Luka Tembak

01Wound Ballistics and Mechanism of Injury

The foundation of understanding gunshot wounds lies in wound ballistics, which is the study of how a projectile interacts with tissue once it enters the body.

When a firearm is discharged, the burning of gunpowder generates high-pressure gas that propels the bullet through the barrel at velocities ranging from 300 to 900 m/s depending on the weapon type. The amount of kinetic energy transferred to tissue is determined by the formula:

$$KE=\frac{1}{2}m{v}^{2}KE\; =\; \backslash frac\{1\}\{2\}mv^2$$

This equation is critical because it tells you that velocity contributes far more to tissue destruction than mass. A small-caliber, high-velocity rifle round (e.g., 5.56mm) inflicts more tissue damage than a larger, slower handgun round (e.g., 9mm), even though the handgun round is heavier. This is a frequently tested concept.

As the projectile enters the body, it creates two injury zones. The permanent cavity is the direct path of tissue destruction along the bullet track. The temporary cavity is a transient expansion of tissue caused by the transfer of kinetic energy radially outward. In high-velocity rounds, this temporary cavity can be many times the diameter of the bullet and causes significant injury to surrounding organs and vessels even if the bullet path does not directly traverse them. This is why a high-velocity wound to the thigh can fracture the femur and shred the femoral artery despite the bullet passing centimeters away from these structures.

The projectile may also tumble, fragment, or deform inside the body, increasing the surface area of energy transfer and worsening tissue destruction. Hollow-point bullets are designed to expand on impact, creating a larger permanent cavity. Jacketed rounds tend to maintain their shape and penetrate more deeply.

In injuries over bony prominences (skull, sternum), the entry wound can appear stellate (star-shaped) rather than the classic round defect. This happens because gases from close-range discharge enter the wound, reflect off the underlying bone, and blow the skin outward, tearing it in a radial pattern. Do not confuse a stellate contact wound over bone with an exit wound or blunt trauma.

02Classification of Gunshot Wounds

A. By Range of Fire (Distance from Muzzle to Skin)

This is the most tested classification in forensic medicine and is the cornerstone of medicolegal determination.

B. By Wound Type

C. By Velocity

03Diagnostic Workup and Forensic Examination

The diagnostic workup in a gunshot wound case runs on two parallel tracks: clinical (life-saving) and forensic (medicolegal), and the exam tests both.

Clinically, the approach follows standard trauma protocol. The best initial step is always the primary survey (ABCDE): secure the Airway, assess Breathing (look for tension pneumothorax, open pneumothorax), evaluate Circulation (hemorrhage control, two large-bore IVs, fluid resuscitation), check Disability (GCS, pupils), and Exposure (fully undress to find all wounds). Two entry wounds do not always mean two bullets; remember the re-entry wound concept.

For abdominal gunshot wounds, the best initial test depends on hemodynamic status. In a hemodynamically unstable patient with abdominal gunshot wound, the next best step is immediate exploratory laparotomy, not imaging. In a stable patient, a CT abdomen with IV contrast is the best test to map the bullet trajectory and identify organ injury. FAST ultrasound is a rapid screening tool for free fluid but does not define organ-level injury.

For head gunshot wounds, CT head without contrast is the best initial and most accurate test. It identifies the projectile path, bone fragments, intracranial hemorrhage, and brain herniation. Note that MRI is contraindicated when a metallic projectile or fragments may be retained in the body.

Forensically, the physician must document all wound characteristics before any surgical alteration. This includes wound location (using anatomical landmarks and measured distances from fixed reference points), wound shape and dimensions, presence of soot/stippling/burning, and the abrasion collar. The clothing must be preserved and handed to law enforcement because it can contain gunshot residue and help determine range of fire. Cutting through a bullet hole in clothing during trauma resuscitation destroys forensic evidence; the exam may test your awareness of cutting around the wound site on clothing.

04Management and Treatment

The management of gunshot wounds proceeds in a prioritized, stepwise fashion.

