Diagnostic approach to neonatal sepsis US Medical PG Practice Questions and MCQs
Practice US Medical PG questions for Diagnostic approach to neonatal sepsis. These multiple choice questions (MCQs) cover important concepts and help you prepare for your exams.
Diagnostic approach to neonatal sepsis US Medical PG Question 1: A neonate born at 33 weeks is transferred to the NICU after a complicated pregnancy and C-section. A week after being admitted, he developed a fever and became lethargic and minimally responsive to stimuli. A lumbar puncture is performed that reveals the following:
Appearance Cloudy
Protein 64 mg/dL
Glucose 22 mg/dL
Pressure 330 mm H20
Cells 295 cells/mm³ (> 90% PMN)
A specimen is sent to microbiology and reveals gram-negative rods. Which of the following is the next appropriate step in management?
- A. MRI scan of the head
- B. Start the patient on IV ceftriaxone
- C. Provide supportive measures only
- D. Start the patient on IV cefotaxime (Correct Answer)
- E. Start the patient on oral rifampin
Diagnostic approach to neonatal sepsis Explanation: ***Start the patient on IV cefotaxime***
- The cerebrospinal fluid (CSF) analysis with **cloudy appearance, elevated protein, low glucose, high pressure, and predominant PMNs**, coupled with **gram-negative rods** on microscopy, is highly suggestive of **bacterial meningitis** in a neonate.
- **Cefotaxime** is a third-generation cephalosporin commonly used for neonatal meningitis caused by gram-negative organisms due to its excellent CSF penetration and broad-spectrum activity, particularly against common neonatal pathogens like *E. coli* which can present as gram-negative rods.
*MRI scan of the head*
- An MRI would be considered **after initiating appropriate antibiotic treatment** to assess for complications like abscess formation or ventriculitis, not as the immediate next step in an acute, life-threatening infection.
- Delaying antibiotic treatment for imaging in acute bacterial meningitis can lead to increased morbidity and mortality.
*Start the patient on IV ceftriaxone*
- While ceftriaxone is a third-generation cephalosporin, it is **generally avoided in neonates** due to the risk of **biliary sludging** and **kernicterus**.
- Ceftriaxone competes with bilirubin for albumin binding sites, which is particularly risky in neonates who are already prone to hyperbilirubinemia.
*Provide supportive measures only*
- Given the strong evidence of **bacterial meningitis**, providing only supportive measures without specific antibiotic treatment would be inadequate and would lead to rapid deterioration and potentially fatal outcomes.
- Bacterial meningitis requires prompt and aggressive antimicrobial therapy.
*Start the patient on oral rifampin*
- **Rifampin is never used as monotherapy for bacterial meningitis** due to rapid resistance development and its primary role is in specific infections like tuberculosis or as part of combination therapy for certain resistant bacteria.
- Oral administration is also not ideal for acutely ill neonates with meningitis needing rapid, high-concentration antibiotics in the CSF.
Diagnostic approach to neonatal sepsis US Medical PG Question 2: A 6-day-old newborn is brought to the emergency department by his mother due to a high fever that started last night. His mother says that he was born via an uneventful vaginal delivery at home at 38 weeks gestation and was doing fine up until yesterday when he became disinterested in breastfeeding and spit up several times. His temperature is 39.5°C (103.1°F), pulse is 155/min, respirations are 45/min, and O2 sats are 92% on room air. He is lethargic and minimally responsive to stimuli. While on his back, his head is quickly lifted towards his chest which causes his legs to flex. The mother had only a few prenatal care visits and none at the end of the pregnancy. What is the most likely source of this patients infection?
- A. Tick bite
- B. During birth (Correct Answer)
- C. Infection from surgery
- D. Contaminated food
- E. Mother’s roommate
Diagnostic approach to neonatal sepsis Explanation: ***During birth***
- The newborn's age (6 days old) and presentation with **fever**, **lethargy**, and **meningeal signs** (legs flexing upon lifting head, likely Brudzinski sign) are highly suggestive of **neonatal sepsis** or **meningitis**.
