Late-onset sepsis US Medical PG Practice Questions and MCQs
Practice US Medical PG questions for Late-onset sepsis. These multiple choice questions (MCQs) cover important concepts and help you prepare for your exams.
Late-onset sepsis US Medical PG Question 1: A newborn infant is born at 40 weeks gestation to a G1P1 mother. The pregnancy was uncomplicated and was followed by the patient's primary care physician. The mother has no past medical history and is currently taking a multi-vitamin, folate, B12, and iron. The infant is moving its limbs spontaneously and is crying. His temperature is 98.7°F (37.1°C), blood pressure is 60/38 mmHg, pulse is 150/min, respirations are 33/min, and oxygen saturation is 99% on room air. Which of the following is the best next step in management?
- A. No further management needed
- B. Intramuscular (IM) vitamin K and topical erythromycin (Correct Answer)
- C. Fluid resuscitation
- D. Vitamin D and IM vitamin K
- E. Silver nitrate eye drops and basic lab work
Late-onset sepsis Explanation: ***Intramuscular (IM) vitamin K and topical erythromycin***
- All newborns should receive **intramuscular vitamin K** to prevent **Vitamin K Deficiency Bleeding (VKDB)**, as placental transfer of vitamin K is poor and infant gut flora producing vitamin K is not fully established.
- **Topical erythromycin** ophthalmic ointment is routinely administered to newborns to prevent **gonococcal ophthalmia neonatorum**, a serious eye infection that can lead to blindness.
*No further management needed*
- This is incorrect because **prophylactic treatments** (vitamin K and erythromycin) are standard of care for all newborns, primarily for preventing VKDB and gonococcal ophthalmia.
- Omission of these standard treatments can lead to preventable and severe health complications in the infant.
*Fluid resuscitation*
- The infant's vital signs are within **normal limits for a newborn** (heart rate 110-160 bpm, respiratory rate 30-60 bpm, blood pressure 60/40 mmHg at birth), indicating no immediate need for fluid resuscitation.
- There are no signs of **dehydration** or **shock**, such as poor perfusion or lethargy, that would necessitate fluid intervention.
*Vitamin D and IM vitamin K*
- While **IM vitamin K** is essential, routine **vitamin D supplementation** for newborns (typically 400 IU daily) is usually initiated after discharge, especially for breastfed infants, and not an immediate management step in the delivery room.
- Placing vitamin D at the same urgency as vitamin K for immediate post-delivery care is inappropriate in this context.
*Silver nitrate eye drops and basic lab work*
- **Silver nitrate eye drops** are an older method for ophthalmia prophylaxis and have largely been replaced by **erythromycin due to fewer side effects** and similar efficacy against gonorrhea.
- **Basic lab work** is not routinely recommended for a healthy, term newborn with an uncomplicated delivery and stable vital signs; it would only be indicated if there were specific risk factors or clinical concerns.
Late-onset sepsis US Medical PG Question 2: 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
Late-onset 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.
Late-onset sepsis US Medical PG Question 3: A 6-year-old boy and his parents present to the emergency department with high-grade fever, headache, and projectile vomiting. The boy was born at 39 weeks gestation via spontaneous vaginal delivery. He is up to date on all vaccines and is meeting all developmental milestones. Past medical history is noncontributory. He has had no sick contacts at school or at home. The family has not traveled out of the area recently. He likes school and playing videogames with his younger brother. Today, his blood pressure is 115/76 mm Hg, heart rate is 110/min, respiratory rate is 22/min, and temperature is 38.4°C (101.2°F). On physical exam, the child is disoriented. Kernig’s sign is positive. A head CT was performed followed by a lumbar puncture. Several aliquots of CSF were distributed throughout the lab. Cytology showed high counts of polymorphs, biochemistry showed low glucose and elevated protein levels, and a gram smear shows gram-positive lanceolate-shaped cocci alone and in pairs. A smear is prepared on blood agar in an aerobic environment and grows mucoid colonies with clearly defined edges and alpha hemolysis. On later evaluation they develop a ‘draughtsman’ appearance. Which one of the following is the most likely pathogen?
