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CCRN Neonatal study materials
CCRN Neonatal study resources

CCRN Neonatal practice questions

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Question 1Clinical Judgment: Cardiovascular

In fetal circulation, which structure shunts blood from the pulmonary artery directly into the descending aorta?

  1. Ductus arteriosus Correct answer.
  2. Foramen ovale
  3. Ductus venosus
  4. Superior vena cava

Explanation

The ductus arteriosus connects the pulmonary artery to the descending aorta, allowing most right ventricular output to bypass the lungs. The foramen ovale shunts blood between the atria, and the ductus venosus carries umbilical venous blood to the inferior vena cava.

Question 2Clinical Judgment: Cardiovascular

Which heart rate range is expected for a healthy term newborn at rest?

  1. 110 to 160 beats/min Correct answer.
  2. 170 to 220 beats/min
  3. 220 to 260 beats/min
  4. 60 to 100 beats/min

Explanation

A resting term newborn typically has a heart rate of about 110 to 160 beats/min, with variability related to sleep, activity, and respiratory effort. Rates outside this range warrant evaluation for arrhythmia, hypoxia, or other causes.

Question 3Clinical Judgment: Cardiovascular

Which medication is given to promote closure of a hemodynamically significant patent ductus arteriosus in a preterm newborn?

  1. Indomethacin Correct answer.
  2. Milrinone
  3. Prostaglandin E1
  4. Digoxin

Explanation

Indomethacin is a prostaglandin synthesis inhibitor that promotes ductal constriction and closure in preterm infants. Prostaglandin E1 has the opposite effect and is used to keep the ductus open in ductal-dependent lesions.

Question 4Clinical Judgment: Cardiovascular

Prostaglandin E1 infusion is used in a newborn with a ductal-dependent congenital heart lesion primarily to do which of the following?

  1. Increase pulmonary vascular resistance
  2. Reduce systemic vascular resistance
  3. Keep the ductus arteriosus patent Correct answer.
  4. Close the ductus arteriosus

Explanation

Prostaglandin E1 relaxes the ductus arteriosus and maintains patency, preserving pulmonary or systemic blood flow in ductal-dependent lesions. This stabilizes the infant until definitive repair or palliation can be performed.

Question 5Clinical Judgment: Cardiovascular

Which congenital heart defect is classically cyanotic because of right-to-left shunting and decreased pulmonary blood flow?

  1. Atrial septal defect
  2. Tetralogy of Fallot Correct answer.
  3. Ventricular septal defect
  4. Patent ductus arteriosus

Explanation

Tetralogy of Fallot includes right ventricular outflow tract obstruction, ventricular septal defect, overriding aorta, and right ventricular hypertrophy. The outflow obstruction causes right-to-left shunting and decreased pulmonary blood flow, producing cyanosis.

Question 6Clinical Judgment: Cardiovascular

A newborn with a moderate ventricular septal defect is most likely to have which murmur?

  1. Soft systolic ejection murmur along the left sternal border
  2. Continuous machinery murmur under the clavicle
  3. Mid-diastolic rumble at the apex
  4. Harsh holosystolic murmur at the left lower sternal border Correct answer.

Explanation

A ventricular septal defect produces a harsh holosystolic murmur at the left lower sternal border because blood shunts from the higher-pressure left ventricle to the right ventricle during systole. A continuous murmur suggests a patent ductus arteriosus.

Question 7Clinical Judgment: Cardiovascular

Which capillary refill time is considered normal in a well newborn?

  1. 6 to 8 seconds
  2. 4 to 5 seconds
  3. Less than 3 seconds Correct answer.
  4. More than 10 seconds

Explanation

Capillary refill of less than 3 seconds is generally considered normal in a well-perfused newborn. Prolonged refill suggests poor peripheral perfusion, shock, or hypothermia.

Question 8Clinical Judgment: Cardiovascular

Which fetal vessel carries oxygenated blood from the umbilical vein to the inferior vena cava?

  1. Umbilical artery
  2. Pulmonary vein
  3. Descending aorta
  4. Ductus venosus Correct answer.

Explanation

The ductus venosus connects the umbilical vein to the inferior vena cava, allowing well-oxygenated blood to reach the heart. The umbilical arteries carry deoxygenated blood away from the fetus toward the placenta.

