Pediatric Path Flashcards
Neonates
First 4 weeks
Infants
First year
Toddler
1-3 years
Preschool age
3-6 years
School age
6-12 years
Adolescent
10-19 years
What are birth injuries?
Spectrum of mechanical trauma to anoxic damage during birth
Predisposing factors for Birth Injuries
- Cephalopelvic disproportion (CPD)- Head of baby is too big or Mother’s pelvic is too small
- Difficult labor/ Breech presentation - Head of baby is not the first presenting part
- Prematurity - Before 32 weeks of gestation
Common Birth Injuries
Cranial
- caput succedaneum
- cephalohematoma
- skull fractures
- intracranial hemorrhage
Peripheral nerve injuries
- brachial palsy
- facial nerve palsy
Fractures
- clavicle
- humerus
- Rupture of liver
Congenital Anomalies
Morphological defects that are present at birth
NB: Some may present clinically years later
Etiology of Congenital Anomalies
1.Genetic
- Chromosomal aberration
- Genetic mutations
2. Environmental
- Maternal or placental infections
- Maternal disease
- Drugs & chemicals
- Irradiation
3. Multifactorial
- Combination of genetic & environmental
Pathogenesis of Congenital Anomalies
Embryonic Period - Up to week 9
Week 3
1. Injury will kill all cells –> Death
2. Injury kills some cells –> Recovery w/o defects
Week 4-9
3. Extreme susceptibility to teratogenesis (4-5 wks.) - time of organ formation from germ cell layers
Fetal period - After week 9
1. Injury/ growth restriction to already formed organs
- Reduced teratogenesis susceptibility
Intrauterine Growth Retardation (IGR)
Effects of Thalidomide
Limb malformations (Phocomelia)
Drug banned; but was used as an antiemetic to treat severe morning sickness
Effects of Alcohol in pregnancy on baby
Fetal Alcohol Syndrome
- Growth restrictions (pre & post-natal)
- Facial anomalies –> Microcephaly, Short palpebral fissures & Maxillary hypoplasia
- Psychomotor dysfunction - unable to meet milestones
Effects of Nicotine use during pregnancy
- Spontaneous abortion
- Premature labor
- Placental abnormalities
- Low birth weight
- Sudden Infant Death Syndrome (SIDS)
Catecholamine release –> Vasoconstriction –> Dec blood flow to placenta
Effects of Maternal Diabetes on babies
Fetal Hyperinsulinemia –> Fetal Macrosomia
- Organomegaly
- Inc body fat & muscle
- Hypoxia & Malnourished bc blood supply cant meet needs
Diabetic Embryopathy
- Cardiac defects
- Neural tube defects - Spinal bifida, etc
- CNS malformation
Down Syndrome Etiology
- Trisomy 21 –> Meiotic non-disjunction –> extra Chr 21 in every cell
- MC chromosomal disorder
RFs of Down Syndrome
- Inc Maternal age –> Inc risk of non-disjunction
CFs of Down Syndrome
- Severe intellectual disability
- Flat face & Present Epicanthic folds
- Abundant neck skin
- Simian crease
- Cardiac malformations - AVSD (VSD more common)
- Duodenal & Esophageal atresia/ stenosis
- Hypotonia
- Gap between 1st & 2nd toe
What does Down syndrome Pre-dispose to?
