Sunday, 13 March 2016

Latest 80 Trauma and Burns Multiple choice Questions and Answers

1.  Nasotracheal intubation:
A.  Is preferred for the unconscious patient without cervical spine injury.
B.  Is preferred for patients with suspected cervical spine injury.
C.  Maximizes neck manipulation.
D.  Is contraindicated in the patient who is breathing spontaneously.
Answer: B

DISCUSSION: The first principle in the management of any injured patient is to secure an adequate airway. This can be particularly difficult in the presence of facial or laryngeal trauma, or in the unconscious patient with a suspected cervical spine injury. The mechanical removal of oral debris followed by the “chin lift” or “jaw thrust” maneuvers to relieve soft tissue obstruction of the pharynx are the first steps. However, when there is any question regarding the adequacy of the airway, or in the presence of severe head injury, or when the patient is in profound shock, more definitive airway control is required. In most patients this involves oral endotracheal intubation. However, the insertion of an oral endotracheal tube often involves hyperextension of the neck with the potential for aggravating cervical spine ligamentous or bony injury. Nasotracheal intubation is the preferred option for the patient with suspected cervical spine ligamentous or bony injury since the head and neck can be maintained in the neutral position with minimal manipulation. This technique requires a breathing patient, as the passage of air must be heard through the nasotracheal tube prior to its insertion through the larynx into the trachea. Nasotracheal intubation is contraindicated in the presence of mid-face fractures. In this situation, a surgical airway (cricothyroidotomy, tracheostomy, or needle cricothyroidotomy) is the preferred option.

2.  Cardiac contusions caused by blunt chest trauma:
A.  Are fairly easy to diagnose.
B.  Occur in up to 20% to 40% of patients with major blunt thoracic trauma.
C.  Do not usually cause right ventricular dysfunction.
D.  Demonstrate arrhythmia as the most common complication.
Answer: BD

DISCUSSION: Cardiac contusions are often difficult to diagnose, but have been estimated to occur in 5% of major trauma patients, and up to 20% to 40% of patients with severe blunt chest injury. The difficulty in diagnosing cardiac contusions is that they remain a pathologic diagnosis, confirmed only at autopsy or on direct cardiac examination. The injury may vary from superficial epicardial petechiae to complete transmural damage. Although significant myocardial injuries, such as ventricular rupture, coronary vessel thrombosis, and valvular disruption, have been reported, the most common clinically significant result of cardiac contusion is the occurrence of arrhythmias. Hence, an initial electrocardiogram (ECG) and subsequent continuous cardiac monitoring for at least 24 hours is generally recommended. Alternative methods of diagnosing myocardial contusion include creatine phosphokinase cardiac isoenzymes (CPK-MB), two-dimensional echocardiography, gated ventricular scintigraphic angiography (GVA), radioactive thallous chloride ( 201Tl) uptake, and right ventricular monitoring. Unfortunately, none of these tests is adequately sensitive or specific in the diagnosis of cardiac contusion, and their correlation with the presence of arrhythmias or ECG changes is also imprecise.

3.  According to the recommendations of the American College of Surgeons Committee on Trauma, which of the following patients should be transported to a trauma center?
A.  Fifty-year-old female who fell 8 feet from a step ladder, with isolated hip fracture and normal vital signs.
B.  Fifteen-year-old bicyclist with closed head injury and Glasgow Coma Scale score of 12.
C.  Twenty-three-year-old male assault victim with stab wound to the back, normal vital signs, and respiratory distress.
D.  Three-year-old infant passenger (restrained) in motor vehicle accident with normal vital signs and no apparent injuries except abdominal wall contusion.
Answer: BCD

