Answer Key to TCRN Manual Practice Questions

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Answer key image - TCRN.jpg

Answer Key to TCRN Manual Practice Questions

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Download the answer key to the practice questions at the end of the TCRN Exam Review Course Manual.  

 

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CHALLENGE QUESTIONS (ANSWERS AND RATIONALES) 

  • Question # 1:

The correct answer is B.

Rationale: A decrease in urinary output is associated with decompensatory hypovolemic shock, therefore an increase in this parameter is an indication of successful treatment.  Pulse pressure, respiratory rate and serum lactate levels all increase with decompensatory shock, therefore an elevation in these levels is not associated with successful treatment. 
Question # 2: The correct answer is A.  Rationale: Disseminated intravascular coagulation (DIC) results in abnormal increase in clotting. Fibrin degradation products are released from the breakdown of formed clots therefore increasing the D-dimer. The bleeding associated with DIC would cause the hematocrit to decrease rather than elevate.  Consumption of clotting factors caused by abnormal clotting would cause the platelet count and fibrinogen level to drop rather than elevate. 

  • Question # 3:  

The correct answer is A.

Rationale: Tissue hypoxia causes the base deficit to decrease. Since tissue hypoxia is associated with inadequate fluid resuscitation, normalization of the base deficits associated with successful treatment. Alteration of mental status and an elevation in blood pressure are associated with successful treatment of hypovolemic shock but these parameters may be altered by many other factors including the use of beta-blocker medication, vasoconstriction associated with shock and use of alcohol or other illicit substances. Therefore, these indicators are less accurate than the base deficit. Similarly, an increase in urinary output is associated with successful resuscitation but may be altered by pre-existing renal failure, diabetes insipidus and other confounding factors. Therefore arterial base deficit is the most accurate indicator of adequate fluid resuscitation in the patient with hypovolemic shock.  

  • Question # 4:

The correct answer is A.  

Rationale:  One of the advantages of effective crisis management is the development of new skills which allows the individual to handle future crisis more effectively.  The onset of sepsis is independent of the ability of the patient to handle crisis early.  A patient who is able to handle the crisis of a traumatic injury is more likely to assist the family to deal with the crisis rather than alienate them.  Patients who deal with the crisis immediately after the injury do not have a higher rate of decompensation during the rehabilitation phase of recovery. 

  • Question # 5:

The correct answer is B.  

Rationale: Although the onset of post-traumatic stress disorder can occur at any time interval following a traumatic event, the most likely time of onset is approximately 3 months after the event.  It generally does not appear as early as 4 weeks after the event and frequently occurs before one or three years.

 

  • Question # 6: The correct answer is D.  

Rationale:  Patients with crush injuries may suffer hyperkalemia as a complication of the muscular damage they incur.  One treatment for hyperkalemia is intravenous glucose and insulin.  The insulin facilitates the movement of potassium from the serum to the cells (and the dextrose prevents decreases in serum glucose levels that may occur with administration of insulin).  The purpose of giving insulin and dextrose is not to change the color of the urine, to improve the level of consciousness or to alter the white blood cell count.   

  • Question # 7:

The correct answer is D.  

Rationale: Electricity is known to cause severe muscular contractions which can break bones, including bones of the vetebral column.  The electrical current can also cause the patient to be thrown away from the electrical source further increasing the risk of a cervical spinal injury.  Therefore, patients with electrical burns should have appropriate cervical spinal precautions undertaken as a priority of care.  Although this patient’s clothing should be removed to facilitate a secondary survey for additional injuries, this does not constitute a higher priority than ensuring appropriate cervical spinal stabilization.  Elevation of burned extremities is not indicated in electrical burns.  This patient is awake and there is no indication that endotracheal intubation is indicated, therefore this is not a priority of care for this scenario. 

  • Question # 8:

The correct answer is A.  

Rationale: Symptoms of radiation sickness includes nausea, vomiting, diarrhea, malaise, anorexia and gastrointestinal bleeding.  Ascending paralysis, hemoptysis, severe headaches, muscle tremors, a generalized pustular rash and a burning sensation on the skin are not associated with radiation sickness. 

  • Question # 9:

The correct answer is A.  

