Sunday, 13 March 2016

Trauma and Burns Interview Questions and Answers pdf

41. Which of the following statement(s) is/are true concerning hypothermia following traumatic injury?
a. The majority of patients presented to a level I trauma center are hypothermic at some time
b. The initial temperature for trauma-associated hypothermia is associated with no seasonal variation
c. Moderate levels of hypothermia (34°–32°C) has no effect on mortality in the trauma patient
d. The coagulation system is most affected in hypothermic patients who have sustained major trauma
Answer: a, b, d

Mild hypothermia is very common following traumatic injury and is considered a form of secondary accidental hypothermia. It has been reported that 57% of trauma patients admitted to a level I trauma center are hypothermic at some time, with temperature loss most significant in the Emergency Room. This effect appears to have no seasonal variation. Although the mortality rate for moderate (28°–32°C) degrees of primary accidental hypothermia is only approximately 21%, the same level of hypothermia in surgical patients who are victims of trauma can be associated with mortality rates approaching 100%. Hypothermia affects multiple systems, however, the system most affected in patients sustaining major trauma are those involved in clotting. This effect seems to involve both abnormalities in platelet and clotting function.

42. Which of the following statement(s) is/are true concerning injuries to the chest wall?
a. The mortality rate currently associated with sternal fractures is as high as 25–30%
b. The severe ventilatory insufficiency associated with a flail chest is due to the paradoxical motion of the involved segment of chest wall
c. In most cases of an open pneumothorax, or sucking chest wound, surgical closure is necessary
d. Persistent chest tube bleeding at a rate greater than 200 ml/hour for four hours, or greater than 100 ml/hour for eight hours is an indication for thoracotomy for control of hemorrhage
e. A 20% incidence of splenic injury is associated with fractures of ribs 9, 10 and 11 on the left
Answer: c, d, e

Rib fracture is the most common injury associated with blunt chest trauma and may occur directly at the site of force or laterally as the result of significant antero-posterior compression of the chest. The location area of the rib fracture may be indicative of associated injuries. A 20% incidence of splenic injury is associated with fracture of ribs 9, 10, and 11 on the left with a similar association with right lower rib fractures and hepatic parenchymal injuries. The mortality rate associated with sternal fractures in older series was as high as 25–30%, mainly because of other injuries to the chest, such as aortic transection, cardiac contusion, tamponade or tracheo-bronchial rupture. More recent studies have suggested a change in the pattern and severity of injuries associated with sternal fracture. Widespread improvements in automobile safety have likely contributed to this change such that isolated sternal fractures may result from shoulder belt use and may not necessitate hospital admission in the stable patient. A flail chest occurs when consecutive ribs are fractured in more than one place, creating a free-floating segment of the chest wall. The creation of a free-floating segment may result in paradoxical chest wall motion with respiration. The intact chest wall expands during inspiration, but the negative intrathoracic pressure generated causes the flail segment to move inappropriately inward. Historically it was believed that the paradoxical motion was the cause of severe ventilatory insufficiency associated with the flail chest. Gradually, understanding of the pathophysiology of the flail chest has evolved. The ventilatory impairment is not simply due to paradoxical motion of the chest wall, but rather due to underlying pulmonary parenchymal injury in combination with the hypoventilation and splinting that results from the pain of multiple contiguous rib fractures. The open pneumothorax, or sucking chest wound, is an uncommon injury usually caused by impalement, high-speed motor vehicle accident, or shotgun blast, which causes a large chest wall defect. The diagnosis of a sucking chest wound can be made on simple inspection of the chest wall and hearing the flow of air through the wound. The defect should be occluded immediately with an impermeable dressing, essentially converting the situation to a closed pneumothorax. Tube thoracostomy is then performed to re-expand the lung. The chest wall defect usually requires operative debridement and formal chest wall closure. A hemothorax is the accumulation of blood in the pleural space and it occurs in 50–75% of patients with severe blunt or penetrating chest trauma. Massive hemothorax (i.e., larger than 1000–1500 ml) may require thoracotomy. Persistent bleeding, at a rate of > 200 ml/hour for four hours, or > 100 ml/hour for eight hours, is also an indication for thoracotomy. If the patient manifests any hemodynamic instability during the period of observation, urgent thoracotomy is mandatory.

