Neonatal path. Flashcards
def. birth
complete expulsion or removal of fetus that at any time did breath or show signs of life
def. premature
def. postmature
> 42 weeks GA
what is small and large for GA
90th
def. neonatal period
birth to one month
how does mortality compare to premature
inverse relationship - big jump between 24 and 23 weels
2 main causes of neonatal death
- premature
2. congential/chromo anomalies
5 parts of apgar
- heart rarte
- resp. effort
- muscle tone
- response to cath. in nostril
- color
how does apgar compare to mortality
high score = less death
3 fetal circ. bipass systems
- ductus venosus - liver
- foramen ovale - lungs
- ductus areteriosus - lungs
what happens to circ at birth
- pulm art. dilate and reduce pressure
- high LA pressure and low placental flow close foramen ovale
- duct arteriosus and venosus close
what happens to lung as age
get more alveoli - can survive at 36 weks
what happens to lungs at birth
- vag pressure squeezes fluids from lungs
- alveoli inflate with first few breaths
- alveoli don’t collapse b/c of surfactant
where does sufactant come from
type 2 pneumocytes
when do we have enough surfactant
35 wks
what is sufactant made of and what is important ratio
lecitin and shynogmyelin - need > 2:1 L:S
3 general causes of failed adaptation
- immaute physiological systems
- congenital malformations
- supression of central controls and reflexes - no practice breathing
2 causes of pulm. hypoplasia
- ogliohydramnos - too little fluid
2. fetal hydrops - too much fluid
2 types of congenital heart malformations
- obstructions to circulation
2. persistence of fetal shunts
def. congenital cardiomyopathy
thickening of LV so can’t contract and relax
5 birth factors
- breech
- forceps/vacuum assisst
- large bb
- cephalopelvic
- prolonged labor
3 traumas caused by birth
- head injuries
- fractures
- rupture/laceration of organs
most common cause of neonate mortality
prematurity
3 placental causes of prematurity
- premature rupture of placental membranes
- chorioamnionitis
- other - twins, placenta previa
2 important complications of prematurity
- hyaline membrane disease
2. necrotizing enterocolitis
def. hyaline membrane dissease
acute injury to alveoli and term. bronchioles with epithelial necrosis, exudation of fluid and formation of membranes in distal airspaces
signs of HMD
tachypnea, hypoxia, increased work brething
- ground glass CXR
how does HMD compare to age
inverse relat.
main cause of HMD
lack of suractant
2 main complications of treatment of HMD
- pulmonary barotrauma - high pressures used
- reparative proliferation and metaplasia of stroma - oxygen toxicity - bronchopulm. dysplasia
- pulmonary fibrosis, arrest in dev. of acini, decrease cap. bed
clinical def. of pulmonary dysplasia
persistence of Sx of resp, disease beyond the neonatal period
HMD prophylaxis (3)
- delay birth
- give steroids
- exogenous surfactant
what does HMD prog. depend on
GA and birth weight - better now with surfactant
what is necrotizing enterocolitis (NEC)
acute iscemic necrosis of the intestines of a newborn
3 poss. causes of NEC
- dev. after feeding starts
- assoc. with poor perf. of intestines
- assoc. with bact. invasion through damaged mucosa
NEC path.
- necrosis begins at bowel mucosa and progresses full thickness
- mucosa blees
- bubbles of gas form in bowel wall
- necrosis leads to bowel perf.
NEC treatment and prog.
- early treat with ABs and bowel rest (TPN)
- 40% require resection