DISCUSSION: The American College of Surgeons Committee on Trauma has developed a field triage decision scheme to help identify trauma victims with a significant risk of dying as a result of their injuries. This classification is based on four factors: (1) abnormal physiologic signs, (2) anatomic area of injury, (3) mechanism of injury, and (4) concurrent or co-morbid disease states. Major physiologic abnormalities include a Glasgow Coma Scale score of less than 13, systolic blood pressure less than 90 mm. Hg, respiratory rate less than 10 or greater than 29 per minute, or a Revised Trauma Score of less than 11 or a Pediatric Trauma Score of less than 9. Significant anatomic considerations include penetrating injuries to the torso, head and neck, and proximal extremities, flail chest, combination of trauma with burns to greater than 10% of body surface area, two or more proximal long bone fractures, pelvic fractures, paralysis, or traumatic amputation above the wrist or ankle. Significant mechanisms of injury include a death in the same passenger compartment or ejection from the automobile, high-impact (greater than 5 miles per hour) auto-pedestrian injuries, or a pedestrian thrown or run over. The co-morbid factors include pediatric or elderly (<5 or >55) patients or known history of insulin-dependent diabetes or cardiac, respiratory, or psychotic disorders. These criteria should serve as guidelines for medical control and the pre-hospital care providers. Such triage guidelines have been shown to produce the triage of only a small fraction (5% to 10%) of all injured patients to Level I or Level II trauma centers.

4.  Which of the following statements about head injuries is/are false?
A.  The majority of deaths from auto accidents are due to head injuries.
B.  Head injury alone often produces shock.
C.  A rapid and complete neurologic examination is part of the initial evaluation of the trauma patient.
D.  Optimizing arterial oxygenation is part of initial therapy.
Answer: B

DISCUSSION: Head injuries cause the majority of deaths following automobile accidents, with rupture of the thoracic aorta the second most common cause of fatality. Head injury itself rarely produces hypotensive shock. It is only in the terminal phases of brain death that hypotension may be attributable to head injury alone. Therefore, hypotension in trauma patients must be assumed to be secondary to volume depletion or ongoing hemorrhage. An occult site of hemorrhage (chest, abdomen, pelvis, retroperitoneum, or extremities) must be strongly suspected and dealt with accordingly. A rapid and complete neurologic assessment is a crucial part of the initial assessment of all trauma patients. This initial exam gives an excellent indication of injury severity and prognosis. Since the ultimate outcome of a brain injury is dependent on adequate cerebral perfusion and oxygenation, adequate airway control, ventilation, hemorrhage control, volume restitution, and arterial oxygenation are crucial factors in the early management of head injuries.

5.  Which of the following statements about maxillofacial trauma is/are false?
A.  Asphyxia due to upper airway obstruction is the major cause of death from facial injuries.
B.  The mandible is the most common site of facial fracture.
C.  The Le Fort II fracture includes a horizontal fracture of the maxilla along with nasal bone fracture.
D.  Loss of upward gaze may indicate either an orbital floor or orbital roof fracture.
Answer: B

DISCUSSION: Maxillofacial injuries generally do not cause life-threatening injuries, with the exception of those that occlude the airway. Therefore, the first priority in assessing and managing the patient with maxillofacial trauma is to assess and assure the adequacy of the airway. The face is typically divided into thirds when defining injuries. Injuries to the upper third of the face are often accompanied by ocular or central nervous system complications as well as facial deformities. Fractures of the orbital roof are frequently associated with frontal sinus and nasal ethmoid fractures, and are accompanied by a loss of upward gaze due to involvement of the superior rectus muscle. However, the most common cause of loss of upward gaze is orbital floor injury and associated entrapment of the globe or injury to the inferior rectus muscle. Middle third of facial structures include the maxilla, zygoma, orbits, and nose. The Le Fort classifications of facial fractures are commonly employed to describe these complex fracture lines. In a Le Fort II fracture, the superior fracture line is transverse through the nasal bones or through the articulation of the maxillary and nasal bones with the frontal bones. This is also known as the “pyramidal” fracture of the mid-face. The diagnosis is established by digital manipulation of the anterior maxilla and observation for mobility of the central triangle (the maxilla and nose). The lower third of the face contains a single facial bone, the mandible. After the nasal bones, the mandible is the second most commonly fractured facial bone.