Question 9Clinical Judgment: Cardiovascular

A 5-day-old newborn has weak femoral pulses, blood pressure 92/60 mm Hg in the right arm and 62/38 mm Hg in the leg, and poor feeding. Which defect best explains these findings?

  1. Coarctation of the aorta Correct answer.
  2. Complete transposition of the great arteries
  3. Atrial septal defect
  4. Tetralogy of Fallot

Explanation

Coarctation of the aorta narrows the aortic arch and causes upper extremity hypertension with lower extremity hypotension and weak femoral pulses. Poor feeding and shock can develop when the ductus arteriosus closes and systemic perfusion falls.

Question 10Clinical Judgment: Cardiovascular

A newborn with d-transposition of the great arteries and an intact ventricular septum becomes deeply cyanotic shortly after birth. Which intervention is most important initially?

  1. Give high-dose furosemide to reduce preload
  2. Place the infant in prone position
  3. Initiate indomethacin to close the ductus arteriosus
  4. Start prostaglandin E1 to improve mixing Correct answer.

Explanation

In d-transposition, the aorta arises from the right ventricle and the pulmonary artery from the left ventricle, creating parallel circulations. Prostaglandin E1 keeps the ductus open and improves mixing until a balloon atrial septostomy or surgical repair can be performed.

Question 11Clinical Judgment: Cardiovascular

In hypoplastic left heart syndrome, systemic perfusion depends on the ductus arteriosus. Which finding would most concern the nurse?

  1. Increasing oxygen saturation with feeding
  2. Falling femoral pulses and urine output Correct answer.
  3. A soft systolic murmur
  4. Mild cyanosis with feeding

Explanation

When the ductus arteriosus begins to close in hypoplastic left heart syndrome, systemic blood flow falls and the infant develops weak pulses, oliguria, acidosis, and shock. Progressive pulse and urine output changes require urgent prostaglandin therapy.

Question 12Clinical Judgment: Cardiovascular

A newborn with truncus arteriosus develops tachypnea, poor feeding, and hepatomegaly at 3 weeks of age. Which physiologic problem best explains these findings?

  1. Pulmonary overcirculation from a large common arterial trunk Correct answer.
  2. Decreased pulmonary blood flow from severe pulmonary stenosis
  3. Right-to-left shunting through an atrial septal defect
  4. Elevated systemic vascular resistance from aortic coarctation

Explanation

Truncus arteriosus produces complete mixing of systemic and pulmonary blood through a single arterial trunk. As pulmonary vascular resistance falls after birth, pulmonary blood flow rises and heart failure develops with tachypnea, poor feeding, and hepatomegaly.

Question 13Clinical Judgment: Cardiovascular

A 6-week-old infant with a large ventricular septal defect has tachypnea, poor weight gain, and sweating with feeds. Which explanation best fits this presentation?

  1. Obstruction to left ventricular outflow reduces systemic output
  2. Left-to-right shunt raises pulmonary blood flow and cardiac work Correct answer.
  3. Complete mixing of systemic and pulmonary venous blood causes cyanosis
  4. Right-to-left shunting causes chronic hypoxemia

Explanation

A large ventricular septal defect causes left-to-right shunting, increased pulmonary blood flow, and increased cardiac work. Heart failure typically becomes apparent at 4 to 6 weeks as pulmonary vascular resistance falls, producing tachypnea, poor feeding, and poor weight gain.

Question 14Clinical Judgment: Cardiovascular

A term newborn with meconium aspiration has severe hypoxemia, a loud second heart sound, and a preductal oxygen saturation of 95% with a postductal saturation of 80%. Which process is most likely?

  1. Left-to-right shunting through a large ventricular septal defect
  2. Complete transposition with parallel circulations
  3. Obstruction of the aortic arch with upper extremity hypertension
  4. Right-to-left shunting through the ductus arteriosus Correct answer.

Explanation

Persistent pulmonary hypertension of the newborn causes elevated pulmonary vascular resistance and right-to-left shunting at the ductus arteriosus or foramen ovale. A higher preductal than postductal oxygen saturation is a classic sign of ductal-level right-to-left shunting.

Question 15Clinical Judgment: Cardiovascular

Before giving digoxin to a newborn with heart failure, which assessment is most important?

