**5.1. Penetrating trauma**

Penetrating injuries may cause sepsis if they perforate a hollow viscous. Increasing abdominal tenderness demands surgical exploration. White blood cell count elevations and fever appearing several hours following injury are keys to early diagnosis.

Penetrating injuries can cause severe and early shock if they involve a major vessel or the liver. Penetrating injuries of the spleen, pancreas, or kidneys usually do not bleed massively unless a major vessel to the organ (e.g., renal artery) is damaged. Bleeding must be controlled promptly. A patient in shock with a penetrating injury of the abdomen who does not respond to 2 L of fluid resuscitation should be operated on immediately following chest X-ray [11].

The treatment of hemodynamically stable patients with penetrating injuries to the lower chest or abdomen varies. All surgeons agree that patients with signs of peritonitis or hypovolemia should undergo surgical exploration, but treatment is less certain for patients with no signs of peritonitis or sepsis who are hemodynamically stable [12].

Most stab wounds of the lower chest or abdomen should be explored, since a delay in treatment of hollow viscous perforation can result in severe sepsis. Some surgeons have recommended a selective policy in the management of these patients. When the depth of injury is in doubt, local wound exploration may rule out peritoneal penetration. Laparoscopy may ultimately have a role in the evaluation of penetrating injuries. All gunshot wounds of the lower chest and abdomen should be explored because the incidence of injury to major intraabdominal structures is 90% in such cases [13].

### **5.2. Blunt trauma**

Blunt abdominal trauma (BAT) comprises 75% of all blunt trauma and is the most common example of this injury. The majority occurs in motor vehicle accidents, in which rapid deceleration may propel the driver into the steering wheel, dashboard, or seatbelt causing contusions in less serious cases, or rupture of internal organs from briefly increased intraluminal pressure in the more serious, dependent on the force applied. It is important to note that initially there may be little in the way of overt clinical signs to indicate that serious internal abdominal injury has occurred, making assessment more challenging and requiring a high degree of clinical suspicion [14].

There are two basic physical mechanisms at play with the potential of injury to intra-abdominal organs: compression and deceleration. The former occurs from a direct blow, such as a punch, or compression against a non-yielding object such as a seatbelt or steering column. This force may deform a hollow organ, thereby increasing its intraluminal or internal pressure, leading to rupture [15]. Deceleration, on the other hand, causes stretching and shearing at the points at which mobile structures, such as the bowel, are anchored. This can cause tearing of the mesentery of the bowel, and injury to the blood vessels that travel within the mesentery. Classic examples of these mechanisms are a hepatic tear along the ligamentum teres and injuries to the renal arteries [16].

When blunt abdominal trauma is complicated by "internal injury," the liver and spleen are most frequently involved, followed by the small intestine [17].

In rare cases, this injury has been attributed to medical techniques such as the Heimlich maneuver, attempts at cardiopulmonary resuscitation and manual thrusts to clear an airway. Although these are rare examples, it has been suggested that they are caused by applying unnecessary pressure when administering such techniques. Finally, the occurrence of splenic rupture with mild blunt abdominal trauma in those convalescing from infectious mononucleosis is well reported.

A major addition in management of blunt trauma has been the focused assessment with sonography for trauma (FAST) examination. Ultrasound has proved to be an ideal modality in the immediate evaluation of the trauma patient because it is rapid and accurate for the detection of intra-abdominal fluid or blood and is readily repeatable.

The goal of the FAST examination is the identification of abnormal collections of blood or fluid. In this regard, it obviates the need for diagnostic peritoneal cavity, but attention is directed also to the pericardium and to the pleural space.
