Initial Evaluation of the Patient with Blunt Abdominal Trauma

Abdominal Trauma

0039-6109/90 $0.00

+ .20

Initial Evaluation of the Patient with Blunt Abdominal Trauma Oliver ]. McAnena, MGh, FRGSI, * Ernest E. Moore, MD, FAGS, t and]ohn A. Mqrx, MD, FAGEP:j:

Approximately 10% of civilian injuries that require operation are the result of blunt abdominal trauma. 39, 56 Unrecognized injury to intra-abdominal contents remains a distressingly frequent cause of preventable death. 29, 62. 91 The symptoms and signs of these injuries are notoriously unreliable and are often masked by head injury, major fractures, alcohol, or other toxins. As many as one third of patients with an initial benign abdominal examination will require emergency laparotomy. 12, 56 The appropriate management of blunt abdominal trauma depends on a careful initial evaluation, the timely use of diagnostic procedures, and vigorous therapy directed at immediate life-threatening problems. In contrast to penetrating trauma, the decision to perform laparotomy for blunt abdominal trauma is far more complex because structural injury is less obvious and associated multisystem trauma may demand more urgent operation. PATHOPHYSIOLOGY Management of the patient with blunt abdominal trauma requires an understanding of the injury mechanism. In general, injuries can be classified as either high or low energy, and several pathophysiologic processes are operational: (1) sudden, pronounced rise in intra-abdominal pressure cre*Fellow in Trauma Surgery, Denver General Hospital, Denver, Colorado; and Senior Registrar in Surgery, The Royal College of Surgeons in Ireland, Beaumont Hospital, Dublin, Ireland tProfessor and Vice-Chairman of Surgery, University of Colorado Health Science Center; and Chief, Department of Surgery, Denver General Hospital, Denver, Colorado *Assistant Director, Department of Emergency Medicine, Denver General Hospital; and Associate Professor of Surgery, University of Colorado Health Science Center, Denver, Colorado

Surgical Clinics of North America-Vol. 70, No.3, June 1990

495

496

OLIVER

J.

McANENA ET AL.

ated by outward forces can cause rupture of a hollow viscus or burst injury of a solid organ, (2) compression of abdominal viscera between the applied force to the anterior wall and the posterior thoracic cage or vertebral column can produce a crush injury, and (3) abrupt, shearing forces can cause a tear of organs or vascular pedicles. 16. 24 Motor-vehicle accidents account for 75% of cases of blunt abdominal trauma. The severity of mechanism is related to the force and duration of impact as well as the mass of the patient contact area. Deceleration injuries occur in high-speed vehicular accidents and in falls from great heights. On impact, the organs continue to move forward at the terminal velocity, tearing organs at their sites of attachment. Lap-belt restraints can be associated with a sudden elevation in intra-abdominal pressure, producing hollow visceral rupture. Table 1 outlines the relative incidence of injured structures encountered at emergent laparotomy over the past decade at the Denver General Hospital (DGH). The spleen was the organ most frequently injured, followed by liver, mesentery, urologic structures, and pancreas. The relatively greater incidence of mesenteric and hollow visceral perforation compared to older series 12 may be related to the increased use of seat belts.

HISTORY

As much information as possible should be obtained from the paramedics or flight nurses, firemen, police, other parties involved in the accident, and bystanders as soon as possible in the emergency department (ED). Specific details of the injury mechanism are critical. 56 In cases of an automobile accident, one should inquire into the size of the vehicle; the frequency of injury is higher in smaller cars.63 What was the position of the victim in the vehicle? A rear-seat passenger is less likely to have sustained impact against rigid objects within the interior of the car. What was the type of accident? Frontal impact, side impact (T-bone), sideswipe, rear impact, and rollover have their own unique patterns of injury.24 Was the victim wearing a restraint device, and if so, what type? Lap seat belts (twopoint fixation) are associated with injuries distinct from those associated Table 1. Pattern of Injury Encountered at Laparotomy Following Blunt Trauma ORGAN

RELATIVE INCIDENCE

Spleen Liver Mesentery Urologic Pancreas Small bowel Colon Duodenum Vascular Stomach Gallbladder

46% 33%

10% 9% 9% 8%

7% 5% 4%

2% 2%

INITIAL EVALUATION OF THE PATIENT WITH BLUNT ABDOMINAL TRAUMA

497

with a lap seat belt combined with a shoulder harness. 92 In lateral-impact collisions, the seat belt is less effective in protecting wearers from severe or abdominal injuries. 2 On the other hand, ejection from the vehicle frequently results in life-threatening injuries. 21 Auto-pedestrian victims, particularly adults, are also at significant risk for abdominal injury.86 The patient or a third-party witness may be able to provide information regarding the patient's level of consciousness at the scene of the accident and whether or not the patient has been taking drugs or alcohol. It is also important to know the patient's medications, past medical history, and chronic medical conditions. The patient may be allergic to contrast media, and knowledge of this may alter the clinician's selection of radiologic investigations.

PHYSICAL EXAMINATION

Inspection for ecchymoses and abrasions provides clues to internal hemorrhage in the patient with blunt abdominal trauma. Gentle pressure over the lower ribs helps establish whether or not rib fractures are present; lower rib fractures are associated with hepatic or splenic injury. The examiner should note the contour of the abdomen prior to proceeding to superficial and deep palpation to elicit guarding, tenderness, and rebound. In the series by Davis et al,12 the physical findings most often associated with internal injury were abdominal tenderness and guarding, occurring in 75% of patients with positive physical findings. Peritoneal signs of rebound tenderness and rigidity occurred in 28%. Pain or blood on rectal examination, although helpful, was uncommon (3%). Of 437 patients studied, however, 43% had neither complaints nor signs of an intra-abdominal injury; however, 44% of these patients were ultimately explored, and 77% of them had a documented injury requiring repair. This re-emphasizes the unreliability of the initial abdominal examination following acute blunt trauma. The flanks should be palpated and the iliac crest and symphysis pubis compressed to establish the possibility of a pelvic fracture. The hip joints should also be internally and externally rotated. Absence of discomfort on performing these maneuvers usually excludes a major pelvic fracture,84 but signs may be masked by shock, head injury, or intoxicants. 56, 60 Sphincter tone, integrity of the rectal wall, and the presence of blood are primary components of the rectal examination. The presence of a high-riding or non palpable prostate supports the diagnosis of postmembranous disruption of the urethra. The presence or absence of blood at the penile meatus should be noted became this is an indication for urethrography prior to passage of a urethral catheter. The testes should be examined for injury, and in the setting of a pelvic fracture, a perineal or vaginal laceration must be excluded. Abdominal and thoracic trauma should be considered together in the initial evaluation because the dome of the diaphragm can rise to the fourth intercostal space during full expiration. There is a 20% chance of splenic injury and a 10% chance of hepatic injury with fractures of the left and right lower six ribs, respectively. 39, 56

= 498

OUVER

J.

McANENA ET AL.

