CEN IXa ANSWERS & RATIONALES (2022)

CARDIOVASCULAR EMERGENCIES

QUESTION ONE: The correct answer is C: Distributive

Rationale: Distributive shock is marked by vasodilation and vasoconstrictive agents are nearly always included in the treatment plan of a patient in distributive shock. The treatment for obstructive shock is relief of the obstruction and vasopressors will not assist in this goal. Inotropes, as opposed to vasoconstrictors, are the mainstay of treatment for cardiogenic shock. Although there is a subset of patients in cardiogenic shock for whom vasopressors will be effective, many patients in cardiogenic shock will not benefit from the increased preload associated with vasopressor therapy. Therefore, vasopressors are more likely to be used in the treatment of distributive as opposed to cardiogenic shock (This is the BEST answer). Patients in hypovolemic shock has vasoconstriction secondary to the compensatory mechanism of sympathetic stimulation and do not require further vasoconstriction. Therefore, vasopressors are not used in the treatment of hypovolemic shock.

QUESTION TWO: The correct answer is D: an increased stroke volume.

Rationale: 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 THREE: The correct answer is C: Electrocardiogram

Rationale: 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 FOUR: The correct answer is D: Nitroglycerin

Rationale: 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 FIVE: The correct answer is A: Blood Cultures

Rationale: The bacteria that causes endocarditis is found in the blood stream and can be identified using blood cultures. Both blood cultures and an echocardiogram are the two most useful tools in diagnosing endocarditis. The electrocardiogram may help rule out other causes of endocarditis but does not assist in the diagnosis of endocarditis. Serum potassium levels are not affected by endocarditis and will not aid in the diagnosis of this condition. Endocarditis does not cause reproducible pain; therefore, palpation of the chest wall will not be useful in this diagnosis.

QUESTION SIX: The correct answer is D: Non-radiating chest pain

Rationale: 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, they tend to be a delayed finding and would most certainly occur much later than the appearance of chest pain.

RESPIRATORY EMERGENCIES

QUESTION SEVEN: The correct answer is B: 6 hours

Rationale: 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 EIGHT: The correct answer is B: Diffuse pulmonary edema

Rationale: 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 NINE: The correct answer is A: lift the occlusive dressing.

Rationale: 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.

MEDICAL EMERGENCIES

QUESTION TEN: The correct answer is B: Intravenous calcium chloride

Rationale: The rhythm noted here is known as the “sine wave” and is associated with severe hyperkalemia. An intravenous bolus of calcium chloride may stabilize the cardiac membrane, reducing the chance that this rhythm will deteriorate into ventricular fibrillation or asystole. Carotid massage is used to treat supraventricular tachycardia, which is not represented in this rhythm. Defibrillation is reserved for ventricular fibrillation, which is not represented in this rhythm. Calcium, rather than magnesium, is used to stabilize the cellular membrane in cases of hyperkalemia.

QUESTION ELEVEN: The correct answer is B: Hypothyroidism

Rationale: Myxedema coma is caused by severely low thyroid levels and occurs in patients with hypothyroidism. Type II diabetes will cause hyperosmolar hyperglycemic syndrome as opposed to myxedema coma. Addison’s disease may lead to an Addisonian crisis as opposed to myxedema coma. Von Willebrand’s disease is a genetic bleeding disorder that is not associated with myxedema coma.

QUESTION TWELVE: The correct answer is C: diaphoretic skin.

Rationale: In early hypoglycemia, the patient’s sympathetic nervous system is stimulated causing symptoms such as tachycardia (as opposed to bradycardia, hypertension (as opposed to hypotension) and diaphoretic skin. Blurred vision is a sign of neuroglycemia and is more likely to occur as a later symptom.

QUESTION THIRTEEN: The correct answer is A: “I will immediately seek medical care if I become short of breath.”

Rationale: Thrombocytosis is a condition which causes an abnormally high platelet count. Patients with this condition have an increased risk of developing blood clots which can cause disorders such as a deep vein thrombosis or a pulmonary embolism. Discharge teaching should involve teaching the patient about these complications and how to recognize them as well as to seek medical care. Encouraging a patient to avoid high risk activities that could cause bleeding would be appropriate for patients with thrombocytopenia rather than thrombocytosis. The avoidance of potassium rich foods is not required in patient’s diagnosed with thrombocytosis. Thrombocytosis is generally not chronic and does not require blood transfusions.

QUESTION FOURTEEN: The correct answer is A: Low-grade fever

Rationale: Symptoms such as redness, swelling and discharge from the site of an infection are caused by the presence of white blood cells as opposed to the bacteria causing the infection. Therefore, patients with low white blood cell counts (neutropenia) are unlikely to develop streaking, discharge or edema causing a decreased range of motion. Fevers, however, are caused by the bacteria rather than the white blood cells and would be present in a patient with neutropenia.

NEUROLOGICAL EMERGENCIES

QUESTION FIFTEEN: The correct answer is D: Inability to remember commonly used words

Rationale: 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 SIXTEEN: The correct answer is C: a posterior cord syndrome.

Rationale: 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 SEVENTEEN: The correct answer is C: Administer 100% oxygen via non-rebreather mask

Rationale: 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 EIGHTEEN: The correct answer is D: Oxygen saturation monitor

Rationale: Gillian Barré causes paralysis and can potentially cause paralysis or weakening of respiratory muscles. A major goal of treatment in patients with Gillian Barré is support of respiratory function and effect treatment may be tracked by ensuring adequate oxygen saturation. Gillian Barré does not affect blood sugars and is not associated with pain, so monitoring these parameters will not determine effective treatment. Gillian Barré 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.