- Acute leukemias - ALL, AML (M7 most commonly)
- Infections
Etiology of Turner Syndrome
- 45X Karyotype –> Partial/complete monosomy of genes of the short arm of X chromosome
CFs of Turner Syndrome
- Short stature
- Webbed neck
- cubitus valgus
- CVS malformations - Aorta coarctation, Bicuspid Aortic valve
- Horseshoe kidney
- Amenorrhea & Infertility
- Lacks sexual characteristics
- Fibrotic/ “Streak” ovaries
- Low posterior hairline
- Peripheral lymphedema @ birth
- Broad chest w/ widely spaced nipples
- Pigmented nevi
Errors in Morphogenesis
- Malformation
- Disruption
- Deformation
Malformation
INTRINSIC defect –> Poor localized development
- Child normal other than defect
- Genetic or Chromosomal or Multifactorial
Types of Malformations
- Polydactyly - 1 or more digits
- Syndactyly - Fusion of digits
- Cleft lip & palate - Trisomy 13
- Congenital Heart defects - ASD
Disruption
EXTRINSIC
Secondary destruction of an organ/ body region that was previously normal in development
Rupture of amnion w/ amniotic bands (Chorion is still intact) –> Encircle/ compress/ attach to parts of fetus –> Dec blood supply –> Ischemia/ necrosis
Deformation
EXTRINSIC
localized or generalized compression of growing fetus by abnormal biomechanical forces –> Structural abnormalities
- Eg. = Uterine constraint (MC) –> As baby grows and the amnionic decreases, there is less cushioning
Maternal causes of Deformities
- 1st pregnancy
- Malformed or small uterus - Generalize compression
- Leiomyomas/ Fibroids
Fetal/placental causes of Deformities
- Oligohydramnios
- Multiple fetuses
- Abnormal/ breech presentation
Sequence
Cascade of anomalies ff an initiating aberration
- Malformation/ Disruption/ Deformities –> Secondary effects in other organs
Example of Sequence
Oligohydramnios Potter Syndrome
Pathogenesis of Oligohydramnios Potter’s Syndrome
Maternal HTN –> Uteroplacental insufficiency , Renal agenesis & Urinary tract obstruction
- Dec amniotic –> Less protection/ Inc pressure
CFs of Potter’s Syndrome
- Short/ small
- Hypoplastic lungs (Dec proline)- COD
- Dislocated hips
- Flat facial features
- Deformed feet
Malformation Syndrome
Presence of >1 developmental anomalies of >2 systems due o a common etiology (viral infection, chromosomal anomalies affecting affecting multiple tissues)
N: Simultaneous involvement of different tissues rather than sequential as w/ sequence
Klinefelter Syndrome
Male hypogonadism in the presence of at least 2 X chromosomes & 1+ Y chromosome
- MC cause o male hypogonadism
Etiology of Klinefelter Syndrome
Non-disjunction of Sex chromosomes during MEIOSIS
Karyotypes of Klinefelter Syndrome
- 47XXY - Most common
- 48XXXY
- Any other combination w/ 2+ X-chromosome & 1+ Y-chromosome
CFs o Klinefelter Syndrome
- Testicular atrophy & Sterility
- Dec body hair
- Gynecomastia
- Eunuchoid body habitus
- Narrow shoulders
- Long legs
- Wide hips
- Female-type pubic hair pattern
What diseases can Klinefelter Syndrome predispose pts. to?
- Breast cancer
- Extragonadal germ cell tumors
- Autoimmune disease
22q11.2 Deletion Syndrome
Malformations affecting the face, heart, thymus & parathyroid glands due to deletion of 22q11.2
Diagnosis of 22q11.2 deletion
FISH
Syndromes that can arise due to 22q11.2 deletion
- Di George Syndrome
- Thymic hypoplasia- Impaired T-cell immunity
- Parathyroid hypoplasia - Hypocalcemia
- Psychosis - Schizophrenia / Bi-polar - Velocardiofacial Syndrome
- Congenital heart disease of Outflow tracts
- Palatal abnormalities/ Facial dysmorphism
- Developmental delay
- Psychosis
Appropriate for gestational age (AGA)
Birth weight b/w 10th - 90th percentile for GA
Small for gestational age (SGA)
Birth weight < 10th percentile for GA
- Indicator of fetal growth restriction
- Marker for
Large for gestational age (LGA)
Birth weight > 90th percentile for GA
- Indicator of Inc fetal growth eg. Gestational diabetes
- Associated w/ birth injuries
Prematurity
<37 weeks of gestation
Low Birth weight
< 2500 gm @ birth
Causes of Low Birth Weight
- Prematurity
- Preterm Premature rupture of membrane (ROM) - Rupture before Labor pain
- Intrauterine infections - Toxoplasma, Rubella,
- Structural abnormalities of uterus, cervix or placenta
- Multiple gestations - Fetal growth restrictions
- Term infants < 2500 gm (undergrown NOT immature)
Fetal causes of Prematurity & Low Birth weight
- Chromosomal disorders eg. Trisomies
- Congenital malformations
- Congenital infections - TORCH
- Usually symmetric restriction - The size of all organs are reduced but formed equally
Placental Prematurity & Low Birth weight