LABORATORY INVESTIGATION Hematologic and blood chemistry values are oflimited use immediately following blunt abdominal trauma, but baseline tests are important because subsequent changes may be the first sign of occult injury. Hematocrit reflects a balance of acute blood loss, endogenous plasma refill, and administration of crystalloid. 34 Serial measurements are helpful in monitoring continued hemorrhage. A leukocytosis following blunt abdominal trauma is common and generally nonspecific. Serum amylase lacks sensitivity and specificity for intra-abdominal injury.65 A normal level does not exclude major pancreatic injury, and isoenzymes do not improve diagnostic accuracy.4 Conversely, elevations may occur following trauma to the parotid gland, proximal small bowel, and the genitourinary tract. 56 For patients hospitalized with major trauma, baseline serum levels of electrolytes and renal and liver function are appropriate. A preliminary blood coagu1ation screen is important in patients who require massive transfusions or who have concomitant hepatic disease. Arterial blood gases are warranted in intubated patients or those who are at risk for subsequent pulmonary decompensation. Urinalysis should be an integral part of the work-up for all patients with blunt abdominal trauma to detect otherwise asymptomatic urologic trauma. tJ rinalysis for toxic drug metabolites is also appropriate in select patients.

RAD10LOGY Radiologic procedures in the stable patient with blunt abdominal trauma may be helpful when physical examination and laboratory investigations are inconclusive. However, trained personnel must supervise and monitor any patient suspected of having a serious injury, as the abandonment of a patient in the radiology department for even a brief period can have disastrous consequences. Anteroposterior chest radiographs provide clues to associated thoradc and diaphragmatic injury. Malposition of the nasogastric tube is often the first sign of a ruptured left diaphragm. Small amounts of free intraperitoneal or retroperitoneal air may be detectable in patients with gastric, duodenal, small Bowel, or colonic perforations. 3 • 25 A search should be made for rib, pelvic, vertebral body, and transverse spinous process fractures, as these warrant special consideration for nearby visceral damage. At least 800 ml of intraperitoneal blood is required to be evident on plain abdominal radiograph. 39 The following supportive findings may be observed: (1) the flank-stripe sign is a fluid-dense zone separating the ascending or descending colon from a distinctly outlined lateral peritoneal wall, and the colon is displaced medially; (2) the dog-ear's sign results from accumulations of blood that gravitate between the pelvic viscera and side walls on each side of the bladder; and (3) the hepatic-angle sign is loss of definition of the usually distinct inferior and right lateral borders of the liver as blood accumulates between the hepatic angle. and the right peritoneal wall. 3 • 25 With extensive hemoperitoneum, small bowel may float

INITIAL EVALUATION OF THE PATIENT WITH BLUNT ABDOMINAL TRAUMA

499

toward the center of the abdomen with the production of a "ground-glass" appearance. There may also be loss of the psoas shadow or renal shadow in cases of retroperitoneal hemorrhage. The injured spleen may cause displacement of the gastric bubble medially or indentation of the splenic flexure of the colon.

DIAGNOSTIC PERITONEAL LAVAGE Initial physical examination of the abdomen often fails to detect significant intra-abdominal injury. 12, 66, 79, 82 Delay in diagnosis results in increased morbidity ahd mortality, more hospitalization time, and higher health care costs. On the other hand, unnecessary laparotomies are associated with a definable risk. 39 The introduction of diagnostic peritoneal lavage (DPL) by Root et al. in 196572 provided a rapid, inexpensive, aCcurate, and relatively safe adjunctive diagnostic modality in the management of patients with blunt abdominal trauma. We believe DPL remains an integral part of the evaluation of the seriously injured patient. There are three fundamental methods of introducing the DPL catheter into the perittmeal cavity. The closed approach consists of inserting the catheter in a blind percutaneous fashion; the major problem is uncontrolled depth of penetration, rendering the underlying intraperitoneal or retroperitoneal structures at risk for perforation. The open procedure, transversing the abdominal wall under direct visualization, is safer but more time consuming and introduces air into the peritoneal cavity. We prefer the semi-open technique performed at the infraumbilical ring as a compromise; this approach is rapid, safe, and extremely reliable. 21, 59, 73, 8~ The same approach can be employed in the patient with a major pelvic fracture because the enlarging anterior hematoma is limited by the infraumbilical ring. Before lavage, the stomach and bladder are decompressed with a nasogastric tube and a Foley catheter, respectively. The periumbilical area is shaved,' prepped with povidone-iodide solution, and draped sterilely. The area is infiltrated generously with local anesthesia (1 % xylocaine without epinephrine). A gently curved incision is made to one side of the umbilicus, at the level of the infraumbilical ring (Fig. 1). The advantages of making the incision at this site include relative avascularity, paucity of pre peritoneal fat, and adherence of the peritoneum resulting from obliteration of the umbilical arteries and urachus. 59 The incision is carried down to the linea alba, ensuring meticulous hemostasis. A 5-mm incision is made in the linea alba, and the free edges are grasped with towel clips. While elevating the abdominal wall by traction on the towel clips, a standard dialysis cathl:lter with the trocar is inserted toward the pelvis. Once the peritoneum is punctured; the trocar is withdrawn and the catheter is advanced into the pelvic floor. the tap is considered positive if greater than 10 ml of blood is aspirated. Otherwise, 1 L of warmed 0.9% sodium chloride is infused (15 ml/kg in children). If the clinical condition permits, the patient is rolled from side to side, and the bottle lowered to the floor for the return of lavage fluid by siphonage. A minimum of 75% of lavage efHuent is required for the test to be considered valid. The fluid is sent for laboratory analysis

500

OLIVER

J.

McANENA ET AL.

Figure 1. Diagnostic peritoneal lavage in the adult is performed using the semi-open technique at the infraumbilical ring. The free edges of the incised fascia are elevated with towel clips to eliminate contact between the trocar and the underlYing abdominal viscera.

of red and white blood cell counts, amylase (LAM) and alkaline phosphatase (LAP) levels, and examination for the presence of bile. The criteria for positive DPL are outlined in Table 2. In the context of blunt abdominal trauma, visceral damage is present in more than 95% of patients in whom the red blood cell count is greater than l00,000/mm 3 but less than 5% of those in whom the red blood cell count is less than 20, 000/mm 3 • 1, 6, 21, 26, 33, 41,53,80 Red blood cell counts between 20 and 100,OOO/mm3, however, may reflect serious injury in 15 to 25% of cases and merit further diagnostic evaluation; our current preference is abdominal computed tomographic (CT) scanning (Fig. 2). Occasionally, elevated white blood cells (>5001 mm 3), LAM,I, 45 or LAP50, 52 will signal an otherwise occult intestinal injury, when the sensitivity of DPL based on laboratory red blood cell criteria is Table 2. Criteria for Diagnostic Peritoneal Lavage Following Blunt Abdominal Trauma INDEX

POSITIVE

EQUIVOCAL

Aspirate Blood Fluid

>lOml Enteric contents

>5ml

Lavage Red blood cells White blood cells

> lOO,OOO/mm3 >500/mm3 (confirmed by

>50,OOO/mm3 >200/mm3

Enzyme Bile

repeat DPL) Amylase ~20 IU/L, and alkaline phosphatase ~3 IU Confirmed biochemically

Abbreviation: DPL = diagnostic peritoneal lavage.