MENTAL HEALTH EMERGENCIES

QUESTION NINETEEN: The correct answer is B: “I need you to stay in this room and someone will stay here with you.”

Rationale: 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 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 TWENTY: The correct answer is B: poison mushrooms.

Rationale: Poisoned mushrooms exert a cholinergic effect and are treated with anti-cholinergics (e.g., atropine). Atropine would not be effective for overdoses caused by antihistamines (a sedative- hypnotic), lysergic acid diethylamide (a sympathomimetic) or the Jimson weed plant (an anti-cholinergic)

QUESTION TWENTY-ONE: The correct answer is A: Digoxin

Rationale: 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 TWEENTY TWO: The correct answer is B: serum pH above normal.

Rationale: 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.

MAXILLOFACIAL AND OCULAR EMERGENCIES

QUESTION TWENTY-THREE: The correct answer is B: Increased pain in the left eye

Rationale: Iritis can cause intense photophobia because it involves inflammation of the iris and ciliary body. 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-FOUR: The correct answer is C: "Scanning the environment with my eyes may help reduce further symptoms."

Rationale: 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-FIVE: The correct answer is C: Handling the avulsed tooth by the crown, gently irrigate the root end with saline solution

Rationale: 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-SIX: The correct answer is D: insertion of a balloon-tipped device to apply direct pressure.

Rationale: 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.

GASTROINTESTIONAL, GENITOURINARY, OBSTETRICAL AND GYNECOLOGICAL EMERGENCIES

QUESTION TWENTY-SEVEN: The correct answer is D: Reduction in core body temperature

Rationale: 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 TWENTY-EIGHT: The correct answer is C: Hepatitis C

Rationale: Chronic hepatitis is defined as hepatitis whose symptoms last more than six months. Viruses that cause both hepatitis A and E tend to be mild and short-lived and do not cause chronic cases of hepatitis. Although both hepatitis B and hepatitis C can cause chronic hepatitis, it is far more common with hepatitis C. Most cases of hepatitis B are acute.

QUESTION TWENTY-NINE: The correct answer is B: "It really hurts when I urinate."

Rationale: A common complaint of patients with chlamydia is dysuria. Pressure in the rectum, blood in the urine and a difficulty urinating are not associated with chlamydia.

QUESTION THIRTY: The correct answer is D: an incomplete abortion.

Rationale: An incomplete abortion is defined as an abortion in which the products of conception are located in the cervical os causing it to be irritated. This causes increased pain, cramping and vaginal bleeding. The patient may require assistance to assist with completion of the abortion to reduce bleeding and cramping. In a complete abortion, all products of conception have evacuated from the uterus. A complete abortion does not cause increased bleeding and cramping. An inevitable abortion is one in which the woman is pregnant but the cervical os is opened. An inevitable abortion does not cause an increase in bleeding and cramping. A threatened abortion is one in which there is vaginal bleeding during pregnancy but the cervical os is closed. This type of abortion does not cause an increase in bleeding and cramping.

QUESTION THIRTY-ONE: The correct answer is D: A fetal heart rate of 95 beats per minute one minute after birth.

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.

ENVIRONMENTAL AND TOXICOLOGICAL EMERGENCIES AND COMMUNICABLE DISEASES

QUESTION THIRTY-TWO: The correct answer is D: Cardiac monitor

Rationale: 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 THIRTY-THREE: The correct answer is D: a core body temperature of 102°F (38.9°C).

Rationale: 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 THIRTY-FOUR: The correct answer is B: Arterial blood gases

Rationale: 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 THIRTY-FIVE: The correct answer is A: encephalitis causing fear of air currents and water.

Rationale: 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 THIRTY-SIX: The correct answer is B: reddened, painful, purulent lesion with a yellow center.

Rationale: 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 THIRTY-SEVEN: The correct answer is A: all lesions have crusted over.

Rationale: 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.

ORTHOPEDIC AND WOUND EMERGENCIES

QUESTION THIRTY-EIGHT: The correct answer is A: visualization of leg length.

Rationale: 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: scarring.

Rationale: 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 A: Opioids

Rationale: Opioids have been used to successfully manage the dyspnea associated with terminal illness (dyspnea is a common complaint in patients with terminal illness). Keeping the patient cool (e.g., placing fans around the bed or removing additional blankets) is known to reduce the sensation of dyspnea (as opposed to warming measures). Elevation of the head of the bed (as opposed to Trendelenburg’s position) is more likely to reduce the sensation of dyspnea. Although intubation and mechanical ventilation may be discussed with the patient, these are strongly discouraged to reduce the incidence of ventilator dependence near the end of life. Therefore, this intervention would not be “most likely” to be undertaken.

QUESTION FORTY-ONE: The correct answer is B: are less likely to cry during painful procedures.

Rationale: Children who are abused are more likely to be stoic during painful procedures and are less likely to cry. They are also less likely (rather than more likely) to seek solace from their caregiver. Children who experience abuse do not tend to present for care at certain times of the day and they are just as likely to have external trauma as those who experience unintentional injuries.

QUESTION FORTY-TWO: The correct answer is D: Preparedness

Rationale: Developing mutual aid agreements is part of preparing for a disaster. Mitigation involves determining what risks a community and institution are vulnerable to. Response is actually utilizing preparation done during the preparedness phase. Recovery involves returning to a pre-disaster level of functioning after a disaster as well as evaluating the effectiveness of the disaster plan and preparations.