Arab Board Pediatrics Part 1 key terms

A phospholipid-protein mixture secreted by type II pneumocytes that lowers alveolar surface tension, preventing alveolar collapse at end-expiration. Deficiency in premature infants causes respiratory distress syndrome with grunting, retractions and hypoxemia.

Acute lung disease of preterm infants caused by surfactant deficiency and immature lung structure, presenting soon after birth with tachypnea, grunting, nasal flaring, retractions and ground-glass chest radiograph. Treated with exogenous surfactant and positive airway pressure.

Delivery of a constant positive pressure to the airways throughout the respiratory cycle while the infant breathes spontaneously. It recruits and stabilizes alveoli, reduces work of breathing, and is first-line support for neonatal respiratory distress and apnea of prematurity.

Pause in breathing lasting 20 seconds or more, or shorter if accompanied by bradycardia or desaturation, occurring in infants born before 37 weeks due to immature respiratory control. Treated with caffeine citrate and respiratory support.

The volume of gas remaining in the lungs at the end of a normal passive expiration. It reflects the balance between lung elastic recoil and chest wall outward pull, and is reduced in surfactant deficiency and other restrictive neonatal lung diseases.

Unconjugated hyperbilirubinemia appearing after the first 24 hours of life in otherwise well newborns, reflecting immature hepatic conjugation and increased bilirubin load. It peaks around days 3 to 5 and resolves without treatment unless levels exceed age-specific thresholds.

Permanent neurologic injury from bilirubin deposition in the basal ganglia and brainstem, causing hypotonia, lethargy, deafness, choreoathetosis and gaze palsy. It is prevented by treating severe neonatal hyperbilirubinemia promptly with phototherapy or exchange transfusion.

Treatment of neonatal jaundice using blue-green light that converts bilirubin in the skin into water-soluble isomers excreted without hepatic conjugation. Its intensity and duration depend on bilirubin level, gestational age and hemolytic risk factors.

Birth weight below the 10th percentile for gestational age, reflecting intrauterine growth restriction or constitutional smallness. Affected infants risk hypoglycemia, hypothermia, polycythemia and meconium aspiration, and need careful feeding and glucose monitoring.

Birth weight above the 90th percentile for gestational age, often associated with maternal diabetes or post-term gestation. These infants are at risk of birth trauma, hypoglycemia, polycythemia and respiratory problems and require screening for these complications.

A standardized physical and neuromuscular assessment used to estimate gestational age in newborns, scoring features such as posture, square window, arm recoil and skin maturity. It is most accurate between 20 and 28 weeks and helps guide care of preterm infants.

Bacterial infection of the bloodstream in the first 28 days of life, classified as early-onset (within 72 hours, usually from maternal genital flora) or late-onset (from environment or nosocomial sources). Presents nonspecifically with poor feeding, lethargy, temperature instability and apnea.

A gram-positive coccus colonizing the maternal genital tract that is the leading cause of early-onset neonatal sepsis and meningitis. Intrapartum antibiotic prophylaxis is offered to colonized mothers or those with risk factors such as prolonged rupture of membranes.

An acute-phase reactant produced by the liver that rises within hours of inflammation or infection. In neonates it is used serially to support or exclude the diagnosis of sepsis, though its low specificity means it must be interpreted with clinical findings and cultures.

Persistence of the fetal vessel connecting the pulmonary artery to the descending aorta after birth, causing a left-to-right shunt with bounding pulses, wide pulse pressure and pulmonary overcirculation. It is common in preterm infants and may be treated medically or by closure.

Pulmonary vascular disease with reversal of a long-standing left-to-right shunt to right-to-left flow, producing cyanosis and polycythemia. Once established, shunt closure is contraindicated because it worsens right ventricular failure.

A defect in the interventricular septum producing a left-to-right shunt whose severity depends on defect size and pulmonary vascular resistance. Small defects cause a loud holosystolic murmur, while large defects cause heart failure and failure to thrive in infancy.

An infusion used to keep the ductus arteriosus open in ductal-dependent congenital heart lesions such as transposition of the great arteries or pulmonary atresia. Its main adverse effects are apnea, hypotension and fever, so airway support must be available.