6.  What percentage of patients with thoracic trauma require thoracotomy?
A.  10%–15%.
B.  20%–25%.
C.  30%–40%.
D.  45%–50%.
Answer: A

DISCUSSION: Twenty-five per cent of civilian trauma deaths are caused by thoracic trauma, and two thirds of these deaths occur after the patient reaches the hospital. Mortality of hospitalized patients with isolated chest injury ranges from 4% to 8% and increases to 35% when multiple additional organ systems are involved. Despite high mortality, only 10% to 15% of thoracic injuries require thoracotomy. Most injuries are successfully managed by the rather simple life-saving maneuvers of airway control and tube thoracotomy. Unrelenting hemorrhage following either penetrating or blunt thoracic trauma is a primary indication for immediate thoracotomy. An initial thoracic blood loss of greater than 1500 ml. (30% of blood volume) or an ongoing loss of 250 ml. for 3 consecutive hours serves only as a practical guideline. The patient's hemodynamic status and overall condition should be the most influential factors.

7.  The radiographic findings indicating a torn thoracic aorta include:
A.  Widened mediastinum.
B.  Presence of an apical “pleural cap.”
C.  First rib fractures.
D.  Tracheal deviation to the right.
E.  Left hemothorax.
Answer: ABCDE

DISCUSSION: All of the listed radiographic findings should arouse suspicion of a possible torn thoracic aorta. The most common abnormality noted is a widening of the mediastinal shadow, although only 20% to 40% of patients with a wide mediastinum have aortic injury. In addition to the radiographic signs listed, other findings that may alert the physician to the possibility of an aortic tear include loss of aortic contour, elevation of the left mainstem bronchus, depression of the right mainstem bronchus, shift of the nasogastric tube to the left, and the presence of retrocardiac density. Aortography remains the “gold standard” diagnostic modality and is indicated if aortic injury is suspected on the basis of mechanism of injury and any of these suggested findings.

8.  Which of the following statements about diagnostic peritoneal lavage (DPL) is/are false?
A.  DPL is the diagnostic procedure of choice for gunshot wounds to the abdomen with no obvious intra-abdominal injuries.
B.  The average reported incidence of false-positive DPL in patients with significant pelvic fractures is 20% to 30%.
C.  Accuracy rates for DPL have generally been reported between 95% and 97%.
D.  DPL has been entirely replaced by computed tomography as the diagnostic procedure of choice following blunt abdominal trauma.
Answer: AD

DISCUSSION: DPL remains the most sensitive and specific indicator of intra-abdominal injury in the trauma patient. The accuracy rates for DPL in several large collective series reveal an overall sensitivity of 95%, specificity of 98% to 99%, and overall accuracy of 97%. As result, DPL remains the mainstay for diagnosis of intraperitoneal injury in the trauma patient; however, not every trauma patient requires DPL. In the awake, alert, and responsive patient with isolated abdominal injuries, the physical examination and history are very helpful in predicting the presence of significant injury. In the patient with lower torso (nipples to pubis) or back or flank gunshot wounds, the incidence of intra-abdominal injury is so high that exploratory laparotomy without further diagnostic modalities is generally advocated. In addition, DPL is generally inaccurate in the diagnosis of retroperitoneal injuries (duodenum, renal, pancreas), and significant retroperitoneal hemorrhage in association with pelvic fractures produces a false-positive DPL rate of up to 30%. Computed tomography (CT) scans have proved extremely valuable in these situations. General recommendations for the use of abdominal CT scans in trauma victims include patients who are hemodynamically stable (normal) with (1) equivocal abdominal examination, (2) closed head injury, (3) spinal cord injury, (4) hematuria, and (5) pelvic fractures with significant bleeding. These five indications are appropriate if the patient is truly hemodynamically stable and the time required to perform CT does not delay any surgical procedures.

9.  A 28-year-old male was injured in a motorcycle accident in which he was not wearing a helmet. On admission to the emergency room he was in severe respiratory distress and hypotensive (blood pressure 80/40 mm. Hg), and appeared cyanotic. He was bleeding profusely from the nose and had an obviously open femur fracture with exposed bone. Breath sounds were decreased on the right side of the chest. The initial management priority should be:
A.  Control of hemorrhage with anterior and posterior nasal packing.
B.  Tube thoracostomy in the right hemithorax.
C.  Endotracheal intubation with in-line cervical traction.
D.  Obtain intravenous access and begin emergency type O blood transfusions.
E.  Obtain cross-table cervical spine film and chest film.
Answer: C

