilatory drive by stimulating inspiratory and vasomotor centers in the medulla (causing increased VT followed by increased RR, increased CO and increased SVR).
section 2: regulation of respiration: peripheral chemoreceptors: 1. what do they respond to? 2. where are they located? 3. what does their stimulation result in?
- respond to decreased O2 levels (decreased paO2, SaO2, Hb, pH as well as vastly increased paCO2 and methemoglobinemia)
- located in carotid bodies
- stimulation results in increased VE and CO (by increasing VT, RR, HR, BP, PVR also increased bronchial smooth muscle tone, adrenal cortical and cerebral cortex activity).
section 3. gas transport:
- what is pO2 AT the nose?
- what is pO2 at the larynx? why?
- what is pO2 at the alvoeli? why? what is co2?
- what is pO2 at the left ventricle? why?
- what is pO2 at right ventricle/ PA? why? what is CO2?
- at nose=160 mmhg
- at larynx=150 mmhg; d/t mixing with H20 (.21 x (760-47))
- at alveoli=102 mmhg; d/t mixing with CO2 (which is 40mmhg)
- at LV=94 mmhg; d/t mixing with “blue” shunt blood from thebesian, bronchial and pleural vessels
- at RV/PA=40 mmhg; 46 mmhg d/t drop off of O2 to tissues and pick up of co2
section 3. gas transport:
what happens to barometric pressure (pB) with an increase in altitude?
pB drops as altitude increases
section 3. gas transport:
- what percentage of air is oxygen?
- nitrogen?
- Co2?
- 21%
- 78%
- 0%
section 3. gas transport:
what is the alveolar pressure at end expiration?
equal to atmospheric pressure
section 3. gas transport:
what does an increase in pACO2 (alveolar CO2) do to pAO2 (alveolar O2)?
increased pACO2 decreases pAO2 (since nitrogen level doesnt change and vapor pressure is dependent on temp; if one tension increases (co2) the other (o2) must decrease).
section 3. gas transport:
- what does the respiratory quotent (R) state?
- what does this mean for pAO2 when pACO2 increases?
- that for every 250 ml of oxygen that enters the body, 200 ml CO2 must leave (quotent=0.8)
- for every increase in CO2 by 1 mmHg, PAO2 will decrease by 1.2 mmHg
section 3. gas transport:
1. Is alveolar O2 (pAO2) equal to arterial O2 (paO2)?
- shunted blood causes arterial O2 to ALWAYS be lower than pulmonary end capillary (or alveolar) pO2
section 3. gas transport:
what is the formula for (alveolar) pAO2?
pAlvO2=(Fio2 x [pB-47]) - (1.2 x paCO2)
ex. —.21 x (760-47) - 1.2 x 40 =
- –149.73-48
section 3. gas transport:
what does an elevated alveolar-arterial gradient reflect?
lung disease
section 3. gas transport:
how much oxygen does nasal canula give you?
1 to 6 L=24 to 44% (4% per Liter)
section 3. gas transport:
how much oxygen does a face mask give?
8 to 10 liters (at least more than 5 Liters) equals 40-60%
section 3. gas transport:
How much oxygen does a face mask with reservior (NRB)give?
a flow of 6 to 10 L; yields 60-100%
section 3. gas transport:
venturi mask delivers how much oxygen?
4-8L yields 24-48%
section 3. gas transport:
what is denitrogenation absorptive atalectasis?
- when there is a stenosis of an alveolar duct and a patient is given 100% o2 (for denitrogenation), the oxygen leaves the alveoli faster than more oxygen can get in (past the narrowing)
- the alveoli then collapses