BCEN CPEN Exam Questions

Correct answer: A systolic pressure that is more than 10 mmHg higher in the right upper extremity compared with the lower extremity

Coarctation of the aorta is the narrowing of the aorta, causing elevation of pressure proximally and decreased pressure distally.

Infants with this defect are at risk for decreased cardiac output and should have their blood pressure evaluated frequently, as well as frequent monitoring of capillary refill and peripheral pulses. A blood pressure reading should be taken in both arms and both legs. A systolic pressure that is more than 10 mmHg higher in the right upper extremity compared with the lower body is an expected finding of coarctation of the aorta, aortic arch hypoplasia, or an interrupted aortic arch.

Correct answer: Autoimmune hemolytic anemia (AIHA)

The Coombs test, or DAT, is used to detect antibodies that act against the surface of the patient's RBCs, indicating a condition known as AIHA. In this condition, the RBCs are prematurely destroyed, so the body's RBC store is constantly being depleted, resulting in anemia. Clumping of RBCs occurs if the RBCs are coated with antibodies or complement. The greater the number of antibodies against the RBCs is, the more clumping will occur. Any clumping is read as a positive result using a scale of 1 to 4+. Coombs test differentiates types of hemolytic anemia and detects immune antibodies.

Indirect Coombs testing is a type of antibody screening that detects specific serum antibodies (IgG) to RBC antigens that are in the serum but not attached to the RBCs. It is used to detect IgG-positive antibodies in maternal blood and newborns and is performed before RBC transfusions to detect incompatibilities other than major ABO groups.

Erythrocyte sedimentation rate (ESR) is a nonspecific indicator of an acute inflammatory response and is often used in conjunction with other laboratory values to assess inflammation.

Histocompatibility testing identifies HLA antigens.

Correct answer: Grade II

Grade I hemorrhage usually has a good outcome, whereas the prognosis of grade IV hemorrhage is frequently poor. Grade I hemorrhage is confined to the germinal matrix. This is the last fetal germinal matrix to mature and is prone to hemorrhage in preterm babies.

Grade II intracranial hemorrhage involves intraventricular blood. Grade III hemorrhage is associated with ventricular dilation as the intraventricular clot enlarges the lateral ventricles. Grade IV hemorrhage is defined by parenchymal extension.

Correct answer: Intravenous access

When the decision is made to end or not begin aggressive medical intervention, a child receives end-of-life care, which is also referred to as palliative or comfort care. During this time, all invasive procedures (e.g., measurement of vital signs, monitors, machines, and artificial feedings) are discontinued. 

Intravenous access may remain in place for the administration of pain medications or sedatives. Medications are given in doses sufficient to provide comfort, relieve pain, and ensure the child does not suffer at the end of life.

Correct answer: Oxygen toxicity

Children with PARDS often require higher levels of oxygen; those receiving greater than 50% FiO₂ for prolonged periods may develop parenchymal changes from oxygen exposure, resulting in oxygen toxicity.

Oxygen should be treated as a medication with strict adherence to prescription guidelines. Cautious monitoring of O₂ is strongly recommended. The lowest acceptable SpO₂ measurement for the child should be clearly established while FiO₂ is maintained at the lowest possible level.

Correct answer: Pulmonary stenosis

Pulmonary stenosis (PS) results from an embryologic error in the formation of the pulmonary leaflets. This condition involves a narrowing of the pulmonary valve that causes an obstruction to blood flow from the right ventricle to the pulmonary artery, leading to right ventricular hypertrophy (RVH), congestive heart failure (CHF), and hypoxemia (manifested by cyanosis at birth) if left unrepaired.

With mitral stenosis, the component of the mitral valve is abnormal and, if left untreated, could cause pulmonary artery (PA) hypertension, elevated pulmonary vascular resistance (PVR), and right ventricular (RV) dysfunction from PVOD (pulmonary veno-occlusive disease). Due to a decreased left ventricular (LV) volume load, ischemia, fibrosis, and decreased CO ensue.

Subaortic stenosis consists of a membranous diaphragm or fibrous ring encircling the LV outflow tract underneath the base of the aortic valve; complications include increasing exercise intolerance, dyspnea, fatigue, chest pain, and aortic insufficiency.

Aortic stenosis is the malformation of the aortic valve, obstructing the ejection of blood from the left ventricle (LV). If severe, symptoms of circulatory shock are present at birth from obstruction to systemic blood flow.

Correct answer: Arteriovenous malformation (AVM)

Stroke is a neurologic injury that is relatively rare in children and results from one of two main causes; occlusion of blood vessels (acute ischemic stroke) or rupture of blood vessels (hemorrhagic stroke). The etiologies of hemorrhagic stroke are primarily from vascular malformations (aneurysms or AVMs), but underlying disease or trauma may also cause an acute intracranial hemorrhage (ICH).