.

Overt peritonitis Massive hemoperitoneum

/

//

I High risk' 4

/

BLUNT ABDOMINAL ( TRAUMA

/


•

Aspirate

•

I

Diagnostic peritoneal lavage

Lavage

/

e

• .. ,

UUUUt:"ClI


,

study

Lavage @ ..

•

E

X p L

0 R A T

0

Acute

R Y

Low risk _

~:~~:ynamic(

I~

r---

A

~

Major (Grade ""-Ill)

Delayed presentation ........ (>12 hr)....................

•

I'

~ ~ solid organ Abdominal CT

L -_ _ _ _ _ _ _ _ _ _ _~

..................

-

0

Hollow viscus perforation

.. M y

Minor (Grade ",;;11) solid organ "'-

..................

.............................

,.-_"....;:0.._ _-.

' " Normal examination

~

1-1

T

..

I OBSERVE

Figure 2. Algorithm for the initial evaluation of blunt abdominal trauma in the adult emphasizes the central role of diagnostic peritoneal lavage in the severely injured patient. Computed tomography of the abdomen is valuable as a complementary test and in the low-risk patient. (*High risk = major mechanism, multisystem trauma, unreliable examination.)

,.'s,H.I."Dl' 40

502

OLIVER

J.

McANENA ET AL.

limited. The contents of a perforated viscus should evoke a migration of leukocytes into the peritoneal cavity, but this response is delayed for at least 3 hours after injury.72 A lavage alkaline phosphatase of greater than 3 IU IL has been shown to have superior accuracy when compared with laboratory white blood cell count in the detection of small bowel injury.49. 50 From a series of 1969 DPLs performed over a 4-year period, we found that, in an otherwise negative DPL, a LAM greater than 20 lUlL combined with a LAP greater than 3 lUlL was 97% specific and 78% sensitive, with a positive predictive value of 88% for significant hollow visceral injury. 52 Repeat DPL is performed when the initial lavage result is negative, but patients with multisystem trauma develop signs of hypovolemia or unexplained blood loss. Diagnostic peritoneal lavage has consistently attained an accuracy of greater than 95% and a significant morbidity rate less than 1%. These complications occur more frequently with the closed technique and include perforations of the small bowel, mesentery, bladder, and retroperitoneal vascular structures. The only absolute contraindication to a DPL is an existing indication for laparotomy. Prior abdominal surgery, a gravid uterus, and massive obesity are relative contraindications because the risk of complications in these circumstances is greater. In patients with previous midline abdominal wounds, DPL can be performed through a left lower quadrant transverse incision, but this is technically more challenging. The presence of intra-abdominal adhesions can loculate both the lavage fluid and free blood and, thus, increases the risk of a false-negative result. Abdominal CT scanning is particularly valuable in this group of patients.

SPECIAL RADIOLOGIC INVESTIGATIONS Contrast Duodenography Duodenal injury may occur as an isolated event, and delayed recognition is a notorious complication of blunt trauma. 28, 46, 58, 78, 93 Contrast duodenography with Gastrografin is useful for identifying duodenal perforation and is a simple, safe screening test for the high-risk patient (e. g., the unrestrained, intoxicated driver striking the steering column).18, 56 The procedure consists of instilling 250 ml of Gastrografin via the nasogastric tube and then rolling the patient into the right lateral decubitus position. If this part of the study is normal, an injection of barium is used to confirm duodenal integrity. In our recent analysis, 6 of 104 such studies were positive. Of note, two of these perforations had not been identified by CT scanning done immediately prior to the "C-loop" study. Radiologic signs of duodenal hematoma include defects in the normal contour of the duodenal loop and obstruction to contrast flow. 3, 25, 93 Computed Tomography of the Abdomen Computed tomography plays an important role in the evaluation of blunt abdominal trauma when applied in the appropriate clinical setting (see Fig. 2), The safe and timely completion of CT is a critical issue. The

INITIAL EVALUATION OF THE PATIENT WITH BLUNT ABDOMINAL TRAUMA

503

CT suite may be contiguous with the emergency department, but more often it is well outside its confines. Experienced personnel must be available to monitor the patient throughout the obligatory 45 to 60 minutes required to execute the study. Radiologists and CT technicians are needed on a 24hour basis, and delay in their arrival must be factored into the necessary study time. The scanner may not be available immediately because of equipment malfunction, required maintenance, or other patients' needs. These inconsistencies make strict reliance on CT, on a round-the-clock basis, problematic. The cost of the procedure, including radiologic interpretive fee, is widely variable but considerable. Finally, the oral and intravenous contrast-enhancing agents are not without hazard. It is the differential absorption of radiation by traumatic lesions, hemorrhage, and normal parenchyma that enables the CT scan to distinguish pathology. The time required to scan each slice of tissue ranges from 2 to 6 seconds, according to the model of scanner. The uncooperative patient either precludes study, compromises accuracy, or requires sedation. In the head-injured or hemodynamically labile patient, sedation may be ill-advised. An additional variable among scanners is low-contrast resolution, the ability to discern two areas in which the differential in contrast is low. This is particularly important in abdominal CT studies and significantly alters reliability. The ability of CT to serve as a primary triage tool has been strongly challenged. In blunt trauma, DPL has been employed in this role since its inception in 1965. Several clinical studies have prospectively compared CT to DPL in the acutely traumatized patient. Davis et aP3 found DPL to be 100% accurate in five patients requiring operation, whereas CT failed to detect four injuries in three of these same five patients. One patient developed hypotension during CT, and two others aspirated oral contrast. Our experience with 100 patients produced similar results. 48 Diagnostic peritoneal lavage was sensitive for each of five actively bleeding solid-organ injuries following blunt trauma. Computed tomography was positive in only two of these. Peritoneal lavage also predicted the need for celiotomy in each of seven patients who had penetrating abdominal wounds. Computed tomography was positive in only one. Moreover, CT scans missed hemoperitoneum in excess of 500 ml in four patients. The same conclusions can be drawn from the more recent investigation by Fabian et al. 22 On the other hand, CT has a remarkable potential as a diagnostic agent in abdominal trauma. In retrospective series, it has revealed intraperitoneal and retroperitoneal hemorrhage and specifically identified the culprit organs. 23. 32 Clearly, select patients with isolated and self-limiting injury to the liver or spleen can be managed expectantly. At this time, we believe CT should complement diagnostic peritoneal lavage in the evaluation of blunt abdominal trauma (see Fig. 2). The unstable patient with a positive lavage requires immediate laparotomy. When the lavage is positive but the patient is stable, or when lavage is indeterminate, CT has the potential to delineate specific viscus damage. Four groups of patients are particularly suitable for CT scanning: (1) patients with delayed (> 12 hours) presentation who are hemodynamically stable and do not have overt signs of peritonitis; (2) patients in whom DPL results are equivocal and repeated physical examination is unreliable or untenable

504

OLIVER

J.