Acute Stabilization follows the Advanced Trauma Life Support (ATLS) protocol. Hemorrhagic shock is the most common cause of death, so hemorrhage control is the immediate priority after airway management. For extremity wounds with uncontrollable bleeding, application of a tourniquet proximal to the wound is lifesaving. In the resuscitation bay, two large-bore (16-18G) IV lines are placed for volume resuscitation. The current standard for hemorrhagic shock management is damage control resuscitation, which favors balanced blood product transfusion (1:1:1 ratio of packed red blood cells, fresh frozen plasma, and platelets) over aggressive crystalloid infusion to prevent the "lethal triad" of hypothermia, acidosis, and coagulopathy.

Surgical Decision-Making is anatomy-dependent. All gunshot wounds penetrating the anterior abdominal peritoneum mandate exploratory laparotomy, regardless of hemodynamic status, because the rate of intra-abdominal organ injury exceeds 90%. This is different from stab wounds, where selective non-operative management is acceptable. For thoracic injuries, the initial step is chest tube (tube thoracostomy) insertion. Indications for emergency thoracotomy include initial chest tube output exceeding 1500 mL of blood or ongoing output exceeding 200 mL/hour for 2-4 hours. For extremity wounds without vascular compromise, management is typically non-operative with wound care.

Wound Care principles differ from clean surgical wounds. Gunshot wounds are considered contaminated because the bullet carries skin, clothing fibers, and bacteria into the wound track. Primary wound closure is contraindicated for most gunshot wounds. Instead, wounds undergo irrigation, debridement of devitalized tissue, and are left open for delayed primary closure (typically at 3-5 days) or healing by secondary intention. High-velocity wounds require more extensive debridement because the zone of devitalized tissue (from temporary cavitation) extends far beyond the visible wound margin.

Bullet Retrieval is a commonly tested topic. The bullet is NOT routinely removed unless it is (a) easily accessible and causing symptoms, (b) within a joint space (risk of lead arthropathy), (c) causing vascular compromise, or (d) in the spinal canal with progressive neurological deficit. Retained bullets rarely cause lead toxicity unless embedded in joint fluid or a pseudocyst, which accelerates lead dissolution.

When a bullet is retrieved surgically, it must be handled with instruments padded with gauze (not metal-on-metal contact, which can alter ballistic markings), placed in a dry paper envelope (not plastic, not formalin), and documented in a chain of custody log before transfer to law enforcement.

05Medicolegal Aspects in Indonesia

This section covers the forensic medicine and legal obligations that are highly testable.

A. Visum et Repertum (VeR)

The Visum et Repertum is a written medico-legal report prepared by a physician at the formal request of an authorized law enforcement investigator. It is legally recognized as expert evidence in Indonesian criminal proceedings for determining the cause, manner, and circumstances of injury or death. Every physician in Indonesia is legally obligated to prepare this document when requested by the police; refusal carries legal consequences.

The VeR for a living victim of a gunshot wound (VeR Perlukaan) must include:

• Preamble: The identity of the requesting officer, the requesting letter number, and the date/time of examination.

• Report (Hasil Pemeriksaan): Objective description of all wound findings (location, dimensions, shape, edges, surrounding features like soot, stippling).

• Conclusion (Kesimpulan): The type of force causing the wound (kekerasan tajam / tumpul / senjata api) and the degree of injury (derajat luka).

B. Wound Degree Classification Under the Indonesian Criminal Code (KUHP)

The physician's conclusion in the VeR determines which criminal charge applies to the perpetrator. The classification of wound severity is based on Articles 351, 352, and 90 of the Criminal Code (KUHP), which implicitly divide injuries into three degrees: mild (ringan), moderate (sedang), and severe (berat).

Most gunshot wounds will be classified as moderate or severe. A penetrating gunshot wound to the abdomen requiring laparotomy, for example, causes temporary inability to work and constitutes at least a moderate injury. A gunshot wound causing loss of a limb, blindness, or permanent paralysis qualifies as severe under Article 90.