- A. Streptococcus pneumoniae (Correct Answer)
- B. Staphylococcus aureus
- C. Neisseria meningitidis
- D. Staphylococcus epidermidis
- E. Streptococcus agalactiae
Late-onset sepsis Explanation: ***Streptococcus pneumoniae***
- The CSF findings of **high polymorphs**, **low glucose**, and **elevated protein** are classic for bacterial meningitis. The Gram stain showing **Gram-positive, lanceolate-shaped cocci in pairs** is highly characteristic of *Streptococcus pneumoniae*.
- The growth of **mucoid colonies** with **alpha hemolysis** on blood agar in an aerobic environment, which later develop a **'draughtsman' appearance**, are further confirmatory characteristics of *S. pneumoniae*.
*Staphylococcus aureus*
- *Staphylococcus aureus* is a Gram-positive coccus but typically presents in **clusters** on Gram stain, not lanceolate pairs.
- While it can cause meningitis, it usually exhibits **beta-hemolysis** and is catalase-positive, unlike *S. pneumoniae*.
*Neisseria meningitidis*
- *Neisseria meningitidis* is a **Gram-negative diplococcus**, which would appear distinctly different on Gram stain compared to the described Gram-positive lanceolate cocci.
- Although it is a common cause of bacterial meningitis, its colonial morphology and Gram stain characteristics do not match the case.
*Staphylococcus epidermidis*
- *Staphylococcus epidermidis* is a **Gram-positive coccus in clusters**, similar to *S. aureus*, and is commonly a **skin commensal** or found in infections related to indwelling devices.
- It typically exhibits **gamma-hemolysis** (non-hemolytic) and is usually **coagulase-negative**, differentiating it from the alpha-hemolytic, 'draughtsman' appearing colonies described.
*Streptococcus agalactiae*
- *Streptococcus agalactiae* (**Group B Streptococcus**) is a Gram-positive coccus that typically grows in **chains** and causes **beta-hemolysis**, particularly in neonates.
- While it can cause meningitis, its characteristic hemolytic pattern and arrangement on Gram stain differ from the alpha-hemolytic, lanceolate-shaped cocci in pairs described.
Late-onset sepsis US Medical PG Question 4: Five days after being admitted to the hospital for a scald wound, a 2-year-old boy is found to have a temperature of 40.2°C (104.4°F). He does not have difficulty breathing, cough, or painful urination. He initially presented one hour after spilling a pot of boiling water on his torso while his mother was cooking dinner. He was admitted for fluid resuscitation, nutritional support, pain management, and wound care, and he was progressing well until today. He has no other medical conditions. Other than analgesia during this hospital stay, he does not take any medications. He appears uncomfortable but not in acute distress. His pulse is 150/min, respirations are 41/min, and blood pressure is 90/50 mm Hg. Pulse oximetry on room air shows an oxygen saturation of 99%. Examination shows uneven, asymmetrical scalding covering his anterior torso in arrow-like patterns with surrounding erythema and purulent discharge. The remainder of the examination shows no abnormalities. His hemoglobin is 13.4 g/dL, platelet count is 200,000/mm3, and leukocyte count is 13,900/mm3. Which of the following is the most appropriate initial pharmacological treatment for this patient?
- A. Vancomycin and metronidazole
- B. Amoxicillin/clavulanic acid and ceftriaxone
- C. Ampicillin/sulbactam and daptomycin
- D. Vancomycin and cefepime (Correct Answer)
- E. Piperacillin/tazobactam and cefepime
Late-onset sepsis Explanation: ***Vancomycin and cefepime***
- The patient presents with classic signs of **burn wound infection**, including fever, purulent discharge, and a rapid pulse, necessitating broad-spectrum antibiotic coverage.
