CEN IX ANSWERS & RATIONALES (2022)

 MENTAL HEALTH EMERGENCIES

QUESTION ONE: The correct answer is B. This statement reflects an authoritative, yet non-threatening statement which is meant to ensure the patient’s safety. Open-ended questions such as “I want you to tell me what you are feeling right now” or “Tell me what is going on in your life right now that may have made you feel out of control for three past few days” are not therapeutic for the patient in the manic phase of bipolar disorder. Instead, simple statements or “yes”/”no” questions should be asked. Statements made to someone in the manic phase of bipolar disorder should also be brief and succinct to prevent misinterpretation.

QUESTION TWO: The correct answer is B. Poisoned mushrooms exert a cholinergic effect and are treated with anti-cholinergics (e.g., atropine). Atropine would not be effective in treatment an overdose caused by antihistamines (a sedative-hypnotic), lysergic acid diethylamide (a sympathomimetic) or the seeds of the Jimson weed plant (an anti-cholinergic)

QUESTION THREE: The correct answer is A. An overdose of digoxin is known to cause a variety of arrhythmias including bradycardia, heart blocks, ventricular arrhythmias and even asystole. This rhythm strip demonstrates a third-degree heart block with would be consistent with a digoxin overdose. Although lorazepam overdoses may cause a slowed heart rate, third degree heart blocks are not generally associated with this overdose. The bigger issue with lorazepam overdoses is severe bradypnea and a decreased level of consciousness. Ethylene glycol causes profound metabolic acidosis and tachycardia rather than a third-degree heart block. Acetaminophen overdoses cause liver toxicities as opposed to third-degree heart blocks.

QUESTION FOUR: The correct answer is B. One of the main treatments for tricyclic antidepressant overdoses is administration of large doses of sodium bicarbonate. Alkalinization of the serum is both cardioprotective and may also enhance excretion of the drug. The goal of treatment is to elevate the serum pH to more than 7.45 and preferably above 7.50. The QT interval is usually elongated as part of the toxicity so further widening of the QT interval is not desired. Similarly, the patient is normally hypotensive after an overdose on a tricycle antidepressant therefore further reduction of the blood pressure would not indicate effective treatment. The size of the pupils is not affected by an overdose on tricyclic antidepressants therefore dilation of the pupils would not indicate effective treatment.

ENVIRONMENTAL AND TOXICOLOGICAL EMERGENCIES AND COMMUNICABLE DISEASES

QUESTION FIVE: The correct answer is D. Carbon monoxide poisoning causes systemic hypoxia which can lead to complications such as hypoxic cardiac arrhythmias. Therefore, continuous cardiac monitoring should be undertaken while a patient is being treated for carbon monoxide poisoning. Carbon monoxide poisoning does not tend to cause alterations in either serum glucose or urinary output, therefore monitoring of these parameters is not as crucial as monitoring the cardiac monitor. Pulse oximetry is known to be inaccurate with carbon monoxide poisoning as it measures the color of blood to determine oxygen saturation, but the color of carboxyhemoglobin cannot be differentiated from oxyhemoglobin with pulse oximetry and the readings are considered inaccurate.

QUESTION SIX: The correct answer is D. The target temperature when reducing core body temperatures in a patient with heat stroke is 102ºF (38.9ºC). Patients in heat stroke do not tend to sweat; therefore, lack of sweating does not indicate effective treatment. Shivering is undesired as it re-elevates core body temperature. The initiation of sweating is not an indication of effective cooling. Although Glasgow Coma Scores may improve as core body temperatures drop, this is not necessarily an indication of effective cooling measures (the Glasgow Coma Score is not always decreased in every case of heat stroke and permanent brain damage due to heat stroke may cause the Glasgow Coma score to be decreased even after effective treatment.)

QUESTION SEVEN: The correct answer is B. The venom of a coral snake is neurotoxic and causes muscular weakness. In the hours following envenomation, the patient will likely become weak, including the muscles supporting respiration and the patient’s respiratory status may decline leading to a respiratory and ultimately metabolic acidosis. The venom of the coral snake is not coagulopathic and will not change the coagulation studies and hematology tests. This is more likely to be seen with snakes in the crotalid family. Renal function tests are unlikely to be impacted by the venom of a coral snake in the hours following envenomation.