McANENA ET AL.

(e.g., those who require prolonged general anesthesia for orthopedic or neurosurgical procedures; patients with an altered mental status from head injury, drugs, or alcohol; or patients with spinal cord injury); (3) patients in whom DPL is difficult to perform (e.g., morbid obesity, late-term pregnancy, or multiple previous laparotomies); peritoneal adhesions pose a technical problem to catheter placement and, more importantly, may loculate peritoneal contents from the DPL sampling; and (4) patients at high risk for retroperitoneal injuries in whom the DPL is unremarkable (e.g., an unrestrained, intoxicated driver who strikes the steering column or a patient with postinjury hyperamylasemia). It must be emphasized that CT scanning is not always accurate for the early assessment of blunt pancreatic fractures, and it is largely unreliable for detection of acute intestinal perforation. 8. 13, 21, 22, 48, 73, 76 Computed tomography may also provide valuable information about the extent and configuration of acute pelvic fractures. 5• 17 Diagnostic Ultrasound As quality ultrasound machines have become portable, their application in the initial evaluation of blunt abdominal trauma is being assessed critically. Indeed, diagnostic ultrasound is currently used routinely in emergency departments in Japan and Europe. 30, 37 Ultrasonography can demonstrate the presence of free intraperitoneal fluid as well as the extent and precise location of solid-organ hematomas. Because it involves no hazard from radiation or contrast media, the procedure is particularly appealing for pediatric trauma. Ultrasonography, of course, is limited in the assessment of acute hollow visceral perforation. Moreover, ultrasonography requires immediate availability of an experienced ultrasonographer and can be compromised by the presence of lower rib fractures, extensive skin lesions, soft-tissue injuries, or dressings. Gruessner et aP7 found that DPL was superior to ultrasonography in assessing the need for surgical intervention and concluded that the studies should not be viewed as competitive, but rather complementary. Intravenous Pyelography Indications for intravenous urography in the initial evaluation of blunt trauma remain unsettled. 36, 38, 45 The intravenous urogram is a test of function, and its main purpose is to identify irreparable parenchymal disruption as well as renovascular occlusion. Major kidney fractures are invariably associated with gross hematuria, which clearly requires an early pyelogram. Microscopic hematuria, however, does not warrant an immediate study unless a risk for vascular pedicle injury (Le" rapid deceleration) exists. A Single-shot intravenous urogram may be sufficient in the unstable patient prior to laparotomy, but absence of hematuria does not exclude renal arterial injury. Computed tomographic scan of the abdomen, performed with intravenous contrast, is more specific than intravenous urography but more costly. Presently, intravenous urography is regarded as the diagnostic screening test of choice; it should be followed by CT scanning or arteriography for better definition of poor renal function.

INITIAL EVALUATION OF THE PATIENT WITH BLUNT ABDOMINAL TRAUMA

505

Other Radiologic Studies Double-contrast CT scanning of the abdomen has largely eclipsed the role of radionuclide imaging for the evaluation of acute abdominal trauma. However, hepatosplenic technetium sulfur colloid scanning remains a valuable tool in the evaluation of the patient who presents in a delayed fashion (> 12 hours after injury) with isolated abdominal trauma or of the child who arrives hemodynamically stable following a minor mech~nism of injury (sports injury).73 In fact, Uthoff et alB5 reported sUPerior results with nuclear scintigraphy compared to CT scanning in a prospective study of blunt abdominal trauma. Abdominal aortography and splanchnic ap.giography are rarely warranted for the evaluation of acute abdominal trauma, but they may be of value as adjuncts for selective viscer;:tl embolization suggested by CT scanning. Occasionally, lumbar arterial embolization is useful for massive retroperitoneal bleeding associated with unstable thoracolumbar spine fractures. 75 Pelvic angiography with selective embolization via the hypogastric artery is an integral part of the management of active hemorrha~ associated with major pelvjc fractures. 60 The details of this complex subject, however, are beyond the scope of this article. Magnetic resonance imaging (MRI) is extremely accurate in anatomic definition of structural injury, but logistics virtually eliminate its practical application in the evaluation of acute abdominal trauma. lO Similarly, a number of other diagnostic tests, such as biliary31 and labeled red blood cell68 scintigraphy, are primarily employed for delayed complications of abdominal trauma.

EVALUATION OF THE CHILD WITH BLUNT ABDOMINAL TRAUMA Trauma is the leading cause of death in children 1 to 14 years of age, and blunt trauma causes 90% of these critical injuries. 19. 71 Aut~obile and auto-pedestrian accidents account for the majority of injuries, although the role of child abuse is increasing. 9 Injuries inconsistent with the history provided, or not in keeping with the child's level of physical maturity, should alert the physician to the possibility of child abuse. Because the child's abdomen has poorly developed musculature and a relatively smaller anteroposterior diameter, the abdominal contents are more vulnerable to injury. The rib cage is extremely resilient in children and less prone to fractures, but it nonetheless provides only partial protection for intraperitoneal contents. The initial assessment of pediatric patients is frequently made more difficult by age-related difficulties in communication, fearinduced uncooperative behavior, or concomitant head injury. The trauma surgeon must be familiar with the normal physiologic range of vital signs adjusted for age (Table 3). Decompressive nasogastric tubes are particularly important to aid abdominal examinatiop., as children are prone to aerophagia. Children are also more susceptible to hypothermia resulting from the administration of unwarmed fluids and blood products. The use of overhead heated lamps, blood warmers, and prewarmedintravenous fluids minimizes this complication.

506

OLIVER

J.

McANENA ET AL.

Table 3. Physiologic Indices in the Normal Child AGE

WEIGHT

(yr)

(kg)

SYSTOLIC BLOOD PRESSURE

HEART RATE

RESPIRATION

HEMATOCRIT

(%)

