Page 221 - Concise Pathology for Exam Preparation ( PDFDrive )

206 SECTION I General Pathology

(ii) Permanent neurological sequelae common.
(iii) Positive serologic test (TORCH) indicates disease.
(e) Syphilis
(i) Primarily transplacental transmission.
(ii) Symptoms and signs appear in first 1–2 months after birth and include
mucocutaneous lesions, lobar pneumonia, persistent rhinitis (snuffles),
osteochondritis and hepatomegaly.
(iii) Prominent late manifestations are bone abnormalities (saber shins) and
Hutchinson’s triad (malformed, notched upper central incisors, interstitial
keratitis leading to blindness and nerve deafness).
(iv) Rising VDRL titer; positive FTA-ABS-IgM are diagnostic.

Q. Write briefly on the disorders associated with prematurity.
Ans. Newborns may be classified as appropriate for gestational age (AGA), small for gestational
age (SGA) or large for gestational age (LGA).
• Term newborns are those born between 37 and 42 weeks, pre-term newborns are those born
before 37 weeks and post-term newborns are those born after 42 weeks.
• Infants born before completion of gestation usually weigh less than normal (2500 g).
• Prematurity is second only to congenital malformations as a cause of infant mortality.
• Preterm infants have immature organs, which predisposes them to various compli-
cations, eg, immature lungs (that lack surfactant and are prone to develop respira-
tory distress syndrome), necrotizing enterocolitis and intraventricular haemorrhage.

PART II: DISEASES OF INFANCY AND CHILDHOOD
Q. Write briefly on neonatal respiratory distress syndrome/hyaline
membrane disease.
Ans. Characterized by formation of pulmonary hyaline membrane, neonatal respiratory
distress syndrome is associated with the following conditions:
• Preterm infants.
• Infants born to diabetic mothers.
• Caesarean section delivery.
• Excessive sedation of mother during labour.
• Other birth-related asphyxias.

Aetiopathogenesis (Flowchart 8.1):
Decreased alveolar surfactant

Increased alveolar surface tension and atelectasis

Uneven perfusion and hypoventilation leading to hypoxaemia and CO retention
2

Acidosis and further reduction in surfactant synthesis

Pulmonary vasoconstriction and hypoperfusion

Endothelial and epithelial damage

Leakage of plasma into alveoli

Accumulation of fibrin and necrotic cells

Hyaline membrane formation
FLOWCHART 8.1. Aetiopathogenesis of hyaline membrane disease.
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