DISCUSSION: Airway remains the first priority in the management of any patient with multiple injuries. Control of the airway in a patient with head, face, and neck injury can be extremely challenging. In the patient presented, the best option given for control of the airway is endotracheal intubation with in-line cervical traction. This requires at least two persons, one to maintain the head in the neutral position and one to insert the endotracheal tube under direct vision. An alternative in this case would be emergency cricothyroidotomy, tracheostomy, or needle-jet insufflation. Nasotracheal intubation is not an option in the presence of a mid-face fracture and a nasal hemorrhage. Clearly, attention must also be directed at assuring adequacy of ventilation (potential right pneumothorax), assessing and treating obvious hemorrhage, determining if there is occult intra-abdominal or thoracic hemorrhage, and determining the patient's neurologic status. While management of these other issues can occur simultaneously, they do not take priority over securing an adequate airway. In this patient the airway is so tenuous that time should not be spent obtaining a cross-table cervical spine film and chest film prior to definitive control of the airway.

10.  True or False?
A.  Trauma is second only to congenital heart disease as the leading cause of death in children.
B.  Each year in the United States, approximately 50,000 people die from injuries.
C.  Motor vehicle accidents (MVAs) involving intoxicated drivers are responsible for 50% of all MVA fatalities.
D.  Active prevention strategies (e.g., seat belts, helmets) have not proved effective in reducing injuries and fatalities.
E.  Falls and diving accidents comprise approximately 30% to 40% of cervical spine injuries.

DISCUSSION: The statistics on injuries highlight trauma as “the principal public health problem in America today.” Trauma remains the leading cause of death in children and adults up to the age of 44 years, and injuries kill more Americans age 1 to 34 years than all diseases combined. Each year more than 140,000 Americans die of injuries, 50,000 due to motor vehicle accidents. Just over 50% of motor vehicle injuries involve intoxicated drivers. Injury prevention would be the most cost-effective method of dealing with this major social and economic burden. Active injury prevention strategies are those that require active continued cooperation on the part of the individual, such as wearing a helmet when driving a motorcycle or wearing seat belts in automobiles. Passive approaches such as fitting all motor vehicles with driver air bags require little or no individual cooperation and have clearly proved the more effective option, but active prevention strategies have repeatedly been demonstrated to reduce injury fatalities. States with seat belt and child restraining laws show an increase in seat belt use of more than 60% with a concurrent 9% to 12% reduction in occupant fatalities. Motor vehicle accidents are responsible for approximately 60% of spinal cord injuries, falls for 20% to 30%, and diving accidents for an addition 5% to 10%. Spinal cord injury acute care and rehabilitation represent some of the most expensive medical treatment, with an average hospital charge of $50,000 in 1988 for a quadriplegic survivor.

11.  Regarding the diagnosis and treatment of cardiac tamponade, which of the following statements is/are true?
A.  Accumulation of greater than 250 ml. of blood in the pericardial sac is necessary to impair cardiac output.
B.  Beck's classic triad of signs of cardiac tamponade include distended neck veins, pulsus paradoxicus, and hypotension.
C.  Approximately 15% of needle pericardiocenteses give a false-negative result.
D.  Cardiopulmonary bypass is required to repair most penetrating cardiac injuries.
Answer: C

DISCUSSION: Cardiac tamponade is most frequently caused by penetrating thoracic injury, but may occasionally be observed following blunt thoracic trauma from cardiac chamber rupture, coronary artery laceration, or ascending dissection of an aortic tear. Accumulation of as little as 150 ml. of blood in the pericardium will sufficiently decrease diastolic filling to produce distended neck veins, cyanosis, and decreased cardiac output. Beck's classic triad of distended neck veins, muffled heart sounds, and hypotension is present in only one third of patients with tamponade. Pulsus paradoxicus is even less frequently discernible. Immediate temporary treatment consists of pericardiocentesis, which also provides a diagnosis. However, approximately 15% of pericardiocenteses give false-negative results because of a clotted hemopericardium. Therefore, echocardiography prior to needle aspiration is generally advisable if promptly available. In the patient in extremis, emergency thoracotomy with pericardiotomy and cardiac repair should be performed. Most patients with penetrating cardiac wounds do not require cardiopulmonary bypass to repair their injuries.

