Surgeons whose patients are the victims of terror bombings are likely to be confronted with unique and challenging injury patterns. These patients are at high risk for having their injuries missed during evaluation, which can be devastating in terms of morbidity and mortality. Reducing the incidence and impact of overlooked injuries requires a carefully thought-out and disciplined plan that incorporates close observation, repeated trauma surveys, and close coordination between multidisciplinary treatment teams. Surgeons at home or abroad may find themselves directing treatment for these complex trauma patients. To illustrate the difficulties described, the authors present three cases typical of those encountered at a combat support hospital deployed in Iraq.

Victims of terror bombings sustain unique patterns of injury and present particular diagnostic and treatment challenges. These blasts can originate from a variety of sources, including an improvised explosive device (IED), a vehicle-born IED, or a suicide bombing. Although the delivery system may vary, the perpetrator’s goal is fixed: to cause the greatest degree of damage to the largest number of victims. Casualties are indiscriminate and may encompass both military and civilian targets. While caring for casualties of these asymmetric weapons continues to evolve, there are multiple reasons why these patients remain at high risk for missed injuries. To illustrate some of those reasons, we report three cases that are typical of those encountered at a combat support hospital deployed in Iraq.

Case reports
Case 1—A 35-year-old man sustained blast injuries from a suicide bombing during a mass casualty (MASCAL) event. In an attempt at damage control, he underwent an immediate laparotomy at another institution before being transferred by military helicopter to our combat support hospital. The patient arrived intubated and sedated, with his abdomen packed to control a grade III penetrating liver injury and a bladder injury repaired using a suprapubic catheter. His initial vital signs were a heart rate of 142 beats per minute, blood pressure of 142/64 mm Hg, a respiratory rate of 21 breaths per minute, and a core temperature of 101.1°F. Physical examination revealed abdominal distension with skin closure and numerous penetrating injuries on his lower back, buttocks, and thighs, inflicted by spherical pellets (Figure 1). A laboratory evaluation was significant for a base deficit of —11 mmol/L, prothrombin time of 22.6 seconds, and hematocrit of 31%.

The patient underwent 12 hours of resuscitation, after which a second exploratory laparotomy was performed. This found a spherical missile at the junction of his anterior rectum and the posterior bladder, with a 1.5-cm hematoma at the peritoneal reflection. Rigid proctoscopy identified blood but no discrete rectal injury. After a rectal washout, an end colostomy with a Hartmann’s pouch was created and the bladder was revised over a Foley catheter for anatomic drainage. An attempt to remove the liver packs was unsuccessful, and the liver had to be repacked with administration of whole blood and activated factor VIIa.

Over the next 48 hours, a limited neurological examination observed a complete motor deficit in flexion and extension of the patient’s right foot and loss of strength at hip flexion, but preserved sensation throughout the limb. Four days after presentation, the patient’s liver was unpacked, the fascia was closed, and several ball bearings were removed through a right hip arthrotomy. Once the patient was hemodynamicallystable and could tolerate transfer and movement, a computed tomography (CT) scan of the abdomen and pelvis was performed. The CT scan revealed the severity of penetrating injuries to the spinal column at vertebrae L4 and caudal (Figure 2), which prompted transfer of the patient to a higher care facility with neurosurgical capabilities.

Case 2—A 32-year-old man was the victim of an IED during a MASCAL event and sustained multiple penetrating injuries to his right flank, arm, and leg. Despite a negative FAST (Focused Assessment by Sonography in Trauma) examination, his abdomen was tender on palpation. A portable radiograph of the patient’s chest did not identify any pneumothorax, but a spherical pellet was noted at the level of the right hemidiaphragm. Other injuries included a right ulnar fracture with massive tissue loss, an intra-articular foreign body in the right knee, and a through-and-through, penetrating injury to the right calcaneus.