A conotruncal anomaly comprising ventricular septal defect, pulmonary stenosis, right ventricular hypertrophy and an overriding aorta. It causes cyanosis worsened by crying or feeding, and hypercyanotic spells are treated with knee-chest positioning, oxygen, morphine and fluid boluses.

Acute viral laryngotracheitis, usually from parainfluenza virus, causing barking cough, hoarse voice and inspiratory stridor in children aged six months to three years. It is treated with a single dose of oral dexamethasone and nebulized epinephrine for severe cases.

Acute bacterial inflammation of the epiglottis, most often caused by Haemophilus influenzae type b, presenting with high fever, drooling, muffled voice and tripod positioning. The airway must be secured by skilled personnel without agitating the child.

Viral lower respiratory infection of infants, most commonly by respiratory syncytial virus, causing wheeze, crackles and increased work of breathing after a coryzal prodrome. Management is supportive with oxygen and hydration; bronchodilators and steroids are not routinely effective.

The maximum speed of forced expiration, measured with a portable meter and expressed as a percentage of the child's predicted or personal best value. It supports asthma diagnosis and monitoring but is effort-dependent and less reliable in young children.

Chronic airway inflammation with reversible bronchoconstriction causing recurrent wheeze, cough and breathlessness triggered by allergens, infection or exercise. Treatment uses inhaled corticosteroids for control and short-acting beta-agonists for relief, with stepwise escalation.

The volume of air forcibly exhaled in the first second of a maximal expiration from full inspiration, measured by spirometry. A reduced ratio to forced vital capacity indicates obstructive lung disease and reversibility after a bronchodilator supports asthma.

Hypertrophy of the pyloric muscle causing non-bilious projectile vomiting at two to six weeks of age, visible gastric peristalsis and a palpable olive-shaped mass. Hypochloremic hypokalemic metabolic alkalosis is corrected before pyloromyotomy.

Vomiting of green-stained fluid indicating obstruction distal to the ampulla of Vater, as in malrotation with volvulus or intestinal atresia. It is a surgical emergency in the newborn and requires immediate evaluation with abdominal imaging.

Telescoping of a proximal bowel segment into a distal one, usually ileocolic, in infants aged six months to three years. It causes colicky pain, drawing up of legs, a sausage-shaped mass and red currant jelly stool, and is reduced by air or contrast enema.

Passage of gastric contents into the esophagus, common and usually benign in infants as a functional immaturity. It causes regurgitation and possetting; red flags such as poor weight gain, bilious vomiting or apnea warrant investigation.

An immune-mediated enteropathy triggered by dietary gluten in genetically susceptible children, causing villous atrophy with malabsorption, diarrhea, abdominal distension and failure to thrive. Diagnosis uses tissue transglutaminase antibodies and small bowel biopsy, treated by lifelong gluten exclusion.

Excess fat in stool producing bulky, pale, foul-smelling and floating stools, reflecting fat malabsorption from pancreatic insufficiency, cholestasis or mucosal disease. It is assessed by fecal fat measurement and treated by addressing the underlying cause and supplementing fat-soluble vitamins.

Inadequate weight gain or growth in a child, usually defined as weight below the third to fifth percentile or crossing two major percentile lines downward. Causes include inadequate intake, malabsorption and increased metabolic demand, and management is multidisciplinary.

A glomerular disorder causing heavy proteinuria, hypoalbuminemia, edema and hyperlipidemia, most often minimal change disease in children. Corticosteroids induce remission in most cases; relapses and steroid resistance require biopsy and alternative immunosuppression.

Immune-complex glomerular inflammation occurring one to three weeks after group A streptococcal pharyngitis or impetigo, causing hematuria, hypertension, edema and low complement C3. Management is supportive with salt and fluid restriction and antihypertensives.

Presence of red blood cells in urine, either microscopic or visible as smoky or frankly bloody urine. It requires distinguishing glomerular from lower urinary tract sources and evaluating for infection, stones, glomerulonephritis and structural anomalies.

Retrograde flow of urine from the bladder into the ureter and kidney due to an incompetent ureterovesical junction. It predisposes to pyelonephritis and renal scarring, and is graded by voiding cystourethrography and managed with antibiotic prophylaxis or surgery.

Bacterial infection of the urinary tract, common in children and often caused by Escherichia coli, presenting with fever, dysuria, frequency or abdominal pain. Prompt treatment and imaging for structural anomalies reduce the risk of renal scarring.