- **Vancomycin** provides excellent coverage against **MRSA (methicillin-resistant *Staphylococcus aureus*)**, a common pathogen in burn infections, while **cefepime** covers **gram-negative bacteria**, including *Pseudomonas aeruginosa*, which is also frequently implicated.
*Vancomycin and metronidazole*
- While vancomycin covers gram-positive bacteria like **MRSA**, **metronidazole** primarily targets **anaerobic bacteria**, which are less common as primary pathogens in burn wound infections.
- This combination lacks adequate coverage for crucial gram-negative bacteria such as *Pseudomonas aeruginosa*.
*Amoxicillin/clavulanic acid and ceftriaxone*
- This combination provides coverage against some common community-acquired pathogens but is insufficient for the broad-spectrum needs of a severe **hospital-acquired burn infection**.
- It lacks reliable coverage for **MRSA** and *Pseudomonas aeruginosa*, which are critical in this setting.
*Ampicillin/sulbactam and daptomycin*
- **Ampicillin/sulbactam** covers some gram-positive and gram-negative bacteria but would not reliably cover **MRSA** or *Pseudomonas aeruginosa*.
- **Daptomycin** is effective against gram-positive bacteria, including **MRSA**, but does not cover gram-negative pathogens, leaving a significant gap in treatment.
*Piperacillin/tazobactam and cefepime*
- Both **piperacillin/tazobactam** and **cefepime** are excellent broad-spectrum antibiotics covering gram-negative pathogens, including *Pseudomonas aeruginosa*, but are largely redundant in this combination.
- This regimen lacks specific coverage for **MRSA**, which is a significant concern in nosocomial burn wound infections.
Late-onset sepsis US Medical PG Question 5: A 25-day-old male infant presents to the emergency department because his mother states that he has been acting irritable for the past 2 days and has now developed a fever. On exam, the infant appears uncomfortable and has a temperature of 39.1 C. IV access is immediately obtained and a complete blood count and blood cultures are drawn. Lumbar puncture demonstrates an elevated opening pressure, elevated polymorphonuclear neutrophil, elevated protein, and decreased glucose. Ampicillin and cefotaxime are immediately initiated and CSF culture eventually demonstrates infection with a Gram-negative rod. Which of the following properties of this organism was necessary for the infection of this infant?
- A. K capsule (Correct Answer)
- B. M protein
- C. Fimbriae
- D. IgA protease
- E. LPS endotoxin
Late-onset sepsis Explanation: ***K capsule***
- The K capsule (specifically **K1 antigen**) is a specific virulence factor found in **E. coli** strains, which are a common cause of neonatal meningitis.
- This capsule is **antiphagocytic** and helps the bacteria evade the immune system, allowing it to cross the **blood-brain barrier** and cause meningitis in neonates.
*M protein*
- **M protein** is a major virulence factor associated with **Streptococcus pyogenes** (Group A Strep), playing a role in attachment and immune evasion.
- While *S. pyogenes* can cause infections, it is not typically the Gram-negative rod responsible for **neonatal meningitis** and its M protein is not relevant here.
*Fimbriae*
- **Fimbriae** (pili) are important for bacterial **adhesion** to host cells, often in the initial stages of infection, particularly in urinary tract infections (UTIs).
- While gram-negative rods possess fimbriae, the specific virulence factor critical for **meningitis** caused by *E. coli* in neonates is the K1 capsule, not fimbriae which are more for initial colonization.
*IgA protease*
- **IgA protease** is an enzyme produced by some bacteria (e.g., *N. meningitidis, H. influenzae, S. pneumoniae*) that cleaves **IgA antibodies**, helping them colonize mucous membranes.
- This enzyme is not a primary virulence factor for the **Gram-negative rod** causing neonatal meningitis, where capsule formation is more critical for invasion.