43. A 22-year-old male driving a car at a high speed and not wearing a seatbelt, leaves a road and crashes with a full frontal impact into a tree. Which of the following injury patterns may be predictable from this type of motor vehicle accident? 
a. Orthopedic injuries involving the knees, femurs, or hips
b. Laceration to the aorta
c. Hyperextension of the neck with cervical spine injury
d. Diaphragmatic rupture due to marked increase in intraabdominal pressure
Answer: a, b, c

With frontal impact, when the vehicle stops abruptly, unrestrained front-seat occupants move in one of two predictable pathways—down and under the dashboard or up and over the steering wheel. With the former movement, the knees strike the dashboard, and the upper legs absorb the primary energy transfer. Dislocated knees, fractured femurs, and posterior fracture dislocation of the hips are expected injuries. After the knees impact, the upper body flexes forward and up and over the steering wheel. The chest or abdomen impacts the steering wheel and the head impacts the wind shield.
Predictable injury patterns following the up-and-over component of a frontal impact include the following: 1) anterior chest wall compression; 2) compression injuries to both hollow and solid abdominal viscera; 3) shear injuries such as lacerations to the aorta or liver, kidneys or other solid viscera; 4) injury to the brain from direct compression with scalp lacerations, skull fractures and cerebral contusions or from deceleration or shear forces; 5) acute neck flexion, hyperextension or both resulting in cervical spine injury.
Three-point passenger restraints and air bags, although overall very effective in reducing injury, can cause specific related injuries. Common injuries when lap belts are incorrectly strapped above the anterior iliac spine include compression injuries of intraabdominal organs (liver, pancreas, spleen, small bowel, large bowel), increased intraabdominal pressure and diaphragmatic rupture.

44. Which of the following statement(s) is/are correct concerning the pathophysiology of frostbite? 
a. Frostbite injury may have two components: initial freeze injury and a reperfusion injury that follows during rewarming
b. The formation of extracellular ice crystals in the tissue begins to occur at -10°C
c. The release of oxygen free radicals and arachidonic acid metabolites aggravates vasoconstriction and platelet and leukocyte aggregation
d. Experimental evidence suggests that a substantial component of severe cold injury may be mediated due to platelet aggregation
Answer: a, c

Recent evidence suggests that frostbite injury may have two components: the initial freeze injury, and a reperfusion injury that occurs during rewarming. The initial response to tissue cooling is vasoconstriction and arterio-venous shunting, intermittently relieved by vasodilatation. With prolonged exposure, this response fails, and the temperature of the freezing tissues will approximate ambient temperature until -2°C. At this point, extracellular ice crystals form, and as these crystals enlarge, the osmotic pressure of the interstitium increases resulting in movement of intracellular water into the interstitium. Cells begin to shrink and become hyperosmolar, disrupting cellular enzyme function.
During rewarming, red cell, platelet and leukocyte aggregation is known to occur and results in patchy thrombosis of the microcirculation. These accumulated blood elements are thought to release, among other products, the toxic oxygen-free radicals and the arachidonic acid metabolites which further aggravate vasoconstriction and platelet and leukocyte aggregation. Recent experimental evidence suggests that a substantial component of severe cold injury may be neutrophil-mediated in that a monoclonal antibody to neutrophil-endothelial and neutrophil-neutrophil adherence can markedly ameliorate the pathology of severe injury.

45. The management of a patient with frostbite includes:
a. Gradual spontaneous warming
b. Emersion of the tissue in a large water bath with a temperature of 40–42°C
c. Immediate initiation of prophylactic antibiotics
d. Systemic anticoagulation with heparin
e. Immediate debridement of necrotic tissue
Answer: b

The treatment of frostbite with rewarming should begin in the Emergency Room and not in the field. Gradual, spontaneous warming is generally inadequate and delayed thawing, or rubbing the injured part in ice or snow often results in marked tissue loss. Rapid rewarming should be achieved by immersing the tissue in a large bath of 40–42°C. The water should feel warm, but not hot to the normal hand. The skin should be gently but meticulously cleansed, air dried, and affected area elevated to minimize edema. Infection develops in only about 13% of urban frostbite victims, but half of these infections are present at the time of admission. Therefore, most clinicians reserve antibiotics for identified infections. Following rewarming, the treatment goals are to prevent further injury while awaiting demarcation of the irreversible tissue destruction. The use of sympathetic blockade, surgical sympathectomy, and intraarterial vasodilating drugs has generally been ineffective. Heparin, thrombolytic agents, and hyperbaric oxygen have also failed to demonstrate any substantial treatment benefit. The difficulty in determining the depth of tissue injury and cold injury has led to a conservative approach to the care of frostbite injuries. As a general rule, amputation and surgical debridement are delayed for 2–3 months unless infection with sepsis intervenes. The natural history of full thickness frostbite is gradual demarcation of the injured area with dry gangrene and mummification clearly delineating a nonviable tissue.