QUESTION EIGHT: The correct answer is A. Once the virus that causes rabies crosses the blood brain barrier, it will cause encephalitis which can cause symptoms such as paranoia, delirium, hydrophobia (fear of water) and aerophobia (fear of air). The virus that causes rabies is not associated with a descending paralysis, cardiomyopathies or an inflammatory response that causes fluid shifting.

QUESTION NINE: The correct answer is B. Methicillin-resistant Staphylococcus Aureus painful, reddened, purulent lesions with a yellow or white center (sometimes referred to as the “head’). Methicillin-resistant Staphylococcus Aureus does not cause necrotic tissues or open areas draining copious amounts of serous drainage. Generally, there is a break in the skin near the wound through which the bacteria entered.

QUESTION TEN: The correct answer is A. Once the lesions associated with chicken pox are crusted over, the risk of transmission has passed, and the child can return to school or other activities. The risk of transmission is not related to the itchiness of the lesions or the child’s fever. The child may still be able to transmit chicken pox 24 hours after the last lesion appears.

CARDIOVASCULAR EMERGENCIES

QUESTION ELEVEN: The correct answer is D. Stroke volume is directly related to three things, preload, afterload and contractility. An increase in preload and an increase in contractility cause an increase in stroke volume whereas an increase in afterload causes a reduction in stroke volume. By increasing the force of contraction (contractility), more blood is ejected from the ventricle which is the definition of stroke volume. Contractility does not cause a reduction in either preload or afterload and does not cause an elevation in the heart rate. In fact, increased contractility often improves stroke volume which increases the cardiac output and the body responds to an elevated cardiac output by reducing the heart rate.

QUESTION TWELVE: The correct answer is A. This patient presents with supraventricular tachycardia (as evidenced by the rhythm strip) but the patient is stable (stable vital signs, normal level of consciousness, lack of chest pain, normal skin condition). The initial intervention for stable tachycardia with a regular rhythm is vagal maneuvers. This may slow the heart rate down permanently or may temporarily slow it down so that the undying rhythm can be seen, and the appropriate treatment chosen. If vagal maneuvers are ineffective, then intravenous Adenosine (Adenocard) may be given. Synchronized cardioversion is usually reserved for patients with unstable tachycardia (unstable indicates symptoms such as hypotension, chest pain, diaphoresis). Intravenous beta-blockers such as metoprolol are more likely to be used to treat an irregular tachycardia (usually atrial fibrillation). This patient’s oxygen saturation is greater than 94%, therefore oxygen is not indicated.

QUESTION THIRTEEN: The correct answer is C. A hypertensive urgency and a hypertensive emergency are both defined as a blood pressure with a systolic greater than 180 mm Hg and a diastolic greater than 120 mm Hg. Therefore, a blood pressure cuff can be used to recognized both of these syndromes but not differentiate them. A hypertensive emergency, however, causes symptoms of organ damage that does not exist with a hypertensive urgency. Changes on the electrocardiogram (e.g., ST segment changes or axis deviations) may be indicative of damage to the heart which might be seen with a hypertensive emergency but not a hypertensive urgency. There is no difference in glucose levels between these two conditions, therefore a glucometer will not be useful. A tongue blade will not be useful in differentiating a hypertensive emergency from a hypertensive urgency.

QUESTION FOURTEEN: The correct answer is D. Allowing the legs to dangle over the edge of a stretcher reduces return of blood to the heart. This in turn reduces preload. This effect would be like a venous vasodilator such as nitroglycerin. Dopamine and beta-blockers such as metoprolol are vasoconstrictors and would increase rather than reduce preload. Dobutamine is a positive inotrope (improves cardiac contractility). Positive inotropy does not exert the same effect as dangling the legs over the edge of the stretcher to reduce preload.

