**2. General consideration**

The mortality and morbidity associated with abdominal trauma can be attributed to the disturbance of anatomical and functional integrity of abdominal structures. Based on understanding the anatomy and physiological processes performed by abdominal organs, it is possible to plan and enhance measures designed to avoid the occurrence of the complications associated with the management of abdominal trauma. To achieve such tasks more efforts should be directed to avoiding all possible risk factors leading to the occurrence of abdominal trauma, try as much as possible to avoid the removal of any injured abdominal organ, and ensure as quick as possible to restore functions of any injured abdominal organ.

#### **2.1 Anatomical and functional consideration of abdominal organs**

Knowledge of anatomy and physiological processes of abdominal organs is paramount for understanding and avoiding complications which occur secondary to abdominal trauma and those associated with chosen management approach. Abdomen is flexible and dynamic part of the body which lies between diaphragm and pelvis. Abdominal cavity houses all structures that involve in gastrointestinal and genitourinary system. Some abdominal structures are intra-peritoneal while others are


#### **Table 1.**

*Components of abdominal wall and classification of abdominal organs which can assist to make diagnosis.*

retroperitoneal. Shown in **Table 1** are the components of abdominal wall and the classification of abdominal organs. The fact that, abdominal organs have minimal bony protection they are frequently injured during trauma event [2]. Like any other injuries following abdominal trauma two responses happen namely: (1) biological adaptation to condition of external stress (injury and starvation), and (2) maintenance of internal constancy. These responses are useful for increasing the chance of survival for traumatic abdominal victim. However, in certain instances these responses can be dangerous; for instance if they occur in uncontrolled manners, in excessive and for prolonged time and when there is removal or failure multiple organs. The primary function of abdominal organs is to maintain homeostatic process. Thus, while managing traumatic abdominal patient, it is crucial to restore the functions of abdominal organs as quick as possible and as well as to avoid the removal of any abdominal organ as much as possible.

#### *2.1.1 Liver*

Liver is a solid and the largest organ of the body, located in the right upper quadrant of the abdomen under the right lower rib cage against the diaphragm [3]. It receives dual blood via: (1) hepatic arteries which deliver about 20% blood oxygen rich, and (2) portal vein which carries about 80% blood nutrient rich from stomach, intestine, pancreas and spleen via portal vein. Moreover, at rest liver receives about 25% of cardiac output and has the capacity to reserve about 450 ml of blood in healthy person and up to 1 liter for congestive heart failure patient. Liver is the most commonly injured organ during trauma due to its big size and because of its high vascularity, hemorrhage is the most frequent complication to associate with liver injury.

Liver serves as a hub of metabolic processes of which life depends. Eight main metabolic processes taking place in the liver are: (1) bile formation and excretion, (2) carbohydrate metabolism, (3) protein metabolism, (4) fat metabolism, (5) blood coagulation, (6) vitamin metabolism, (7) detoxification and (8) phagocytosis and immunity. It is very unlikely for human being to survive without liver. One of the events which can lead to the loss of liver is severe injury of which hepatectomy would be warranted. In such case liver transplant would be only possible solution. However, liver transplant is too expensive, not available as an emergency treatment and it is associated with other numerous complications. Evidence has shown that liver cells have the capacity to regenerate. This regeneration is mainly achieved with the support of portal blood; because portal blood contains hepatotrophic portal blood factor (HPBF) which supports hepatic cells to regenerate [4]. Given this evidence it is very crucial for the physician to ensure enough portal blood supply to any injured liver. No hepatectomy should be done at all unless there is immediate liver transplant.

#### *2.1.2 Spleen*

Spleen is situated in the left upper quadrant of the abdomen. Spleen is encircled superiorly and laterally by diaphragm and left lower rib cage, inferiorly by the colon, medially by stomach and posteriorly by the kidney. Spleen is highly vascularized organ. Spleen also receives dual blood supply via splenic artery and short gastric artery, and it receives about 5% of cardiac output. Though, it seems that, the spleen is protected by ribs and muscular parieties, the spleen is commonly injured during abdominal trauma because, it is friable, and it has suspended ligaments that are attached to an adherent capsule. Thus, even relatively minor trauma can lead to avulsion of splenic substances or tearing of the blood vessels that are present within its suspensory ligaments which result into abundant bleeding.

Spleen has a number of functions in the body including: (1) filtering blood elements and foreign material, (2) production of lymphocytes and antibodies. Human being can survive without spleen indicating that functions that are carried out by the spleen can be performed by other organs elsewhere in the boy. However, it has been confirmed that, loss of spleen is associated with overwhelming infectious complications caused by encapsulated bacteria (e.g., *Haemophilus influenzae*, *Streptococcus pneumoniae*, *and Neisseria meningitidis*) [5]. The recognition of high rates of infections after spleenectomy led to the shift of paradigm of management of splenic injury from mandatory operative to selective conservative management, and then to nonoperative management and splenic artery embolization, etc. Studies have shown that more than 60% of splenic injury can be managed with non-operative approach.