46. There are a number of injuries associated with common orthopedic injuries. Which of the following diagnosed orthopedic injuries is associated with the injury listed? 
a. Sternal fracture—cardiac contusion
b. Posterior dislocation of the knee—popliteal artery thrombosis
c. Pelvic fracture—ruptured bladder or urethral transection
d. Posterior dislocation of hip—-sciatic nerve injury
Answer: a, b, c, d

Diagnosed Injury                   Associated Injury
Fracture—temporal, parietal bone Epidural hematoma
Maxillofacial fracture          Cervical spine fracture
Sternal fracture                  Cardiac contusion
First and second rib fracture  Descending thoracic aorta, intraabdominal bleeding
Fractured scapula                  Pulmonary contusion
Fractured ribs 8–12, right  Lacerated liver
Fractured ribs 8–12, left          Lacerated spleen
Fractured pelvis                  Ruptured bladder, urethral transection
Fractured humerus                  Radial nerve injury
Supracondylar humerus          Brachial artery injury
Distal radius fracture          Median nerve compression
Supracondylar femur fracture          Thrombosis popliteal artery
Anterior dislocation shoulder  Axillary nerve injury
Posterior dislocation of hip  Sciatic nerve injury
Posterior dislocation of knee  Popliteal artery thrombosis

47. Correct statement(s) concerning cold injury include:
a. Chilblain is a form of local cold injury characterized by pruritic papules, macules, or plaques on the skin associated with repeated exposure to cold temperatures
b. Trenchfoot is a freeze injury of the hands or feet due to chronic exposure to cold, wet conditions below freezing
c. Frost nip is reversible with warming of the tissue and will result in the return of sensation and function with no tissue loss
d. Characteristic large blisters can be seen with all degrees of frostbite
Answer: a, c

Cold injuries limited to digits, extremities, or exposed surfaces are the result of either direct tissue freezing (frostbite) or more chronic exposure to an environment just above freezing (Chilblain or pernio; trenchfoot). Chilblain or pernio are descriptive forms of local cold injury characterized by pruritic, red-purple papules, macules, plaques or nodules in the skin. This pathology appears to be provoked by repeated exposure to cold but not freezing temperatures. Trenchfoot or cold emersion foot describes a non-freezing injury of the hands or feet, typically in sailors, fishermen, or soldiers resulting from chronic exposure to wet conditions and temperatures just above freezing. Frost nip is the mildest form of cold injury characterized by initial pain, pallor, and subsequent numbness of the affected body part. The injury is reversible and warming of the cold tissue results in return of sensation and function with no tissue loss. Frostbite is more severe and common form of cold injury and essentially describes local freezing of tissues. The mildest form (first degree injury) is associated with hyperemia and edema but without blistering. Second, third and fourth degree frostbite have progressive degrees of tissue injury and are noted by either characteristic clear blisters (second degree) or more hemorrhagic vesicles which are generally smaller than second degree blisters (third degree frostbite). In fourth degree frostbite, tissue necrosis, gangrene and full thickness tissue loss can be seen.

48. A 37-year-old man driving an automobile travelling at a rapid speed hits a tree. At arrival to the Trauma Center, aortic disruption is suspected. Which of the following statement(s) is/are true concerning the patient’s diagnosis and management? 
a. If undiagnosed, a thoracic aortic disruption is associated with a 50% mortality within the first 24 hours
b. Transesophageal echocardiography is a promising new modality for the diagnosis of aortic injury
c. Repair of aortic disruption is best completed with cardiopulmonary bypass
d. Pharmacologic control of blood pressure with sodium nitroprusside should be used routinely in the preoperative management
Answer: a, b