QUESTION FIFTEEN: The correct answer is A. Jugular venous distension is associated with right sided heart failure. A posterior infarction affects the posterior wall of the right ventricle and may cause right ventricular failure. Tall R waves in leads V1 and V2 are consistent with a posterior infarction. ST elevations in leads V3 and V4 are associated with an anterior infarction that would cause left as opposed to right-sided heart failure (left-sided failure does not cause jugular venous distension. ST depression in leads V5, V6, I and aVL is consistent with myocardial ischemia on the lateral aspect of the heart (circumflex artery_ and this would also cause signs of left as opposed to right sided failure. Elongated PR intervals in leads II, III and aVF is not associated with myocardial ischemia and is unlikely to cause jugular venous distension.

QUESTION SIXTEEN: The correct answer is D. A blunt cardiac injury causes chest pain that does not radiate. That pain is often present immediately after the injury. Murmurs are not expected after a blunt cardiac injury. Crackles to auscultation would be consistent with left-sided heart failure. A blunt cardiac injury nearly always injures the right ventricle causing right-sided heart failure and this would not cause crackles to auscultation. (heart failure is also a delayed finding that would not be present shortly after the injury)). Although arrhythmias may occur following a blunt cardiac injury, leading to an irregular pulse, like heart failure, this tends to be a delayed finding and would most certainly occur much later than the appearance of chest pain.

MEDICAL EMERGENCIES

QUESTION SEVENTEEN: The correct answer is C. This rhythm strip has ST depression followed by a U wave. This is associated with hypokalemia. Aside from these electrocardiogram changes, patients with hypokalemia develop muscular weakness. Hypokalemia does not cause pale skin, hypertension or decreased urinary output.

QUESTION EIGHTEEN: The correct answer is B. Myxedema coma is known to cause reduced core body temperature and treatment involves passive rewarming measures such as warming blankets or warmed intravenous fluids. Prone positioning is considered for patients with respiratory distress syndrome but would have no therapeutic effect for patients in myxedema coma. Packed red blood cells are used to treat anemia but anemia is not associated with myxedema coma and packed red blood cells are not indicated. Intravenous corticosteroids would have no therapeutic value in the treatment of myxedema coma.

QUESTION NINETEEN: The correct answer is D. Thrombocytopenia is a decrease in the platelet count instead of an increase in the platelet count. It does not change the hematocrit.

QUESTION TWENTY: The correct answer is B. Both hypothermia and acidosis are known to exacerbate the onset of coagulopathies by altering the clotting cascade and the reactivity of platelets. Minimizing hypothermia and preventing acidosis may reduce the onset and/or severity of coagulopathies in the critically ill patient. Warming measures are less likely to prevent sepsis, acute kidney injury or fat embolism syndrome.

QUESTION TWENTY-ONE: The correct answer is D. If the initial dose of IM (or SQ insulin is ineffective, it can be repeated every 15 minutes (up to two doses). Although IV methylprednisolone and aerosolized beta-agonists such as albuterol can be used as adjunctive therapy along with epinephrine, they have a slower onset of action and are used for long-term control of symptoms rather than emergent treatment. Although intubation may be required for severe anaphylaxis, administration of epinephrine may reverse the underlying condition making intubation unnecessary.

NEUROLOGICAL EMERGENCIES

QUESTION TWENTY-TWO: The correct answer is D. A cerebral contusion can cause a variety of symptoms depending on the area of the brain that is affected. Symptoms may include personality changes, nausea and vomiting, deficits in memory, executive function, behavior, contralateral motor deficits, language deficits (such as the inability to remember commonly used words) and visual disturbances. An impaired gag reflex is more likely to be associated with damage to cranial nerve IX and is often associated with a posterior basilar skull fracture. A Glasgow Coma Score of three and bilateral dilated non-responsive pupils are associated with severely elevated intracranial pressures or diffuse axonal injuries but cerebral contusions tend to evolve over time and significant elevations in intracranial pressure are unlikely to occur shortly after the injury.

