Pediatric Annals

Pediatric Abdominal Trauma

Max L Ramenofsky, MD

Abstract

Injury in individuals 44 years of age and under continues to be the leading cause of death in the United States. In the pediatrie age group, 17 years and under, it is not only the leading cause of death, but it causes more death and disability than all other causes combined. Although great strides have been made in treatment of heart disease, infectious disease, and cancer, progress in the treatment of traumatic disease has been slow in coming in the general population. This is even more true in the pediatrie age group.

Annually there are 1.5 million injuries in the pediatrie age group. Of these, one half are minor and of no consequence. Seven hundred fifty thousand children are seen by a physician annually for injury and of these 500,000 are hospitalized. Mortality due to injury in childhood has been gauged to be between 15,000 to 25,000 victims annually. The mortality rate in hospitalized children from injury is approximately 3%.' The overall mortality rate in the pediatrie age group is 1.5%.

The demographics of pediatrie injury are now well known.1 Ages of childhood injury victims are depicted in Figure 1. It is evident that there is little difference in the occurrence of serious injury by age when the ages are broken down into five year groups. Sex distribution of injury reveals a 2 to I male to iemale preponderance at all ages except in the newborn where the distribution is nearly equal.

Blunt injury continues to be the most common form of injury in childhood, accounting for nearly 88% of all injuries (Figure 2). Penetrating injury occurs in nearly 10% of injured children. The rate of penetrating injury appears to be increasing in many of the nation's largest cities. The automobile is the prime culprit in over 40% of childhood injuries. This includes children injured while riding in automobiles as passengers, riding bicycles, riding motorcycles, and walking down the street. Falls from a height is another major category of injury, amounting to 39% of all injuries (Figure 3).

Body areas injured and their frequencies are also well known. The most common, non-seriously injured organ system is the skin and subcutaneous tissue. The most frequently injured organ system requiring hospitalization is skeletal, followed by the CNS, and the thorax and abdomen. The most common organ system in;ury resulting in death has, for years, been thought to be the CNS. However, some authorities are now questioning this long held dogma. It appears from early data that many children succumbing to head injury the from a secondary CNS insult rather than a primary injury. This will be discussed later.

The purpose of this article is to describe a method of simultaneously evaluating and resuscitating a child who has suffered blunt abdominal injury.2,3

There are three problem areas which must be kept at the forefront of one's mind when evaluating a child with abdominal trauma: blood loss, sepsis due to peritoneal contamination which occurs late, and organ dysfunction which may be either an early or late occurrence.

The forces which are exerted on an organ during a traumatic occurrence are such that organ disruption frequently occurs. This disruption results in a loss of organ homeostasis with at least a diminution of that organ's normal function. Hence if the blunt injury results in damage to one or both renal arteries, renal function will be compromised. Similarly, if the spleen is disrupted, some loss of immunologie function may eventually result, but not in the immediate resuscitative or post-resuscitative period. Disruption of the liver is usually not manifested as a measurable loss of physiologic function, unless the…

Injury in individuals 44 years of age and under continues to be the leading cause of death in the United States. In the pediatrie age group, 17 years and under, it is not only the leading cause of death, but it causes more death and disability than all other causes combined. Although great strides have been made in treatment of heart disease, infectious disease, and cancer, progress in the treatment of traumatic disease has been slow in coming in the general population. This is even more true in the pediatrie age group.

Annually there are 1.5 million injuries in the pediatrie age group. Of these, one half are minor and of no consequence. Seven hundred fifty thousand children are seen by a physician annually for injury and of these 500,000 are hospitalized. Mortality due to injury in childhood has been gauged to be between 15,000 to 25,000 victims annually. The mortality rate in hospitalized children from injury is approximately 3%.' The overall mortality rate in the pediatrie age group is 1.5%.

The demographics of pediatrie injury are now well known.1 Ages of childhood injury victims are depicted in Figure 1. It is evident that there is little difference in the occurrence of serious injury by age when the ages are broken down into five year groups. Sex distribution of injury reveals a 2 to I male to iemale preponderance at all ages except in the newborn where the distribution is nearly equal.

Blunt injury continues to be the most common form of injury in childhood, accounting for nearly 88% of all injuries (Figure 2). Penetrating injury occurs in nearly 10% of injured children. The rate of penetrating injury appears to be increasing in many of the nation's largest cities. The automobile is the prime culprit in over 40% of childhood injuries. This includes children injured while riding in automobiles as passengers, riding bicycles, riding motorcycles, and walking down the street. Falls from a height is another major category of injury, amounting to 39% of all injuries (Figure 3).