An AVM is the most common cause of hemorrhagic stroke beyond infancy. It is an abnormal connection between arteries and veins; it can occur anywhere in the brain and varies in size from very small to very large.

Aneurysms may be associated with SBE and unrepaired coarctation of the aorta. Hypertension is another risk factor for ICH.

Correct answer: Cheyne-Stokes respirations

Cushing's triad includes three primary signs that often indicate an increase in intracranial pressure (ICP). These signs are:

• increased systolic blood pressure (widening pulse pressure)
• decreased pulse (bradycardia)
• irregular respirations

Cheyne-Stokes respirations are characterized by a shallow breathing pattern, building to deep and then back to shallow respirations; they are a common indicator of an increased ICP.

When a pediatric patient presents with vital signs that are seemingly the opposite of those of shock (e.g., decreased blood pressure, increased pulse, and increased respirations), they are most likely experiencing an increase in ICP.

Correct answer: 12 to 24 hours after birth

The ductus arteriosus is a structure that should be present in utero, as it permits blood flow to be diverted away from the high-resistance pulmonary circulation to the descending aorta and the low-resistance placental circulation. Patent ductus arteriosus (PDA) occurs when the vessel that normally connects the aorta and pulmonary artery in utero has failed to close at birth, which leads to a left-to-right shunting of blood. Blood flow to the lungs will be increased as a result of this abnormal shunting, which can cause pulmonary hypertension and eventually lead to left-sided heart failure (particularly if the PDA is large).

Closure normally occurs 12-24 hours after birth, which is initiated by a rise in the perivascular PO₂ and a decrease in endogenous prostaglandin (producing functional closure).

Anatomic closure occurs between 2 and 3 weeks and is produced by fibrosis of the ductal tissue with permanent sealing of the lumen to produce the ligamentum arteriosum. Following anatomic closure, the ductus cannot be reopened.

Correct answer: A platelet transfusion

ITP occurs in about one in 10,000 children annually, making it the most common autoimmune disorder affecting a blood element. There are two forms of ITP: acute and chronic.

• Acute ITP is usually self-limiting and involves children younger than ten years of age. It often follows a vaccination or a viral infection.
• Chronic ITP is persistent thrombocytopenia for greater than six months. Chronic ITP is associated with age older than ten years, female gender, and insidious onset.

A unilateral headache is a sign of intracranial hemorrhage, making platelet transfusion the priority with a goal of elevating the platelet count above 10,000/mm³. A head CT and a neurosurgery consult will likely be part of the treatment, but the priority is to elevate platelet count via a platelet transfusion. Aspirin is contraindicated in the presence of suspected hemorrhage.

Correct answer: Headache

Nausea, vomiting, and headache can occur in select ocular emergency conditions but are not considered the classic symptoms of an ophthalmological emergency. 

The other choices are the major signs/symptoms of an ophthalmological emergency. In more limiting eye problems, such as viral or bacterial conjunctivitis, there are no visual changes (once eye discharge is wiped away), and the affected eye can be irritated but not painful. The eye can also have a slightly red "pink eye" appearance. 

Correct answer: Sexually transmitted infections (STIs)

STIs are a strong indicator that a child is being sexually abused. The child with suspected sexual abuse may be brought in for treatment by a caregiver. The caregiver may state that abuse is known or that the child has a vaginal or penile discharge or dysuria. Herpatic lesions to the mouth may be another complaint for treatment. Sexual abuse should be suspected in the presence of sexually transmitted diseases, vaginal or penile discharges, or rectal or vaginal pain.

Testicular torsion, failure to thrive, and anorexia may all be signs that sexual abuse is occurring. However, none of these signs are as strong an indicator of sexual abuse as the presence of an STI.

Correct answer: Hypocalcemia and hyperphosphatemia

The parathyroid glands keep serum calcium levels within a normal range in the body, and parathyroid hormone (PTH) is the most important regulator of calcium. With hypoparathyroidism, there is either an absence of PTH or under-activity of one or more (four total) of the parathyroid glands. The result is decreased levels of plasma calcium in the circulating blood (hypocalcemia) and increased levels of phosphate (hyperphosphatemia), as PTH indirectly affects serum phosphate levels (by affecting calcium).

Hypoparathyroidism can occur as a result of surgery near the parathyroid glands, hypomagnesemia, genetic syndromes (such as DiGeorge), or autoimmune/idiopathic conditions.

Correct answer: Targeted sedation

Treating pediatric patients with ARDS involves supportive measures to maintain adequate oxygenation and pulmonary perfusion, treatment of the infection source or the precipitating cause, and maintaining adequate cardiac output. Patients should receive minimal yet targeted sedation to facilitate their tolerance to mechanical ventilation and to optimize oxygen delivery, VO₂, and work of breathing.