2 4 6 8 10

12 16 20 24 29

90 94 96 104 llO

120 llO 100 96 90

35 31 26 23 21

37 38 39 39 40

The management of blunt abdominal trauma in children has changed radically over the past decade. 20. 40. 42. 44. 55. 64. 90 Recognition of overwhelming postsplenic sepsis revolutionized the approach to splenic injury, which was once considered a mandatory indication for laparotomy as well as splenectomy. As the impetus for splenic salvage grew, it was observed that bleeding from minor splenic lacerations in children had often ceased at the time of abdominal exploration. This phenomenon has been ascribed to a greater capsule-to-parenchyma ratio in younger individuals. 57 The pioneering work of Simpson et a}2o, 90 and the subsequent studies of other groups40. 42, 44, 55, 64 established that the majority of isolated splenic injuries in the child heal without surgical intervention. The advent of double-contrast CT scanning of the abdomen added further confidence in the nonoperative management of solid visceral injury. The timely recognition of major pancreatic injury or hollow visceral perforation is problematic. The penalty for delayed recognition of these injuries is severe. Although the incidence of blunt intestinal disruption in children is considered low, recent clinical reviews have indicated a rate as high as 18%.7. 27, 83 Our study73 and others88 confirm the high risk of pancreatic transection in acutely injured children. Diagnostic peritoneal lavage may miss isolated injury of these organs owing to the relative insensitivity oflavage effiuent amylase and the delay in peritoneal leukocytic response. Computed tomography has been largely unsuccessful in visualizing small bowel perforation; its accuracy in the evaluation of 'acute pancreatic trauma in the child has also been disappointing. Enzyme analysis of free intraperitoneal blood may prove valuable for a selective laparotomy policy in the child. The aspiration of intraperitoneal blood formerly mandated celiotomy; thus, further characterization of this collection has received vanishing attention. The recent concept of nonoperative management for stable patients with grossly bloody aspirate presumes isolated injury to the liver or spleen. Submitting this aspirate to amylase and alkaline phosphatase measurement may help assure integrity of the pancreas and hollow viscera. Prior study supports this hypothesis. 50. 73 Assessment of diagnostic methods should carefully consider the qualifications of the specific institution. The ability to perform CT accurately in children is compromised by their lack of cooperation as well as their paucity of retroperitoneal fat. The role of DPL in children at high risk for abdominal injury has been reconsidered favorably by several groups with extensive experience in managing pediatric trauma. 19, 70, 71 We believe the best

INITIAL EVALUATION OF THE PATIENT WITH BLUNT ABDOMINAL TRAUMA

507

approach is to combine DPL and scanning to determine the need for laparotomy. Diagnostic peritoneal lavage is a rapid, sensitive test to confirm the presence of intraperitoneal blood. In the child younger than 10 years of age, the Seldinger wire/closed technique of DPL is particularly useful owing to the paucity of omentum and mesenteric fat.73 The need for laparotomy can be further clarified by scanning. We have adhered to a protocol at DGH designed to avoid life-threatening complications from delayed abdominal exploration and, at the same time, to reduce the number of unnecessary laparotomies (Fig. 3). Diagnostic peritoneal lavage is performed in children at high risk for abdominal injury, particularly following major multisystem insults, and in those in whom physical examination is compromised. If the DPL is grossly positive by aspiration of free blood and the child demonstrates clinical instability, laparotomy is performed. Selective observation is permitted when DPL is positive for blood, depending upon Memodynamic and clinical parameters and corroborative CT findings. Laparotomy is mandatory for DPL effluent positive by criteria other than blood. In the stable child with DPL positive by blood or red blood cell count alone, laparotomy is done if the scans fail to demonstrate suspected hepatosplenic injury or if hollow visceral disruption or major pancreatic injury is identified. Selective nonoperative management of pediatric trauma requires frequent abdominal examinations, monitoring of vital signs, frequent laboratory tests, and close monitoring by nursing personnel experienced in pediatric intensive care. 47

EVALUATION OF BLUNT ABDOMINAL TRAUMA DURING PREGNANCY Trauma is the leading cause of death in women of child-bearing age. 51, 62 Accidental injuries occur in 5 to 10% of all pregnancies. As the pregnancy progresses, the incidence of minor trauma increases. By the third trimester, minor trauma occurs more frequently than at any other time during female adulthood. The most common cause of fetal death is maternal death. Therefore, initial resuscitation efforts are directed primarily toward the mother. The approach to the injured pregnant patient is the same as for the nonpregnant person. Prehospital information is critical; the more significant the injury mechanism, the more concerned and aggressive the physician must be in patient care. Rothenberger74 reviewed 103 cases of blunt maternal trauma and found successful pregnancy outcome in only 39% of cases associated with major maternal injuries, 73% of cases with minor injuries, and 100% of cases with insignificant maternal injuries. A knowledge of the physiologic processes unique to pregnancy is important to interpret the pregnant woman's response to the stress of trauma (Table 4). During the first trimester, the mother's physiology is only mildly altered. By the tenth week, the mother's cardiac output has reached 7 Limin, and this level is maintained throughout the remainder of pregnancy. In the third trimester, however, cardiac output can be transiently lowered by inferior vena cava compression from the gravid uterus. This so-called supine hypotensive syndrome also can cause placental abrup-

""o ex>

Overt peritonitis Massive hemoperitoneum

BLUNT ABDOMINAL ( TRAUMA

/

/

/

/

/

•

I

Aspirate GI contents Lavage enzymes High risk'

(±) --------------------------.,

p L

.. I Aspirate blood Lavage RBC

..

(E) ___________---<~ E .. I X

Io~

(E)

(E) _

0

Hemodynamic stability

e

... T

R

Acute

y

(±) Low risk _

L A p

Hemodynamic stability

..I "

Delayed ..... -_......... presentation (>12 hr)

Abdominal CT

~

Major (Grade solid organ

A R

~III)

0 T

-

0

' H o l l o w viscus perforation

..

L..-_ _ _ _ _ _ _ _ _ _ _---'

-.........

M Y

Minor (Grade ,,;;11) solid organ '\.

.................. _ ......... _

~~----,

r---

..,.". Normal examination

..

j

OBSERVE

Figure 3. Algorithm for the initial evaluation of blunt trauma in the child outlines a selective laparotomy policy based on injury mechanism as well as physiologic status. Diagnostic peritoneal lavage is a key triage step in the critically injured. Computed tomography is particularly valuable in reducing unnecessary laparotomy and entails a low risk. (*High risk = major mechanism, multisystem trauma, unreliable examination.)

4

INITIAL EVALUATION OF THE PATIENT WITH BLUNT ABDOMINAL TRAUMA

509

Table 4. Hemodynamic Changes in Pregnancy TRIMESTER

TRIMESTER

TRIMESTER

NONPREGNANT

Heart rate (beats/minute) Systolic blood pressure (mm Hg) Diastolic blood pressure (mm Hg) Cardiac output (liters/minute) Systemic vascular resistance (dynes/cm2) Blood volume (ml) Hematocrit without iron (%) Hematocrit with iron (%) White blood count (per mm3)

