1. MedPix Medical Image Database COW - Case of the Week Case Contributor: Paul J Cunningham Affiliation: Madigan Army Medical Center

2. MedPix No: 2573 - History Pt Demographics: Age = 20 y.o. Gender = man This patient is a 20 year old black male active duty US Army E-4 who was shot during a firefight in the Mekong Delta in Vietnam. The patient*s unit was pinned down in a rice paddy by direct fire from the opposing tree line when the patient screamed, *I*m hit! I*m hit!* and dropped his weapon. He was immediately attended by his squad sergeant, who called the platoon medic forward. The medic dressed the entrance wound in the left axilla and stayed with the patient. No other medical treatment was given. The patient could not be evacuated due to the heavy fire and subsequently died 2 1/2 hours after being wounded. Downloaded by (-1)

3. MedPix No: 2573 - EXAM & LABS

4. GSW Hemopneumothorax Bullet in anterior soft tissues of neck. - Fractures of the first three left ribs. - Massive left hemopneumothorax resulting in marked mediastinal shift toward the right. (Post-mortem radiographs.) - (Post-mortem radiographs.) Downloaded by (-1)

5. GSW Hemopneumothorax Bullet in anterior soft tissues of neck. - Fractures of the first three left ribs. - Massive left hemopneumothorax resulting in marked mediastinal shift toward the right. - (Post-mortem radiographs.) Downloaded by (-1)

6. FINDINGS The films consist of AP supine and lateral films taken at postmortem. The bullet is the most obvious feature and appears over the spine in the superior mediastinum pointing superiorly in the AP film. The quality of the lateral film is marginal, but correlation with the AP film shows the bullet is actually lodged in the superficial tissues of the neck. The bullet is intact; there are no other metallic fragments seen here.On the AP film the first three ribs on the left side have been fractured by the passage of the bullet. There is a large amount of fluid density peripherally throughout the left hemithorax surrounding the collapsed lung. The left hemidiaphragm has been displaced downward and is not seen, while the heart and mediastinal structures have been displaced to the right. There are streaky lucencies seen in the left supraclavicular soft tissues which suggest subcutaneous emphysema. All of these findings point to a massive left tension hemopneumothorax as the presumable cause of death. This diagnosis was confirmed at autopsy, where some 2200 mL of blood was found in the left pleural cavity.

7. DIFFERENTIAL DIAGNOSIS What is your Differential Diagnosis? Gunshot wound - hemopneumothorax - hemothorax - pneumothorax

8. Diagnosis: Gunshot wound, hemopneumothorax Dx Confirmed by: Autopsy

9. DISCUSSION Case contributed by David Dorsey, medical student. - - This is a tragic case for a number of reasons. The path of the bullet in the patient*s body suggests that a number of critical structures may have been injured, such as the subclavian vessels. However, the patient did not exsanguinate immediately; rather, his condition deteriorated steadily over 2 1/2 hours until he expired. The most likely explanation is that his left pleural cavity continued to fill with blood until the tension physiology compromised his cardiopulmonary function. If a simple chest tube thoracostomy had been performed the patient may have been salvaged. Failing this intervention, treatment on the battlefield is predicated on timely evacuation, which was not possible in this case. - - Another tragic finding concerns the bullet itself. By x-ray, the bullet demonstrates the typical intact silhouette of a standard 7.62 mm round. A 5.56 mm M-16 round invariably breaks up when it strikes flesh, which explains its shocking lethality. A standard 7.62 mm AK-47 round is similar to the one seen here, but has a more squat appearance due to its shorter length. The round seen here is a NATO 7.62 mm M-60 machine gun. This patient was shot and killed by one of his fellow soldiers. Such fratricidal encounters on the battlefield are more frequent than is realized and may in fact account for 20% or more of all combat casualties. - - REFERENCES: - - US Army Weapons Data Munitions Effectiveness Team (USAWDMET) database - - Textbook of Military Medicine, Vol. 5, No. 2; The Borden Institute (1992) -