A laparotomy was performed, and five colotomies in the mid-transverse colon were repaired, while a ball bearing was retrieved from within the posterior falciform ligament. Further mobilization of the triangular ligaments had to be halted due to a contained hematoma. Investigation of the right superficial femoral and popliteal arteries revealed no arterial compromise, and a right knee arthrotomy was performed to retrieve an intra-articular ball bearing. The extent of tissue destruction in the patient’s leg and degree of resuscitation mandated a four-compartment fasciotomy.

His right arm had to be amputated at the elbow because of tissue loss and nonviability. During the 12 hours that followed, his right leg lost distal pulses, necessitating an arterial thrombectomy of the popliteal artery followed by reverse saphenous vein graft bypass around the injured segment of the posterior knee. A postoperative arteriogram administered prior to the patient’s departure from the operating room (OR) demonstrated bypass patency.

Several weeks later, radiographs of the patient’s chest were taken, and everything appeared normal; however, 72 hours after these radiographs were taken, attempts to insert a routine subclavian central line were complicated by the withdrawal of bilious fluid from the right pleural space. This prompted a tube thoracostomy.

A postoperative radiograph of the patient’s chest subsequent to his departure from the OR revealed the degree of bilious effusion that had developed in this 72-hour interim (Figure 3). After 5 days of drainage, a right thoracotomy for empyema revealed a penetrating injury through the hepatic diaphragm (Figure 4), which had been overlooked.

Case 3—A 28-year-old man was involved in an IED blast in which his right arm was shattered and nonviable to the shoulder. A tourniquet and chest tube were placed while the patient was in the field.

The patient arrived obtunded, with an initial heart rate of 99 beats per minute, blood pressure of 95/32 mm Hg, respiratory rate of 22 breaths per minute, and a core temperature of 97.4°F. Physical examination revealed his lungs were clear and his abdomen was soft on palpation.An initial FAST examination was normal, and a rectal examination was negative for blood.

The right upper extremity was mangled beyond salvage to the humeral head, with active arterial hemorrhage. No other entrance or exit wounds were identified. A portable chest radiograph showed both lungs inflated with a properly positioned chest tube and a large, dense foreign body over the right hemidiaphragm, although it was difficult to differentiate this foreign body from other debris littering the stretcher and patient (Figure 5). The patient’s laboratory results were significant for a pH of 7.2, lactate of 6.2 mmol/L, and hematocrit of 38%.

A right shoulder disarticulation was performed immediately for vascular control, and wounds were packed open. An intraoperative fluoroscopy examination did not identify the foreign object noted earlier, but a postoperative CT scan of the chest confirmed a dense, disk-shaped object measuring 5 x 5 x 2 cm in the inferior right hemidiaphragm (Figure 6).

After 36 hours of resuscitation, a large metal missile was retrieved through a right thoracotomy, and a missed diaphragmatic injury was repaired. Serial washouts with eventual myodesis and skin closure were performed on the right shoulder, and the patient was discharged to an allied hospital for further rehabilitation.

Discussion
Much has been written about blast injuries in the medical literature, and it is well known that these injuries can be particularly devastating. A blast has five mechanisms for causing injury, categorized as follows: primary from the blast wave, secondary from projectiles, tertiary from the victim being thrust against stationary objects, quaternary from the generated heat, and quinary from the explosive material’s toxicity.¹Multiple simultaneous mechanisms for causing injury result in numerous types of injuries afflicting several body regions at once.

Terror bombing victims pose a tremendous challenge for health care teams and medical organizations. Surgeons, as team leaders, must be especially aware of the diagnostic complexity that accompanies these patients. Blast patients are at especially high risk for overlooked injuries, which can be defined as those “not discovered during the initial evaluation either in the emergency department or the operating room” and may suffer devastating morbidity as a result.²Understanding the causes of blast injuries and implementing a disciplined assessment strategy can reduce the number of missed incidents and decrease the severity of their impact.

