Pneumothorax- Witwer Flashcards
The lung surface is covered by a serous membrane called the ________ pleura
visceral
*this membrane dips into the Fissures between the lobes of the lungs.
The inner surface of the thoracic cavity is covered by a serous membrane called the ______ Pleura. This pleura also separates the Pleural cavity from the Mediastinum.
Parietal
What lies between the visceral and parietal pleura?
Pleural space (=pleural cavity, or pleural sac)
which contains serous pleural fluid
Serous fluid acts by _______ action to help keep the visceral and parietal pleura together
capillary
What is the major reason the lungs stay inflated?
pressure in the lungs > pressure in the pleural space
At rest:
the elastic recoil of the chest wall tends to pull the chest ______.
&
the Elastic recoil of the lung will pull the lung ______
outward
inward
When air enters the pleural space through a hole in the chest wall or lung surface, the lung ________
collapses
**due to pressure in the pleural space becomes equal or greater to pressure in the lungs
Closed Pneumothorax:
Pleural cavity pressure is _____ than atmospheric pressure
less
Open pneumothorax:
Pleural cavity pressure is ______ atmospheric pressure
equal to
Tension pneumothorax:
Pleural cavity pressure is _____ than atmospheric pressure
greater
**air in pleural space increasing and unable to escape
How does a closed pneumothorax occur?
Due to a tear in the lung’s visceral pleura.
*Pleural space is open to the air in the lung
Note: the chest wall IS intact
How does an open pneumothorax occur?
hole in the Chest Wall
*Pleural space is open to the atmospheric air
If the hole in the chest wall becomes a one-way valve, ie allowing air to enter the pleural space but not exit out of the pleural space, with each breath air will move into and not out of the pleural space creating a ______
tension pneumothorax!
*pressure in the Pleural space is greater than the atmospheric pressure in the lung
Tension Pneumothorax can be secondary to an Open (One Way Valve Phenomenon) with a hole in the chest wall or a _______
Closed Pneumothorax with a hole in the lung
Closed pneumothorax arises from a small tear in the visceral pleura secondary to: (list 4 causes)
- Can occur spontaneously, from bleb that ”pops”.
- Lung disease: Pneumonia, Interstitial fibrosis, COPD
- Sudden increased pressure within the lung such as with a cough, Valsalva maneuver, or sudden blow to the chest.
- A broken rib pokes a hole in the Visceral Pleura
What is the ”One Way Valve” Phenomenon?
allows the flow of fluid or air (in the case of a tension pneumothorax) in only one direction.
Also termed a Check Valve, Ball valve, Flap valve, Non-return valve.
Ex’s: Aortic, Pulmonary, Mitral and Tricuspid valves, Vein valves
Open pneumothorax VS Tension Pneumothorax
Open: air moves freely in & out of the chest cavity thus the pressure of air within the Chest Cavity is equal to the ambient atmospheric air & air in lungs.
Tension: pressure of the air within the chest cavity increases incrementally with each breath creating an air pressure within the chest cavity that is greater than the air in the lung. This will push the Mediastinum to the opposite side and tamponade the Heart and opposite lung. Leads to EMERGENCY.
S/Sx of Pneumothorax
- Chest pain- pleuritic
- SOB/Dyspnea
- Tympani with percussion
- Absence of Breath Sounds on auscultation.
- Anxiety
- Acute Epigastric Pain
Why did professor Witwer emphasize the importance of “DON’T FORGET” when it comes to a pneumothorax
S/sx of tension pneumothorax can be subtle— beware that you don’t forget! make sure you think of it
**NOTE: you can have a pneumothorax in the absence of distended neck veins and a deviated trachea away from the collapse. These signs may only appear late, in an emergent case.
“Nature abhors a vacuum” and you may get _______ with a Pneumothorax
pleural effusion
air fluid level on chest x-ray
Pneumothorax causes can be __________ or traumatic
spontaneous
T/F: spontaneous pneumothorax is more likely to occur in men than women
True! Tall, thin young men 20-40 yrs
A left pneumothorax will cause a mediastinal shift to the _____
right
For a Central Venous procedure (CVP), why would you order a chest film after CVC placement?
Central venous catheter (CVC) is typically inserted into the subclavian vein–> which CAN cause a spontaneous pneumothorax
**Order chest film after CVP placement to ensure line was placed accurately
If a subtle pneumothorax is present, how would you determine if there is a pneumothorax present or not?