12.  Which of the following statements or descriptions typically characterizes the syndrome of overwhelming postsplenectomy sepsis?
A.  A syndrome of fulminant gram-negative bacteremia and septicemia in asplenic individuals, characterized by the presence of as many as 10 6 bacterial organisms per cu. mm. circulating in the bloodstream.
B.  A syndrome caused primarily by impaired host ability to mount an effective humoral (immunoglobulin) response to infection.
C.  A syndrome that occurs in 5% to 7% of patients following traumatic splenectomy.
D.  A syndrome of rapidly appearing septic shock unresponsive to antibiotic therapy, with an average mortality of 50%.
E.  The syndrome may be prevented by preserving as little as 15% of splenic mass in adult trauma victims.
Answer: D

DISCUSSION: In 1952 King and Schumaker suggested that children who had undergone splenectomy were at risk for the development of bacterial infections, and the syndrome of overwhelming postsplenectomy sepsis (OPSS) was suggested by Diamond in 1969. The syndrome is unlike fulminating bacteremias and septicemia in individuals with normal splenic function. The onset is sudden, with nausea, vomiting, headache, and confusion leading to coma. The new infecting organism is a gram-positive organism in over half the cases, primarily Streptoccoccus pneumoniae. Blood cultures may occasionally demonstrate up to as many as 10 6 bacterial organisms per cu. mm. circulating in the bloodstream. Disseminated intravascular coagulation is common along with hypoglycemia, electrolyte imbalance, and shock unresponsive to antibiotics and fluid or pharmacologic support. Mortality has generally been reported as high as 50% and even up to 80% for pneumococcal infections. The true incidence of overwhelming postsplenectomy sepsis following a splenectomy from trauma is not well defined. Green and colleagues suggested that the risk of OPSS is 166 times the rate expected for the general population. Eraklis and Filler suggested that the incident rate of mortality from sepsis and OPSS is 78 times greater than that expected for the general population. Despite this increased frequency, overwhelming postsplenectomy sepsis remains a rare event. Singer's large review of 688 children who had undergone splenectomy for trauma demonstrated only a 1.45% incidence of postsplenectomy sepsis, but a 40% mortality. The occurrence of OPSS appears to be less following splenectomy for trauma when compared with splenectomy for congenital hematologic disorders. Nonetheless, the recognition of the severe nature of this entity has prompted many trauma surgeons to more aggressively attempt splenic salvage. Animal laboratory evidence suggests that at least 50% of the splenic tissue mass must be preserved to prevent overwhelming postsplenectomy sepsis. The immunologic function of the spleen that appears to be most beneficial in preventing OPSS is the spleen's capacity for clearance of blood-borne particles and the provision of circulating opsins, which assist in cell-mediated immunologic functions.

13. Trauma deaths most commonly occur at three distinct time periods after injury. Which of the following statement(s) is/are true concerning the time pattern of trauma mortality?

a. Only 10% of trauma deaths occur within seconds or minutes of the injury
b. A second mortality peak occurs within hours of injury with deaths in this time period being markedly reduced with the development of trauma and rapid transport systems
c. Death one day to weeks after the injury are almost entirely due to infection and multiple organ failure
d. Late mortality in trauma patients, occurring days to weeks after the injury, has not been affected by better trauma delivery systems
Answer: b

Trauma deaths occur at three traditionally recognized times after injury. About half of all trauma-related deaths occur within seconds or minutes of injury and are related to lacerations of the aorta, heart, brain stem, brain, and spinal cord. Few of these patients are saved by health care systems, regardless of efficiency. The second mortality peak occurs within hours of injury and accounts for about 30% of deaths, half of which are due to hemorrhage and half due to central nervous system injuries. Important reductions in mortality during this period have resulted from the development of trauma and rapid transport systems. Overall, trauma mortality rates have been reduced from about 30% to 2% to 9% where well-organized trauma care systems exist. The third mortality peak includes deaths that occur one day after trauma to weeks later. This mortality rate is usually attributed to infection and multiple organ failure. Ten to 20% of trauma deaths occur during this period. The development of efficient trauma systems, however, has changed the epidemiology of these deaths. During the first week after trauma, refractory intracranial hypertension after severe head injury now accounts for a significant number of these deaths. The incidence of sepsis and multiple organ failure has diminished as the result of aggressive and better early resuscitation and care. Sepsis and multiple organ failure now account for about 5% of overall mortality and only 30% of late mortality where organized trauma systems exist.