- Given the history of a home birth with limited prenatal care, the most probable source of infection would be vertical transmission **during passage through the birth canal**, especially if the mother was colonized with pathogens like Group B Streptococcus (GBS), E. coli, or had an untreated sexually transmitted infection.
*Tick bite*
- While tick-borne illnesses can cause fever, they are generally less common in this age group and the symptoms presented are more indicative of a widespread bacterial infection rather than a localized vector-borne illness.
- The neurological signs (meningeal irritation) are more consistent with meningitis, which is typically bacterial in newborns, rather than a common manifestation of a tick-borne disease in this age group.
*Infection from surgery*
- The patient had an **uneventful vaginal delivery at home**, meaning there was no surgical procedure involved, ruling out a surgical site infection.
- Surgical infections are typically seen after procedures like C-sections or circumcisions and would present differently.
*Contaminated food*
- A 6-day-old newborn is typically fed breast milk or formula and has no exposure to **solid or contaminated food** that would cause such an infection.
- Foodborne illnesses would usually present with prominent gastrointestinal symptoms like severe vomiting and diarrhea, which are not the primary features here.
*Mother’s roommate*
- While exposure to sick individuals can cause illness, the severe symptoms and rapid progression of the newborn's condition, along with the meningeal signs, point more towards a serious **vertical transmission during birth** rather than horizontal transmission from casual contact with a roommate.
- Diseases transmitted this way would also typically affect the respiratory tract before causing severe systemic illness.
Diagnostic approach to neonatal sepsis US Medical PG Question 3: A 53-year-old diabetic man with cellulitis of the right lower limb presents to the emergency department because of symptoms of fever and chills. His pulse is 122/min, the blood pressure is 76/50 mm Hg, the respirations are 26/min, and the temperature is 40.0°C (104.0°F). His urine output is < 0.5mL/kg/h. He has warm peripheral extremities. The hemodynamic status of the patient is not improving in spite of the initiation of adequate fluid resuscitation. He is admitted to the hospital. Which of the following is the most likely laboratory profile?
- A. WBC count: 11,670/mm3; low CVP; blood culture: gram-negative bacteremia; blood lactate level: 0.9 mmol/L
- B. WBC count: 1234/mm3; high CVP; blood culture: gram-negative bacteremia; blood lactate level: 1.6 mmol/L
- C. WBC count: 16,670/mm3; low CVP; blood culture: gram-negative bacteremia; blood lactate level: 2.2 mmol/L (Correct Answer)
- D. WBC count: 6670/mm3; low CVP; blood culture: gram-positive bacteremia; blood lactate level: 1.1 mmol/L
- E. WBC count: 8880/mm3; high CVP; blood culture: gram-positive bacteremia; blood lactate level: 2.1 mmol/L
Diagnostic approach to neonatal sepsis Explanation: ***WBC count: 16,670/mm3; low CVP; blood culture: gram-negative bacteremia; blood lactate level: 2.2 mmol/L***
- This profile aligns with **septic shock** driven by gram-negative bacteria, presenting with **tachycardia**, **hypotension**, **fever**, and **poor urine output** despite fluid resuscitation.
- A **high WBC count** (leukocytosis), **low CVP** (due to vasodilation and relative hypovolemia), **gram-negative bacteremia** (common in severe sepsis), and **elevated lactate** (indicating tissue hypoperfusion) are characteristic findings.
*WBC count: 11,670/mm3; low CVP; blood culture: gram-negative bacteremia; blood lactate level: 0.9 mmol/L*
- While most components suggest sepsis (WBC count and low CVP), a **lactate level of 0.9 mmol/L** is within the normal range, contradicting the severe hypoperfusion and shock observed in the patient.
- The patient's presentation with **hypotension** unresponsive to fluids and **oliguria** strongly indicates significant tissue hypoperfusion, which would typically result in a higher lactate.
*WBC count: 1234/mm3; high CVP; blood culture: gram-negative bacteremia; blood lactate level: 1.6 mmol/L*
- A **WBC count of 1234/mm3 (leukopenia)** is an atypical response for severe infection and sepsis; often, sepsis presents with leukocytosis.