QUESTION TWENTY-THREE: The correct answer is C. A posterior cord syndrome causes damage to the posterior portion of the cord, which transmits light touch, proprioception and vibration. This means the patient will lose the ability to feel below the level of the injury. The anterior cord transmits motor impulses and in a posterior cord injury, this part of the cord is not injured, therefore the patient retains movement below the level of the injury. Brown-Sequard syndrome is a rare syndrome which causes damage to the spinal cord laterally causing loss of movement to one side of the body and loss of sensation to the other side of the body. A central cord syndrome, as the name implies, causes greater damage to the center of the cord than the periphery of the cord. The center of the cord allows movement and sensation to the upper body, therefore a central cord syndrome will cause greater weakness to the upper body but may leave motor function to the lower body intact including bowel and bladder function.

QUESTION TWENTY-FOUR: The correct answer is C. The symptoms this patient is relating is consistent with a cluster headache and the pain of a cluster headache can often be reduced through the administration of high flow oxygen. There is no therapeutic value to providing a 500 mL bolus of crystalloid solution and non-steroidal anti-inflammatory drugs are not known to reduce the pain of a cluster headache. The blood pressure is not high enough to warrant the administration of hydralazine and the blood pressure will likely reduce with the administration of oxygen to reduce the pain making a vasodilator unnecessary.

QUESTION TWENTY-FIVE: The correct answer is D. Gillian Barre causes paralysis and can potentially cause paralysis or weakening of respiratory muscles. A major goal of treatment in patients with Gillian Barre is support of respiratory function and effect treatment may be tracked by ensuring adequate oxygen saturation. Gillian Barre does not affect blood sugars and is not associated with pain, so monitoring these parameters will not determine effective treatment. Gillian Barre affects the peripheral nervous system, not the central nervous system, so the Glasgow coma score will not be affected. Therefore, tracking the Glasgow Coma Score is not an effective way to determine effectiveness of treatment.

MAXILLOFACIAL AND OCULAR EMERGENCIES

QUESTION TWENTY-SIX: The correct answer is B. Iritis can cause intense photophobia because it involves inflammation of the iris and ciliary body which are responsible for changes in the cornea associated with changes in light. Because of consensual eye movement, when light is shone into one eye, it can cause changes in pupil size in the other eye. If the patient has iritis, this change in pupil size can cause intense pain. This is a classic finding in patients with iritis. Shining light in the unaffected eye would not cause nystagmus in an eye with iritis (nystagmus is usually related to neurological disorders). Iritis does not cause loss of pupillary function in the unaffected eye. Visualization of bright flashes of light in both eyes is usually associated with a neurological disorder, not iritis.

QUESTION TWENTY-SEVEN: The correct answer is C. Meniere’s disease is a disorder of the inner ear that results in dizziness. When a patient experiences dizziness, they should close their eyes to reduce the sensation as opposed to “scanning the environment”. To reduce the incidence of falling, it is appropriate for patients to remain in bed while they are having symptoms such as dizziness. Meniere’s disease is known to be associated with fluid imbalances and reducing salt and sugar intake is known to reduce symptoms. Diuretics are also used in the treatment of this illness to help maintain fluid balance. Meniere’s disease is a chronic illness marked by exacerbation and remission. The symptoms may resolve but tend to recur throughout life, especially with fluid imbalances.

QUESTION TWENTY-EIGHT: The correct answer is C. If a patient present with an avulsed tooth, it should be gently cleansed with saline solution to remove any dirt or debris from the root end before implantation. It is important to do this gently and avoid handling the root end or scrubbing it to prevent damage to the periodontal ligament (this could prevent replantation of the tooth.) The tooth should be submerged in a balanced salt solution rather than water which is hypotonic and the improper pH for tooth preservation. It is not appropriate to rinse the tooth socket with half-strength hydrogen peroxide and there is no need to put gauze in the area left by the avulsed tooth as the tooth will be replaced if possible as a way to maintain alignment.

QUESTION TWENTY-NINE: The correct answer is D. Bleeding in the posterior portion of the nasopharynx occurs behind the bony structures of the face. Therefore, direct pressure cannot be applied to the site of bleeding (direct pressure is used to treat the bleeding of an anterior epistaxis because this bleeding occurs in front of the bony structures of the face). There is no evidence that placing ice on the back of the neck will control bleeding from the posterior nasopharynx, therefore this should not be an initial intervention. It is difficult to get silver nitrate sticks into the posterior nasopharynx so this treatment is reserved for treatment of an anterior epistaxis. Therefore, the only treatment used to effectively reduce bleeding in a posterior epistaxis is insertion of a balloon tipped device.

