Witwer Barton Lower Resp Tract Flashcards
Type one alveolar cells comprise the cell well while type two have the important function of producing 1._______. Which reduces 2.______ ______ and prevents alveolar collapse
- Surfactant
2. surface tension
The respiratory membrane between the capillary and alevolus is about ______ to _____ micron ( an RBC is 8 microns )
.5 to 1 micron
Witwer would really like you to know that surfactant does what…
increases lung compliance
Prevents atelectasis
The primary muscles of inspiration are
Diaphragm
external intercostals
Active breathing occurs when
a. always
b. excercise and pathological states
c. only when sleeping
b. exercise & pathological states
this effing guy poiseuille made a law. Basically the ______ of the airway plays a big role in respiration a. lengthb. elasticity c. diameter d. blood flow
c. diameter
straw analogy
Pressure in the alveoli is _______ to the pressure in the environment a. the same b. lessc. more
a. the same
In obstructive respiratory diseases what is the source of the pathology, the airway or the ability of the lung to fuly expand
the airway
Elasticity is _____ related to compliance a. directly b. not related c. inversley
c. inverse
Elasticty is …..
recoil property of the lungs and chest wall
Compliance
measure of the ability of the lungs and chest wall to expand / distend (change in volume for a given pressure)
In restrictive disease the compliance is ______
low (the lungs are stiff)
increase in intrathoracic pressure will ______ the diameter of the airways and result in increased expiratory ______a. decrease, resistanceb. increase, resistance c. decrease, compliance
a. decrease
One liter of blood hold ______ ml of O2a. 300b. 200c. 400
b 200mL of O2
Ideal V/Q ratio is _____a. 1.0b. 1.5 c. 2
a. 1.0
because the ideally one liter of blood should have 200 ml of o2 and one liter of air should have 200 ml of o2 200/200= you get it
Ideal V/Q ratios do not acutally happen. Normally the ratio is actually ______.
0.8 the alveolar ventilation in L/ min is 80 % of the value for pulm blood flow per minute
Upper lungs have the _____ blood flow and ventilation. Lower lungs have ____a. greatest, lowest b. equal c. Lowest, greatest
c. LOWEST, GREATEST
When there is perfusion but NO GAS EXCHANGE there is_____
right to left pulmonary shunt
in this situation there is always hypoxemia.
This hypoxemia cannot be corrected with oxygen admin
In right to left cardiac shunts hypoxemia occurs NOT because there is no gas exchange but because there is ……
mixing of oxygenated and deoxygenated blood
dont get this confused with pulm shunts
When there is ventilation and no perfusion there is ______
dead space
this can occur with a PE
value of tidal volume
.5 L
Value of vital capacity
4.5 L
This is what is used in the Forced Vital Capacity FEV1 Test
Value of anatomic dead space
150ml
Alveoli that do not participate in gas exchange
functional dead space
The acinar unit is composed of
bronchioles alveoli pulmonary blood vessels
Most common cause of Lung CA (80% of cases)
Non Small Cell Lung Cancer (NSCLC)
Pancoast Tumor cause
Findings?
primary small cell lung cancer
Destruction of Cervical Sympathetic
Ganglion>Horner’s Syndrome
Asbestosis
- occupational dz
- no longer used
- thickening of plura, superimposed mesothelioma.
Rational For O2 therapy
beware of?
- Supplemental O2
- COPD SPO2 <88% or PaO2 <55mmHg
(target 88-92%)
O2 toxicity
Retrolentil fibroplasia in infants=blindness
↓ O2 drive to breathe (COPD)= worsening Hypercapnea
Mechanical ventilation goals (4)?
Method used?
- Oxygenation- critically ill or under anesthesia
- CO2 elimination
- Maintain adequate Tidal Vol
- Maintain RR
(+) Pressure ventilation
Indications for Mechanical Ventilation
1. Acute Resp Failure (PNA, Sepsis, Postop infect, HF, ARD, Trauma, Aspiration) 2. Coma 3. COPD exacerbation 4. Neuromuscular weakness
Mechanical Ventilation Variables
- TV
- RR
- PEEP
- Fraction of inspired O2= FIO2
- Peak Pressure
- Plateau Pressure
- Trigger sensitivity
- Flow Rate
- Flow Pattern
PEEP
too mcuh/too little precautions?
Positive End Expiratory Pressure
= alveolar pressure above ATM pressure @ END EXPIRATION (1mmHg=3-5cmH2O)
This keeps alveoli, bronchioles, bronchi open
prevents collapse
too much PEEP= blow out alveoli
too little PEEP= alveoli wont open
Mechanical Ventilation Precautions (7)
- Lung Inj
- Overinflation
- Sheer stress between adjacent structures
- Collapse of bronchi, bronchioles, and alveoli
- Alveolar damage w/ loss of surfactant
- Atelectasis
- Oxygen Toxicity to lungs occurs above a FIO2 of 50%
What is obstructed in Obstructive Lung Dz?
The air flowing through airways.
Work needed to overcome
flow resistance in abnormal airways
What is obstructed in Restrictive Lung Dz?
The ability of the lung to expand.
Work needed to overcome elastic forces of abnormal lung
What is obstructed in Restrictive Lung Dz?
The ability of the lung to expand.
Work needed to overcome elastic forces of abnormal lung
Residual volume
1.5L
Total lung capacity
6L
Inspiratory capacity
4.5L
Neonate respiratory distress syndrome is a risk of premies born before _____ since this is when _______ is produced.
- 28th week
2. Surfactant
What happens to lung volumes in Obstructive lung Dz?
Lung capacities?
Decreased vital capacity
INCREASED functional residual capacity (HIGH increase in residual volume)
FEV1/FVC decrease
FEV1 decreased even more so.
(ratio <0.8)
Resistance to Inspiration – alveoli don’t open adequately
Restrictive lung disease
Restrictive lung Dz examples
-Stiff lungs with thick alveolar walls (inflammatory, connective tissue disease) -Stiff chest wall -Respiratory Muscle weakness -Central Sleep Apnea
What happens to lung volumes in Restrictive lung Dz?
Lung capacities?
Decrease Vital Capacity
Decreased Functional Residual Capacity
Esp decrease total ratio of FEV1/FVC
will be close to NL but overall low