-Order inspiration & expiration films –> On expiration volume of air in the pneumothorax will NOT change, but the volume of air in the collapsed lung will! (making the pneumothorax look bigger)
Tracheal deviation suggests a pneumothorax is present, BUT what is important about this finding?
tracheal deviation is not always present with tension pneumothorax
**tension pneumothorax may be subtle & difficult to dx. Make it one of your “don’t forgets”
Why is a Tension Pneumothorax a Medical Emergency?
Compression of Vena cavae –> decreased venous return to the heart –> decreased Cardiac Output –> Hypotension and Tachycardia
Compression of the Heart –>decreased diastolic filling of the low-pressure Right ventricle –> decreased Cardiac Output and backup of venous blood –> Hypotension, Tachycardia, increased JVP
*this is an EMERGENT case–> place chest tube
Tension pneumothorax also results in compressed ipsilateral & contralateral lungs causing…
impaired gas exchange–> Ventilation/Perfusion mismatch and shunting–> hypoxia –> decreased oxygenation of the blood–> decreased pO2 –> and Tachypnea
*this is an EMERGENT case–> place chest tube
Tx for Small tension pneumothorax
100% oxygen–> will reduce partial pressure of nitrogen increasing the rate of absorption of pneumothorax
Tx for large pneumothoraces
Chest tube
What happens with an inverted diaphragm?
Paradoxical Respirations
Describe what is happening during inspiration & expiration with Paradoxical respirations
During Inspiration: with contraction of the Hemidiaphragm, air will not go into a lung, but will leave a lung–>Because when the Hemidiaphragm is either inverted or paralyzed the Hemidiaphragm moves up
During Expiration: air will not leave a lung but will go into a lung–>Because when the Hemidiaphragm is inverted or paralyzed the Hemidiaphragm moves down
Paradoxical Respirations– with an intact phrenic nerve
- Flail Chest= Paradoxical Breathing
- Inverted Diaphragm – moves paradoxically
- Diaphragmatic Paradox – Hemidiaphragm moves paradoxically
Paradoxical Respirations– with paralyzed phrenic nerve
Paralyzed Diaphragm – not inverted, moves paradoxically
Diaphragmatic paradox usually occurs on the _____ side
left! Since liver limits descent of the Hemidiaphragm on the right. May occur on the Right.
Causes of Diaphragmatic Paradox:
- Large Pleural Effusion – Phrenic nerve intact, inverted Hemidiaphragm moves paradoxically
- Large Tension Pneumothorax – Phrenic nerve intact, inverted Hemidiaphragm moves paradoxically
- Diaphragmatic paralysis – Phrenic nerve paralyzed, Hemidiaphragm not inverted but moves paradoxically.
Flail chest occurs 2/2:
2 or more ribs being broken in 2 or more placesand that segment of the chest moves paradoxically with breathing
**Note: Air moves back and forth between the lungs and is not expired interfering with gas exchange –> hypoxia
Pleural effusion= fluid in the _____ space
pleural
**Movement of fluid from the parietal pleura to pleural space depending on Starling forces
Causes of pleural effusions
- Increased hydrostatic pressure in lungs secondary to increased venous pressure (CHF) or decreased oncotic pressure (nephrotic syndrome).
- Increased vessel permeability of visceral pleural capillaries – pulmonary infarction, pneumonia
- Metastases to pleura
Fluid build-up in a pleural effusion can be:
- fluid, blood or pus
- transudates (ultrafiltrate of plasma- CHF)
- exudates (protein or cell rich fluid- tumor, infection)
-Can be Chyle (rupture of the thoracic duct causes lipid chylomicrons
What will deviate the trachea?
Something will either push the Trachea:
- Tension Pneumothorax
- Large Pleural Effusion
- Large Tumor, Thyroid, Mediastinum, Lungs.
Or something will pull the Trachea:
- Atelectasis of a Lung
- Pneumonectomy
With pleural effusion, what would you find with percussion and auscultation?
Percussion: normally hear resonance over the lung. But with pleural effusion, you hear dullness
Auscultation: -Diminished or no breath sounds
-Egophany (“e” to “a” changes)
With a pneumothorax, what would you find with percussion and auscultation?
Percussion: hyper-resonance
Auscultation: diminished breath sounds