The blast victim’s altered level of consciousness has been implicated as the major factor in missed diagnoses.³ This is especially true for victims of terror bombings. In addition to direct intracranial injury, blast-injured patients may exhibit a number of central nervous symptoms such as “retrograde amnesia, mental blockage, apathy, psychomotor agitation, and anxiety.”⁴ Encountering victims of various ethnic origins can further confound the ability to communicate effectively and obtain an accurate neurological assessment. Even when using an interpreter, information can be lost or misconstrued during translation. Medications administered in the field during prolonged extraction and evacuation may further impair the patient’s ability to communicate.

Patients may arrive at the hospital with seemingly minimal injuries, but they still require serial diagnostic screenings.⁵ Overlapping mechanisms for causing damage contribute to the complexity of a patient’s injuries, and most will have more than one impairment or fracture.⁵These injuries can compromise multiple body compartments and organ systems.

Because the patient’s body may have been breached at multiple points, identifying the causal wound for hypotension or bleeding can be difficult to impossible.⁶ Even skeletal injuries tend to be labor-intensive because of the degree of tissue destruction and contamination and often require multiple operative interventions.⁵

Blast victims may present with dramatic injuries such as traumatic amputation or massive soft tissue loss that can distract health care teams and the surgeon from performing a more complete evaluation and result in less obvious but more devastating injuries being overlooked. It has been demonstrated that traumatic amputations are often associated with other, more critical injuries. For example, multiple fragments can penetrate the skin and disperse in unusual patterns, causing significant soft tissue injury that masks more serious fractures.

Often, secondary projectiles such as ball bearings are placed intentionally within the explosive to increase its lethality. Injuries caused by these low-velocity projectiles pose a special challenge, because entrance wounds are miniscule, with multiple angles of trajectory and varying degrees of tissue penetration. The wound tracts of low-velocity projectiles often show little tissue deformation, and exit wounds may be nonexistent. This makes exploration of the trajectory path difficult and complicates the identification of involved organs.⁷ It should be noted that in many cases, attackers approach victims from behind, causing posterior and flank wounds. By “positioning the patient in the supine position for abbreviated laparotomy,” clinicians “may actually postpone treatment of these potentially more serious injuries.”⁶

Conventional measures to gauge the degree of injury, such as the Injury Severity Score (ISS), may markedly underestimate the clinical behavior observed in bombing victims.¹ Kluger and Peleg have shown that ISS scores do not correlate between traditional trauma patients and terror-bombing casualties.^1,8 Blast victims have a greater number of injuries and inpatient mortality, lower Glasgow Coma Scale, more body regions involved, and require more surgical procedures and longer stays in intensive care than conventional trauma victims with similar ISS scores.^1,8 In a situation involving multiple bombing victims, rapid damage-control procedures may be required, and the need for rapid turnover of rooms gives the surgeon less time to conduct clinical investigation and make diagnostic decisions.⁵

Under-triage is another factor that contributes to missed injuries. There are several reasons why patients may be under-triaged. In the case of a MASCAL event, patients may present with minimal symptoms despite having serious intra-abdominal injuries. Some authors estimate this may happen with as many as 40% of conventional trauma victims and an even greater percentage of victims of nonconventional trauma.² Even injuries as significant as bowel perforation may be missed with ancillary studies such as ultrasonography or diagnostic peritoneal lavage, especially if these studies are performed shortly after the incident.^2,4 The false assurance provided by negative diagnostic studies contributes to the problem of overlooked injuries. While no triage system will be perfect, some authors find that missed injuries, although unavoidable, can be minimized by conducting repetitive surveys and examinations.⁵

Terror bombings produce a large number of casualties with penetrating soft tissue injuries and a predominant need for wound care. Interspersed with patients who have numerous minor injuries are smaller numbers of “victims with more serious injuries seeded into every category.”⁹ Compared with victims of conventional trauma, IED blast victims have more severe injuries and higher rates of resource utilization, including longer hospitalizations, more procedures, and increased use of the intensive care unit. The end result is a small number of patients producing an extensive workload. This is especially true for patients with penetrating wounds, whose care requires the involvement of multiple treatment teams from various specialties.⁸ These teams must communicate and coordinate carefully with one another in order to prevent missed injuries.¹ This can be particularly difficult if you have treatment teams assembled in a difficult setting, with members who are physically and emotionally exhausted or have spent minimal time working together as a coordinated unit.⁶