Body areas injured and their frequencies are also well known. The most common, non-seriously injured organ system is the skin and subcutaneous tissue. The most frequently injured organ system requiring hospitalization is skeletal, followed by the CNS, and the thorax and abdomen. The most common organ system in;ury resulting in death has, for years, been thought to be the CNS. However, some authorities are now questioning this long held dogma. It appears from early data that many children succumbing to head injury the from a secondary CNS insult rather than a primary injury. This will be discussed later.

The purpose of this article is to describe a method of simultaneously evaluating and resuscitating a child who has suffered blunt abdominal injury.2,3

There are three problem areas which must be kept at the forefront of one's mind when evaluating a child with abdominal trauma: blood loss, sepsis due to peritoneal contamination which occurs late, and organ dysfunction which may be either an early or late occurrence.

The forces which are exerted on an organ during a traumatic occurrence are such that organ disruption frequently occurs. This disruption results in a loss of organ homeostasis with at least a diminution of that organ's normal function. Hence if the blunt injury results in damage to one or both renal arteries, renal function will be compromised. Similarly, if the spleen is disrupted, some loss of immunologie function may eventually result, but not in the immediate resuscitative or post-resuscitative period. Disruption of the liver is usually not manifested as a measurable loss of physiologic function, unless the injury is of such a magnitude to have disrupted the majority of the hepatic parenchyma.

One of the more disastrous consequences of injury is blood loss resulting in hypovolemic shock. Fortunately hypovolemic shock, although occasionally difficult to recognize, is most often easy to treat. The result of untreated hypovolemic shock is such that there are a number of subtle and obvious derangements in physiologic function. The immediate result of a loss of more than 25% of blood volume is a change from aerobic to anaerobic metabolism. This results in a reduction in the availability of the energy substrate ATP. Aerobically when 1 mole of glucose is metabolized, the result is the liberation of 36 moles of ATP. When the same amount of glucose is metabolized anaerobically the result is 1 mole of ATP. Hence one might expect to see, in the early stages of hypovolemic shock, a child who is alternately lethargic and combative. This evident lethargy becomes more pronounced as more and more blood is lost. Thus, one of the early interventions in the child in shock is the provision of higher ambient oxygen concentrations.

It is not uncommon for a child to suffer two or more system injuries simultaneously. The head, skeleton, and spleen are frequently injured. Blood loss from long bone fractures or splenic disruption can be great; when the resulting hypovolemia is combined with a minor degree of CNS injury, the resultant head injury is made significantly worse. This has been referred to as secondary head injury and is much more common than previously thought.1

Another result of blood loss which is not commonly considered is when more than one episode of hypovolemia occurs in the same patient in a relatively short period. Most children can easily withstand one episode of hypovolemia if it is appropriately treated. Not infrequently a second episode supervenes due to continuing, uncontrolled bleeding. The injured tissues are generally in the process of eliminating the byproducts of an episode of anaerobic metabolism, ie, CO2, organic acids, which have damaged the cellular membranes. This damage is generally repairable unless a second episode of shock occurs before the cell membrane and the cellular contents are fully recovered. The second episode will render many cells incapable of recovering from that insult, resulting in cell death. Hence, any operative repair may well be torn asunder by this second episode of shock.

Sepsis due to abdominal organ injury is uncommon and does not generally occur early in the post-traumatic period. Hollow viscus disruption in the child is frequently subtle in its presentation, particularly that resulting from blunt trauma. The only early sign may be a subtle degree of abdominal tenderness without other peritoneal signs. The diagnosis of duodenal, jejuna!, or ileal disruption is generally made by repeated abdominal examination, noting any subtle changes in the abdominal findings from one exam to the next.

Figure 3. The injuring mechanisms in 3,045 children are indicated. Motor vehicles were responsible for 38% of the injuries in this group and included injuries caused by motorcyles (MCY), bicycles (BCYJ, pedestrians (PEDJ, and passengers in automobiles IMVA).

Figure 3. The injuring mechanisms in 3,045 children are indicated. Motor vehicles were responsible for 38% of the injuries in this group and included injuries caused by motorcyles (MCY), bicycles (BCYJ, pedestrians (PEDJ, and passengers in automobiles IMVA).

The result of a missed hollow viscus injury is intervening sepsis due to slow but continued peritoneal contamination. This is a disastrous situation which can result in overwhelming sepsis and death unless identified early. There are, however, a number of modalities which can be used to identify this type of occurrence quite early and hence avoid the septic complications.