14. Which of the following statement(s) is/are true concerning the epidemiology of trauma?

a. Trauma is the leading cause of death of individuals less than 44 years of age
b. Trauma follows only cancer and heart disease as leading causes of productive life lost
c. Motor vehicle accidents are the most common cause of traumatic death in young males of all ethnic groups
d. Young males are the population at highest risk for trauma death
Answer: a, d

Although injury affects all age groups, it is epidemic within the younger population of our society. In the United States, injury is the leading cause of death in individuals less than 44 years and results in 70% of the total hospital admissions. Young males are the highest risk group, not because of physiologic distinctions, but because of their propensity to engage in high-risk activities. Although the three leading causes of traumatic death in all ethnic groups are motor vehicle accidents, homicide, and suicide, for individuals under 35 years of age, the order in which these occur differs. In the African-American population, the leading cause of death in this age group is homicide, while in all other groups it is motor vehicle accidents. Although morbidity and mortality figures are important, another important method of analyzing the toll injury places on a society is in years of productive life lost. Years of productive life lost is used to reflect the amount of productive working time lost due to premature death. Since injury is so prevalent in the younger population, a traumatic death in this age group will result in a large number of years of productive life lost, more so than deaths in the older age groups due to chronic diseases. In fact, years of productive life lost due to injury are approximately 40% higher than those found in cancer or heart disease patients, the second and third leading causes of productive life lost.

15. Which of the following statement(s) is/are true concerning the biomechanics of blunt trauma?

a. A small child and a large adult have a markedly different level of energy transfer in a high speed vehicular collision
b. Shear strain injuries result from rapid acceleration or deceleration
c. Tensile strain results from direct compression of tissues
d. The tolerance of biologic tissue to trauma injury is directly proportional to the elasticity of the organ
Answer: b, c, d

The severity of any injury is directly proportionate to the amount of kinetic energy transferred to the tissues and the properties of that tissue which accept and dissipate the energy. Kinetic energy (KE) is a function of the mass (M) of an object and its
velocity (V):

KE = M x V^2 /2

It is clear from this relationship that changes in velocity alter the kinetic energy transferred more significantly than changes in mass. Therefore, a small child and a large adult, though significantly different in size and weight, are subjected to similar levels of energy transfer in a high-speed vehicular collision, the primary determinant being velocity rather than mass. The tolerance of a biologic tissue to traumatic injury is directly proportional to the elasticity of the organ—that is, its ability to return to its original shape and position. Elasticity is directly affected by the rate of loading, or the rate at which strain is applied to the tissues. Applying the force more rapidly increases the likelihood of exceeding tolerance. Blunt trauma results in two types of forces during impact. First, changes in speed (acceleration or deceleration) create shear strain, and second, deformity changes (stretch or compression) creates tensile strain.

16. The patient described above has also suffered major facial trauma. Which of the following statement(s) is/are true?

a. A frontal bone fracture and injury to the frontal sinus is a common facial injury in a young adult
b. The optic nerve can be injured in a LeFort type II fracture
c. A facial nerve injury may occur with the fracture of the temporal bone
d. Coronal CT scan images can be a useful adjunct to the evaluation of the patient with facial and head injuries
Answer: c, d