*LPS endotoxin*
- **Lipopolysaccharide (LPS) endotoxin** is a component of the outer membrane of Gram-negative bacteria and is responsible for many symptoms of sepsis and **systemic inflammation**.
- While LPS contributes to the overall disease severity, it primarily mediates **inflammation and fever**, and is not the specific factor necessary for **invasion and survival within the central nervous system**, which is facilitated by the K capsule.
Late-onset sepsis US Medical PG Question 6: A 7-year-old boy is brought to the emergency department because of a 3-day history of generalized fatigue, myalgia, and fever. He has sickle cell disease. His current medications include hydroxyurea and folic acid. He appears ill. His temperature is 39.2°C (102.6°F), pulse is 103/min, and respirations are 28/min. Examination shows pale conjunctivae. The lungs are clear to auscultation. The abdomen is soft and nontender. Neurologic examination shows no focal findings, His hemoglobin concentration is 10.3 g/dL and leukocyte count is 14,100/mm3. Intravenous fluid is administered and blood cultures are obtained. Which of the following is the most appropriate next step in treatment?
- A. Clindamycin
- B. Prednisone
- C. Vancomycin
- D. Ceftriaxone (Correct Answer)
- E. Levofloxacin
Late-onset sepsis Explanation: ***Ceftriaxone***
- This patient presents with **fever** and **sickle cell disease**, placing him at high risk for bacterial infections, especially from **encapsulated organisms** like *Streptococcus pneumoniae* and *Haemophilus influenzae*. **Ceftriaxone** is a broad-spectrum third-generation cephalosporin that provides excellent coverage against these common pathogens.
- Due to the high risk of **sepsis** and rapid progression of infection in sickle cell patients, empiric, prompt administration of **intravenous antibiotics** is crucial, even before culture results are available.
*Clindamycin*
- **Clindamycin** is primarily effective against **anaerobic bacteria** and some gram-positive organisms, including methicillin-sensitive *Staphylococcus aureus* (MSSA).
- It does not provide adequate coverage against the most common and life-threatening pathogens in febrile sickle cell patients, such as encapsulated bacteria.
*Prednisone*
- **Prednisone** is a corticosteroid used for its **anti-inflammatory** and immunosuppressive effects. It is not indicated for the initial management of fever and suspected bacterial infection.
- Administering corticosteroids in a patient with suspected infection without appropriate antibiotic coverage could worsen the infection.
*Vancomycin*
- **Vancomycin** is a powerful antibiotic primarily used to cover **multi-drug resistant gram-positive bacteria**, especially **MRSA** and drug-resistant *S. pneumoniae*.
- While it covers gram-positive organisms well, it does **not cover gram-negative bacteria** such as *H. influenzae* or *Salmonella* species, which are important pathogens in sickle cell patients. **Ceftriaxone** provides broader coverage including both gram-positive and gram-negative encapsulated organisms, making it the preferred empiric choice.
*Levofloxacin*
- **Levofloxacin** is a fluoroquinolone that provides broad-spectrum coverage, including against atypical organisms and some gram-negatives and gram-positives.
- However, **fluoroquinolones** are generally avoided in children due to potential adverse effects on cartilage development, and it is not the first-line empiric choice for severe bacterial infections in this age group, especially when **cephalosporins** are highly effective and safer.
Late-onset sepsis US Medical PG Question 7: A 3580-g (7-lb 14-oz) male newborn is delivered at 36 weeks' gestation to a 26-year-old woman, gravida 2, para 1 after an uncomplicated pregnancy. His temperature is 36.7°C (98.1°F), heart rate is 96/min, and respirations are 55/min and irregular. Pulse oximetry on room air shows an oxygen saturation of 65% measured in the right hand. He sneezes and grimaces during suction of secretions from his mouth. There is some flexion movement. The trunk is pink and the extremities are blue. The cord is clamped and the newborn is dried and wrapped in a prewarmed towel. Which of the following is the most appropriate next best step in management?