- Placental previa - Covers cervical os
- Indication of Early ROM - Placenta abruption
- Trauma, accident, hit
- Extremely painful - Blood supply is cut off - Placental infarction
- No blood supply, nutrition or oxygen
-
Maternal causes of Prematurity & Low Birth weight
- Dec placenta blood flow
- Toxemia or pregnancy - Proteinuria & HTN that develops in 2nd trimester in pt. that had normal HTN before
- Chronic HTN - Prevents blood flow o placenta
- Alcoholism, narcotic abuse or smoking - Vasoconstriction & Dec blood flow
- Drugs: Phenytoin (Dilantin) - Dec Blood flow to placenta
- Malnutrition - Prolonged Hypoglycemia
APGAR Score
- Determines chances of newborn survival by assessing physiologic condition & responsiveness
- Evaluated @ 1 (How baby tolerated birthing process) & 5 (how baby is adapting to new environment) minutes after birth
- Max score = 10
APGAR “A” Category & Scoring
- Appearance
- Blue = 0
- Pink body & Blue extremities = 1
- Pink = 2
APGAR “P” Category & Scoring
- Pulse “Heat Rate”
- Absent = 0
- <100 = 1
- > 100 = 2
APGAR “G” Category & Scoring
- Grimace “ Response to catheter in throat”
- None = 0
- Grimace = 1
- Cough or sneeze = 2
APGAR “A”2 Category & Scoring
- Activity “Muscle one”
- Limp = 0
- Some flexion = 1
- Active motion = 2
APGAR “R” Category & Scoring
- Respiratory effort
- Absent = 0
- Slow & irregular = 1
- Good & crying = 2
Complications of Prermaturity
- Hyaline Membrane Disease
- Necrotizing Enterocolitis
Respiratory Distress Syndrome
AKA: Hyaline Membrace Disease
RFs of RDS
- Prematurity
- Perinatal asphyxia
- Maternal Diabetes
- C-section before labor onset
- Twin gestation
- Male sex
Pathogenesis of RDS
Surfactant
- Dec surface tension –> Open alveolar
- Production @ week 35 - 36
CFs of RDS
- Normal @ birth (usually)
- Labored, grunting respirations that progressively worsens (mins to hours)
Gross pathology of RDS
LUNGS
- Normal size
- Solid, airless & Red-purple color (Looks like liver)
Radiologic features o RDS
“Ground glass lungs”
Microscopic features of RDS
Eosinophilic thick hyaline membrane lining the dilated alveoli
Several hours
- Necrotic cellula debris in terminal brochioles & alveolar ducts
12-24 hours
- Smooth homogenous pink membranes lining terminal & respiratory bronchioles & alveolar ducts
- Membranes composed of necrotic alveolar Type 2
- Minimal Neutrophillic inflammatory reaction
Several days
-
Prevention of RDS
- Delay labor so lungs can mature
- Give steroids to enhance lung development & surfactant production - Evaluate Amniotic fluid phospholipids
- Good estimate of fetal surfactant levels
After birth
1. Oxygen
2. Surfactant replacement Therapy
Complications of RDS
- Retrolental fibroplasia (Retinopathy of Prematurity)
- Oxygen toxicity - Bronchopulmonary dysplasia
- Dec alveolar septation –> Large simplified alveolar structure & dysmorphic capillary configuration
Due to high conc of Ventilator-administered Oxygen for prolonged periods
Neonatal Necrotizing Enterocolitis (NEC)
Affects premature infants & term infants of low birth weight
Etiology of NEC
Multifactorial
- 25-50% mortality
-Occurs in 2nd - 3rd week of life
Predisposing factors for NES
- Intestinal ischemia
- Bacterial colonization of gut
- Formula feeding
CFs of NEC
Presents in week 2-3 of life
- Signs of intestinal obstruction after oral feeding in preterm infants w/ a Hx of Asphyxia
- Abdomen distention - Bacterial fermentation
- Bloody stools
- Shock
- DIC –> Death
Diagnosis of NEC
- Abdominal radiograph - Dilated loops of bowels
- Pneumatosis intestinalis - Gas w/i intestinal wall
Pathological features of NEC
- Distended bowel w/ thin & delicate walls showing spotty areas of necrosis & possible perforation
- Pneumatosis intestinalis
(Terminal ileum, Cecum & Rt. colon)
Microscopic features of NEC
- Mucosal coagulative necrosis (Submucosa & muscular layers involved)
- Pneumatosis intestinalis (beneath mucosa)
Early Complications of NEC
Early
- Intestinal perforation
- Sepsis
- Shock
- Acute tubular necrosis
- DIC
Late Complications of NEC
- Short gut syndrome
- Malabsorption
- Strictures
Neonatal Intraventricular Hemorrhage
Bleeding into germinal matrix w/ extension into ventricles
Germinal Matrix
Source of nerve cells in embryo & fetuses (up to 33 wks of gestation)
- Richly vascular areas w/ many thin-walled capillaries that are very sensitive to anoxia
Evolution & Sequelae of Neonatal Intraventricular Hemorrhage
Massive hemorrhage w/ tears in Falx cerebri or tentorium –> Rapid death
Long-term survivors
- Cavitation or Pseudocysts surrounded by hemosiderin laden macrophages & gliosis
- Hydrocephalus