A major cause of maxillofacial trauma are motor vehicle accidents. Facial skeletal fractures and soft tissue damage in the frontal, orbital, nasal, zygomatic, maxillary and mandibular regions are included. The frontal bone, which houses the frontal sinuses, is particularly strong due to its arched configuration as well as thick, hard bone. The amount of force necessary to fracture the frontal sinus is two to three times greater than that necessary for other facial bone fractures. Consistent fracture patterns from blows to the maxilla have been classified by LeFort and occur within and along the maxilla at its junction with weaker and aerated bone of the paranasal sinuses and nasal cavity. The classic LeFort fractures are classified as LeFort I, LeFort II and LeFort III and are of increasing complexity and morbidity. The cribriform plate, ethmoidal arteries, optic nerve and internal maxillary artery are all vulnerable to injury with a LeFort III fracture.
Soft tissue injuries of the face are encountered even more often than facial fractures. The facial nerve is the most important underlying structure at risk since blunt or penetrating trauma to the nerve or branches can cause complete or partial ipsilateral facial paralysis. The most common cause of facial nerve injury is fracture of the temporal bone, but injury can occur anywhere from the intracranial to the extracranial facial course of the nerve.
After securing the airway and controlling life-threatening hemorrhage, the secondary survey including the facial area is carried out. The nose is inspected for deformity, pain, mobility, septal hematoma and obstruction. Bleeding should be managed immediately. Leakage of cerebral spinal fluid suggests a cribriform plate or ethmoidal fracture and a presence should warn against insertion of any nasal tubes or packing. Since CT scan is part of the standard management of the head-injured patient, sections of the facial skeleton can be obtained simultaneously, providing information on the extent of facial fractures in addition to the status of the brain. Axial and coronal sections (obtained with the patient’s head hanging with the neck extended) are complimentary and are especially helpful in delineating the cribriform plate and ethmoid roof region, the orbital rims, and the overall vertical facial height.

17. There are a number of options for resuscitative fluids. Which of the following statement(s) is/are true concerning fluids used for resuscitation of shock?

a. Resuscitation with crystalloid requires volume replacement in a ratio of 1:1 to volume lost
b. The literature strongly supports the use of colloid as being superior to crystalloid in the resuscitation of shock
c. Risks of autotransfused blood include disseminated intravascular coagulation and activation of fibrinolysis
d. Hypertonic saline solution results in volume expansion, an increase in left ventricular performance, decreased peripheral resistance, and redistribution of cardiac output to kidneys and viscera
e. The use of perfluorocarbons as an experimental resuscitative fluid has been demonstrated to stimulate the immune system
Answer: c, d

Balanced salt solutions are the most commonly used resuscitative fluids, and their use to restore extracellular volume significantly decreases the transfusion requirement after hemorrhagic shock. Lactated Ringers and normal saline are the most effective crystalloid solutions in common use. Resuscitation with crystalloid require a volume administration ratio of 3:1 to 4:1 over volume lost. Although colloids do not replete the interstitial space, they have a volume-expanding effect somewhat greater than the amount used. Colloids commonly used for volume expansion in hypovolemia include albumen, dextran 70, dextran 40, and hydroxyethyl starch (hetastarch). Significant controversy exists concerning the use of crystalloid versus colloid resuscitation. Although the question has not been resolved, several recent studies have indicated an advantage to crystalloid in resuscitation. A meta-analysis of colloid versus crystalloid resuscitation after hemorrhagic shock has demonstrated a higher mortality rate in the colloid resuscitated patients, partly due to pulmonary complications. Patients who lose more than 25 to 30% of total blood volume will need blood for resuscitation. Type O, Rh-negative (universal donor blood) is immediately available without a cross match. Type-specific blood is available within most blood banks within five to ten minutes of receipt of the blood specimen, while the patient is being resuscitated with balanced salt solutions. Although not cross matched, this blood can be administered safely, and therefore its rapid availability and safety make type-specific blood the blood of choice for resuscitation in trauma. Autotransfusion involves the collection of shed blood and its reinfusion through a filter back into the patient. Autotransfused blood may produce disseminated intravascular coagulation (DIC) and activation of fibrinolysis. In addition, blood collected from the peritoneal cavity after hollow viscus injury, even with cell washing, may lead to bacterial contamination of the autotransfused blood. Hypertonic solutions have been used in the resuscitation of patients after burn, shock, elective vascular surgery and trauma. In addition to volume expansion, hypertonic saline solutions have been shown to increase left ventricular performance, decrease peripheral resistance from arteriolar dilatation, and redistribute cardiac output to the kidneys and viscera. Perfluorocarbons are an experimental resuscitation fluid comprised of large, branched or cyclic aliphatic compounds which have the ability to dissolve and carry oxygen. Although effective in volume resuscitation with improved oxygen delivery and oxygen-carrying capacity, perfluorocarbon infusion has been shown to depress platelet counts, plasma immune globulin levels and depress other aspects of immune function.