Nursing care should include maintaining a clear airway and close monitoring of respiratory frequency, heart rate/rhythm, pulse oximetry, and noninvasive blood pressure. Hemodynamic monitoring is recommended to guide volume expansion. The patient's response to ventilator assistance must be closely monitored. Chest imaging is indicated for initial diagnosis and to detect complications.

Corticosteroids, chest physiotherapy, and iNO therapy are not recommended for routine use in pediatric ARDS.

Correct answer: Type III

Type III hypersensitivity reactions, otherwise known as immune-complex reactions, result in local edema, neutrophil attraction, and degradative lysosomal enzymes that cause tissue injury. They are triggered by the formation of antigen-antibody complexes that activate the complement cascade and are deposited in blood vessels or healthy tissue. Examples include serum sickness and glomerulonephritis, among others.

Correct answer: Metabolic acidosis

In an effort to achieve an acid-base balance, the lungs regulate carbon dioxide, and the kidneys regulate bicarbonate. With normal digestion, metabolic acids are produced. But, intestinal secretions high in bicarbonate are lost through diarrhea and vomiting; this decrease in the patient's bicarbonate level creates the actual base deficit of metabolic acidosis.

The other options are unlikely to occur in a patient with vomiting and diarrhea.

Correct answer: Cardiomegaly and widening pulse pressure

In utero, the ductus arteriosus permits blood flow to be diverted from the high-resistance pulmonary circulation to the descending aorta and the low-resistance placental circulation. Closure of this structure normally occurs from contraction of the medial smooth muscle in the wall of the ductus arteriosus during the first 12 to 24 hours after birth, which is initiated by a rise in the perivascular PO₂ and a decrease in endogenous prostaglandin.

In PDA, where the ductus fails to close normally, blood shunts from left to right into the pulmonary artery (PA) and lungs. This occurs as the PVR drops and the pressure in the aorta exceeds that of the PA. Pulmonary blood flow increases, boosting venous return to the left ventricle. Left artery and left ventricle volume overload and congestive heart failure ensue. This causes cardiomegaly. The increased flow and pressure on the pulmonary circulation changes the pulmonary vasculature, resulting in hypertension and increased pulmonary vasculature resistance.

Examination of the infant reveals a machine-like continuous murmur that is auscultated at the left upper sternal border. Poor feeding, irritability, tachycardia, tachypnea, and slow weight gain are often present. The pulse pressure is wide, and peripheral pulses are bounding.

Correct answer: Hypocapnia

The oxyhemoglobin dissociation curve is a graph (S-shaped curve) representing hemoglobin's affinity for oxygen. The partial pressure of oxygen (PaO₂) is on the x-axis, and oxygen saturation (% hemoglobin saturation) is on the y-axis.

A left shift represents hemoglobin with more affinity for oxygen; factors shifting the curve to the left include alkalosis, hypocapnia (decreased PaCO₂), and hypothermia.

A shift to the right reflects hemoglobin with less affinity for oxygen; factors shifting the curve to the right include acidosis, fever (hyperthermia), and hypercapnia (increased PaCO₂).

Correct answer: 12 hours post-injury

The majority of blunt abdominal injuries in children are stable and successfully managed without surgical intervention. Nonoperative management (NOM) is considered to be the standard of care, with a 90% to 95% success rate. Only about 5% of NOM treatments fail and generally will occur within the first 12 hours post-injury; the critical period for bleeding is the first 12 hours after injury. A delayed hemorrhage is a rare event. Other reasons for surgical intervention include peritonitis, shock, pancreatic injury, hollow viscus injury, or ruptured diaphragm.

If surgical exploration is warranted, laparotomy is the most common procedure performed.

Correct answer: 6 hours

Iron in the form of adult-strength supplements and prenatal vitamins with iron causes dangerous overdose in children younger than six years old. Iron supplements are occasionally used in suicide attempts by others, especially pregnant adolescents. When toxicity occurs, iron causes significant corrosive injury to the GI tract, injures blood vessels, damages hepatocytes, and produces metabolic acidosis.

Severe iron poisoning is typically described in five sequential phases, although individual patients may not always exhibit each phase. Phase I usually occurs within the first 6 hours after ingestion and includes GI tract symptoms (often severe) consisting of hemorrhagic gastritis, vomiting, hematemesis, diarrhea, lethargy, and pallor. A patient first experiences GI symptoms, which are then followed by systemic toxicity.

• Phase I: within the first 6 hours after ingestion
• Phase II: about 6 to 12 hours after ingestion
• Phase III: about 12 to 24 hours after ingestion
• Phase IV: 2 to 3 days post-ingestion
• Phase V: 2 to 6 weeks post-ingestion