RESPIRATORY EMERGENCIES

QUESTION THIRTY: The correct answer is B. Although coughing and choking may occur immediately after aspiration in the conscious patient, the signs of pneumonia tend to occur within hours of the event. The symptoms generally begin before 48 hours.

QUESTION THIRTY-ONE: The correct answer is B. Respiratory distress syndrome causes diffuse pulmonary edema. The pulmonary edema is due to an inflammatory response within the lungs rather than heart failure, therefore the cardiac silhouette will be normal (heart failure tends to cause an enlarged cardiac silhouette). With respiratory distress syndrome, the fluid gathers inside the lungs causing pulmonary edema. A pleural effusion causes fluid to gather in the pleural space rather in the lungs themselves, therefore this is not common with respiratory distress syndrome. Flattening of the diaphragm is most likely to be seen with overinflation of the lungs (e.g., emphysema) as opposed to respiratory distress syndrome.

QUESTION THIRTY-TWO: The correct answer is A. Tachypnea and hypotension, especially in the face of an open pneumothorax, are consistent with obstructive shock, specifically a tension pneumothorax. Normally, the treatment for a tension pneumothorax is either a needle thoracostomy or insertion of a chest tube, but since this patient already has an opening in the pleural space (open pneumothorax) that has been covered with an occlusive dressing, the tension in the pleural space can be relieved by temporarily lifting the occlusive dressing. (A needle thoracostomy is not required since the opening already exists with the open pneumothorax). Although this patient may benefit from intubation, this will not relieve the symptoms of a tension pneumothorax, therefore intubation is not the best “next” course of action. Applying tape to the fourth side of the dressing would actually decrease air escape from the pleural space. This will not improve a tension pneumothorax and has the potential to worsen the patient’s condition.

GASTROINTESTIONAL, GENITOURINARY, OBSTETRICAL AND GYNECOLOGICAL EMERGENCIES

QUESTION THIRTY-THREE: The correct answer is D. Many patients with pancreatitis will develop a fever and require antipyretics, therefore one of the goals of treatment is to reduce the core body temperature. A diseased pancreas does not produce insulin and therefore serum glucose tends to be elevated as a variance of pancreatitis. Therefore, a goal of treatment would be to reduce rather than increase serum glucose. Serum calcium levels are often decreased in patients with pancreatitis because the pancreas is unable to assist with the digestion of fat. This causes fat levels to climb in the serum and calcium is attracted to the fat. An elevation in serum calcium, rather than a reduction, would be a goal of treatment. The pain associated with pancreatitis frequently causes tachycardia so a goal of treatment would not be a further increase in the pulse rate.

QUESTION THIRTY-FOUR: The correct answer is D. Both red meat and dairy product are difficult to digest and may increase the pain and discomfort associated with diverticulitis. Many patients with diverticulitis will have diarrhea and the inflamed area of the bowel may not absorb fluids as readily, leaving the patient vulnerable to dehydration. Therefore, decreasing fluid intake would not be therapeutic. The patient should INCREASE fluid intake. Keeping warm packs over the site is appropriate to reduce pain due to muscular irritability but the pain of diverticulitis is due to inflammation, therefore warm packs are unlikely to help. Warm packs also cause local vasodilation and if the patient were to rupture their diverticula and require emergent surgery, vasodilation would cause increased blood loss intra-operatively. Therefore, warm packs are not appropriate. There is no therapeutic value to bed rest with diverticulitis. The patient should be encouraged to undertake “activity as tolerated.”

QUESTION THIRTY-FIVE: The correct answer is B. Factors which tend to exacerbate the pain of pelvic inflammatory disease include intercourse, movement/exercise and during menstruation (as opposed to during ovulation). It is not exacerbated by the supine position or restrictive clothing.