C. Firearm Regulations

Emergency Law Number 12 of 1951 (UU Darurat No. 12 Tahun 1951) is the cornerstone of Indonesia's strict gun control regime. It imposes severe penalties, including the death penalty, life imprisonment, or up to twenty years in prison, for unauthorized possession, import, manufacture, or use of firearms, ammunition, or explosives. Civilian ownership is extremely restricted and requires a permit from the Indonesian National Police, governed by the Chief of Police Regulation (Perkapolri) No. 1/2022.

Because civilian firearm ownership is tightly controlled, a gunshot wound on the exam carries an automatic medicolegal implication. The physician is not just a clinician but also a forensic examiner. The physician must:

1. Document wound characteristics meticulously before any surgical intervention.

2. Preserve clothing and projectiles for law enforcement.

3. Prepare a Visum et Repertum upon official police request.

4. Report the case to law enforcement (this is a criminal matter by default in Indonesia).

06Differential Diagnosis and Distractors

This table helps you distinguish gunshot wounds from look-alikes, and more importantly, helps you determine the manner of injury (homicide vs. suicide vs. accident).

A. Wound Mimics

B. Manner of Death/Injury Determination (Suicide vs. Homicide vs. Accident)

07Traps and High-Yield Pearls

Trap 1: Confusing entry and exit wounds. The single most tested concept is the distinction between an entry wound (round, smaller, inverted margins, abrasion collar) and an exit wound (larger, irregular, everted margins, NO collar). The exam traps you with the shored exit wound, which mimics an entry wound because the skin is compressed against a firm surface (belt, wall, floor), producing a pseudo-abrasion collar. Whenever a vignette describes an "abrasion collar" on a wound that is larger and irregular, think shored exit wound.

Trap 2: Assuming distance from wound size. The size of the entry wound does NOT reliably indicate the caliber of the bullet. Elastic skin contracts around the wound, making it appear smaller than the bullet diameter. Do not pick an answer that correlates entry wound diameter to bullet caliber.

Trap 3: Ordering MRI with retained projectile. If a bullet or metallic fragments are retained in the body, MRI is contraindicated. The ferromagnetic projectile can migrate, causing further injury. Always choose CT over MRI in gunshot wound cases until the projectile composition is confirmed.

Trap 4: Soot vs. Stippling (tattooing). Soot can be wiped off with a cloth because it sits on the skin surface. Stippling (powder tattooing) cannot be wiped off because unburnt powder grains are embedded in the dermis. If the vignette says the dark discoloration "was removed by cleaning," it is soot (close range). If it "remained after cleaning," it is stippling (intermediate range). This distinction determines range of fire and is the key discriminator between close-range and intermediate-range wounds.

Trap 5: Abdominal GSW management. Unlike stab wounds, which can be managed with serial observation and selective intervention, all gunshot wounds penetrating the peritoneum require exploratory laparotomy. The exam tests whether you know this distinction. If the vignette gives you a stable patient with an abdominal gunshot wound and asks for the next best step, do not pick "serial abdominal exams." The answer is surgery.

Trap 6: Stellate wound over bone mistaken for exit wound. A contact wound over the skull or sternum produces a stellate, torn appearance due to gas expansion against bone. Students mistake this for an exit wound because of its irregular shape. The presence of soot within the wound track and cherry-red tissue (from CO) confirms it as a contact entry wound.

Trap 7: Forgetting the forensic obligation. In a vignette set in Indonesia, the physician who treats a gunshot wound victim has a legal obligation to document the wound in detail (for a future Visum et Repertum) and preserve evidence (clothing, projectile). Failing to mention forensic documentation or evidence preservation in a management question is a tested error. The VeR conclusion must state the type of force and the degree of injury (mild, moderate, or severe per KUHP Articles 352, 351, and 90).

The core competency being tested with gunshot wound questions spans three domains: (1) your ability to correctly identify and interpret wound characteristics to determine range of fire and distinguish entry from exit wounds, (2) your ability to prioritize trauma management according to ATLS principles (especially knowing when to go straight to surgery), and (3) your understanding of the medicolegal documentation obligations placed on the treating physician under Indonesian law.