Rationale:  In high speed frontal crashes, the patient moves forward towards the dashboard or the dashboard may be posteriorly displaced.  This drives the knee into the dashboard causing patellar,acetabular and femur fractures, and hip disloctions.  Cauda equine syndrome is associated with falling on the coccyx rather than a high-speed frontal crash.  Although forward movement of the body in a frontal collision may cause lumbar vetebral fractures, thoracic vetebral fractures are uncommon with this mechanism of injury.  A rupture of the Achilles tendon is associated with forced plantar flexion or dorsiflexion of the foot, not high-speed frontal collisions. 

  • Question # 10:

The correct answer is A.  

Rationale:  A priority carefor patients with rib fractures is effective pain management.  This will reduce splinting by the patient improving gas exchange.  Although patient positioning may also improve gas exchange, this is not a higher priority than pain management. Patients may actually find that lying on the injured side allows the stretcher to serve as a splint improving oxygenation (as opposed to laying on the less injured side).  In the absence of hypovolemia (there is no indication of hypovolemia in this scenario), fluids should be restricted to reduce the risk of acute respiratory distress syndrome (ARDS) and decrease fluid in the lungs associated with pulmonary contusions.  Although this patient may need to be intubated if effective pain management cannot be secured or if blood gases do not improve, this is not a higher priority than pain management.  Lower tidal volumes are often used with chest injuries to reduce the risk of ARDS in the post-injury phase. 

  • Question # 11:

The correct answer is B.

 Rationale:  A PaO2:FiO2 (P:F) ratio above 400 is considered normal.  A P:F ratio of 200 – 300 is defined as mild acute respiratory distress syndrome, a P:F ratio between 100 and 200 is defined as moderate acute respiratory distress syndrome and a P:F ratio less than 100 is defined as severe respiratory distress syndrome. 
Question # 12:  The correct answer is B.  Rationale:  The pancreas is located in the retroperitoneum and bleeding secondary to pancreatic injuries may accumulate in the retroperitoneal space.  Retroperitoneal bleeding generally manifests as Tbruising in the flanks but may be delayed by twelve hours or more.  Furrthermore, the symptoms of pancreatic trauma are often absent on initial presentation and may show up 6 or more hours after injury.  Liver lacerations and ruptures of the small bowel are more likely to bleed into the peritoneum causing abdominal distension as opposed to bruising in the flanks.  A diaphragmatic tear is more likely to cause dyspnea then bruising in the flanks. 

  • Question # 13:

The correct answer is A.  

Rationale:  Although gastric trauma should be suspected in all patients with significant mechanisms of injury, the stomach is well protected under the rib cage and is rarely injured in blunt trauma such as falls and motor vehicle collisions.  20% of all gastric trauma is related to penetrating trauma such as a gunshot wound to the abdomen.  Even if the external wound from the gunshot is not directly over the stomach, pressure waves from the projectile moving through the abdomen can cause ruptures of hollow organs such as the stomach.  The projectile can also ricochet off bony structures once inside the body, injuring organs far from its entry point. 

  • Question # 14:

The correct answer is A.  

Rationale: Bleeding from rectal trauma frequently accumulates in the pelvic space.  This blood can then run into the scrotum causing a scrotal hematoma.  Blood from a femur fracture will accumulate in the thigh as opposed to the pelvis.  Blood from a shattered kidney will accumulate in the retroperitoneal space causing bruising of the flanks as opposed to a scrotal hematoma.  Blood and urine from an intreperitoneal bladder rupture will accumulate in the peritoneum causing rebound tenderness and abdominal distension rather than a scrotal hematoma.  Extraperitoneal bladder rupture can cause urine to extravasate into the scrotum causing scrtoal swelling. 

  • Question # 15:

The correct answer is B.  

Rationale:  A palpable flank mass is a strong indication of a tamponaded renal hematoma.  Although bruising at the 11th and 12th ribs is also an indication of renal trauma, more likely renal trauma with capsular rupture, it will take several hours or longer for the blood to discolor and appear as blank bruising, therefore this is likely to noted later than a palpable flank mass.  Abdominal distension is more likely to occur with intraperitoneal organ damage and the kidneys are in the retroperitoneum.  Referred shoulder pain is associated with irritation of the diaphragm, which occurs with damage to the organs inside the peritoneum, not in retroperitoneal injuries.   

  • Question # 16:  

The correct answer is D.