QUESTION THIRTY-SIX: The correct answer is D

Rationale: After birth, a fetal heart rate of at least 100 is required to properly perfuse the infant. If the fetal heart rate is less than 100 after birth, either supplemental oxygen or positive pressure ventilation should be initiated. An Apgar score of 7 or greater is considered normal after birth. The umbilical cord should continue to pulsate after birth until it is manually clamped (it will also clamp down on its own after birth but not within the first two minutes). Therefore, a pulsating cord two minutes after birth is considered normal. The placenta often doesn’t deliver until as long as 30 minutes after birth, therefore if it has not delivered within 10 minutes of birth, this is not concerning.

QUESTION THIRTY-SEVEN: The correct answer is D. Vasoconstrictors, such as phenylephrine, may be injected locally into the penis to constrict local blood vessels reducing blood flow into the penis with the goal of eliminating the priapism. There is no therapeutic advantage to administering chewable aspirin, or intravenous carbamazepine, nor is there any therapeutic reason to inject lidocaine into the urethra.

ORTHOPEDIC AND WOUND EMERGENCIES

QUESTION THIRTY-EIGHT: The correct answer is A. When applying traction via a traction splint, enough traction should be applied to ensure that the length of the affected leg is approximately the same length as the unaffected leg. Palpation of the fracture site will not yield any information useful to determining how much traction to apply via a traction splint. While a radiograph may be used to determine the severity of a fracture, it is not useful in determining the amount of traction to apply via a traction splint. A traction splint will generally reduce a patient’s pain but this parameter is not useful in determining the amount of traction to apply with a traction splint.

QUESTION THIRTY-NINE: The correct answer is A. New skin associated with wound or burn healing is vulnerable to both sun and wind for the first few months and should be protected. Keeping these areas out of the sun is ideal but if this is not possible, sunscreen of at least 15 SPF should be applied to reduce scarring and dark discoloration of the skin. Sunlight is not associated with bleeding, infection or an increased risk of dehiscence.

PROFESSIONAL ISSUES

QUESTION FORTY: The correct answer is C. Express consent allows a medically competent patient to provide or withdraw consent for care. If the patient chooses to leave without receiving the recommended care, they have simply withdrawn express consent for that care. A just culture is a model that encourages the reporting of mistakes with the focus of investigating those mistakes being on improvement of the system rather than individual blame. Patient safety, as the name implies, is the creation of a culture that focuses on proactively creating an environment that reduces negative patient outcomes. The ethical principle of beneficence means to take actions to benefit a patient. Allowing a patient to leave against medical advice embodies the ethical principle of autonomy rather than the ethical principle of beneficence.

QUESTION FORTY-ONE: The correct answer is A. The ethical principal of justice can be defined as “fair, equitable and appropriate treatment in light of what is due or owed to persons” and it is embodied in the fact that emergency medical care must be provided to all individuals. The ethical principal of veracity involves honesty and providing information freely to patients. EMTALA is more about justice then veracity. Autonomy denotes having the freedom to make choices about the issues that affect one’s life. This provision of EMTALA is a better representation of justice rather than autonomy. Principle of double effect is an ethical framework used to debate issues in which there are opposing outcomes from an intervention and is not represented by this provision of EMTALA.

QUESTION FORTY-TWO: The correct answer is B. Unless an emergency condition exists, nurses should avoid entering the room or potentially violent patients until they are supported by other staff. This prevents the onset of violence. Scanning the room for objects that could be used as missiles, removing objects that could be used for harm and taking part in annual training designed to protect an individual in the event of a violent episode are all appropriate interventions to reduce injury related to a violent episode but do not actually reduce the incidence of that episode from happening.

QUESTION FORTY-THREE: The correct answer is A. One side effect of testosterone is polycythemia causing an elevated hematocrit. Testosterone does not cause an elevated calcium level, amylase level or troponin level.

QUESTION FORTY-FOUR: The correct answer is A. Patients triaged as “red” during a disaster have injuries that require immediate medical intervention and should be given the highest priority for transport. The next most urgent category for transport is “yellow”. The transport of patient’s triaged as “green” can be delayed as their condition is unlikely to deteriorate. Patients who are triage as “black” may not be transported unless they have vital signs, but their transport is not more urgent than a patient triaged with a “red” tag.