Superior Mediastinum and Great Vessels

Question 1

Draw diagram of the ‘great veins of the thorax’

Answer 1

…

Question 2

What is at the Angle of Louis / trans-thoracic plane

Answer 2

Arch of aorta
Arch of azygos vein
Thoracic duct
Trachea (bifurcation into mainstem bronchi)
Ligamentum arteriosum
Pulmonary trunk bifurcates

**JVP can be measured

Question 3

What is a central line? Why is it sometimes better the peripheral lines?

Answer 3

a cannuler you insert into a vein to deliver contents as close to the heart as possible.
You want it to get to the SVC > heart so it’s straight into the systemic circuit.
Good for long-term management
CL is useful for very toxic medicines that would damage soft tissues.

*peripheral lines: back of hand, fine most of the time for non-urgent situations.

Question 4

Two vessels used most commonly for central lines

Answer 4

Internal Jugular Vein

Subclavian Vein

Question 5

Pros and cons of ‘internal jugular vein’ for a CL

Answer 5

Pros:
Relative easy to find
Reliable

Cons:
Carotid artery behind > arterial injury (can lead to brain clot)
Very uncomfortable
Not good long term
Difficult w CPR/intubation

Question 6

Pros and cons of ‘Subclavian vein’ for CL

Answer 6

Pros:
More comfortable
okay w intubation

Cons:
Subclavian art behind > arterial injury (the can't be compressed!)
Pneumothorax risk
More difficult due to angle
brachial plxus injury

Question 7

Pros and cons of ‘External Jugular Vein’ for CL

Answer 7

Pros:
Easier to find (more SF)
Low pneumothorax risk
Low bleeding risk so ok w clots

Cons:
90degree angle w Subclavian, hard to thread
Uncomfortable

Question 8

Pros and cons of ‘Femoral Vein’ for CL

Answer 8

Pros:
CPR/intubation fine
Easily found
Quick
Straighter line

Cons:
Low steility (so not long-term)
Mobility uncomfortable
Clot risk > pulmonary embolism

Question 9

Draw artery diagram

Answer 9

..

Question 10

Phrenic nerve, where they start and what they supply

Answer 10

Start high in neck @C3-5.

Run down & supply heart and diaphragm. some branches to pericardium

Question 11

Why does it matter how high a neck injury is??

Answer 11

A cause of concern as if it is too high and phrenic is damage > loss of resp control

Question 12

Vagus nerves and branches. What do these all supply?

Answer 12

R. vagus has a branch R. recurrent laryngeal nerve that loops around the R. subclavian artery

L vagus has a branch L. recurrent laryngeal nerve that loops around the aortic arch.

L and R vagus come together to form a plexus on the esophagus, then passes into the thorax.

Re-currents travel back superiorally to supply larynx

Question 13

What of L and R vagus nerves are slightly anterior and posterior

Answer 13

Left vagus: slightly anterior

Right Vagus: slightly posterior