Blunt injuries to the thoracic aorta occur in as many as 20% fatalities due to motor vehicle accidents. About half of these patients die at the scene. It is estimated that of the 50% who survive the initial injury, half will die within the first 24 hours and 90% will die within 10 weeks without surgical treatment. Blunt aortic disruption is associated with the mechanism of abrupt deceleration. Therefore, this mechanism of injury should lead to high index of suspicion. A chest radiograph is a useful screening procedure. Abnormal findings on chest film, or suspicion of the injury, must be aggressively investigated. Due to the very high morbidity of missed injuries, angiography is the diagnostic study of choice in patients at significant risk. Transesophageal echocardiography is a promising modality for the diagnosis of aortic injury, especially in patients who cannot be transported to the angiography suite. Early experience has shown transesophageal echo to be a very sensitive method, with very few missed injuries in experienced hands.
Injuries to the aorta require surgical repair. The technique of aortic repair has been the subject of some controversy primarily due to the risk of spinal cord ischemia with cross clamping of the thoracic aorta. The complete use of cardiopulmonary bypass with full heparinization, however, has been shown to increase the mortality of patients who have other cerebral and vascular injuries, and is probably contraindicated in the blunt trauma patient. Most surgeons favor cross clamping of the aorta with expeditious repair of the injury. Rapid surgical repair is vital to survival of the patients. Preoperative management of patients with aortic disruption involves careful control of blood pressure and avoidance of hypertension. Pharmacologic control of blood pressure is indicated to avoid possible rupture before surgical repair. The use of sodium nitroprusside, however, should be avoided in patients with head injuries because the vasodilatory effect of this drug may cause an increase in intracranial pressure. A short-acting beta agonist such as esmolol or labetolol is probably the best choice if blood pressure control is needed.

49. Which of the following statement(s) is/are true concerning endotracheal intubation at the site of injury? 
a. Bag valve mask systems are equally as efficient as endotracheal intubation for early management of the trauma patient
b. Paramedic intubation in the field is successful in over 90% of cases
c. Indications for intubation in the field include respiratory distress, significant head injury, severe chest injury and hypovolemic shock
d. If patients clench their teeth violently, endotracheal intubation is impossible without the use of paralytic agents
Answer: b, c

The most immediately life-threatening problem to the injured patient is loss of airway patency and therefore this is the first priority of the first response team upon arrival at the injury site. Basic life support skills such as suctioning, placement of oropharyngeal airways, the use of a bag mask device are usually sufficient at least to temporarily restore oxygenation at the injury site. On the other hand, approximately 10% of patients require endotracheal intubation and up to 20% would benefit from field intubation. Endotracheal intubation is the best procedure for airway control in patients who are in shock, have abnormal breathing patterns, or who are unable to protect their airways due to unconsciousness. Endotracheal intubation is far superior than that of bag valve mask systems because it provides larger total volumes and less risk of aspiration.
Indications for endotracheal intubation in the field should include respiratory distress, hypovolemic shock, unconsciousness, significant head injury, and severe chest injury. Reported paramedic intubation success rates range between 90 and 98% in the literature, and complications are rare. On the other hand, there are problems with intubation at pre-hospital sites. Patients with head injuries may have C-spine injuries so in-line mobilization techniques are necessary to insure intubation without further injury to the cervical spine or cord. Patients often clench their teeth in which case either nasotracheal intubation or the use of paralytic agents such as succinylcholine may be necessary for successful intubation.

50. Which of the following statement(s) concerning the operative approach to abdominal trauma is/are correct? 
a. Pelvic hematomas associated with pelvic fractures should be explored
b. Central retroperitoneal hematomas should be explored after control of other injuries within the peritoneal cavity
c. Stable hematomas in the perinephric space lateral to the midline should be explored to rule out renal injury
d. The initial approach is control of hemorrhage by packing and controlling ongoing contamination from enteric injuries
Answer: b, d

Once the abdomen is opened at laparotomy for trauma, obvious blood and clot is sequentially removed, first from the lower abdomen and then from the upper abdomen by packing all four quadrants of the abdomen. Any areas found to be a source of hemorrhage can be repacked. Obvious hollow viscus wounds should be rapidly sutured or controlled with noncrushing clamps. Once hemorrhage is controlled by packing and ongoing contamination is stopped, time is then taken to allow resuscitation of the patient’s circulating blood volume. Retroperitoneal hematomas may be the source of exsanguinated hemorrhage if rupture into the free peritoneal cavity has occurred. If not, these can be left for investigation at a later time, depending on the location. Hematomas of the pelvis that are associated with pelvic fractures should not be disturbed. Similarly, stable hematomas of the perinephric space lateral to the midline are also best left undisturbed. Central hematomas that may involve injuries to the major vascular structures, pancreas or duodenum are noted and explored after control of injuries within the peritoneal cavity.