- A. Administer positive pressure ventilation (Correct Answer)
- B. Perform endotracheal intubation
- C. Administer intravenous epinephrine
- D. Perform chest compressions
- E. Administer erythromycin ophthalmic ointment
Late-onset sepsis Explanation: ***Administer positive pressure ventilation***
- The newborn exhibits **cyanosis** (oxygen saturation 65%), **respiratory distress** (irregular respirations, 55/min), and a **heart rate below 100/min** (96/min), which are indications for positive pressure ventilation.
- Initial steps like drying, warming, and stimulation have been performed, and the infant's condition has not improved, necessitating ventilatory support.
*Perform endotracheal intubation*
- Endotracheal intubation is generally reserved for situations where positive pressure ventilation is ineffective or prolonged, or for specific conditions requiring **direct airway management**, such as meconium aspiration with poor respiratory effort.
- Given the current vital signs and initial response, **bag-mask ventilation** (a form of positive pressure ventilation) should be attempted first.
*Administer intravenous epinephrine*
- Epinephrine is typically administered when the heart rate remains **below 60 bpm** despite adequate positive pressure ventilation and chest compressions.
- The newborn's heart rate of 96/min does not meet the criteria for epinephrine administration at this stage.
*Perform chest compressions*
- Chest compressions are indicated when the heart rate is persistently **below 60 bpm** despite 30 seconds of effective positive pressure ventilation.
- The newborn's heart rate of 96/min is above this threshold, making chest compressions premature.
*Administer erythromycin ophthalmic ointment*
- Erythromycin ophthalmic ointment is a prophylactic measure against **gonococcal ophthalmia neonatorum** and is typically administered after the stabilization of the newborn's vital signs.
- It is not an immediate life-saving intervention and should be delayed until the infant's respiratory and circulatory status is stable.
Late-onset sepsis US Medical PG Question 8: A worried mother brings her 12-day-old son to the emergency room concerned that his body is turning "yellow". The patient was born at 39 weeks via spontaneous vaginal delivery without complications. The mother received adequate prenatal care and has been breastfeeding her son. The patient has had adequate urine and stool output. Physical exam demonstrates a comfortable, well nourished neonate with a jaundiced face and chest. The patient's indirect bilirubin was 4 mg/dL at 48 hours of life. Today, indirect bilirubin is 10 mg/dL, and total bilirubin is 11 mg/dL. All other laboratory values are within normal limits. What is the next best treatment in this scenario?
- A. Exchange transfusion
- B. Stop breastfeeding and switch to formula
- C. Phototherapy (Correct Answer)
- D. Reassure mother that jaundice will remit, advise her to continue breastfeeding
- E. Phenobarbital
Late-onset sepsis Explanation: ***Phototherapy***
- The infant's bilirubin levels (total bilirubin 11 mg/dL, indirect bilirubin 10 mg/dL at 12 days old) are within the range that warrants **phototherapy** for a healthy term neonate to prevent **kernicterus**.
- Phototherapy helps convert unconjugated bilirubin into water-soluble isomers that can be excreted more easily.
*Exchange transfusion*
- **Exchange transfusion** is reserved for much higher bilirubin levels, typically above 20-25 mg/dL, or if there are signs of **acute bilirubin encephalopathy**.
- The current bilirubin levels do not meet the criteria for this invasive procedure.
*Phenobarbital*
- **Phenobarbital** induces hepatic enzymes, including UDP-glucuronosyltransferase, which aids bilirubin conjugation, but its effect is delayed and primarily used to prevent jaundice in specific high-risk situations (e.g., in infants of mothers with anti-Rh antibodies) or in treating **Crigler-Najjar syndrome**.
- It is not the immediate treatment for typical neonatal jaundice at these bilirubin levels.
*Stop breastfeeding and switch to formula*
- While **breast milk jaundice** can cause prolonged unconjugated hyperbilirubinemia, the infant's bilirubin levels are not dangerously high, and there is no indication to interrupt breastfeeding.