  1. Axillary temperature
  2. Blood glucose level
  3. Apical heart rate Correct answer.
  4. Urine specific gravity

Explanation

Digoxin toxicity can cause bradycardia and arrhythmias, so the apical heart rate should be checked before each dose. If the rate is below the prescribed threshold, the dose is withheld and the provider is notified.

Question 16Clinical Judgment: Cardiovascular

Which finding is a contraindication to indomethacin therapy for closure of a patent ductus arteriosus in a preterm infant?

  1. Mild respiratory distress
  2. A systolic murmur at the left upper sternal border
  3. A small PDA on echocardiogram
  4. Necrotizing enterocolitis Correct answer.

Explanation

Indomethacin causes vasoconstriction and can worsen gastrointestinal and renal perfusion, so necrotizing enterocolitis is a contraindication. Renal dysfunction and bleeding disorders are other important contraindications.

Question 17Clinical Judgment: Cardiovascular

A newborn with Tetralogy of Fallot suddenly becomes deeply cyanotic and irritable during a feeding. Which action should the nurse take first?

  1. Give a bolus of furosemide
  2. Place the infant in a knee-to-chest position Correct answer.
  3. Lay the infant flat and suction the airway vigorously
  4. Start indomethacin

Explanation

A hypercyanotic spell is treated by increasing systemic vascular resistance and reducing right-to-left shunting. Knee-to-chest positioning, calming the infant, oxygen, morphine, and fluid boluses are used as ordered.

Question 18Clinical Judgment: Cardiovascular

Which physical finding is most characteristic of an atrial septal defect in a newborn?

  1. A weak femoral pulse
  2. A fixed split second heart sound Correct answer.
  3. A continuous machinery murmur beneath the clavicle
  4. A single second heart sound

Explanation

An atrial septal defect causes a fixed split second heart sound because left-to-right atrial shunting increases right ventricular volume and delays pulmonic valve closure. The split does not vary with respiration.

Question 19Clinical Judgment: Cardiovascular

A newborn has a systolic ejection murmur at the upper right sternal border, weak brachial and femoral pulses, and poor perfusion. Which lesion is most likely?

  1. Patent ductus arteriosus
  2. Aortic stenosis Correct answer.
  3. Atrial septal defect
  4. Pulmonary stenosis

Explanation

Aortic stenosis obstructs left ventricular outflow, causing weak pulses, poor perfusion, and a systolic ejection murmur at the base that may radiate to the carotids. Severe obstruction can present with shock as the ductus closes.

Question 20Clinical Judgment: Cardiovascular

Which set of findings best describes compensated shock in a newborn?

  1. Hypotension with widened pulse pressure and bounding pulses
  2. Normal heart rate with warm extremities and brisk cap refill
  3. Tachycardia with cool extremities and normal blood pressure Correct answer.
  4. Hypotension with bradycardia and absent pulses

Explanation

In compensated shock, tachycardia and peripheral vasoconstriction maintain blood pressure near normal while perfusion to the extremities decreases. Cool extremities and delayed capillary refill are early signs before hypotension develops.

Question 21Clinical Judgment: Cardiovascular

A newborn with pulmonary atresia is started on prostaglandin E1. Which adverse effect requires the most immediate nursing intervention?

  1. Transient fever
  2. Mild flushing
  3. Apnea Correct answer.
  4. Diarrhea

Explanation

Prostaglandin E1 can cause central apnea, so respiratory status must be monitored closely and intubation equipment kept ready. Other common effects include fever, flushing, and irritability.

Question 22Clinical Judgment: Cardiovascular

A newborn with d-transposition of the great arteries remains severely hypoxemic despite prostaglandin E1. Which procedure is most likely needed to improve mixing?

  1. Placement of a Blalock-Taussig shunt
  2. Ligation of the patent ductus arteriosus
  3. Repair of a ventricular septal defect
  4. Balloon atrial septostomy Correct answer.

Explanation

When prostaglandin E1 does not provide adequate mixing in transposition with an intact ventricular septum, a balloon atrial septostomy enlarges the atrial communication. This improves oxygenated and deoxygenated blood mixing until surgical repair.

Question 23Clinical Judgment: Cardiovascular

A newborn has cyanosis, a widely split second heart sound, and a large right atrium on echocardiography. Which defect is most consistent with these findings?