70 110

70 4.5 1743 2600 40 40 7200

78 105 60 4.5-6 979 3150 36 36 9100

82

85

102

108

55

67

6

6

1277 3850 33 34 9700

1224 3950 34 36 9800

tion by increasing the pressure in the intervillous spaces. Compression of the lower abdominal venous system by the gravid uterus increases peripheral venous pressure in the lower extremities and thereby increases the amount of blood loss from leg wounds. Blood volume may increase by 50% at term. Consequently, with this much reserve, 30 to 35% of blood volume may be lost before clinical signs of maternal hypovolemia are observed. The uterus can be a major source of blood loss when injured because, at term, the patient's total circulating blood volume flows through the uterus every 10 minutes. During the second trimester, systolic and diastolic pressures are 5 to 15 mm Hg below nonpregnant levels because of reduced systemic vascular resistance. At term, the blood pressure returns to normal. Therefore, if the blood pressure is elevated, one must consider the presence of pre-eclampsia or eclampsia. Decreased gastrointestinal motility, from the smooth muscle relaxant effeot of progesterone, increases the possibility of aspiration during trauma and intubation, and the stomach's increased acid production during pregnancy makes aspiration more ominous than usual. Hypovolemia and hypoxia may profoundly affect uterine blood flow and, therefore, well-being of the fetus. Animal studies imply that the uterine vascular bed in pregnancy is a low-resistance system, dependent upon arterial blood pressure to maintain uterine blood flow but responsive to central nervous system and catecholamine stimulation during trauma. 35, 43 Thus, diagnostic procedures for the seriously injured pregnant patient must be performed aggressively, Cardiopulmonary resuscitation of the mother is of paramount importance, as maternal death is the most common cause of fetal death. Peritoneal lavage should be performed with an open technique at a site cephalad to the palpable uterus, As with nonpregnant patients, surgical intervention is undertaken when the mother demonstrates hemodynamic instability, peritoneal irritation, pneumoperitoneum, significant gastrointestinal hemorrhage, or a positive DPL, Ultrasonography may serve as a valuable adjunct in the hemodynamically stable patient, The fundamental guidelines used in managing nonpregnant patients with abdominal trauma apply in pregnancy, with certain modifications. Lateral positioning in late pregnancy, with uterine displacement away from the vena cava, may augment uterine blood flow by as much as 30%,51,62 Fetal status should be assessed by physical examination and ultrasonography as well as by con tin-

510

OLIVER

J.

McANENA ET AL.

uous monitoring. The uterus is palpated for evidence of rupture, and the cervix is inspected for evidence of placental abruption. The presence of a pelvic fracture is frequently complicated by rupture of the uterus or placental abruption. Consequently, serial evaluation of the coagulation profile is routine, and evidence of a progressive coagulopathy is an indication for evacuation of the uterus. 43 In the event of maternal death, immediate action should be taken to deliver the fetus. The chances of infant survival are poor if the elapsed time from maternal death exceeds 15 minutes. 89

EVALUATION OF THE ELDERLY WITH BLUNT ABDOMINAL TRAUMA The geriatric population is increasing progressively in the United States, and owing to improved health and social attitude, the elderly are more active, rendering them at greater risk for major trauma. Recent studies have demonstrated that people aged 65 years or older are more likely to sustain serious injury in an equivalent accident, and that risk of life is greater for an equivalent injury severity.l4· 15.54.67. 77 The common causes of serious injury in the geriatric age are falls,77 vehicular trauma, 54 and auto-pedestrian accidents. 14 Perhaps the most frequent reason for injury is delayed reaction time due to errors in perception as well as limited physical adjustments. Initial evaluation and resuscitation of the injured elderly are the same as designed for the younger counterpart, except that one must recognize the limited physiologic response as well as reserve (Table 5). Cardiac output declines with age and is less responsive to catecholamines. Blood must be Table 5. Normal Biologic Changes in the Elderly Cardiovascular

Reduced cardiac output Decreased response to catecholamines Pre-existing conduction abnormalities Diffuse atherosclerosis (hypertension is the rule)

Pulmonary

Decreased vital capacity Decreased forced expiration Reduced compliance Increased closing volume

Central nervous system

Cerebral atrophy Impaired balance

Gastrointestinal

Diffuse atrophy Exaggerated ileus Reduced gastrointestinal competence

Renal

Decreased glomeruler filtration rate Tubular degeneration

Immunity

Altered humoral and cellular Protein-calorie malnutrition

Endocrine

Abnormal glucose tolerance

Skeletal

Osteoporosis

INITIAL EVALUATION OF THE PATIENT WITH BLUNT ABDOMINAL TRAUMA

511

replaced early to facilitate oxygen delivery. The anticipated tachycardia associated with hypovolemia is often absent; conversely, a systolic blood pressure of 120 mm Hg is abnormally low for the aged patient. Early invasive hemodynamic monitoring is clearly warranted. Vital capacity is diminished, and the inability to generate ventilatory pressures often leads to precipitous respiratory failure when postinjury oxygen consumption demands rise. Presumptive endotracheal intubation as well as empiric chest-tube placement are clearly justified. The basic principle in the management of blunt abdominal trauma in the elderly is to assume the worst and aggressively pursue diagnostic confirmation. Early DPL is a valuable triage instrument. On the other hand, CT scanning and associated nonoperative care of intraperitoneal injury have a very limited role in the older patient. Pelvic fracture hemorrhage is notoriously insidious and frequently lethal owing to delayed recognition. The prompt distinction between ongoing pelvic versus intraperitoneal bleeding is particularly critical in the auto-pedestrian accident victim.

SUMMARY Unrecognized abdominal injury remains a distressingly frequent cause of preventable death following blunt trauma. Peritoneal signs are often subtle, overshadowed by pain from associated injury, and masked by head trauma or intoxicants. The initial management of the patient with blunt abdominal trauma should parallel the primary survey of airway, breathing, and circulation. Diagnostic peritoneal lavage remains the cornerstone of triage in patients with life-threatening blunt abdominal trauma. The only absolute contraindication to the procedure is an existing indication for laparotomy. Computed tomography is useful as a complementary diagnostic tool in selected patients, and it is the critical test for guiding nonoperative management of known intraperitoneal trauma. Routine ancillary tests for potentially occult injuries include nasogastric-tube placement for ruptures of the left diaphragm, Gastrografin contrast study for duodenum perforation, and pyelography for urologic injury. Ultrasonography may become a valuable tool in the initial assessment of the injured abdomen. Ultimately, the most important principle in the management of blunt abdominal trauma is repeat physical examination by an experienced surgeon.

REFERENCES 1. Alyono 0, Perry JF: Value of quantitative cell count and amylase activity of peritoneal lavage fluid. J Trauma 21:345, 1981 2. Arajarvi E, Santavirto S, Tolonen J: Abdominal injuries sustained in severe traffic accidents by seatbelt wearers. J Trauma 27:393, 1987 3. Ben-Menachem Y, Fisher RG: Diagnostic and interventional radiology in trauma. In Mattox KL, Moore EE, Feliciano DV (eds): Trauma. Norwalk, CT, Appleton & Lange, 1988, p 187 4. Bouwman DL, Weaver OW, Walt AJ: Serum amylase and its isoenzyme-a clarification of their implications in trauma. J Trauma 24:573, 1984

512

OLIVER

J.

McANENA ET AL.

