Alright, the last diagnosis to talk about is massive hemithorax.
So hemothoraces are defined as any collection of blood in the pleural space.
So if you’ve got blood in the pleural space
which normally shouldn’t have anything in it, you’ve got a hemithorax.
There’s a number of different injuries that can lead to hemithorax
so injury to the lung parenchyma itself is the most common.
Fortunately, the lungs are highly vascularized
but you’re generally talking about pretty small vessels
with parenchymal injuries so these will typically clot off and heal themselves
and the bleeding into the pleural space will be self limited.
By contrast, if you have injury to the intercostal arteries,
the mammary arteries or the great vessels,
these are larger vessels that may or may not be able to clot themselves off
and you’re typically gonna have more sustained bleeding
that can potentially be life threatening.
Now, hemithorax does impair ventilation
especially if it’s a large quantity hemithorax
so if you’ve got one hemithorax completely filled with blood,
that is gonna impair ventilation but only on the affected side.
It is possible to get a tension hemithorax.
This really only occurs with large vessel injuries, specifically arterial injuries,
because arterial bleeding is pushed into the pleural space under pressure
so it can actually increase the pressure in the thoracic region
and cause tension physiology.
This is very rare.
I’ve actually never seen a case of this myself in practice
but it is theoretically possible and something for you to be aware of.
So on physical exam,
you probably will see some signs of hemorrhagic shock for your patient.
Each hemithorax holds a liter to a liter and a half of blood
depending on the size of the person
so you can imagine that you’re gonna get some signs and symptoms
associated with bleeding if you have that much blood in your chest wall.
You’re gonna typically have absent or decreased breath sounds on the affected side
and if you do percuss the lungs you’re gonna find that they’re dull
because instead of being filled with air they’re now filled with fluid.
Your chest x-ray’s your best initial test for this.
Upright chest x-rays are better when you can do it safely
because it will allow you to see the layering of the blood
and will show you how much blood roughly is in the chest cavity.
But if you can’t sit your patient up safely,
a supine test will also tell you there’s a hemithorax.
It won’t let you estimate the quantity as well
because the blood will layer out if the patient is supine
so you usually just see diffused haziness or opacity on the affected side.
A CT scan of the chest offers you a little bit more of a definitive diagnosis
and allows you to more reliably quantitate how much blood is in the pleural space.
You can see the arrow on this image marks the large hemithorax
that’s present on the patient’s left hand side.
So what do we do for hemothoraces?
Generally, these patients are all gonna need chest tubes and the reason for that is one,
we wanna monitor ongoing bleeding, right?
We can’t be sending our patients back to the CT scanner every half hour
so we need a way of knowing
if their hemithorax is improving, expanding, or staying the same.
So we wanna monitor their bleeding by looking at their chest tube output
and we also wanna allow that injured lung to re-expand and heal.
Patients with hemothoraces
do sometimes need to go to the operating room for thoracotomies
and that occurs when they have large volumes of blood in the pleural space
and might have vascular injuries that need repair in order to stop bleeding.
So anytime you get 1500 cc of blood out on initial chest tube insertion,
you wanna go to the operating room,
that’s a sign again that you have a vascular injury
rather than just injury of the pulmonary parenchyma.
And anytime you have persistent brisk bleeding overtime,
so more than 200 cc of blood per hour for 3 or more hours,
again, that’s a sign that you’ve got a vascular injury that’s not able to clot itself off
and you need to consider operative management.
So patients with massive hemithorax may be hemodynamically unstable,
they may have whiteout on their chest x-ray.
These massive hemithorax patients
so they have complete filling of one hemithorax with blood
are much more likely to have vascular injuries
and they’re much more likely to need surgery
but we’re always going to place a chest tube in these patients
and define whether or not their hemithorax require surgery
based on their chest tube output as we just discussed.
So just remember, ABCs first, right?
If you’ve got a massive hemithorax,
that’s a sign that you’ve got internal bleeding somewhere in the chest
and you potentially need to resuscitate your patient so don’t just focus on the lungs,
focus as well on the need for adequate IV access, volume resuscitation, et cetera.
Severe respiratory distress is actually uncommon in these patients
because the other lung will usually meet the patient’s physiologic needs
from a respiratory standpoint, however, the blood loss might be significant
and patients often need volume resuscitation.
In rare cases, especially for patients with underlying lung disease,
you may end up needing to give them some respiratory support
even intubate and mechanically ventilate them,
but most often the complications associated with massive hemithoraces
are related to bleeding rather than to lung function.