51. Which of the following statement(s) is/are true concerning trauma involving children?

a. The greater head/body ratio in children compared to adults leads to a higher frequency of head injuries in children
b. Unfused cranial sutures and open fontanels serve as a protective mechanism against intracranial hemorrhage
c. A greater propensity to hypothermia is seen in children
d. A propensity to single organ system injury is seen in the child
Answer: a, c

The smaller size of pediatric patients results in an increased likelihood of multiple system trauma because of the force of impact is dissipated over a relatively small area. A higher frequency of head injuries in children is partially explained by the proportionately greater head/body ratio, the thin skull, and the weaker supporting cervical musculature. In infants with unfused cranial sutures and open fontanels, intracranial hemorrhage can be perfuse and result in shock. The protuberant abdomen of the child obtains little protection from either the thoracic cage or pelvis, accounting for a higher incidence of intraabdominal injuries.
The physiologic response to hypovolemia after pediatric trauma is characterized by the immediate constriction of small and medium-sized arteries, thus maintaining normal blood pressure. Decompensation generally occurs with a blood volume deficit of 20% to 25%. Tachycardia, tachypnea, diminished peripheral perfusion, and change in the level of consciousness are better potential indicators of early shock than blood pressure. The thin skin, lack of subcutaneous fat, and large surface area/body weight ratio all contribute to the propensity of the young child for hypothermia.

52. Indications for Cesarean section during laparotomy for trauma include:

a. Maternal shock after 28 weeks gestation
b. Unstable thoracolumbar spinal injury
c. Mechanical limitation for maternal repair
d. Maternal death if estimated gestational age is at least 28 weeks
nswer: b, c, d

The indications for exploratory laparotomy in a pregnant patient are the same as in all other trauma patients. However, Cesarean section should not be added unless indicated due to the prolongation of operative time and the increase in blood loss (approximately 1 liter). Vaginal delivery is always encouraged even in the postoperative period. During laparotomy for trauma, indications for Cesarean section are as follows:

1. Maternal shock, pregnancy near term
2. Threat to life from exsanguination
3. Mechanical limitation for maternal repair
4. Risk of fetal distress exceeding risk of prematurity
5. Unstable thoracolumbar spinal injury

The outcome of postmortem C-section depends on the duration of the gestation and the time interval between maternal death and delivery. Under optimal conditions, at 26 to 28 weeks gestation, estimated fetal survival is about 50%. Post-mortem C-section is justified if the estimated age is about 26—28 weeks. If the time interval between maternal death and delivery is less than 5 minutes, the fetal prognosis is considered excellent. If the time interval since maternal death is prolonged to about 20 minutes, fetal prognosis is poor.

53. A 75-year-old man is involved in a motor vehicle accident. Which of the following statement(s) is/are true concerning this patient’s injury and management?

a. Acceptable vital sign parameters are similar across all age groups
b. Hypertonic solutions should not be used for resuscitation due to concerns for fluid overload
c. The patient would be more prone to a subdural hematoma than a younger patient
d. There is no role for inotropic agents in the management of this patient
Answer: c

Although most principles of management of the elderly trauma patient are similar to their younger counterpart, some important differences must be noted. Evaluating the circulatory system following injury in the elderly, it must be remembered that elderly patients most likely are accustomed to a higher than normal blood pressure. Thus, while a systolic blood pressure of 100 mm Hg is not alarming in a 25 year old, in a 75 year old, this may very well represent hypotensive shock if the “normal” pressure is 150 mm Hg systolic. Recent reports have suggested that pulmonary arterial catheters can be useful in the monitoring of patients with evidence of shock or hypoperfusion or history of intercurrent disease. In patients with a low pulmonary capillary wedge pressure, volume replacement can be provided as needed, however, in the face of an elevated pulmonary capillary wedge pressure, inotropic support may be of benefit. Lactated Ringer’s solution remains the resuscitation fluid of choice in the elderly patient. However, the initial experience with hypertonic solutions have been very favorable. Hypertonic fluids can reduce elevated blood pressures and improve cardiac performance with much smaller volumes when compared to isotonic solutions.
Cerebral atrophy accompanies aging. In addition, the cerebral vasculature is fragile, particularly the veins. The combination of these factors make the elderly more prone to develop subdural hematomas, which may initially be subtle.