  1. Total anomalous pulmonary venous return
  2. Pulmonary atresia with intact ventricular septum
  3. Ebstein anomaly Correct answer.
  4. Tricuspid atresia

Explanation

Ebstein anomaly involves downward displacement of the tricuspid valve into the right ventricle, causing tricuspid regurgitation and massive right atrial enlargement. Cyanosis occurs when right-to-left shunting happens at the atrial level.

Question 24Clinical Judgment: Cardiovascular

In a preterm infant with a hemodynamically significant PDA, which finding best indicates that treatment is needed?

  1. Mild tachypnea that resolves with feeding
  2. Worsening respiratory status with bounding pulses and oliguria Correct answer.
  3. A systolic murmur without ventilator changes
  4. A small murmur with normal pulses

Explanation

A hemodynamically significant PDA causes pulmonary overcirculation, worsening respiratory support needs, bounding pulses, and reduced systemic perfusion with oliguria. These findings indicate that medical or surgical closure should be considered.

Question 25Clinical Judgment: Cardiovascular

A newborn with coarctation of the aorta develops metabolic acidosis, weak femoral pulses, and hypotension at 10 days of life. Which initial therapy is most appropriate?

  1. Indomethacin administration
  2. Prostaglandin E1 infusion Correct answer.
  3. High-dose epinephrine alone
  4. Immediate surgical repair without stabilization

Explanation

Coarctation can be ductal-dependent for systemic perfusion in the newborn period. Prostaglandin E1 reopens or maintains the ductus arteriosus, improves lower body perfusion, and stabilizes the infant before definitive repair.

Question 26Clinical Judgment: Cardiovascular

A 4-day-old preterm infant has a continuous murmur heard best at the left infraclavicular area, bounding pulses, and a widened pulse pressure. Which diagnosis is most likely?

  1. Patent ductus arteriosus Correct answer.
  2. Ventricular septal defect
  3. Aortic stenosis
  4. Tetralogy of Fallot

Explanation

A continuous "machinery" murmur at the left infraclavicular area, bounding pulses, and a wide pulse pressure are classic for a patent ductus arteriosus, because blood flows from the higher-pressure aorta into the lower-pressure pulmonary artery throughout systole and diastole.

Question 27Clinical Judgment: Cardiovascular

A term newborn is being screened for critical congenital heart disease with pulse oximetry. When should this screening be performed?

  1. Immediately after birth, before the first feeding
  2. At 2 weeks of age at the first well-child visit
  3. Only if a murmur is heard on examination
  4. At 24 to 48 hours of age or before discharge Correct answer.

Explanation

Universal pulse oximetry screening is performed at 24 to 48 hours of age or before discharge, because many ductal-dependent lesions do not cause hypoxemia until the fetal-to-neonatal transition is complete.

Question 28Clinical Judgment: Cardiovascular

A newborn whose mother took lithium throughout pregnancy has cyanosis and a holosystolic murmur at the lower left sternal border. Which congenital heart defect should be suspected?

  1. d-Transposition of the great arteries
  2. Pulmonary atresia with intact ventricular septum
  3. Coarctation of the aorta
  4. Ebstein anomaly Correct answer.

Explanation

Maternal lithium exposure is associated with Ebstein anomaly, in which the septal tricuspid leaflet is displaced downward, causing tricuspid regurgitation, right atrial enlargement, and often cyanosis from right-to-left shunting through a patent foramen ovale.

Question 29Clinical Judgment: Cardiovascular

A 10-day-old infant is feeding poorly and has a heart rate of 280 beats per minute on the monitor. The rhythm is narrow-complex and regular, and no P waves are clearly visible. Which rhythm is most likely?

  1. Atrial flutter
  2. Sinus tachycardia
  3. Ventricular tachycardia
  4. Supraventricular tachycardia Correct answer.

Explanation

Supraventricular tachycardia in neonates is a narrow-complex, regular tachycardia at 220 to 300 beats per minute, often with hidden P waves and abrupt onset.

Question 30Clinical Judgment: Cardiovascular

An infant of a diabetic mother has a systolic murmur, tachypnea, and echocardiographic evidence of asymmetric septal hypertrophy with systolic anterior motion of the mitral valve. Which management approach is most appropriate?