- A **high CVP** indicates fluid overload or cardiac dysfunction, which is not consistent with the initial low blood pressure and the need for fluid resuscitation seen in distributive shock.
*WBC count: 6670/mm3; low central venous pressure (CVP); blood culture: gram-positive bacteremia; blood lactate level: 1.1 mmol/L*
- A **WBC count of 6670/mm3** is within the normal range and does not reflect an adequate inflammatory response to severe infection and shock.
- A **normal lactate level (1.1 mmol/L)** does not support the clinical picture of shock and tissue hypoperfusion despite the presence of gram-positive bacteremia.
*WBC count: 8880/mm3; high CVP; blood culture: gram-positive bacteremia; blood lactate level: 2.1 mmol/L*
- A **WBC count of 8880/mm3** is normal, which is unlikely in a severe sepsis presentation.
- A **high CVP** is not consistent with the distributive shock state where there is often relative hypovolemia and vasodilation leading to low CVP.
Diagnostic approach to neonatal sepsis US Medical PG Question 4: A 3100-g (6.9-lb) male newborn is brought to the emergency department by his mother because of fever and irritability. The newborn was delivered at home 15 hours ago. He was born at 39 weeks' gestation. The mother's last prenatal visit was at the beginning of the first trimester. She received all standard immunizations upon immigrating from Mexico two years ago. Seven weeks ago, she experienced an episode of painful, itching genital vesicles, which resolved spontaneously. Four hours before going into labor she noticed a gush of blood-tinged fluid from her vagina. The newborn is ill-appearing and lethargic. His temperature is 39.9°C (103.8°F), pulse is 170/min, respirations are 60/min, and blood pressure is 70/45 mm Hg. His skin is mildly icteric. Expiratory grunting is heard on auscultation. Skin turgor and muscle tone are decreased. Laboratory studies show:
Hemoglobin 15 g/dL
Leukocyte count 33,800/mm3
Platelet count 100,000/mm3
Serum glucose 55 mg/dL
Which of the following is the most likely causal organism?
- A. Clostridium botulinum
- B. Staphylococcus epidermidis
- C. Streptococcus agalactiae (Correct Answer)
- D. Staphylococcus aureus
- E. Neisseria meningitidis
Diagnostic approach to neonatal sepsis Explanation: ***Streptococcus agalactiae (Group B Streptococcus)***
- **Most common cause of early-onset neonatal sepsis** (0-7 days of life), typically presenting within hours of birth
- Key risk factors present: **inadequate prenatal care** (no GBS screening at 35-37 weeks or intrapartum antibiotic prophylaxis), **home delivery**, and possible **prolonged rupture of membranes**
- Classic presentation: **fever, lethargy, respiratory distress** (grunting), **hemodynamic instability**, leukocytosis with left shift, and thrombocytopenia
- The mother's history of genital vesicles 7 weeks ago is a **distractor** (resolved HSV would not cause this presentation; neonatal HSV presents with vesicular rash, seizures, or disseminated disease)
*Clostridium botulinum*
- Causes **infant botulism**, presenting with **descending flaccid paralysis** ("floppy baby syndrome"), constipation, poor feeding, and weak cry
- Does NOT cause fever or acute sepsis syndrome
- Acquired through ingestion of **spores** (e.g., honey), not vertical transmission during birth
*Staphylococcus epidermidis*
- Causes **late-onset sepsis** (>7 days) or **nosocomial infections** in hospitalized neonates, especially those with indwelling catheters or central lines
- **Not** a typical cause of early-onset sepsis in a full-term newborn delivered at home
- Associated with **coagulase-negative** staphylococci and biofilm formation on devices
*Staphylococcus aureus*
- Can cause neonatal infections but typically presents as **skin/soft tissue infections, omphalitis, or osteomyelitis** rather than early-onset sepsis
- When causing sepsis, usually occurs **later** in the neonatal period
- Less common than GBS for early-onset sepsis acquired during delivery
*Neisseria meningitidis*
- **Rare** cause of neonatal sepsis; more common in older infants and children
- Vertical transmission is uncommon
- When present, often associated with **petechial or purpuric rash** and fulminant sepsis with rapid progression
Diagnostic approach to neonatal sepsis US Medical PG Question 5: A baby is born after the 32nd gestational week by cesarean delivery. The mother suffered from gestational diabetes; however, she had no other pregnancy-related diseases and was otherwise healthy. The baby has a blood pressure of 100/58 mm Hg, heart rate of 104/min, and oxygen saturation of 88%. The child has tachypnea, subcostal and intercostal retractions, nasal flaring, and cyanosis. The cyanosis is responding well to initial administration of oxygen. The nasogastric tube was positioned without problems. Which of the following is the most likely diagnosis?