54. Important physiologic alterations of pregnancy which may alter the injury response include:

a. Increased cardiac output
b. Expanded plasma volume
c. Decreased fibrinogen and clotting factors
d. Partial obstruction of the inferior vena cava
Answer: a, b, d

55. A number of systems have been developed in an effort to allow comparison of trauma injuries and trauma patients among institutions. Which of the following statement(s) is/are true concerning trauma scoring systems?

a. The Revised Trauma Score uses the physiologic parameters of blood pressure, heart rate, and head injury to mathematically assess injury severity
b. The Abbreviated Injury Scale (AIS) is a specific anatomic index
c. The Injury Severity Score (ISS) correlates not only the severity of the injury but adjusts for patient age and comorbid risk factors
d. The Triss System is the most complete system in combining trauma score and anatomic component as well as patient age
Answer: a, b, d

Many systems have been developed in an effort to allow comparison of trauma injuries and trauma patients among institutions. The impetus for injury severity scoring system is provided by the need to identify and classify severely injured patients in the pre-hospital phase, to predict mortality, to assess results, and to improve communication. The Revised Trauma Score has been the most widely applied as well as the most useful scoring system for the initial evaluation of trauma victims. It assumes that the physiologic parameters of blood pressure, respiratory rate, and head injury (assessed by the Glasgow Coma Score) can be used mathematically to assess injury severity and predict the most timely and sophisticated medical care. The Abbreviated Injury Scale (AIS), initially devised for blunt trauma and subsequently updated to include penetrating trauma, assesses the severity of nonfatal injuries determined in six different body areas. Thus, it is a specific anatomic index. The Injury Severity Score (ISS) is calculated by assigning the AIS values to each injury in six body parts and then mathematically squaring the three most severely injured areas and adding the total. Unfortunately, this system does not adjust for patient age or patient-related comorbid risk factors. The Triss methodology is of great importance because it attempts to combine the trauma score, or physiologic component, and the ISS, or anatomic component. It also incorporates the patient’s age. The Triss method yields a specific probability of survival, and is recommended for use by the American College of Surgeons Committee on Trauma to be used to maintain a trauma registry and quality assurance program.

56. Alterations in the immunologic response after a major trauma include:

a. Decreased CD3 and CD4 population
b. Depression of neutrophil antimicrobial functions including chemotaxis and phagocytosis
c. Decreased levels of pro-inflammatory cytokines including tumor necrosis factor, interleukin-1, and interleukin-6
d. Impaired macrophage receptor expression and antigen presentation
Answer: a, b, d

Major perturbations in the immune system occur in patients after injury contributing to the late septic mortality in trauma patients. The changes in the immune system are significant and global, affecting both humoral and cellular components of the system. Macrophage receptor expression and subsequent antigen presentation are impaired with similar defects in lymphocyte function including shifts in T-cell populations with decreased CD3 and CD4 subpopulations, depression of B-cell and immunoglobulin production, and a loss of antigen recall. Multiple neutrophil antimicrobial functions are suppressed following trauma including chemotaxis, phagocytosis, respiratory bursts, and intracellular killing.
There are significant changes in humoral mediators following trauma with increased levels of pro-inflammatory cytokines including tumor necrosis factor, interleukin-1 and interleukin-6 along with decreased levels of interleukin-2, interleukin-3, and interferon g.

57. Which of the following statement(s) is/are true concerning penetrating injuries to the colon and rectum?

a. A patient with 2 or more additional organs injured, significant fecal spillage, preoperative hypotension, or intraperitoneal hemorrhage exceeding 1 liter should not have a primary repair of a colon injury
b. If rectal injury is documented, a loop colostomy provides adequate decompression.
c. Irrigation of the rectal stump should be avoided to prevent contamination via the site of injury
d. The rectal wall should be repaired in all cases
Answer: a