There is very little controversy regarding the appropriate evaluation and treatment of a child suffering penetrating abdominal injury. The remainder of this article will concentrate on the child suffering blunt injury, the results of which are much more difficult to identify and quantify.

The assumption is being made that the injured child has been evaluated appropriately in the trauma resuscitation area of the Pediatrie Trauma Center, utilizing the method described by the Committee on Trauma of the American College of Surgeons Advanced Trauma Life Support Course (ATLS).4

The three main causes of death in the injured child are due to airway compromise, uncorrected blood loss, and CNS injury. These potential causes of death are assessed and treated during the initial management phase. Initial evaluation is carried out by the ABCs while any life-threatening condition is simultaneously treated. Appropriate therapy and diagnosis is aimed at the Airway and protection of the cervical spine. The child's Breathing is assessed and treated, if necessary. Circulation will be adequately dealt with and appropriate intravenous lines started. At the same time, areas of blood loss, where external, will be controlled. The Disability has quickly assessed the baseline neurological status and the child has been Exposed or undressed while providing adequate ambient temperature to prevent hypothermia. The purpose of undressing the child is to evaluate the entire body so as not to miss an area of injury which could otherwise be overlooked.

Resuscitation takes place simultaneously with the initial survey by the pediatrie trauma team. The head of that team should be a pediatrie surgeon and the members of the team are each assigned specific duties in the evaluation/resuscitation process.

Intravenous lines are started away from the sites of injuries. The saphenous and brachial veins are usually chosen as the initial sites. On occasion no intravenous access site can be found. In this situation, after all other sites have been exhausted, intraosseous infusion is an acceptable alternative in children under 6 years of age.

The central venous catheter is a modality of intravenous access which requires comment. Its usefulness is not found in its ability to deliver volume to a hypovolemic patient, but in its ability to measure the central venous pressure. The physical characteristics of a CVP catheter, long with a small internal diameter, severely limit the amount of fluid which can be given. Hence, a central venous catheter is not useful in. the resuscitation of the hypovolemic, injured child.

The child in hypovolemic shock requires rapid reconstitution of the circulating blood volume. The initial infusion volume is 20cc/kg of lactated Ringer's solution and is given as a bolus. The child's response is monitored and if hemodynamic stability is obtained and does not deteriorate, no further volume, other than maintenance fluids is required. This is usually indicative of a blood volume loss of less than 25%, If, however, the initial bolus of fluid results in short-term stability followed by recurrent instability, a second bolus of 20 cc/kg of lactated Ringer's is given, again by bolus infusion (Table).

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Again the child's hemodynamic response is monitored. Should the instability recur, packed RBCs (10 cc/kg) are rapidly infused. An alternative to packed RBCs is whole blood given at a volume of 20 cc/kg. Dependent upon the response, the child is then either further evaluated or taken to the operating room for surgical correction (Figure 4).

After the initial assessment and resuscitation, and if intra -abdominal injury has not been deemed lifethreatening, the abdomen is assessed. However, if ultra-abdominal injury is considered to be contributory to a life-threatening process, the abdomen is examined in the initial survey.

The most commonly injured intra-abdominal organs are the spleen, liver, and mesentary of the bowel. All can result in small to major amounts of intraperitoneal blood. Injury to any of these organs can result in significant, or conversely, no physical findings on abdominal examination. Nonetheless, examination of the abdomen starts with observation for the presence of abdominal distension. A child suffering multisystem trauma will generally swallow a large amount of air. Gastric distension can result in significant problems if left untreated. Hence a nasogastric or orogastric tube, depending on the age of the child, is passed and the stomach is decompressed. The gastric contents should be examined to detect the presence of gross blood. The tube itself should be soft and preferably a sump type.

Once the stomach has been decompressed, examination by auscultation and palpation can be done. The presence of bowel sounds has been found to be variously helpful by different authorities. Its utility is basically a personal preference. Palpation of the abdomen of an injured child should be done quickly and gently. The examiner is looking for the presence of peritoneal signs, ie, involuntary guarding, tenderness. Masses are seldom present in the injured child. All quadrants of the abdomen should be evaluated. The abdominal examination is never complete until an adequate rectal exam has been performed. In the child, as in the adult, a high riding, boggy prostate and blood at the urethral meatus is characteristic of urethral disruption. Tenderness on rectal exam in the child can be evaluated easily if the examiner performs the procedure gently, because the distance from the anus to the peritoneum is very short, easily within range of the examining finger.

