Obstetrics and Gynecology
1 questionsMost common antigen involved in erythroblastosis fetalis is:
NEET-PG 2015 - Obstetrics and Gynecology NEET-PG Practice Questions and MCQs
Question 1181: Most common antigen involved in erythroblastosis fetalis is:
- A. C antigen in Rh group
- B. E antigen in Rh group
- C. Duffy antigen
- D. D antigen in Rh group (Correct Answer)
Explanation: ***D antigen in Rh group*** - The **D antigen** is the most immunogenic of the Rh antigens and is responsible for the vast majority of cases of **erythroblastosis fetalis** (hemolytic disease of the fetus and newborn). - When an **Rh-negative mother** is exposed to Rh-positive fetal blood (usually during previous pregnancies or transfusions), she can form antibodies against the D antigen, which can then cross the placenta in subsequent pregnancies and attack Rh-positive fetal red blood cells. *C antigen in Rh group* - While the **C antigen** is part of the Rh blood group system, antibodies to it are much less common and typically cause less severe hemolytic disease compared to anti-D antibodies. - The C antigen is less immunogenic than the D antigen, meaning it is less likely to provoke an immune response in an Rh-negative individual. *E antigen in Rh group* - Similar to the C antigen, the **E antigen** is another Rh antigen, but antibodies against it (anti-E) are also less frequently implicated in severe erythroblastosis fetalis than anti-D. - Antibodies to E can cause hemolytic disease, but their clinical significance is usually milder than that of anti-D. *Duffy antigen* - The **Duffy antigen system** is separate from the Rh system and is known for its role in resistance to certain malarial parasites (e.g., *Plasmodium vivax*). - Although antibodies to Duffy antigens (anti-Fya, anti-Fyb) can cause **hemolytic disease of the fetus/newborn**, they are a far less common cause of erythroblastosis fetalis than antibodies to the Rh D antigen.
Pediatrics
8 questionsWhat is the most common cause of pneumonia in early onset sepsis in neonates?
Which of the following drugs is most commonly used for cardiovascular support in post-resuscitation care of neonates?
Treatment of choice for symptomatic neonatal hypoglycemia is
Which of the following is NOT a recognized cause of neonatal bradycardia?
Which of the following is not a cause of neonatal anaemia?
A 3-month-old child presents with indrawing of the chest and a respiratory rate of 52 breaths per minute. This condition can be classified as:
A 45-day-old infant presents with seizures. Examination reveals he is icteric, has bulging fontanelles, and exhibits opisthotonic posture. Which of the following treatments is NOT indicated?
Chronic lung disease in infancy is defined as
NEET-PG 2015 - Pediatrics NEET-PG Practice Questions and MCQs
Question 1181: What is the most common cause of pneumonia in early onset sepsis in neonates?
- A. H influenzae
- B. Coagulase positive staph aureus
- C. Group B streptococcus (Correct Answer)
- D. Listeria
Explanation: ***Group B streptococcus*** - **Group B Streptococcus (GBS)** is the leading cause of **early-onset sepsis** and pneumonia in neonates, typically acquired during passage through the birth canal. - Maternal GBS colonization is a significant risk factor, and GBS can cause **severe respiratory distress** in affected newborns. *H influenzae* - **_Haemophilus influenzae_** is a more common cause of **late-onset sepsis** or pneumonia in infants and children, rather than early-onset neonatal disease. - While it can cause neonatal infections, it is much less frequent than GBS in the early-onset period. *Coagulase positive staph aureus* - **_Staphylococcus aureus_** is a common cause of **nosocomial infections** or late-onset sepsis in neonates, particularly in ventilated or catheterized infants. - It is not the most common pathogen for community-acquired **early-onset neonatal pneumonia**. *Listeria* - **_Listeria monocytogenes_** can cause severe neonatal sepsis and pneumonia, often associated with maternal consumption of contaminated food. - While it is a significant pathogen, it is less common overall than GBS as a cause of early-onset neonatal pneumonia in most regions.
Question 1182: Which of the following drugs is most commonly used for cardiovascular support in post-resuscitation care of neonates?