The central issue in the operative management of colonic injuries is the controversy between primary repair of low-risk colonic injuries and repair or resection with exteriorization. Primary repair may be selected when additional risk factors have been excluded. Complications increase with primary repair when there is preoperative hypotension, intraperitoneal hemorrhage exceeding 1 liter, more than two additional organs injured, significant fecal spillage, or when more than six hours have elapsed since injury. Many patients with low-risk penetrating colon injuries can be treated with primary closure in the absence of these risk factors. High-risk colon injuries are those associated with severe injuries, as indicated above, and should be treated with resection and colostomy.
Rectal injuries should be suspected when there is any penetrating injury or a significant pelvic fracture. Sigmoidoscopic examination is essential. The principles of operative management include wide debridement of all dead and devitalized tissue and repair of rectal wall when possible. A totally defunctioning colostomy (not a simple loop colostomy) is necessary. Retrorectal drainage is indicated only in selected severe injuries. The distal stump should be washed out to evacuate the fecal contents. Broad-spectrum intravenous antibiotics, nutritional support, and serial debridements are also indicated.

58. Genitourinary injuries are common with both blunt and penetrating trauma. Which of the following statement(s) is/are true concerning genitourinary trauma injuries?

a. All patients with microscopic hematuria and blunt trauma should be evaluated with an intravenous pyelogram
b. The indications for radiographic assessment of renal injury in the face of blunt trauma is more liberal than penetrating trauma
c. CT scan is the current imaging technique of choice for suspected renal trauma
d. Perinephric hematomas occurring after either penetrating or blunt trauma should not be explored
e. Extraperitoneal bladder ruptures can often be treated nonoperatively using urethral catheter drainage alone
Answer: c, e

Renal injuries constitute the greatest proportion of genitourinary tract trauma. The presence of hematuria remains the most sensitive clinical indicator of renal trauma. The specificity of hematuria is low, however, and the practice of performing an IVP in all patients with blunt trauma and microscopic hematuria is both time-consuming and unnecessary. In several studies examining clinical features associated with significant renal trauma, three factors have been identified—shock, gross hematuria, and major associated injuries. The incidence of renal trauma requiring operation in the absence of any of these factors was 0 in several series. The indications for radiographic assessment of renal injury in the face of penetrating trauma should be far more liberal, since there are conflicting reports on the degree of correlation between the injury’s severity and the degree of hematuria. Radiographic studies for the diagnosis of renal trauma include single-or multiple-film IVP, formal nephrotomography, and CT scan. Single-film (“one-shot”) IVP is useful primarily for documenting the presence of two functioning kidneys and has limited use as a screening examination for renal trauma. CT scan, however, has emerged as the imaging technique of choice for most renal trauma. Renal injuries can be staged with respect to those likely to require an operation or to develop complications. CT scan also allows more precise assessment of the degree of perinephric hemorrhage and the degree of collecting system disruption than operative inspection.
A number of major renal injuries are diagnosed at the time of laparotomy. Most commonly, a perinephric hematoma is encountered in association with blunt hepatic or splenic trauma. Indications for renal exploration at laparotomy following blunt trauma include an expanding or pulsatile perinephric hematoma or suspected renal vascular injury. In a patient with blunt injuries, it is preferable to defer exploration of nonexpanding, nonpulsatile perinephric hematomas to complete treatment of intraabdominal and other associated life-threatening injuries. Postoperative CT scan may be useful for formal staging of these injuries. A perinephric hematoma that is found during laparotomy for penetrating trauma should generally be explored carefully. Unlike blunt injuries, continued or recurrent hemorrhage is more often a problem.
Most bladder injuries (over 95%) occur in association with pelvic fractures. Bladder ruptures are classified into those that rupture into the free peritoneal cavity and those with extravasation limited to the retroperitoneum. Intraperitoneal bladder ruptures are characteristically large and require early operative repair. Extraperitoneal bladder ruptures in most cases, however, can be treated nonoperatively using simple urethral catheter drainage alone.