When the abdominal examination has been completed, the decision must be made as to whether to obtain further diagnostic tests. Clearly the child who has a tender or distended abdomen needs further evaluation unless the child is rapidly deteriorating, indicating the need for immediate operative intervention. The abdomen of the child who has sustained a significant CNS injury is difficult to evaluate. This type of child, if there is any indication of abdominal injury, should also have further diagnostic testing.

It is important to note that the examination of the injured child compared to the adult progresses from the general concept of the presence of an injury to the identification of the specific injury (Figure 5). The question always arises as to what diagnostic modality best defines intra-abdominal injury. There are two methods commonly used in determining specific injury. Perhaps the most generally used is the body or abdominal CT scan.5 Computed tomography is extremely accurate in identifying the presence of splenic and/or hepatic injury. It can also identify the presence of blood in the peritoneal cavity. The addition of oral contrast to the CT scan has the potential of identifying hollow viscus injury, particularly if the intestinal rent is high in the gastrointestinal tract. The addition of intravenous contrast provides excellent information on the status of the kidneys, ureters, and bladder.

Figure 4: A flow diagram indicating the progression of intravenous and diagnostic modalities in the injured child with hemodynamic instability.

Figure 4: A flow diagram indicating the progression of intravenous and diagnostic modalities in the injured child with hemodynamic instability.

A second commonly used method of arriving at a specific diagnosis also utilizes the CT scan, but not until a peritoneal lavage has been performed, it has been very well-documented that a properly performed peritoneal lavage has the advantage of being inexpensive and highly accurate.6,7 If the lavage is positive (>100,000 RBCs/cc) and if the hemodynamic status of the child is well-maintained, the CT scan can provide very accurate information on the specific organ which has been injured, using the previously described additional modalities. If the lavage is negative there is essentially no likelihood that there is an injury. Thus by using peritoneal lavage, the expense of the CT scan can be avoided and the time during which the patient is away from the Pediatrie Trauma Center is significantly reduced. Those opposed to the use of diagnostic peritoneal lavage point out that this procedure is quite painful and upsetting to the child and thus changes the abdominal exam. We have not found this to be true in our experience.

Once initial evaluation, resuscitation, examination, and further diagnosis have been completed, and assuming that the child does not have an injury which requires immediate operative intervention, the course of therapy is determined by the pediatrie trauma surgeon. There are protocols for the nonoperative management of the ruptured spleen and liver. 8 There are those who feel that nonoperative management is not optimally advantageous for the injured child and hence, splenic repairs and drainage of large liver lacerations continue to be performed with excellent results.

Regardless of the mode of therapy which is followed, all children suffering major system injury, including the abdomen, must be followed in a pediatrie intensive care unit. Frequent examination and laboratory testing is the rule until the child is deemed to be out of danger.

Figure 5: Diagnosis in the injured child proceeds from general to specific diagnoses as indicated. Generally the CT scan provides the most accurate and specific diagnoses.

Figure 5: Diagnosis in the injured child proceeds from general to specific diagnoses as indicated. Generally the CT scan provides the most accurate and specific diagnoses.

REFERENCES

1. The National Pediatric Trauma Registry: Presented before the American Pediatric Surgical Association, Toronto, Canada, May 1936.

2. Ramenofsky ML: Diagnosis and management of pediatrie blunt abdominal trauma. Infect Surg 1985; 4(9).

3. Eichelberget MR, Randolph JG: Pediatrie trauma: An algorithm for diagnosis and therapy. J Trauma 1983; 23:91.

4. American College of Surgeons Committee on Trauma: Advanced Trauma Life Support 1984.

5. Karp MP, Cooney DR, Berger PE, et al: The role of computed tomography in the evaluation of blunt abdominal trauma in children. J Pediatr Surg 1981; 13; 316.

6. Powell RW, Green JB, Ochsner MG. et al: Peritoneal lavage in pediatric patients sustaining blunt abdominal trauma: A reappraisal. J Trauma 1987; 27:1-5.

7. Powell RW, Smith DE, Zarins CK, et al: Peritoneal lavage in children with blunt abdominal trauma. J Pediatr Surg 1976; 11:971-977.

8. Wesson DE, Filler RM, Ein SH, et al: Ruptured spleen: Where to operale? J Pediatr Surg 1981; 16:324.

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10.3928/0090-4481-19870401-07

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