- A. Dobutamine
- B. Epinephrine
- C. Sodium Bicarbonate
- D. Dopamine (Correct Answer)
Explanation: ***Dopamine*** - **Dopamine** is often the first-line vasopressor used in neonates for **hypotension** unresponsive to fluid resuscitation, especially in the context of post-resuscitation care, due to its dose-dependent effects on cardiac output and systemic vascular resistance. - It increases **cardiac contractility** and **heart rate** at moderate doses (beta-1 adrenergic effects) and can improve renal blood flow at lower doses. *Sodium Bicarbonate* - **Sodium bicarbonate** is used to correct severe metabolic acidosis but is generally not recommended in the initial stages of neonatal resuscitation or for routine cardiovascular support due to potential adverse effects like rebound acidosis and hypernatremia. - Its use is typically reserved for documented severe metabolic acidosis after adequate ventilation and circulation have been established. *Epinephrine* - **Epinephrine** is primarily used during active cardiorespiratory arrest for its potent vasoconstrictive and inotropic effects, and for sustained **bradycardia** unresponsive to ventilation and chest compressions. - While it has strong cardiovascular effects, it is not the most common drug for *post-resuscitation cardiovascular support* unless there is persistent shock or bradycardia despite dopamine. *Dobutamine* - **Dobutamine** is an inotropic agent primarily used to improve myocardial contractility and cardiac output with less chronotropic effect than dopamine, making it beneficial in conditions with low cardiac output and normal blood pressure. - It is less commonly used as an initial agent for post-resuscitation **hypotension** in neonates compared to dopamine, which also offers systemic vasoconstriction to raise blood pressure.
Question 1183: Treatment of choice for symptomatic neonatal hypoglycemia is
- A. Dextrose normal saline
- B. 5% dextrose
- C. 10% dextrose (Correct Answer)
- D. 25% dextrose
Explanation: ***10% dextrose*** - For **symptomatic neonatal hypoglycemia**, 10% dextrose solution is the **standard initial treatment** with a bolus of 2 mL/kg (200 mg/kg) given IV over 5-10 minutes - This concentration safely and effectively raises blood glucose levels while minimizing the risk of **hyperglycemic rebound** or complications like **osmotic injury** - Followed by continuous infusion to maintain normoglycemia *Dextrose normal saline* - This combination is **not used** for acute hypoglycemia management as the saline component is unnecessary - The glucose concentration would be inadequate for rapid correction of **symptomatic neonatal hypoglycemia** - May lead to excessive fluid administration *5% dextrose* - A **5% dextrose solution** is insufficient to rapidly correct symptomatic neonatal hypoglycemia - Would require much faster infusion rates to deliver adequate glucose, potentially leading to **fluid overload** - May be used for maintenance therapy in asymptomatic cases *25% dextrose* - Too concentrated for routine neonatal use - carries significant risk of **vein sclerosis**, **osmotic injury**, and **rebound hypoglycemia** - Risk of extravasation injury and **hyperglycemia** - Reserved only for extreme cases under close monitoring with careful dilution
Question 1184: Which of the following is NOT a recognized cause of neonatal bradycardia?
- A. Hypothermia
- B. Head injury
- C. Hypoxia
- D. BCG Vaccine (Correct Answer)
Explanation: ***BCG Vaccine*** - The **BCG vaccine** (Bacille Calmette-Guérin) is used to prevent tuberculosis and is not a known cause of **neonatal bradycardia**. - While it can cause local reactions or, rarely, disseminated disease in immunocompromised infants, it does not directly affect heart rate. *Hypoxia* - **Hypoxia** is a common and critical cause of **neonatal bradycardia**, as the heart attempts to conserve energy and oxygen in response to insufficient oxygen supply. - Severe or prolonged hypoxia can lead to **myocardial depression** and further compromise cardiac function. *Hypothermia* - **Hypothermia** (low body temperature) can significantly depress the **central nervous system** and **metabolic rate** in neonates. - This physiological response often leads to a decreased heart rate, resulting in **bradycardia**. *Head injury* - **Head injury** in neonates, especially severe forms, can increase **intracranial pressure** and stimulate the **vagal nerve**. - **Vagal stimulation** can lead to a decrease in heart rate, manifesting as **bradycardia**.
Question 1185: Which of the following is not a cause of neonatal anaemia?