- A. Tracheoesophageal fistula
- B. Pneumonia
- C. Neonatal respiratory distress syndrome (NRDS) (Correct Answer)
- D. Sepsis
- E. Congenital heart anomaly with right-to-left shunt
Diagnostic approach to neonatal sepsis Explanation: ***Neonatal respiratory distress syndrome (NRDS)***
- The premature birth (32nd week), presence of **tachypnea**, **retractions**, **nasal flaring**, **cyanosis** responding to oxygen, and maternal **gestational diabetes** are all highly suggestive of NRDS.
- Maternal gestational diabetes can delay fetal lung maturity, increasing the risk of **surfactant deficiency**, which is the primary cause of NRDS.
*Tracheoesophageal fistula*
- This condition typically presents with **choking**, **coughing**, and **regurgitation** during feeding, often with inability to pass a nasogastric tube into the stomach.
- The successful positioning of the **nasogastric tube** makes this diagnosis less likely.
*Pneumonia*
- While pneumonia can cause respiratory distress, the **early onset** in a premature infant with maternal gestational diabetes points more strongly towards **NRDS**.
- Pneumonia would typically have signs of **infection** such as fever, though early neonatal pneumonia can be atypical.
*Sepsis*
- Sepsis can cause respiratory distress, but it's usually accompanied by other signs of systemic infection, such as **fever or hypothermia**, **lethargy**, and poor feeding and often signs of **circulatory compromise**.
- The clinical picture provided primarily points towards a respiratory rather than a systemic infectious cause primarily.
*Congenital heart anomaly with right-to-left shunt*
- While this can cause **cyanosis** and respiratory distress, the prompt response to oxygen management makes a significant right-to-left shunt less likely.
- A significant right-to-left shunt would typically cause **cyanosis** that is refractory to oxygen administration.
Diagnostic approach to neonatal sepsis US Medical PG Question 6: Thirty minutes after delivery, a 1780-g (3-lb 15-oz) male newborn develops respiratory distress. He was born at 30 weeks' gestation via vaginal delivery. His temperature is 36.8C (98.2F), pulse is 140/min, respirations are 64/min, and blood pressure is 61/32 mm Hg. Pulse oximetry on room air shows an oxygen saturation of 90%. Examination shows pale extremities. Grunting and moderate subcostal retractions are present. Pulmonary examination shows decreased breath sounds bilaterally. Supplemental oxygen is administered. Ten minutes later, his pulse is 148/min and respirations are 66/min. Pulse oximetry on 60% oxygen shows an oxygen saturation of 90%. Which of the following is the most likely diagnosis?
- A. Meconium aspiration syndrome
- B. Tracheomalacia
- C. Tracheoesophageal fistula
- D. Neonatal pneumonia
- E. Respiratory distress syndrome (Correct Answer)
Diagnostic approach to neonatal sepsis Explanation: ***Respiratory distress syndrome***
- This premature newborn (30 weeks' gestation, 1780-g) with immediate **respiratory distress**, grunting, retractions, and poor oxygenation despite supplemental oxygen is highly indicative of **respiratory distress syndrome (RDS)** due to surfactant deficiency.
- The **decreased breath sounds bilaterally** are consistent with widespread atelectasis characteristic of RDS.
