First Aid/GSW causing pneumothorax
I am doing research for a story in which our hero is shot in the back with a .22 calibre rifle from about 50 yards. As it plays out at the moment, the bullet passes through her right lung, causing some form of pneumothorax, and is then lodged in her ribcage. She looses consciousness and is washed down river for a few miles. Firstly, is this credible?
Also, what type of traumatic pneumothorax would allow her the greatest chance of survival in these circumstances? Would she have lost a fatal amount of blood? (I'm hoping not.) Would much water from the river seep into her chest or pleural cavity?
Any help would be much appreciated.
Thank you for choosing All Experts. The scenario you describe is not impossible..but VERY unlikely. The nature of the injury would be compounded by pulmonary edema (fluid filling lungs after trauma), hemothorax (fluid filling plural cavity), and (depending upon the angle of the shooter in relation to the hero, the distance between the shooter and the hero, and the resistence against the bullet) the damage the bullet caused to other organs via richochet. One important influence is the calibre of the gun and it's ballistics.
Imagine strategically placing an ice cube against a brick wall and striking the ice cube with a baseball thrown from a pitching machine at 20 feet. The ice cube would shatter or at least crack, correct? Now imagine that same ice cube being struck by a BB gun from the same distance. It would richochet (or lodge in the ice if fired with enough power).
Likewise, A .22 calibre bullet would:
1. richochet against bones like a raquetball (depending upon the angle of the shooter in relation to the hero, the distance between the hero and the shooter, and the resistence against the bullet, such as the density of the bone) and continue to richochet until all resistence against the bullet finally forced it to stop.
2. richochet against a bone like a BB, and subsequently penetrate tissue (forcing an exit wound), or
3. penetrate the bone and immediately force an exit wound (a single instance effect).
Because a .22 calibre has between 125 and 150 pounds of "power" at 50 feet, is travelling at roughly 1/4 mile a second, and falls about a half an inch, i'm comfortable saying that it's possible for a 22 bullet to richochet off one rib and lodge in another (which would likely damage the heart, spleen, kidneys, liver and/or pancreas (resulting in severe hemorrhage/internal bleeding) and increase the liklihood of going into hypovolemic shock).
Additionally, because a 22 calibre bullet is somewhere between 5 and 6 mm in diameter, how much water enters the plural cavity would depend largely upon how far she fell before reaching the water, and the weight of the water pressing against the open wound after being submerged in water. If the entry wound was enlarged by the weight of water submerging the hero, the increase in size would allow for more water to enter the body. Thus, the amount of water entering the pleural cavity is difficult (if at all possible) to ascertain.
That said, while recovery from an open traumatic pneumothorax is possible; the complications arising from secondary trauma (pulmonary edema, hemothorax, hemmorage of internal organs damaged by richochet, etc) in this scenario make it highly unlikely that the hero would survive without immediate lifesaving treatment.
Options might include:
a) changing the calibre of gun
b) changing the distance between hero and antaogonist
c) Consider a non penetrating traumatic pneumothorax caused by a dislocated fractured rib that lacerated the pleura (allowing air to fill the plurasic cavity).
Thank you again for choosing All Experts. Please feel to respond to any additional questions.
---------- FOLLOW-UP ----------
QUESTION: Thanks for this! This has been a great help.
Three follow up questions, if I may:
If the shooter was, say, 150 yards away, still with .22 rifle, is there a greater chance that the bullet simply lodged itself in a rib, fracturing it, causing non-penetrative traumatic pneumothorax, with minimal to no ricochet? I'm obviously trying to avoid, in a credible manner, the complications arising from internal bleeding and hemothorax, etc.
Or does this too blatantly fly in the face of the nature of the .22 rifle? Do you know what a more credible weapon would be for this situation?
Thank you for the response. Upon reviewing the question and response, I must offer correction. The calculations offered were provided in yards (although the response says feet). Next, unless the villain in the book is a sharpshooter, I'd say it's difficult to maintain consistent accuracy over 100 yards and would say a distance of about 100 yards (with clear line of sight and moderate windage) would provide a realistic setting (if the bullet struck the hero during descent).
Since it's logical for an individual to favor an area of pain, it would be feasible for the hero to favor her rib and fall to the ground on her injured side (fracturing the rib in a separate area) which subsequently lacerates the visceral pleura causing a non penetrating pneumothorax.
Any rifle can be credible so long as it considers CRD (caliber, resistence and distance). By increasing the calibre of a rifle, you will need to manipulate other ballistic influences to create a feasible situation where a bullet would likely 'lodge' (or result in some other affect upon human anatomy and/or physiology). Because the 22 caliber gun has a substantial amount of power in relation to the small size of the bullet, the gun is known for its distance. As such, the effects of a 22 upon the human body are more impacted by richochet and the small precise size of the bullet, and would be impacted by distance between two points, and the resistence between the bullet and the point of impact . If you modify the caliber of a weapon, you will need to manipulate distance and/or resistence to create the most realistic outcome.
Please note that this ballistic information is intended to help you gather a "rough idea" of how bullets and other projectiles affect human anatomy and physiology, and isn't intended to be definitive forensic data. As such, there is a certain degree of flexibility you can apply with these principles to balance the "wow factor" of fiction with the of engagement of reality.
Thank you again for choosing All Experts. Please feel free to respond with any additional questions.
Best Wishes and Good Luck,