5. Buckley SL, Burkus JK: Computerized axial tomography of pelvic ring fractures. J Trauma 27:496, 1987 6. Caffee HH, Benfield JR: Is peritoneal lavage for the diagnosis of hemoperitoneum safe? Arch Surg 103:4, 1971 7. Cobb LM, Vinocur CD, Wagner CW, et al: Intestinal perforation due to blunt trauma in children in an era of increased nonoperative treatment. J Trauma 26:46, 1986 8. Cook DE, Walsh JW, Vick CW, et al: Upper abdominal trauma: Pitfalls in CT diagnosis. Radiology 159:65, 1986 9. Cooper A, Floyd T, Barlow B, et al: Major blunt abdominal trauma due to child abuse. J Trauma 28:1483, 1988 10. Council on Scientific Affairs: Report of the panel on magnetic resonance imaging: Magnetic resonance imaging of the abdomen and pelvis. JAMA 261:420, 1989 11. Cox EF: Blunt abdominal trauma: A 5-year analysis of 870 patients requiring celiotomy. Ann Surg 199:467, 1984 12. Davis JJ, Cohn I, Nance FC: Diagnosis and management of blunt abdominal trauma. Ann Surg 183:672, 1976 13. Davis RA, Shayne JP, Max MH, et al: The use of computerized axial tomography versus peritoneal lavage in the evaluation of blunt abdominal trauma: A prospective study. Surgery 98:845, 1985 14. Demarest GB: Geriatric trauma. In Mattox KL, Moore EE, Feliciano DV (eds): Trauma. Norwalk, CT, Appleton & Lange, 1988, p 645 15. DeMaria EJ, Kenney PR, Merriam MA, et al: Aggressive trauma care benefits the elderly. J Trauma 27:1200, 1987 16. DiVincenti FC, River JD, Laborde EJ, et al: Blunt abdominal trauma. J Trauma 8:1004, 1968 17. Dunn EL, Berry PH, Connally JD: Computed tomography of the pelvis in patients with multiple injuries. J Trauma 23:378, 1983 18. Edney JM, Marx JA, Moore EE: Utility of contrast duodenography in the detection of proximal small bowel injury following blunt trauma. Ann Emerg Med, in press 19. Eichelberger MR, Randolph JG: Progress in pediatric trauma. World J Surg 9:222, 1985 20. Ein SH, Shandling B, Simpson JS, et al: Non-operative management of traumatized spleen in children: How and why. J Pediatr Surg 13:117, 1978 21. Evans L, Frick MC: Potential fatality reductions through eliminating occupant ejection from cars. Accid Anal Prev 21:169, 1989 22. Fabian TC, Mangiante EC, White TJ, et al: A prospective study of91 patients undergoing both computer tomography and peritoneal lavage following blunt abdominal trauma. J Trauma 26:602, 1986 23. Federle MP, Crass RA, Jeffrey RB, et al: Computed tomography in blunt abdominal trauma. Arch Surg 117:645, 1982 24. Feliciano DV: Patterns of injury. In Mattox KL, Moore EE, Feliciano DV (eds): Trauma. Norwalk, CT, Appleton & Lange, 1988, p 91 25. Felson B, Klatte EC: Radiology of abdominal trauma. JAMA 231:1377, 1975 26. Fischer RP, Beverlin BC, Engrav LH, et al: Diagnostic peritoneal lavage: Fourteen years and 2,586 patients later. Am J Surg 136:701, 1978 27. Fischer RP, Miller-Crotchell P, Reed RL: Gastrointestinal disruption: The hazard of nonoperative management in adults with blunt abdominal injury. J Trauma 28:1445, 1988 28. Flint LM, McCoy M, Richardson JD, et al: Duodenal injury-analysis of common misconceptions in diagnosis and treatment. Ann Surg 191:697, 1980 29. Foley RW, Harris LS, Pilcher DB: Abdominal injuries in automobile accidents: Review of care of fatally injured patients. J Trauma 17:611, 1977 30. Furtschegger A, Egender G, Jaske G: The value of sonography in the diagnosis and follow-up of patients with blunt renal trauma. Br J Urol 62:110, 1988 31. Gartman DM, Zeman RK, Cahow CE, et al: The value of hepatobiliary scanning in complex liver trauma. J Trauma 25:887, 1985 32. Goldstein AS, Sclafani SJA: The diagnostic superiority of computerized tomography. J Trauma 25:938, 1985 33. Gomez GA, Alvarez R, Plasencia AR, et al: Diagnostic peritoneal lavage in the management of blunt abdominal trauma: A reassessment. J Trauma 27:1, 1987

INITIAL EVALUATION OF THE PATIENT WITH BLUNT ABDOMINAL TRAUMA

513

34. Greenfield RH, Bessen HA, Henneman PL: Effect of crystalloid infusion on hematocrit, and intravascular volume in healthy nonbleeding subjects. Ann Emerg Med 18:51, 1989 35. Greiss FC, Gobble FL: Effects of sympathetic nerve stimulation on the uterine vascular bed. Am J Obstet Gynecol 97:962, 1967 36. Griffin WO, Belin R, Ernst CB, et al: Intravenous pyelography in abdominal trauma. J Trauma 18:387, 1978 37. Gruessner R, Mentges B, Duber C, et al: Sonography vs. peritoneal lavage in blunt abdominal trauma. J Trauma 29:242, 1989 38. Guice K, Oldham K, Eide B, et al: Hematuria after blunt trauma-when is pyelography useful? J Trauma 23:305, 1983 39. Hill AC, Schecter WP, Trunkey DD: Abdominal trauma and indications for laparotomy. In Mattox KL, Moore EE, Feliciano DV (eds): Trauma. Norwalk, CT, Appleton & Lange, 1988, p 401 40. Hoelzer DJ, Brian MB, Balsara VJ, et al: Selection and nonoperative management of pediatriC blunt trauma patients: The role of quantitative crystalloid resuscitation and abdominal ultrasonography. J Trauma 26:57, 1986 41. Hornyak SW, Saftan GW: Value of inconclusive lavage in abdominal trauma management. J Trauma 19:329, 1979 42. Kakkasseril JS, Stewart D, Cox JA, et al: Changing treatment of pediatriC splenic trauma. Arch Surg 117:758, 1982 43. Karlsson K: The influence of hypoxia on uterine and maternal blood flow, and the effects of adrenergic blockage. J Perinatal Med 2: 176, 1974 44. Karp M, Cooney D, Berger P, et al: The role of computed tomography in the evaluation of abdominal trauma in children. J Pediatr Surg 16:316, 1981 45. Klein S, Johs S, Fujitani R, et al: Hematuria following blunt abdominal trauma: The utility of intravenous pyelography. Arch Surg 123:1173, 1988 46. Lucas CE, Ledgerwood AM: Factors influencing outcome after blunt duodenal injury. J Trauma 15:839, 1975 47. MacGilliv~ay DC, Valentine RJ: Nonoperative management of blunt pediatric liver injury-late complications: Case report. J Trauma 29:251, 1989 48. Marx JA, Moore EE, Jorden RC, et al: Limitations of computed tomography in the evaluation of acute abdominal trauma: A prospective comparison with diagnostic peritoneal lavage. J Trauma 25:933, 1985 49. Marx JA, Bar-Or D, Moore EE, et al: Utility of lavage alkaline phosphatase in detection of isolated small intestinal injury. Ann Emerg Med 14:10, 1985 50. Marx JA, Moore EE, Bar-Or D: Peritoneal lavage in small bowel colon injuries: the value of enzyme determinations. Ann Emerg Med 12:68, 1983 51. Maull KI, Rozyiki GS, Pedigo RE, et al: Injury to the female reproductive system. In Mattox KL, Moore EE, Feliciano DV (eds): Trauma. Norwalk, CT, Appleton & Lange, 1988, p 553 52. McAnena OJ, Marx JA, Moore EE: Utility of peritoneal lavage enzyme determinationS following blunt and penetrating abdominal trauma. J Trauma, in press 53. McClellan BA, Hanna SS, Montoya DR, et al: Analysis of peritoneal lavage parameters in blunt abdominal trauma. J Trauma 25:393, 1985 54. McCoy GF, Johnstone BA, Duthie RB: Injury to the elderly in road traffic accidents. J Trauma 29:494, 1989 55. Mohamed G, Reyes HM, Fantus R, et al: Computed tomography in the assessment of pediatric abdominal trauma. Arch Surg 121:703, 1986 56. Moore EE: Resuscitation and evaluation of the injured patient. In Zuidema GG, Ballinger W, Rutherford R: Management of Trauma. Philadelphia, WB Saunders, 1985, p 1 57. Moore FA, Moore EE, Moore GE, et al: Risk of splenic salvage after trauma: Analysis of 200 adults. Am J Surg 148:800, 1984 58. Moore JB, Moore EE: Changing trends in the management of combined pancreatroduodenal injuries. World J Surg 8:791, 1984 59. Moore JB, Moore EE, Markovchick VD, et al: Diagnostic peritoneal lavage for abdominal trauma: Superiority of the open technique at the infraumbilical ring. J Trauma 21 :570, 1981 60. Moreno C, Moore EE, Rosenberger A, et al: Hemorrhage associated with major pelvic fractures-a multispecialty challenge. J Trauma 26:987, 1986