#### *2.1.3 Pancreas*

Pancreas is not commonly injured during abdominal trauma [6]. However, greater considerations should be taken while managing any abdominal trauma involving the pancreas because of its intimate relationship with vital vascular structures. While in its transverse course, pancreas passes immediately anterior to inferior vena cava, the aorta, superior mesenteric artery and vein. It also lies anterior or slightly to the splenic artery and vein. The common serious danger for both penetrating and blunt injury to the pancreas is the risk of injury to these great vessels. The pancreas may obscure the site of bleeding and as such extensive mobilization or transection of the pancreas may be required in order to control the bleeding vessel. Early mortality related to

pancreatic injury is due to massive hemorrhage whereas late mortality can result from the consequence of infections and multiple organ failure. Moreover, the neglected pancreatic injury may result into complications such as: pseudocysts, fistulas, sepsis and secondary hemorrhage [6].

#### *2.1.4 Gastrointestinal tract (GIT)*

The components of gastrointestinal tract (GIT) to consider with regard to abdominal trauma include stomach, small intestine and large intestine. GIT assists in digestion, absorption, assimilation of nutrients, and secretion and excretion of waste products. Absorptive and propulsive actions of GIT are reduced after trauma anywhere in the body. There is profound and prolonged reduction of GIT actions when peritoneal cavity is involved. The disturbed GIT actions leads to the accumulation of fluid within the abdominal cavity causing increased intra-abdominal pressure, abdominal distention and increased risks of aspiration as one of the complications. Moreover, fluid accumulation into the GIT and possibly bleeding causes the reduction of cardiac output. Following this instance the body compensates by transferring adequate blood to vital organs (brain and heart), leaving other organs such as GIT, skin etc. This compensation takes place because brain and heart are vital organs with high metabolic rates and their capacity to store substrates for energy production is very low, as such they need adequate constant blood supply. Reduction of blood supply to GIT causes the development of ischemia which is a common complication to associate with abdominal trauma.

#### *2.1.5 Other abdominal organs*

An appreciation of anatomy and functional physiology of other abdominal organs such as kidneys and bladder, blood vessels, nerves, uterus and ovaries (in female) is also important. These organs have substantial functions in various physiological processes including regulation of homeostasis. During abdominal trauma these organs can also be damaged and some of them are hard to treat. Readers are advised to revise anatomy and physiology of these organs.

#### **2.2 Approach to the patient with abdominal trauma**

#### *2.2.1 General consideration and primary survey*

The patient with abdominal trauma can present with multiple injuries with higher likelihood to compromise functions of vital organs. As such, all traumatic abdominal patients should be managed holistically. Management of traumatic abdominal patient is complex, challenging and typically encompasses all possible interventions to offer to the patient during the course of management. In approaching traumatic abdominal patient the clinician should be prepared to provide various interventions at any of the three phases of trauma care, namely: (1) primary phase that encompasses initial assessment and provision of certain actions to correct any impairment of airway, breathing and circulation, disability and exposure, (2) secondary phase which progresses with resuscitation and full assessment of the patient), and (3) tertiary phase which involves the provision of definitive treatment to specific injuries.

Death is certainly a powerful dependent variable but unwanted one, which is ever seen in all kinds of trauma. All kinds of trauma have the potential to cause death to the victim either directly or by any complications that occur in the trajectory of management. Ideally, in order to avoid such death, the basic principles of advanced and trauma life support (ATLS) protocols are the forefront interventions to offer to any trauma patient and should be started at the scene. The core components of ATLS protocol, namely: (1) Airway management, (2) Breathing, (3) Circulation, (4) Disability or Damage, and (5) Environment/Exposure (ABCDE) are of the first priority [5] in order to secure the functions of vital organs.

### *2.2.1.1 Airway*

The most common cause of death for traumatic patient is asphyxia. To avoid this tragedy to happen an immediate goal of management should be to clear and keep the airway open to ensure adequate ventilation. Shown in **Table 2** are the strategies used for recognizing the compromised airway and actions to do as early as possible to ensure adequate ventilation.


#### **Table 2.**

*Recognition of the compromised airway and the important actions to do as early as possible to ensure adequate ventilation.*

#### *2.2.1.2 Breathing*

Impaired breathing is a common cause of respiratory failure, perhaps the common cause of death among traumatic patients. Quick recognition and correction of impaired breathing is crucial. Shown in **Table 3** are the potential findings indicating impaired breathing and actions to perform in order to correct impaired breathing.