- A. Subgaleal Hemorrhage
- B. Abruptio placentae
- C. Wilson's Disease (Correct Answer)
- D. Diamond Blackfan syndrome
Explanation: ***Wilson's Disease*** - Wilson's disease is a disorder of **copper metabolism** that typically manifests later in childhood or adolescence with **hepatic**, **neurological**, or **psychiatric symptoms**, not neonatal anemia. - While it can cause hemolytic anemia in older individuals due to copper toxicity, it is not a recognized cause of **neonatal anemia**. *Subgaleal Hemorrhage* - A subgaleal hemorrhage is a significant collection of blood in the **subgaleal space** of the scalp, which can lead to substantial **blood loss** and subsequent **neonatal anemia** due to a large potential space. - This type of hemorrhage is often associated with **vacuum extraction** or other traumatic deliveries. *Abruptio placentae* - **Abruptio placentae** involves the premature separation of the placenta from the uterine wall, leading to **fetal-maternal hemorrhage** and sometimes significant **fetal blood loss**. - This acute blood loss in the fetus can manifest as severe **neonatal anemia** at birth. *Diamond Blackfan syndrome* - **Diamond Blackfan syndrome** is a congenital red cell aplasia characterized by a failure of **red blood cell production** in the bone marrow. - This condition presents with severe **macrocytic anemia** early in infancy, often requiring transfusions.
Question 1186: A 3-month-old child presents with indrawing of the chest and a respiratory rate of 52 breaths per minute. This condition can be classified as:
- A. SIRS
- B. Respiratory distress (Correct Answer)
- C. Tachypnoea
- D. ARDS
Explanation: ***Respiratory distress*** - **Indrawing of the chest** is a classic sign of increased work of breathing, indicating the child is struggling to oxygenate. - A respiratory rate of **52 breaths per minute in a 3-month-old** is significantly elevated and, combined with indrawing, points to respiratory distress. - According to **WHO IMCI guidelines**, chest indrawing in a child with fast breathing is classified as **pneumonia/respiratory distress** requiring immediate treatment. *SIRS* - **Systemic Inflammatory Response Syndrome (SIRS)** criteria are typically more comprehensive and include fever or hypothermia, tachycardia, tachypnea, and abnormal white blood cell count. - While tachypnea is present, the other defining features of SIRS are not fully met by the information provided, nor does indrawing directly classify as SIRS. *Tachypnoea* - **Tachypnoea** refers specifically to an elevated respiratory rate, which is present (52 breaths per minute). - However, the presence of **chest indrawing** indicates more than just rapid breathing; it signifies significant respiratory effort and compromise. - The classification must capture both the elevated rate and the increased work of breathing. *ARDS* - **Acute Respiratory Distress Syndrome (ARDS)** is a severe form of lung injury characterized by widespread inflammation, hypoxemia, and bilateral infiltrates on chest imaging. - While respiratory distress is a feature of ARDS, the given information is insufficient to diagnose ARDS, which requires specific criteria relating to oxygenation and radiological findings.
Question 1187: A 45-day-old infant presents with seizures. Examination reveals he is icteric, has bulging fontanelles, and exhibits opisthotonic posture. Which of the following treatments is NOT indicated?
- A. Chlorpromazine (Correct Answer)
- B. Phenobarbital
- C. Phototherapy
- D. Exchange Transfusion
Explanation: ***Chlorpromazine*** - Chlorpromazine is an **antipsychotic medication** and is **contraindicated** in infants, especially in the presence of seizures and central nervous system (CNS) dysfunction, due to its potential to **lower the seizure threshold** and cause severe extrapyramidal symptoms. - Its mechanism of action via **dopamine receptor blockade** is not relevant for treating bilirubin encephalopathy or its symptoms. *Phototherapy* - Phototherapy is a primary treatment for **neonatal jaundice** to reduce unconjugated bilirubin levels and prevent neurotoxicity. - While the infant's condition suggests severe hyperbilirubinemia with complications, phototherapy would still be indicated as an initial step or adjunct to further interventions, especially if the bilirubin levels are still rising. *Exchange Transfusion* - Exchange transfusion is a **definitive treatment** for severe hyperbilirubinemia, especially when there are signs of **acute bilirubin encephalopathy (kernicterus)**, as suggested by seizures, bulging fontanelles, and opisthotonus. - It rapidly removes bilirubin from the blood and is crucial to prevent further neurological damage in such critical cases. *Phenobarbital* - Phenobarbital is an **anticonvulsant** used to manage seizures, which are a prominent symptom in this infant. - It can also help to **induce hepatic enzymes** involved in bilirubin metabolism, thereby potentially aiding in the reduction of bilirubin levels in cases of severe hyperbilirubinemia, though its primary role here would be seizure control.