*Meconium aspiration syndrome*
- This typically occurs in **term or post-term infants** and is unlikely in a 30-week premature infant.
- It usually presents with a history of **meconium-stained amniotic fluid** and chest X-ray findings of patchy infiltrates and hyperinflation.
*Tracheomalacia*
- This condition involves **weakness of the tracheal walls** leading to airway collapse, often presenting with a **barking cough** or **stridor**.
- It does not typically cause the severe, rapidly worsening respiratory distress and diffuse lung findings seen in this case.
*Tracheoesophageal fistula*
- This typically presents with **choking, coughing, and cyanosis during feeding**, due to aspiration of milk into the trachea.
- Respiratory distress in this condition is usually associated with feeding, and there is no mention of feeding issues in this scenario.
*Neonatal pneumonia*
- While possible in a premature infant, pneumonia symptoms often include **fever** and specific chest X-ray findings (e.g., infiltrates), which are not emphasized here.
- The rapid onset immediately after birth and progressive nature in a preterm infant strongly point towards a primary respiratory developmental issue like RDS.
Diagnostic approach to neonatal sepsis US Medical PG Question 7: A P2G1 diabetic woman is at risk of delivering at 29 weeks gestation. Her obstetrician counsels her that there is a risk the baby could have significant pulmonary distress after it is born. However, she states she will give the mother corticosteroids, which will help prevent this from occurring. Additionally, the obstetrician states she will perform a test on the amniotic fluid which will indicate the likelihood of the infant being affected by this syndrome. Which of the following ratios would be most predictive of the infant having pulmonary distress?
- A. lecithin:phosphatidylserine < 1.5
- B. lecithin:sphingomyelin < 1.5 (Correct Answer)
- C. lecithin:sphingomyelin > 1.5
- D. lecithin:phosphatidylserine > 3.0
- E. lecithin:sphingomyelin > 3.0
Diagnostic approach to neonatal sepsis Explanation: ***lecithin:sphingomyelin < 1.5***
- A lecithin:sphingomyelin (L:S) ratio less than 2:1 (or 1.5 in some clinical contexts) indicates **fetal lung immaturity** and a **high risk for respiratory distress syndrome (RDS)**.
- The **lecithin level increases** significantly in the amniotic fluid during the third trimester as fetal lungs mature, while **sphingomyelin levels remain relatively constant**.
*lecithin:phosphatidylserine < 1.5*
- While **phosphatidylserine** is a component of surfactant, the **Lecithin:Sphingomyelin (L:S) ratio** is the established and most commonly used marker for fetal lung maturity.
- There is **no widely recognized or clinically validated threshold** for a lecithin:phosphatidylserine ratio in predicting respiratory distress syndrome.
*lecithin:sphingomyelin > 1.5*
- An L:S ratio **greater than 2:1 (or 1.5, in some labs)** generally indicates **fetal lung maturity** and a low risk for respiratory distress syndrome.
- Therefore, this ratio would suggest a **lower likelihood of pulmonary distress**, which contradicts the aim of identifying risk.
*lecithin:phosphatidylserine > 3.0*
- As with an L:S ratio, a higher ratio would generally indicate **lung maturity**, not increased risk for pulmonary distress.
- There is **no clinical standard for lecithin:phosphatidylserine ratio** to assess lung maturity for preventing RDS.
*lecithin:sphingomyelin > 3.0*
- An L:S ratio of **greater than 2:1 (or 3.0 in certain clinical scenarios)** is a strong indicator of **fetal lung maturity**, meaning the risk of respiratory distress syndrome is low.
- The question asks for a ratio that would be **predictive of pulmonary distress**, whereas this ratio indicates the opposite.
Diagnostic approach to neonatal sepsis US Medical PG Question 8: A 3-month-old boy is brought to the emergency room by his mother for 2 days of difficulty breathing. He was born at 35 weeks gestation but has otherwise been healthy. She noticed a cough and some trouble breathing in the setting of a runny nose. His temperature is 100°F (37.8°C), blood pressure is 64/34 mmHg, pulse is 140/min, respirations are 39/min, and oxygen saturation is 93% on room air. Pulmonary exam is notable for expiratory wheezing and crackles throughout and intercostal retractions. Oral mucosa is noted to be dry. Which of the following is the most appropriate diagnostic test?