 Rationale:  The small bowel is displaced by the gravid uterus and small bowel injuries actually decrease during pregnancy.  Liver and splenic injuries are 25% more common when comparing the pregnant patient to the non-pregnant patient.  The bladder tends to be elevated out of the pelvic ring during pregnancy increasing injury to this organ during pregnancy. 

  • Question # 17:  

The correct answer is A.  

Rationale:  During pregnancy, a woman’s blood volume increases and signs of hypovolemia associated with blood loss, including hypotension, may be delayed, especially when compared to the patient’s non-pregnant counterpart.  Selective uterine vasoconstriction, a response to blood loss, is more likely to cause fetal distress, as evidenced by changes in fetal heart rate before maternal signs of blood loss.  Fetal heart tones tend to increase in early distress and decrease as an indication of later, more serious distress. 

  • Question # 18:

The correct answer is C.  

Rationale:  On average, intracranial pressure tends to spike 48 to 72 hours after a traumatic brain injury.  Although each patient is individual and some may spike earlier than this or even after this time frame, the average time frame for the intracranial pressure to elevated to its highest point after an injury is 48 to 72 hours. 
Question # 19: The correct answer is B.  Rationale:  Subdural hematomas are usually venous in nature which means that the accumulation of blood which will cause the symptoms may take time.  Therefore the onset of symptoms may be delayed by hours or even days.  Most subdural bleeds will ultimately cause some degree of symptoms ranging from headaches to confusion or an alteration in the level of consciousness.  An immediate unconscious state is more consistent with a diffuse axonal injury.  An immediate excruciating headache is more likely associated with a subarachnoid bleed. 

  • Question # 20:  

The correct answer is D.

 Rationale:  Apneustic breathing is associated with lesions in the lower pons and is defined as a breathing pattern with a pause of 2 – 3 seconds noted after a full or prolonged gasping inspiration followed by an inefficient brief expiration.  Bradypneais defined as a slow but regular respiratory pattern.  Central neurogenic hyperventilation is frequently associated with lesions in the pons and midbrain and is described as a regular, sustained, increased rate and depth of respirations with forced inspiration and expiration.  Cluster breathing is also associated with lesions in the pons and upper medulla and is described as slow irregular breaths with periods of apnea at irregular intervals. 

  • Question # 21:

The correct answer is A.

 Rationale:  In younger patients, the most mobile area of the spinal cord is C4 through C7, therefore this is the most common site for spinal cord injury.  After age 65, the mobility of this area decreases and the most common site of injury is C1 and C2.  Although T12 and L1 are more mobile than other areas of the spinal column, injuries here are less common than the cervical spine.  L5 and L6 are held fairly rigid by the ribcage in all age groups and are not common sites of injury. 

  • Question #22:

The correct answer is B.  

Rationale: The vasodilation associated with neurogenic shock, which frequently accompanies spinal cord injuries, may cause poikelothermy (the assumption of room temperature).  Therefore measures to reduce heat loss such as warmed intravenous solutions (as opposed to room temperature intravenous fluids), keeping the patient covered and other measures to reduce radiant heat loss should be undertaken.  There is no therapeutic value in elevating the lower extremities and this could potentially exacerbate spinal cord injuries especially in the lower back.  Although analgesia should be considered for patients with spinal cord injuries who are experiencing pain, prophylactic administration of analgesia is not required.  Because of loss of sensation, not all spinal cord injured patients require analgesia. 

  • Question # 23:

The correct answer is A.

 Rationale: Common symptoms associated with zygomatic fractures include trismus (because of the proximity of the zygomatic bone to the upper palate and mandibular condyle), infraorbital anesthesia (due to involvement of the infraorbital nerve), diplopia (due to fractures into the orbit which may contribute to ocular entrapment), epistaxis and lack of symmetry.  Otorrhea is more likely to be associated with a fracture of the middle fossa of the skull.  Dysphonia is more likely to be associated with laryngeal trauma and mastoid bruising is more likely to be associated with a fracture of the posterior fossa of the skull. 

  • Question # 24:

The correct answer is A.

 Rationale:  A globe luxation is a condition here the globe is found outside the bony orbit.  The affected eye should be covered with a paper cup and reduction of the globe should be facilitated rapidly to minimize traction on the optic nerve.  A paper cup would have no therapeutic value for a hyphema, an orbital fracture or a lens subluxation.