Question 1188: Chronic lung disease in infancy is defined as
- A. Need for supplemental oxygen at 36 weeks postmenstrual age (Correct Answer)
- B. Tachypnoea > 50 breaths/ min within 1 week of birth
- C. Presence of bilateral infiltrates on chest Xray for 2 weeks
- D. Reticulogranular pattern on chest Xray for 6 weeks
Explanation: ***Need for supplemental oxygen at 36 weeks after conception*** - **Chronic lung disease (CLD)**, also known as **bronchopulmonary dysplasia (BPD)**, is defined by the need for **supplemental oxygen** at 36 weeks postmenstrual age (corrected gestational age) or at 56 days postnatal age, whichever comes first, for infants born before 32 weeks gestation. - This definition reflects persistent respiratory morbidity requiring ongoing support, indicative of lung injury and abnormal development. *Tachypnoea > 50 breaths/ min within 1 week of birth* - **Tachypnoea** within the first week of birth can be a symptom of various neonatal respiratory conditions, such as **transient tachypnoea of the newborn (TTN)** or **respiratory distress syndrome (RDS)**, but it is not a defining feature of CLD. - CLD is characterized by a *prolonged* need for respiratory support, not just an acute symptom in the first week. *Presence of bilateral infiltrates on chest Xray for 2 weeks* - **Bilateral infiltrates** on a chest X-ray over two weeks could suggest conditions like **pneumonia** or **ARDS**, but it is not the diagnostic criterion for CLD. - The definition of CLD focuses on the physiological need for oxygen, rather than specific radiographic findings in isolation. *Reticulogranular pattern on chest Xray for 6 weeks* - A **reticulogranular pattern** on chest X-ray is characteristic of **respiratory distress syndrome (RDS)**, typically seen in premature infants due to surfactant deficiency. - While RDS can precede CLD, a **reticulogranular pattern** typically improves with treatment (surfactant therapy, ventilation) and does not persist for 6 weeks as a defining feature of chronic lung disease.
Physiology
1 questionsWhat is the primary change in fetal circulation that occurs at birth?
NEET-PG 2015 - Physiology NEET-PG Practice Questions and MCQs
Question 1181: What is the primary change in fetal circulation that occurs at birth?
- A. Closure of the ductus venosus
- B. Increased activity of the right ventricle
- C. Closure of the foramen ovale (Correct Answer)
- D. Closure of the patent ductus arteriosus
Explanation: ***Closure of the foramen ovale*** - The **foramen ovale** undergoes functional closure within minutes of birth, making it the **primary immediate circulatory change** - At birth, the first breath causes **dramatic decrease in pulmonary vascular resistance** and **increased pulmonary blood flow**, which raises **left atrial pressure** - Simultaneously, umbilical cord clamping **increases systemic vascular resistance** and **decreases right atrial pressure** (loss of placental return) - This **pressure gradient reversal** (left atrial pressure > right atrial pressure) causes the **septum primum** to be pushed against the **septum secundum**, achieving functional closure - This immediately separates the systemic and pulmonary circulations, which is the **most critical primary change** in transitioning from fetal to neonatal circulation *Closure of the patent ductus arteriosus* - The **ductus arteriosus** undergoes **functional closure over 10-15 hours** after birth, followed by **anatomical closure over 2-3 weeks** - Closure occurs due to increased arterial oxygen tension and decreased prostaglandin E2 levels, causing smooth muscle constriction - While important, this is a **secondary change** that occurs more gradually compared to the immediate foramen ovale closure *Closure of the ductus venosus* - The **ductus venosus** closes functionally within 3-7 days as umbilical venous flow ceases - This redirects portal blood through the liver but does not directly impact the critical pulmonary-systemic circulation separation *Increased activity of the right ventricle* - After birth, the **left ventricle** becomes dominant as it pumps against higher systemic vascular resistance - The right ventricle actually experiences **decreased afterload** due to falling pulmonary vascular resistance - This is a consequence of, not the primary change in, the circulatory transition