Conclusion
Our experience with blast victims and a review of the literature suggests that surgeons should be sensitive to the possibility of overlooked injuries or diagnoses for this special category of patients. Occasionally, definitive diagnosis may have to be delayed until the patient can tolerate certain testing modalities. Other times, the severity of one injury may distract attention or resources away from another, more subtle injury. An injury may also present in such an unusual way that the degree of injury is only revealed after careful and thorough investigation. We provided three cases as illustrative examples of such missed injuries. A surgeon’s awareness of the many factors that can confound diagnosis and treatment for the multitude of wounds that blast patients suffer is essential in developing a clear strategy for care amid a chaotic situation.

Measures to reduce the frequency and impact of missed injuries include conducting thorough examinations, performing repeated reassessments, instituting a mandatory observation period with a tertiary trauma survey, and requiring careful coordination between all involved medical personnel.^2,6 These strategies constitute a fundamental framework for providing optimal medical care to terror bombing victims.

The views expressed in this article are those of the authors and do not reflect the official policy of the Department of the Army, Department of Defense, or the United States Government.

References
1. Kluger Y, Peleg K, Daniel-Aharonson L, et al. The special injury pattern in terrorist bombings. J Am Coll Surg. 2004;199(6): 875-879.

2. Sikka R. Unsuspected internal organ traumatic injuries. Emerg Med Clin North Am. 2004;22(4):1067-1080.

3. Buduhan G, McRitchie DI. Missed injuries in patients with multiple trauma. J Trauma. 2000;49(4):600-605.

4. Singer P, Cohen JD, Stein M. Conventional terrorism and critical care. Crit Care Med. 2005;33(1 suppl):S61-S65.

5. Gutierrez de Ceballos JP, Turegano Fuentes F, Perez Diaz D, et al. Casualties treated at the closest hospital in the Madrid, March 11, terrorist bombings. Crit Care Med. 2005;33(1 suppl):S107-S112.

6. Almogy G, Belzberg H, Mintz Y, et al. Suicide bombing attacks: update and modifications to the protocol. Ann Surg. 2004; 239(3):295-303.

7. Kluger Y, Mayo A, Hiss J, et al. Medical consequences of terrorist bombs containing spherical metal pellets: analysis of a suicide terrorism event. Eur J Emerg Med. 2005;12(1):19-23.

8. Peleg K, Aharonson-Daniel L, Michael M, et al. Patterns of injury in hospitalized terrorist victims. Am J Emerg Med. 2003; 21(4):258-262.

9. Arnold JL, Halpern P, Tsai MC, et al. Mass casualty terrorist bombings: a comparison of outcomes by bombing type. Ann Emerg Med.2004;43(2): 263-273.

Self-assessment questions
Choose the best answer for each of the following questions.

1. “Blast lung” and perforated tympanic membranes are examples of which mechanism of blast injury?
a) Projectiles
b) The victim being thrust against stationary objects
c) The blast wave
d) The generated heat
e) Toxicity from the explosive material

2.Why are multiple penetrating injuries from low-velocity projectiles in blast victims associated with missed injuries?
a) Entrance wounds are small
b) Wound tracks are difficult to discern
c) The projectiles have multiple angles of trajectory
d) The projectiles cause variable degrees of tissue penetration
e) All of the above

3.Of the following, what is the primary cause of missed injuries associated with posterior and flank wounds in blast victims?
a) Patients are unconscious
b) Concomitant injuries require patients to be placed supine
c) More dramatic injuries distract health care teams
d) Diagnostic studies are falsely negative
e) Poor communication among exhausted medical teams

4. Name four principles that can be used to reduce missed injuries during a blast MASCAL event.