#### **Table 3.**

*Potential findings indicating impaired breathing and actions to perform to correct the impaired breathing.*

#### *2.2.1.3 Circulation*

Shock secondary to trauma is largely caused by bleeding and perhaps the common cause of circulatory failure and a leading cause of deaths among traumatic patients. The dangerous effect of shock is that all body organs are affected. The hypovolemic shock secondary to bleeding affects all body organs regardless the location of the bleeding. Lack of the capacity to maintain systolic blood pressure at ≥90 mmHg after trauma provokes hypovolemia which is associated with mortality of about 50%. The direct goal of management is to prevent further blood loss and determine the degree of circulatory derangement. Directly identify the site of bleeding, feel central (carotid) and peripheral (radial pulses) and start resuscitative interventions. Shown in **Table 4** are signs of shock and prompt stepwise interventions to execute in order to correct hypovolemic shock in primary phase of trauma management. Despite the control of bleeding, the patient may continue to manifest signs and symptoms of shock as consequences of loss of plasma


#### **Table 4.**

*Signs of shock to look for and prompt interventions for correcting hypovolemic shock during the primary phase of trauma management.*

volume into the interstium, and this effect is compounded by injury induced inflammatory responses. The physician should put this into consideration and give maintenance fluids to the patient after resuscitation phase.

#### *2.2.2 History and physical examination*

Ascertaining the type of abdominal trauma that has occurred is essential in terms of choosing diagnostic approach, selecting appropriate therapy, and providing potential vital information regarding the prognosis; this task is achieved in secondary survey. Typically, two types of abdominal trauma, namely: blunt and penetrating abdominal injuries have been recognized. In secondary survey assessment, the mechanism of injury, time and place of injury, whether the patient had consumed some substances (e.g. alcohol) and other clinical manifestations implying abdominal organ injuries should be elicited. Clinical presentations of traumatic abdominal patient are diverse and depend on the type of abdominal injury sustained.

#### *2.2.2.1 Clinical presentation for penetrating abdominal injury*

Patient with penetrating abdominal injury can present with stab or gunshot wounds. Gunshot wounds are much more difficult injuries to treat. The type of gun used should be determined. The severity associated with gunshot wounds depends on the kinetic energy of the bullet used.

$$\mathbf{MV} = \mathbb{W}^{2} /\_{2\mathfrak{g}},\tag{1}$$

where KE = kinetic energy, M = mass of the bullet, V = velocity of the bullet, g = gravitational acceleration. As it can be seen KE is directly proportional to mass and squared velocity. As such, multiple visceral damage should be ascertained when the bullet of high velocity or great mass has been used and the exit wound may be noted. Exploratory laparotomy must be performed for all gunshot wounds. Surrounding injury warrants extensive debridement of tissues that have been destroyed by concussive forces. Low velocity bullet mostly remains within the abdominal cavity and sometimes can be handled as knife stab wounds. The fact that, some bullets move in different directions while coursing within the body, multiple organ damage should always be anticipated. Abdominal trauma surgeon should perform meticulous assessment to any bullet wounds to avoid missing an injury.

The patient with penetrating stab wounds can present with diverse entities and they should be assessed thoroughly. Assessment of stab abdominal wounds should be done under local anesthesia. If posterior rectus sheath has been penetrated it is wise to perform laparotomy. It is vital to remember that intact peritoneum may be misleading because the perforated peritoneum retracts with abdominal rigidity. Omental protrusion through the stab wounds warrants laparotomy. The patient may present with knife in the abdomen, which should not be pulled out immediately; it should be removed by surgeon via an operation [5].

#### *2.2.2.2 Clinical presentation for blunt abdominal trauma*

The common mechanism of blunt abdominal trauma include: road traffic accident, physical violence. Abdominal pain is usually the presenting complaint of blunt

abdominal trauma. The common signs include: abdominal distention, rigidity, and tenderness which implies peritonism. Bowel sounds can be absent and abdomen moves poorly with respiration. Tachycardia, hypotension and other signs of shock are frequently present which infers laparotomy. Other important signs to look for in case of blunt abdominal trauma include: (1) Seat belt sign (diagonal and lower abdominal abrasion) if positive points to bladder, bowel perforation and fracture of lumbar spine, (2) balance sign (immovable mass or immovable area of dullness in the left upper quadrant) its positivity implies splenic sub-capsular or extra-capsular hematoma, (3) Ker's sign (presence of left shoulder/ neck pain) if positive it is associated with splenic injury, and (4) Cullen's signs (presence of periumblical ecchymosis) in case it is positive it implies hemorrhage in the peritoneum.