  1. Start digoxin to improve cardiac output
  2. Support with careful fluid management and consider a beta-blocker if symptoms persist Correct answer.
  3. Restrict oral feeds and start total parenteral nutrition
  4. Begin a beta-adrenergic agonist infusion to increase contractility and cardiac output

Explanation

Hypertrophic cardiomyopathy in an infant of a diabetic mother causes dynamic left ventricular outflow obstruction; inotropes and digoxin increase contractility and worsen the gradient, so management emphasizes careful fluid balance and beta-blockade when symptoms persist.

Question 31Clinical Judgment: Cardiovascular

A 2-day-old newborn has severe cyanosis, tachypnea, and fine crackles, and the oxygen saturation does not improve with supplemental oxygen. The chest radiograph shows a normal-sized heart with pulmonary edema. Which diagnosis best fits this presentation?

  1. Tetralogy of Fallot with severe right ventricular outflow tract obstruction
  2. Total anomalous pulmonary venous return with obstruction Correct answer.
  3. Large ventricular septal defect
  4. Atrial septal defect

Explanation

Obstructed total anomalous pulmonary venous return causes severe cyanosis, pulmonary venous congestion, and a normal-sized heart because pulmonary venous blood cannot reach the left atrium; supplemental oxygen does not correct the fixed obstruction.

Question 32Clinical Judgment: Cardiovascular

A newborn has a persistent heart rate of 55 beats per minute, a normal QRS, and no response to atropine. The mother has a history of systemic lupus erythematosus. Which intervention is most likely required?

  1. Radiofrequency ablation of the atrioventricular node
  2. Observation only, because the rate will normalize by 1 year
  3. Prostaglandin E1 infusion
  4. Permanent pacemaker placement Correct answer.

Explanation

Congenital complete heart block from maternal anti-Ro/SSA antibodies produces a fixed slow ventricular rate; when the rate is below 55 to 60 beats per minute or symptoms are present, permanent pacing is indicated.

Question 33Clinical Judgment: Cardiovascular

A newborn with cyanosis is found to have absent right ventricular inflow on echocardiography and a small right ventricle. Which initial therapy is most appropriate?

  1. Immediate surgical repair with a two-ventricle circulation
  2. Indomethacin administration
  3. Prostaglandin E1 infusion Correct answer.
  4. Furosemide and fluid restriction

Explanation

Tricuspid atresia with a small right ventricle is ductal-dependent for pulmonary blood flow, so prostaglandin E1 is started to keep the ductus arteriosus open until a systemic-to-pulmonary shunt or staged palliation can be performed.

Question 34Clinical Judgment: Cardiovascular

A 3-week-old has a loud, harsh holosystolic murmur at the lower left sternal border and no signs of heart failure. Echocardiography shows a 2-mm muscular ventricular septal defect. Which counseling is most accurate?

  1. Surgical closure should be scheduled within the next week
  2. The infant should be started on digoxin and furosemide
  3. Pulmonary artery banding will be needed
  4. Likely spontaneous closure with cardiology follow-up Correct answer.

Explanation

Small muscular ventricular septal defects frequently close spontaneously during the first year of life; without heart failure or pulmonary hypertension, observation with cardiology follow-up is appropriate.

Question 35Clinical Judgment: Cardiovascular

A 2-month-old has noisy breathing that worsens with feeding and improves with neck extension. Chest radiograph shows a right-sided aortic arch. Which cardiovascular diagnosis best explains these findings?

  1. Pulmonary valve stenosis
  2. Patent ductus arteriosus
  3. Tetralogy of Fallot
  4. Vascular ring Correct answer.

Explanation

A vascular ring encircles the trachea and esophagus, causing stridor that worsens with feeding and improves with neck extension; a right aortic arch is a common associated finding.

Question 36Clinical Judgment: Cardiovascular

A newborn with Down syndrome has a holosystolic murmur, mild cyanosis, and hepatomegaly. Echocardiography is most likely to show which defect?

  1. d-Transposition of the great arteries with intact ventricular septum
  2. Ebstein anomaly
  3. Bicuspid aortic valve
  4. Complete atrioventricular septal defect Correct answer.

Explanation

Down syndrome is strongly associated with complete atrioventricular septal defects, which produce a holosystolic murmur from a common atrioventricular valve and can cause heart failure and mild cyanosis.

Question 37Clinical Judgment: Cardiovascular

A newborn with heart failure is receiving furosemide. Which laboratory monitoring is most important?