- A. Chest radiograph
- B. Sputum culture
- C. Viral culture
- D. Polymerase chain reaction
- E. No further testing needed (Correct Answer)
Diagnostic approach to neonatal sepsis Explanation: ***No further testing needed***
- This patient presents with classic signs and symptoms of **bronchiolitis**, including a **preterm infant** (risk factor), **URI symptoms** followed by **respiratory distress** (cough, difficulty breathing), **expiratory wheezing**, and **crackles**.
- Bronchiolitis is a clinical diagnosis, and **routine testing** like chest X-rays or viral studies is generally **not recommended** for uncomplicated cases as it rarely changes management unless there are atypical features or concerns for other diagnoses.
*Chest radiograph*
- A chest X-ray is generally **not indicated** for typical bronchiolitis presentations. It may show hyperinflation or peribronchial thickening but these findings often do not alter management.
- It should only be considered if there are atypical signs, such as a localized finding on exam or concern for **pneumonia** or **atelectasis**, which are not strongly suggested here.
*Sputum culture*
- **Infants** typically **do not produce sputum** for culture.
- Bronchiolitis is primarily a **viral infection**, making bacterial sputum cultures **irrelevant** for initial diagnosis and management unless secondary bacterial infection is strongly suspected, for which there is no evidence here.
*Viral culture*
- While bronchiolitis is caused by viruses, typically **RSV**, **routine viral culture** or rapid antigen testing for RSV is usually **not necessary** for diagnosis in typical cases.
- Identification of the specific virus does not change the clinical management, which is primarily **supportive care**.
*Polymerase chain reaction*
- **PCR testing** can identify viral pathogens but is generally **not recommended** for uncomplicated bronchiolitis cases as it does not change the management plan, which focuses on supportive care.
- It might be considered in severe cases, for **infection control** purposes in a hospital setting, or if there is a specific need for **epidemiological surveillance**, none of which are described as immediate priorities for this patient.
Diagnostic approach to neonatal sepsis US Medical PG Question 9: A mother delivers in a rural area under the guidance of a skilled care attendant. Which of the following statements is incorrect regarding the care provided by the skilled care attendant at birth?
- A. Start breastfeeding as early as possible
- B. Cover the baby's head and body
- C. Bathe the baby with warm water (Correct Answer)
- D. Clear the eyes with a sterile swab
- E. Dry the baby thoroughly and stimulate breathing
Diagnostic approach to neonatal sepsis Explanation: ***Bathe the baby with warm water***
- **Delaying the first bath** for at least 6-24 hours after birth is recommended to prevent **hypothermia** and promote **skin-to-skin contact** for bonding and breastfeeding.
- Early bathing can remove **vernix caseosa**, which provides natural antimicrobial protection and moisturization to the newborn's skin.
*Start breastfeeding as early as possible*
- **Early initiation of breastfeeding**, ideally within the first hour of birth, is crucial for both mother and baby.
- It promotes **uterine contractions** to prevent **postpartum hemorrhage** and provides the newborn with **colostrum**, rich in antibodies.
*Cover the baby's head and body*
- Covering the newborn's head and body is essential to prevent **heat loss** and maintain a stable **body temperature**, immediately after birth.
- Newborns are highly susceptible to **hypothermia** due to their large surface area to mass ratio and immature thermoregulation.
*Clear the eyes with a sterile swab*
- Clearing the newborn's eyes with a sterile swab is a standard part of immediate newborn care to remove any **mucus or blood** that might have entered during delivery.
- This helps prevent **ophthalmia neonatorum**, especially if the mother has an infection like gonorrhea or chlamydia.
*Dry the baby thoroughly and stimulate breathing*
- **Drying the baby immediately** after birth is a critical first step in newborn resuscitation and care.