59. In children who sustain multiple trauma, 25% have serious intraabdominal injuries. Which of the following statement(s) is/are true concerning blunt abdominal trauma in children?

a. Peritoneal lavage plays an important role in the evaluation of the patient
b. Most pediatric trauma patients will be hemodynamically unstable at the time of admission
c. Splenic salvage can be achieved in 90% to 100% of patients
d. The indications for laparotomy for splenic injury include refractory hypotension or transfusion requirement in excess of 50% of blood volume within the first 24 hours
e. Unlike splenic injury, hepatic injury will frequently require exploratory laparotomy
Answer: c, d

Diagnostic peritoneal lavage is a rapid and sensitive test for the presence of intraabdominal hemorrhage. In general, however, peritoneal lavage has a limited role in the care of pediatric patients as it provides confirmation of a finding, hemoperitoneum, that does not mandate operation. Unlike adults, 95% of pediatric trauma patients are hemodynamically stable on admission. The single most useful diagnostic maneuver is a CT scan, which delineates solid visceral injuries with a high degree of both sensitivity and specificity. The spleen and liver are injured with about equal frequency in children sustaining blunt trauma, and together these two target organs account for about 75% of childhood abdominal injuries.
Experience at virtually every major children’s trauma center in the world supports the safety and efficacy of nonoperative management of children with splenic ruptures. Most series report splenic salvage in 90% to 100% of children. Although therapy must be individualized, the general guidelines are that operation is not indicated until there is refractory hypotension or a transfusion requirement in excess of 50% of blood volume in the first 24 hours. In reality, few patients approach this, and transfusion practices are such that only 10% to 20% of patients with isolated splenic injuries require blood transfusion at all. The management of liver injuries in pediatric patients has also changed since the advent of routine abdominal CT scan for blunt trauma. Several reports describe successful nonoperative treatment of liver injuries detected radiologically in children. This approach is applicable in most children, with a success rate of 90% and transfusion requirements similar to those patients with ruptured spleens.

60. Which of the following statement(s) is/are true concerning the diagnosis and management of pelvic fractures secondary to blunt trauma?

a. Most pelvic fractures are apparent on the basis of physical examination
b. An infra-umbilical approach to peritoneal lavage in a patient with a major pelvic fracture may yield a false-positive rate approaching 50%
c. If a large expanding pelvic hematoma is found at surgery, the intraabdominal injury should be dealt with, and the hematoma explored
d. The application of pelvic external fixation may be used as the initial step in control of hemorrhage from pelvic fractures
e. A urethral catheter should be placed immediately in patients with suspected pelvic fracture to allow early peritoneal lavage
Answer: b, d

The spectrum of pelvic fracture injuries range from minor isolated non-displaced fractures of the pubic rami to severe injuries with multiple fractures that can be rapidly lethal. Unlike most long bone fractures, only 25% of pelvic fractures are apparent on physical examination. Hemorrhage caused by laceration of the sacral venous plexus, multiple arterial branches of the hypogastric vessels, or bleeding from fractured cancellous bone presents a formidable challenge to the trauma surgeon. Massive hemorrhage is the principle cause of early death in patients with pelvic fracture, and survival depends principally on rapid identification and control. The presence of hemorrhage from associated intraperitoneal injuries should be considered first, therefore diagnostic peritoneal lavage is indicated for most patients with pelvic fractures. A supraumbilical lavage is preferable under these circumstances because the possibility of catheter penetration of a large retroperitoneal hematoma dissecting into the preperitoneal space. Peritoneal lavage performed incorrectly in the infraumbilical site with a major pelvic fracture may yield an incidence of false-positive results as high as 45%. When performed properly in the supraumbilical position, false-positive lavage rates have been reported to be as low as 1%. If laparotomy is indicated once a thorough abdominal exploration is performed and injury is repaired, the size of the pelvic hematoma may be assessed. If a rapidly expanding pelvic hematoma is seen, rapid closure of the abdominal wound is indicated followed immediately by pelvic angiography and embolization of active arterial bleeding. In selected patients with unstable fractures involving the sacrum or pubic diastasis injuries, the application of pelvic external fixation may reduce hemorrhage from cancellous bone and sacral venous plexus. In many centers, pelvic fixation is preferred to arteriography and embolization for the initial control of bleeding.
A urethral tear should be suspected in any male with a pelvic fracture. These patients should be examined carefully for signs of urethral injury including scrotal or perineal hematoma, blood at the urethral meatus, or anterior displacement of the prostate gland on rectal examination. The presence of any of these clinical findings constitutes a contraindication to immediate placement of a urethral catheter. A retrograde urethrogram should be obtained in these cases by the placement of a small balloon catheter in the fossa navicularis and gravity infusion of 10–15 ml of contrast medium.

Part1 Part2 Part3 Part4

No comments:

Post a Comment