Dilatation of the renal pelvis and calyces from obstruction or reflux, often detected antenatally by ultrasound. It requires postnatal imaging and may need surgical relief if obstruction is significant or renal function is threatened.

Thyroid hormone deficiency present at birth, usually from thyroid dysgenesis, causing prolonged jaundice, constipation, hypotonia, large fontanelle and developmental delay if untreated. Newborn screening allows early levothyroxine therapy that prevents intellectual disability.

A metabolic emergency of insulin deficiency with hyperglycemia, ketonemia and acidosis, presenting with polyuria, vomiting, dehydration and Kussmaul breathing. Treatment requires careful fluid and insulin administration with monitoring for cerebral edema.

A public health program testing heel-prick blood spots in the first days of life for treatable conditions such as congenital hypothyroidism, phenylketonuria, galactosemia and hemoglobinopathies. Early detection and treatment prevent severe disability or death.

Deficiency of phenylalanine hydroxylase causing accumulation of phenylalanine and intellectual disability if untreated. It is detected by newborn screening and managed with a low-phenylalanine diet and special formula, with lifelong monitoring.

An inherited hemoglobinopathy in which abnormal hemoglobin S polymerizes and causes red cell sickling, hemolytic anemia and vaso-occlusive crises. Affected children need penicillin prophylaxis, vaccination and hydroxyurea, and acute pain or chest syndrome requires urgent care.

Anemia caused by premature destruction of red blood cells, producing jaundice, splenomegaly and a raised reticulocyte count. Causes in children include hemoglobinopathies, enzyme deficiencies, membrane disorders and immune-mediated destruction.

Removal of a patient's blood with simultaneous replacement by donor blood to rapidly lower bilirubin, remove antibodies or correct severe anemia. It is used in severe neonatal jaundice and in acute complications of sickle cell disease.

A seizure occurring between six months and five years of age with fever but no intracranial infection or prior afebrile seizures. Simple febrile seizures are generalized and brief with good prognosis; complex ones are focal, prolonged or recurrent in 24 hours.

Continuous seizure activity lasting five minutes or more, or repeated seizures without regaining consciousness, requiring immediate benzodiazepine therapy. Prompt treatment prevents neuronal injury and systemic complications such as hypoxia and hyperthermia.

Insertion of a needle into the lumbar subarachnoid space to collect cerebrospinal fluid for analysis or to give intrathecal therapy. In children it is used to diagnose meningitis, and contraindications include raised intracranial pressure and coagulopathy.

Infection of the meninges by bacteria such as Streptococcus pneumoniae or Neisseria meningitidis, causing fever, headache, neck stiffness, vomiting and altered consciousness. It requires immediate intravenous antibiotics and supportive care to prevent death and neurologic sequelae.

A skill or behavior that most children achieve within a predictable age range, such as sitting unsupported by nine months or using two-word phrases by two years. Milestones are used to screen for developmental delay and prompt early intervention.

The orange-red reflection from the retina seen when shining a light into the eye, produced by light reflecting off the fundus. It is checked in newborns to detect congenital cataract, retinoblastoma and other media opacities.

Deep, rapid, sighing respirations caused by metabolic acidosis as the body attempts to blow off carbon dioxide. It is classically seen in diabetic ketoacidosis and other severe acidotic states and resolves as the acidosis is corrected.

A deficit of total body water and electrolytes, classified as isotonic, hypotonic or hypertonic by serum sodium. In children it usually follows gastroenteritis and is assessed by weight loss, capillary refill, mucous membranes and skin turgor, then treated with oral or intravenous fluids.

A balanced glucose-electrolyte drink using the sodium-glucose cotransporter to enhance water absorption, given in small frequent amounts for mild to moderate dehydration. Its reduced-osmolarity formulation is first-line therapy for childhood gastroenteritis.

Protection against infection acquired from transferred antibodies rather than the person's own immune response, as with maternal IgG across the placenta or breast milk IgA. It is temporary and underlies the rationale for maternal immunization and immunoglobulin therapy.

A vaccine made from weakened live organisms, such as measles-mumps-rubella or varicella, that replicates and produces strong lasting immunity. It is generally contraindicated in severe immunodeficiency and pregnancy because replication is uncontrolled.