  1. Serum potassium, sodium, and calcium Correct answer.
  2. Thyroid function and cortisol levels
  3. Liver enzymes and thyroid function
  4. Serum amylase, lipase, and liver enzymes

Explanation

Loop diuretics cause urinary losses of potassium, sodium, calcium, and magnesium, so electrolytes should be monitored to prevent arrhythmias and guide replacement.

Question 38Clinical Judgment: Cardiovascular

A 3-month-old infant has poor feeding, irritability during feeds, and failure to thrive. Examination shows a soft murmur of mitral regurgitation and an ECG with deep Q waves in leads I and aVL. Which diagnosis should be suspected?

  1. Atrioventricular septal defect
  2. Large ventricular septal defect with pulmonary overcirculation
  3. Coarctation of the aorta
  4. Anomalous left coronary artery from the pulmonary artery Correct answer.

Explanation

ALCAPA presents at 2 to 4 months as collateral flow develops; coronary steal causes myocardial ischemia, with irritability during feeds, failure to thrive, mitral regurgitation, and anterolateral Q waves on ECG.

Question 39Clinical Judgment: Cardiovascular

A newborn with a family history of sudden death in a young sibling has a QTc of 0.49 seconds on ECG. Which management is most appropriate?

  1. Fluid restriction and furosemide
  2. Beta-blocker therapy and cardiology referral Correct answer.
  3. Reassurance and routine follow-up at 1 year of age
  4. Prostaglandin E1 infusion

Explanation

A QTc greater than 0.46 to 0.47 seconds, especially with a family history of sudden death, supports long QT syndrome; beta-blockers reduce the risk of torsades de pointes and cardiology follow-up is required.

Question 40Clinical Judgment: Cardiovascular

A preterm infant with an umbilical arterial catheter placed at birth develops blood pressure of 95/65 mm Hg at 5 days of age, with gross hematuria. Which complication is most likely?

  1. Renal artery thrombosis Correct answer.
  2. Congenital adrenal hyperplasia
  3. Coarctation of the aorta
  4. Patent ductus arteriosus

Explanation

Umbilical arterial catheters can cause renal artery thrombosis or embolism, producing hypertension and hematuria; the timing and catheter history point to an acquired renovascular cause.

Question 41Clinical Judgment: Pulmonary

A 28-week gestation infant develops grunting, retractions, and hypoxemia within hours of birth. Which physiologic problem is the primary cause of these findings?

  1. Meconium obstructing the distal airways
  2. Delayed closure of the ductus arteriosus
  3. Surfactant deficiency causing alveolar collapse Correct answer.
  4. Excess fetal lung fluid retained in the alveoli

Explanation

Respiratory distress syndrome results from immaturity of type II pneumocytes, so surface tension stays high, alveoli collapse, and functional residual capacity falls. The resulting atelectasis and ventilation-perfusion mismatch produce grunting, retractions, and hypoxemia that worsen over the first 2 to 3 days.

Question 42Clinical Judgment: Pulmonary

Which infant is at greatest risk for transient tachypnea of the newborn?

  1. A term infant born after 24 hours of ruptured membranes
  2. A post-term infant with meconium-stained fluid
  3. A 32-week infant born vaginally after labor
  4. A term infant delivered by elective cesarean Correct answer.

Explanation

Transient tachypnea of the newborn reflects delayed clearance of fetal lung fluid. Elective cesarean delivery without labor removes both the thoracic squeeze of vaginal birth and the catecholamine surge that drives fluid reabsorption, so term infants delivered this way are at highest risk.

Question 43Clinical Judgment: Pulmonary

Which statement best explains why grunting reduces hypoxemia in a neonate with respiratory distress?

  1. It clears secretions from the upper airway.
  2. It slows the respiratory rate, reducing oxygen demand.
  3. It maintains alveolar patency through end-expiratory pressure. Correct answer.
  4. It increases tidal volume by strengthening diaphragmatic contraction.

Explanation

Grunting is produced by exhaling against a partially closed glottis, which creates end-expiratory pressure. This pressure splints open unstable alveoli, raises functional residual capacity, and improves oxygenation, which is why grunting is a compensatory sign rather than an isolated finding.

Question 44Clinical Judgment: Pulmonary

What is the recommended initial oral endotracheal tube insertion depth for a 1.5 kg infant?