- It helps prevent **hypothermia** and provides **tactile stimulation** to initiate breathing and crying, which is essential for transitioning from fetal to neonatal circulation.
Diagnostic approach to neonatal sepsis US Medical PG Question 10: Three days after delivery, a 1100-g (2-lb 7-oz) newborn has a tonic seizure that lasts for 25 seconds. She has become increasingly lethargic over the past 18 hours. She was born at 31 weeks' gestation. Antenatal period was complicated by chorioamnionitis. Apgar scores were 3 and 6 at 1 and 5 minutes, respectively. She appears ill. Her pulse is 123/min, respirations are 50/min and irregular, and blood pressure is 60/30 mm Hg. Examination shows a tense anterior fontanelle. The pupils are equal and react sluggishly to light. Examination shows slow, conjugate back and forth movements of the eyes. Muscle tone is decreased in all extremities. The lungs are clear to auscultation. Which of the following is the most likely diagnosis?
- A. Intraventricular hemorrhage (Correct Answer)
- B. Spinal muscular atrophy
- C. Galactosemia
- D. Congenital hydrocephalus
- E. Phenylketonuria
Diagnostic approach to neonatal sepsis Explanation: ***Intraventricular hemorrhage***
- The combination of **prematurity** (31 weeks' gestation, 1100g), **tonic seizures**, increasing **lethargy**, tense **anterior fontanelle**, **sluggishly reactive pupils**, and **slow conjugate back-and-forth eye movements** (suggesting brainstem involvement from increased intracranial pressure) are classical signs of intraventricular hemorrhage (IVH) in a neonate.
- **IVH** is common in premature infants due to the fragility of germinal matrix vessels and can manifest acutely with neurological deterioration and increased intracranial pressure, typically within the first 72 hours of life.
- While maternal **chorioamnionitis** and low Apgar scores raise concern for neonatal sepsis/meningitis, the specific **ocular movement pattern** and acute neurological signs on day 3 are more characteristic of IVH in this extremely premature infant.
*Spinal muscular atrophy*
- This is a **neuromuscular genetic disorder** characterized by progressive muscle weakness and hypotonia due to anterior horn cell degeneration.
- It would typically present with **decreased muscle tone but without acute neurological signs** like seizures, tense fontanelle, or sluggish pupillary responses.
- Does not cause acute-onset seizures or rapidly progressing lethargy in the neonatal period.
*Galactosemia*
- This is a **metabolic disorder** that presents with symptoms such as **vomiting, jaundice, hepatomegaly**, and **sepsis-like symptoms** upon introduction of lactose-containing feeds (breast milk or regular formula), typically after several days of feeding.
- While it can cause lethargy and seizures, the acute neurological findings including **tense fontanelle** and **abnormal eye movements** in the immediate postnatal period of a premature infant more strongly suggest an anatomical/structural etiology like IVH.
*Congenital hydrocephalus*
- While **hydrocephalus** can cause a **tense fontanelle** and seizures, the **acute onset** of symptoms (day 3 of life with rapid deterioration over 18 hours following a specific tonic seizure) in an extremely premature infant strongly suggests an **acute hemorrhagic event** rather than congenital hydrocephalus.
- Congenital hydrocephalus typically presents with **progressively enlarging head circumference** over time, rather than such acute neurological deterioration in the first 72 hours of life.
- IVH can lead to secondary post-hemorrhagic hydrocephalus, but the acute presentation favors primary IVH.
*Phenylketonuria*
- This is a **metabolic disorder** caused by phenylalanine hydroxylase deficiency that, if untreated, leads to **intellectual disability** and seizures.
- Symptoms typically manifest **several months after birth** (usually 3-6 months) as phenylalanine accumulates, and are not associated with acute neonatal neurological distress like tense fontanelle, abnormal eye movements, or acute lethargy in the first few days of life.
- Would not explain the acute deterioration on day 3 of life in this clinical context.
More Diagnostic approach to neonatal sepsis US Medical PG questions available in the OnCourse app. Practice MCQs, flashcards, and get detailed explanations.