- Interruption is typically considered if bilirubin levels are very high and unresponsive to phototherapy, to differentiate from **breastfeeding jaundice** caused by inadequate intake.
*Reassure mother that jaundice will remit, advise her to continue breastfeeding*
- Although the infant is comfortable and well-nourished, a bilirubin level of 11 mg/dL at 12 days old in a term infant, especially with an indirect component of 10 mg/dL, is significant enough to warrant intervention like phototherapy to prevent potential complications.
- Simple reassurance without intervention would be inappropriate as it risks allowing bilirubin levels to rise further.
Late-onset sepsis US Medical PG Question 9: Five weeks after delivery, a 1350-g (3-lb 0-oz) male newborn has respiratory distress. He was born at 26 weeks' gestation. He required intubation and mechanical ventilation for a month following delivery and has been on noninvasive pressure ventilation for 5 days. His temperature is 36.8°C (98.2°F), pulse is 148/min, respirations are 63/min, and blood pressure is 60/32 mm Hg. Pulse oximetry on 40% oxygen shows an oxygen saturation of 91%. Examination shows moderate intercostal and subcostal retractions. Scattered crackles are heard in the thorax. An x-ray of the chest shows diffuse granular densities and basal atelectasis. Which of the following is the most likely diagnosis?
- A. Bronchopulmonary dysplasia (Correct Answer)
- B. Tracheomalacia
- C. Bronchiolitis obliterans
- D. Interstitial emphysema
- E. Pneumonia
Late-onset sepsis Explanation: ***Bronchopulmonary dysplasia***
- The presentation of a premature infant (26 weeks' gestation) with persistent respiratory distress requiring prolonged mechanical ventilation and oxygen, along with characteristic chest X-ray findings (diffuse granular densities and basal atelectasis), is highly indicative of **bronchopulmonary dysplasia (BPD)**.
- BPD is a chronic lung disease of prematurity defined by the need for supplemental oxygen and/or positive pressure ventilation for at least 28 days after birth, with severity classified at 36 weeks postmenstrual age (or discharge if earlier).
- The pathophysiology involves ventilator-induced injury, oxygen toxicity, and inflammation in the developing lung, leading to impaired alveolarization and abnormal vascular development.
*Tracheomalacia*
- While **tracheomalacia** can cause respiratory symptoms, it typically presents with expiratory stridor, a characteristic "barking" cough, or wheezing that may improve with neck extension or prone positioning.
- It is a structural abnormality of the trachea involving weakness of the tracheal wall, and would not typically manifest with diffuse granular densities or basal atelectasis on chest X-ray in this context.
*Bronchiolitis obliterans*
- **Bronchiolitis obliterans** is irreversible obstruction of the small airways, often occurring after severe viral infections (especially adenovirus or RSV), lung transplantation, or toxic inhalational injury.
- While it can occur in neonates post-ventilation, it is less common in this specific context and would typically present with more severe obstructive findings, hyperinflation, and air trapping on imaging rather than chronic diffuse granular densities and atelectasis.
*Interstitial emphysema*
- **Pulmonary interstitial emphysema** usually occurs acutely in the first days to weeks of mechanical ventilation, characterized by air dissecting into the lung interstitium and perivascular spaces.
- While it can be a complication that contributes to the development of BPD, the persistent nature of respiratory distress five weeks post-delivery, along with diffuse granular densities and chronic radiographic changes, points toward the established chronic lung disease of BPD rather than acute interstitial emphysema.
*Pneumonia*
- Neonatal **pneumonia** would typically present with acute onset or worsening of respiratory distress, temperature instability, and signs of systemic infection.
- While a chest X-ray might show infiltrates or consolidations, the chronic progressive course over 5 weeks, history of extreme prematurity, and prolonged ventilation make BPD a more fitting diagnosis than acute pneumonia in this clinical scenario.
Late-onset 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
Late-onset 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.
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