514

OLIVER

J.

McANENA ET AL.

61. Neufeld JD, Moore EE, Marx JA, et al: Trauma in pregnancy. Med Clin North Am 5:623, 1987 62. Neuman TS, Bockman MA, Moody P, et al: An autopsy study of traumatic deaths: San Diego, 1979. Am J Surg 144:722, 1982 63. Nygren A: Injurif;!s to car occupants-some aspects of the interior safety of cars. Acta Otol Scand 395(suppl):I, 1984 64. Oldham KT, Guice KS, Ryckman F, et al: Blunt liver injury in childhood: Evolution of therapy and current perspective. Surgery 100:542, 1986 6i>. Olsen WR: The serum amylase in blunt abdominal trauma. J Trauma 13:200, 1973 66. Olsen WfI., Redman fIC, Hildreth DH: Abdominal paracentesis and peritonealll\vage in blunt abdominal trauma. J Trauma 11:824, 1971 67. Oreskovich MR, Howard JD, Copass MK, et al: Geriatric trauma: Injury patterns and outcome. J Trauma 24:565, 1984 68. Orzel JA, Rudd TG, Oreskovich MR: Evaluation of traumatic mesenteric hemorrhage in a hemophiliac with Tc-99m labeled red blood cell scintigraphy. J Trfluma 26:1056, 1986 69. Philips LL, Skrodelis V, Taylor HC: Hemorrhage clue to fibrinolysis in abruptio placentae. Am J Obstet Gynecol 84:1447, 1962 70. Powell RW, Gref;!n JB, Ochsner MG, et al: Peritoneal lavage in pediatric patients sustaining blunt abdomillal trauma: A reappraisal. J Trauma 27:6, 1987 71. Ramenofsky ML, Morse TS: Standards of care for the critically injured pediatric patient. J Trauma 22:921, 1982 72. Root HD, Hauser CW, McKinley CR, et al: Diagnostic peritoneal lavage. Surgery 57:633, 1965 73. Rothenberg S, Moore EE, Marx JA, et al: Selective management of blunt abdominal trauma in children-the triage role of peritoneal lavage. J Trauma 27:1101, 1987 74. Rothenberger DA, Quattlebaum FW, Zabel J, et al: Blunt maternal trauma: A review of . 103 cases. J Trauma 18:173, 1978 75. Scalea T, Goldstein A, Phillips T, et aI: An analysis of 161 falls from a height-the jumper syndrome. J Trauma 26:706, 1986 76. Sherck JP, McCort JJ, Oakes DD: Computed tomography in thoracoflbdominal trauma. J Trauma 25:1015, 1984 77. Sjogren H, Bjornstig U: Unintentional injuries among elderly people; Incidence, causes, severity, and costs. Accid Anal Prev 21:233, 1989 78. Snyder WH, Weigelt JH, Watkins WL, et al: The surgical management of duodenal trauma. Arch Surg 115:422, 1980 79. Thal ER: Evaluation of perjtoneallavage and local exploration in lower chest and abdoplinal stab wounds. J Trauma 17:642, 1977 80. ThaJ. ER, Shires GT: Peritoneal lavage in blunt abdominal trauma. Am J Surg 125:64, 1973 81. Thompson JS, Moore EE: Peritoneal lavage in the evaluation of penetrating abdominal trauma. Surg Gynecol Obstet 153:861, 1981 82. Thompson JS, Moore EE, VanDllzer-Moore S, et al: The evolution of abdominal stab wound management. J Trauma 20:478, 1980 83. Traub AC, Perry JF: Injuries associated for splenic trauma. J Trauma 21:840, 1981 84. Trunkey DD, Chapman MW, Lim RC, et al: Management of pelvic fractures in blunt trauma injury. J Trauma 14:912, 1974 85. Uthoff LB, Wyffels PL, Adams CT, et al: A prospective study comparing nuclear scintigraphy and CAT in the initial evaluation of the trauma patient. Ann Surg 198:611, 1983 86. Vestrup JA, Reid JDS: A profile of urban adult pedestrian trauma. J Trauma 29:741, 1989 87, Ward RE, Miller P, Clark DG, et al: Angiography and peritoneal lavage in blunt flbdominal trauma. J Trauma 21:848, 1981 88. Warner RL, Othersen HB, Smith CD: Traumatic pancreatitis and pseudocyst in children: Current management. J Trauma 29:597, 1989 89. Weber CE: Postmortem cesarean section: Review of the literature and case reports. Am J Obstet Gynecol 110:158, 1971 90. Wesson DE, Filler RM, Ein SH, et l!i: Ruptured spleen: When to operate? J Pediatr Surg 16:267, 1981 91. West J, Trunkey DD, Lim RC: Systems of trauma care: A study of two counties. Arch Surg 114:455, 1979

INffiAL EVALUATION OF THE PATIENT WITH BLUNT ABDOMINAL TRAUMA

515

92. Woelfel GF, Moore EE, Cogbill TH, et al: Severe thoracic and abdominal injuries associated with lap-harness seatbelts. J Trauma 24:166, 1984 93. Wooley MM, Mahour GT, Sloan T: Duodenal hematoma in infancy and childhood. Am J Surg 136:8, 1978

Address reprint requests to Ernest E. Moore, MD Department of Surgery Denver General Hospital 777 Bannock Street Denver, CO 80204-4507

..