Hey Doc, how realistic is a “mild” punctured lung? Like, an ice pick in the top of the lung. Will that kill you after an hour or so?
First, my apologies; Doctor Fiction has spent the last few weeks wrapping up some developmental copyediting coursework and revising the prologue and epilogue of my latest novel. I have a backlog of excellent questions that I will work through as quickly as possible.
An injury of this type is called a Traumatic Pneumothorax.
Pneumothorax has many fiction applications and is a great device to incapacitate, or if the plot warrants, terminate a character. The medical sequelae (outcome) can be mild and develop over hours to days or catastrophic and occur in less than a minute or anything in-between.
As usual, we begin with a little anatomy and physiology, progress to pathology, and finish with a few fiction applications.
The Good, the Bad, and the Ugly:
Anatomy and Physiology: (The Good)
Lungs: Paired organs used to exchange carbon dioxide, the bodies waste gas, carbon dioxide, for oxygen (oxygen makes up approximately 21% of what passes for “fresh air” in our current environment.)
Thoracic Cavity: The lungs are contained within the Thoracic or Chest cavity. This cavity is lined with a slippery membrane called the pleura.
Pleura: This membrane lines the thoracic cavity. It secretes a serous fluid that keeps the lung in direct contact with the inner wall of the chest cavity but allows it to slide freely while breathing.
Pleural Space: This is a potential space between the lung surface and the cavity wall. Any injury or disease process that converts this potential space into an actual space is called a Pneumothorax.
Pericardial Sac: This is a double-walled sac containing the heart. It is located in roughly the center of the chest cavity and contains a pericardial membrane that functions like the pleural membrane for the heart.
Trachea and Bronchi: This is the “breathing tube.” Think of it as an inverted “Y” with one bronchus branching off the trachea to each lung and the trachea or root of the Y accessing the outside air via the mouth and nose.
Alveoli: There are over six hundred million of these tiny air sacs in the lung. Each one communicates with the circulatory system via its own venule and arteriole which are connected by a capillary bed wrapped around the alveoli.
The venules carry oxygen-depleted blood and carbon dioxide to the Capillary Bed where the inspired oxygen is extracted and the carbon dioxide discarded. The arterioles then carry the oxygen-rich blood back to the heart where it is distributed to the body and the whole process repeats itself.
A pneumothorax is the creation of air space between the chest wall and the lungs for ANY reason. Pneumothoraxes (sounds like a character from Dr. Seuss) can be categorized two ways:
By their etiology, that is their cause, which can be spontaneous or traumatic.
· Medical condition: asthma, lung cancer, or chronic pulmonary disease
· Genetics: Cystic Fibrosis, Marfan’s Syndrome, or Ehlers-Danlos Syndrome
· Physical Attributes: Thin males between the ages of 15-34 have a five-fold risk
· Lifestyle: Smokers have a twenty-two-fold risk increase over non-smokers
· Penetrating Chest Wound: gunshot, stabbing, foreign bodies (open to outside)
· Blunt Trauma: fractured rib (closed to outside)
· Barotrauma: sudden pressure change: SCUBA and blast injuries (closed)
The second and more germane classification is by their presentation as Simple or Tension. In the most basic terms, a Simple pneumothorax is the creation of a space between lung and chest wall which is uncomfortable, may require intervention, but does not expand and is not life-threatening.
This qualifies as, The Bad, but it does not qualify as …
Tension Pneumothorax: (The Ugly)
Each time you take a breath, a small amount of air moves into the space between the lungs and the chest wall and cannot escape. This results in several forms of badness:
· The air trapped between the lung and the chest wall does not pass through the alveoli, and as such, cannot replace the carbon dioxide waste with needed oxygen.
· With each breath, the space grows larger and pushes against the lung (tension pneumothorax), compressing the alveoli and further decreasing function.
· This ever-expanding bag of air pushes against the pericardial sac and compresses the heart, decreasing cardiac output. This is rapidly fatal without immediate intervention. The “Adam’s Apple” or trachea shifts or “points” to the side where the pneumothorax is. (this information will be helpful later)
If the stab wound has pierced a blood vessel, potential space may be filling with blood as well, creating a hemopneumothorax an all too common occurrence here in the emergency department knife and gun club.
In a Closed Pneumothorax insert a chest tube with a one-way valve so that each inhalation will force air out, decrease the size of the air pocket, and alleviate the symptoms.
Treating Open Pneumothorax is a rapid-succession two-step procedure:
· Close the sucking chest wound to stop the influx of air through the chest wall
· Insert a chest tube as above to decrease the size of the pneumothorax.
In the case of hemopneumothorax; if the bleed has stopped, the chest tube will clear the blood. If not, surgery is required to “tie-off” the bleeder.
So, your character is in the field, far removed from a hospital. This is well and good if you want him to die. If not …
Suppose your character has suffered a closed tension pneumothorax:
· Blast Injury: the character has punctured a lung due to over-pressure. They may have other injuries as well.
· Blunt Trauma: fall from a height, hit by a car, smacked by a bear, etc.
· SCUBA: saw a monster on the bottom, came up to quickly and dropped a lung due to pressure change
Supplies: a pocket knife, ink pen, plastic glove, duct tape, and left-over alcohol from last night’s festivities.
Technique: have your rescuer pick a spot halfway between the armpit and the nipple on the affected side (remember the tracheal shift) and count down four or five ribs.
Clean the area with the alcohol. Clean the pocket knife with the alcohol. Remove the cartridge from the ink pen and use the barrel without the clicker. Cut a finger off the glove with your knife and cut a hole in the tip of the glove finger. Slip the glove finger over the non-pointy end of the ink pen barrel and secure with a small strip of duct tape.
Your rescuer will need to make a small puncture over the rib and push the pointy end of the ink pen barrel over the top of the rib so that it enters the chest cavity. There will be a slight “whoosh” of air as the pneumothorax decompresses; the vein, artery, and nerve of the rib run along the bottom and MUCH badness will occur if they are injured. The area around the pin is sealed and secured with wide strips of duct tape.
If the injury is an open tension pneumothorax:
· Puncture wound of any type: tree branch, punji stick, fence picket, etc.
If the hole is small, your rescuer could insert the makeshift chest tube as above through the opening. Alternatively, the hole could be covered with duct tape to create a closed pneumothorax and the chest tube inserted in the as above.
If there are no supplies for a chest tube, a flap valve can be created by taking a piece of plastic wrap or thin ground cloth sufficient to cover the wound and securing it on three sides with duct tape. The open side functions as a flap valve, letting the air escape but not reenter the pneumothorax.
This may get your character to a hospital.
This is a long post, but now that you know the anatomy, physiology, and pathophysiology you can use it in your writing.
Click the link below for the rules for questions
https://doctorfiction.tumblr.com/post/181400956523/the-doctor-is-in