18. Hemorrhage initiates a series of compensatory responses. Which of the following statement(s) is/are true concerning the physiologic responses to hemorrhagic shock?

a. An immediate response is an increased sympathetic discharge with resultant reflex tachycardia and vasoconstriction
b. Transcapillary refill is a response serving to restore circulating volume
c. Extracellular fluid becomes increasingly hyperosmolar
d. Adrenergically mediated vasoconstriction is well maintained at the arteriolar and precapillary sphincters
Answer: a, b, c

Hemorrhage initiates both rapid and slower, more sustained compensatory responses. The body responds to maintain hemostasis almost immediately after the onset of hemorrhage. Decreased activation of the arterial baroreceptors, though a decrease in blood pressure or even more subtly, a decrease in pulse pressure, causes an increased sympathetic discharge, resulting in reflex tachycardia and vasoconstriction. Increased adrenergic output with increased secretion of catecholamines also leads to vasoconstriction, increased heart rate, and increased myocardial contractility. Sustained compensatory responses include the release of vasoactive hormones and fluid shifts from the interstitium and the intracellular space. Adrenergically mediated vasoconstriction affects arterial precapillary and postcapillary sphincters and small veins and venules. The decrease in intravascular hydrostatic pressure distal to the precapillary sphincter leads to reabsorption of interstitial fluid into the vascular space and thereby functions to restore circulating volume. This is known as transcapillary refill. The increased release of stress hormones coupled with relative insulin resistance after shock leads to high extracellular glucose concentrations. In addition, products of anaerobic metabolism from hypoperfused cells accumulate in the extracellular compartment, inducing hyperosmolarity. This extracellular hyperosmolarity draws water from the intracellular space, increasing interstitial osmotic pressure, which in turn drives water, sodium and chloride across the capillary endothelium into the vascular space. If the shock state continues, however, the postcapillary sphincter remains in spasm, but the arteriolar and precapillary sphincters cannot maintain the tension, and they become relaxed. As sphincters relax, the capillary hydrostatic pressure increases and sodium, chloride and water move into the interstitium leading to further depletion of intravascular volume.

19. Which of the following steps is/are part of the primary survey in a trauma patient?

a. Insuring adequate ventilatory support
b. Measurement of blood pressure and pulse
c. Neurologic evaluation with the Glasgow Coma Scale
d. Examination of the cervical spine
Answer: a, b, c

The resuscitation team’s first priority is to simultaneously assess the airway, blood pressure and level of consciousness of the patient. The first priority is assessment of the airway. After establishment of an airway, the next priority is to insure adequate ventilatory exchange by rapid auscultation of both lung fields and assessment for mechanical factors that may interfere with breathing. After establishment of an airway, ventilation and appropriate pleural drainage, if necessary, the next priority is the assessment of the patient’s circulatory status. This includes an estimation of blood volume and cardiac function. The initial survey evaluates blood pressure, pulse, and skin perfusion. It is important to emphasize that effective resuscitation from hemorrhagic shock requires both restoration of intravascular volume and control of hemorrhage. The final priority of the primary survey is a brief neurological evaluation using the components of the Glasgow Coma Scale. Although maintaining axial immobilization of the cervical spine is an important early component of all assessments and resuscitation protocols, examination of the cervical spine regardless of injury is part of the secondary survey.

20. Immediate life-threatening injuries that preclude air exchange which can be treated in the field include which of the following?

a. Tension pneumothorax
b. Massive open chest wounds
c. Sucking chest wounds
d. Tracheal disruption
Answer: a, b, c

After establishment of a patent and controlled airway, the next priority is to insure that air exchange is taking place. Immediate life-threatening injuries that preclude air exchange include: tension pneumothorax, massive open chest wounds, sucking chest wounds, and tracheal disruption. There are no maneuvers likely to correct tracheal disruption in the field. Both open chest wounds and sucking chest wounds will respond to endotracheal intubation and positive pressure ventilation. Tension pneumothorax may require field decompression in the rare patient. Field techniques to deal with tension pneumothorax include needle thoracostomy and chest tube thoracostomy.

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