  1. 8.5 cm Correct answer.
  2. 6.5 cm
  3. 7.5 cm
  4. 7.0 cm

Explanation

Initial oral tube depth in centimeters is estimated as 7 plus the infant's weight in kilograms, so a 1.5 kg infant is set at 8.5 cm. Depth is then confirmed with a chest radiograph, aiming for the tube tip between the clavicles and the carina.

Question 45Clinical Judgment: Pulmonary

Which SpO2 range is generally targeted for a preterm infant born at 27 weeks who requires supplemental oxygen?

  1. 90% to 95% Correct answer.
  2. 85% to 89%
  3. 80% to 85%
  4. 96% to 100%

Explanation

Preterm infants are typically managed with a target saturation of 90% to 95% to balance adequate oxygen delivery against the risks of hyperoxia, including retinopathy of prematurity and bronchopulmonary dysplasia. Alarm limits are set to keep the infant within this narrow window.

Question 46Clinical Judgment: Pulmonary

Apnea of prematurity is defined as a respiratory pause of which duration or pattern?

  1. 30 seconds or longer regardless of heart rate or saturation
  2. 20 seconds, or shorter with bradycardia or desaturation Correct answer.
  3. Any pause accompanied by desaturation
  4. 10 seconds or longer with cyanosis

Explanation

Apnea of prematurity is defined as a respiratory pause of 20 seconds or longer, or a shorter pause accompanied by bradycardia or desaturation. The definition matters because brief pauses with physiologic consequences still require monitoring and often treatment with caffeine.

Question 47Clinical Judgment: Pulmonary

A preterm infant on positive pressure ventilation suddenly desaturates with diminished breath sounds on the right and a rightward shift of the point of maximal impulse. Which bedside maneuver best supports the suspicion of a pneumothorax?

  1. Obtain a capillary blood gas sample
  2. Transilluminate the chest with a cold light Correct answer.
  3. Auscultate all lung fields for equality of breath sounds
  4. Perform a heel stick glucose measurement

Explanation

Transillumination with a cold fiberoptic light reveals increased light transmission on the affected side when air accumulates in the pleural space, supporting a rapid bedside diagnosis. It is used to expedite decompression while a chest radiograph is arranged.

Question 48Clinical Judgment: Pulmonary

Which practice reduces the risk of hypoxemia and mucosal injury during endotracheal suctioning of a neonate?

  1. Suction while inserting and while withdrawing the catheter
  2. Suction continuously for 15 seconds per pass
  3. Instill 1 mL of normal saline before every suction pass
  4. Limit each suction pass to 5 seconds or less Correct answer.

Explanation

Suction passes should be brief, generally 5 seconds or less, because prolonged suction removes alveolar gas and promotes atelectasis and hypoxemia. Suction is applied only during withdrawal, and oxygen is restored between passes.

Question 49Clinical Judgment: Pulmonary

A term infant with severe hypoxemia has a simultaneous preductal SpO2 of 99% and a postductal SpO2 of 88% while receiving 100% oxygen. These findings are most consistent with which condition?

  1. Ventricular septal defect with left-to-right shunt
  2. Persistent pulmonary hypertension with right-to-left shunt Correct answer.
  3. Transient tachypnea of the newborn
  4. Respiratory distress syndrome

Explanation

A preductal to postductal saturation difference of more than 5% to 10% indicates right-to-left shunting across the ductus arteriosus, as occurs in persistent pulmonary hypertension of the newborn. The preductal vessel receives better-oxygenated blood from the left ventricle, while postductal blood is diluted by desaturated right ventricular output.

Question 50Clinical Judgment: Pulmonary

Inhaled nitric oxide improves oxygenation in persistent pulmonary hypertension of the newborn primarily by which mechanism?

  1. Reducing alveolar surface tension
  2. Increasing systemic vascular resistance
  3. Dilating pulmonary vessels in ventilated alveoli Correct answer.
  4. Increasing cardiac output through beta-adrenergic stimulation

Explanation

Nitric oxide diffuses into pulmonary vascular smooth muscle and increases cyclic GMP, producing vasodilation. Because it reaches only ventilated alveoli, it improves ventilation-perfusion matching and reduces right-to-left shunting without lowering systemic blood pressure.