11 Maternal + Neonatal physiology Flashcards
Major respiratory changes at birth
Loss plscental gas exchange
initiation ventilation newborn lung
commencement pulmonary g echange
est FRC
Major CVS change birth
Loos umbil circ to placenta
CLose DV
Functional closure - FO
Close Duct arteriosus
Increase pulmonary circ
change skin flow - rleate expore - thermoreg role
change RBF - decrease Renal casvular resistance
How are the 2 changes related
Major change - cesastio umbil flow
Bombardment - external seosnry stimuli when born
Loss placenta gas exchange - asphyxia -
central periph chemo stim
stim resp cent - initiation lung ventilation
(passge thru birth canal compression throax- expel some airway fluid_
Increase LV w/ vent - decre resist ex alveolar vessel
rise alv p02- removal HPV
- large decrease PVR -increase pul flow
rise art po2 constric DA - promote pulm flow
Loss VR _ umb vein - close dv - rall RAP
LAP increase – increase pulom flow
reversal pressure gradient - - func close
remove R->L shunt 0 further promot lung flow
Fxn of placenta
Tranport immunlog metabolic Endcine (TIME)
Transport placental fuxn
Gas exchange
Nutrient
Waste remov
Aater and electro deliv
Tport other - drug
Heat
Immunlog
Metab
endo fxn
Protect infx
Rejection by mother - immune barier
Synth glycogen - cholesterol FA + Enzymes
4 Main homo
HCG HPL Oestriol Progesterone
other hormone - plac cotrico
What mech prevent immune rejection
Acquired defects in maternal immune competence
- Increase susc cert infx (poli hep a+b malaria_ - cell med immune
Trophblast -
dont express Class I / II MHC
CAnt present antigen -> lympho
ant be recog act cytoT
Where is progesterone produce - preg
1st tri- corpus letue in ovary
Ramneder - placenta
Processes - sub X placetna
1 Diffusion
- water, gases, lipid drug
2 Fac diffusion
3 ATP
Both- carrier protein
against conc grad, involve energy expend, sat at high conc, competiton
-> fts fac diffusion - not inolve energy expend
Pinocyto Large non lip sol / no carrier Globulin Plip lipopreot IgG - only class cross plcaetna - baby immune prote months
Foetal gluc level
Maternal level major factor -
What sub Carry placenta by active tpor
AA Ca Fe I Water sol vit
Role HCG
Main CL - early preg - sim LH
Major role HPL =
Also - Chorionic GH + structure sim to HGH
reg gluc fetus
alter mother metab - promote foetal growth (use more fat so more gluc for baby)
Insulin antagonist - secretion controll gluc level - if fall = hpl increase
increased liplysis - more gluc for baby
Neonatal temperature regulation
Thermoneutral zone?
Typical value neonate and aduult
Ambinet temp == maint body temp not increase heat prod
metab - aerobic - min heat prod = min o2 consump
32-34’C term neo
25-30 adults
Prem - higher
Why neonate susecptible heat stress
1 Large SA to Vol ratio
2 Thin Subcut tissue
3 Lim sweat capactiy
4 lim Ability control environment
Evap losses can be large
Higher BMR - more heat to lose to main equil
What mech used neo - control temp
changes position - change skin flow
behavioural - cry SKin vcon Non shiv thermo - brown fat Musc activity and shivery (poor develop) Movement = heat (may lose insulating mat)
Warmth
behavo - cry remove
skin vdil
sweat (lim - evap heat loss can double)
Brown fat
Heat prod by metab
WHite fat- store energy reserve
Bronw - fat glob and large mito
uncopling ox physo = more ehat generate -
Cell cont glycogen - gluc metab
Abdomen, large blood vessl, interscap base neck
2-6% tbw neonate
Total body heat production - double increase brown fat activity
Oxygen reqd
RIch symp innerv - b recp - increase lipolysis
sympathethic control
How keep child warm
Warm blankent
insulating non op site insulating mater
theatre temp
warm humidif insp gas
warm IVF
Radiant heaters
Short op time
Min exporsure - wet surface
High SA to VOl - signif tfer and increase in temp can occur
monitoring important
CVS changes during pregnancy
1 Increase CO - 30% SV + HR
2 Increase blood vol - 40-45% -plasma 50% RCC 30% - phys anaem preg 1200mls b term Most increase - 1st 2 trimester - reamins constant - increase during third trim
3 Increase flow many tissue
4 Decreased TPR - Hormones
Placetna flow - AB shunt flow passive
Vdil - med pregoseterone
Decreased TPR + Inc BV = Inc CO
Most - present end 1st tri
Spirometry preg
1 Decrease FRC - increase RV + ERV
2 TLC - norm/decreased - Elevatin diphargam = increase AP + tv diam
3 Higher MV - increase Vt + slight inc RR
How is the neonatal airway different from the dult
Upper 1 Nasal passage narrow 2 Tongue large 3 Nasal breathers 4 Nasal obstruct ~~ resp distress
Larynx Epiglo - stiff U shpae, angled 45' Glottis high C3-C4 - C5 C6 in adult - anterior angulation back pressure - assis Cricoid narrowest - complete catil ring cant expend -
Lower Airway Trach - short 4-5cm w diam 6m RMB - directer in line vs left L - 45' R - 30'
Periph a/way -diam <2mm - 50% a.way ressitance
Airway contrib 20% adult
can cause severe RDS (bronchilotis)
Less bornch muscle present
bronspasm - uncommon - response bdil poor
What difference lung mechanics
1 Chest wall compliant - Compresion bithc canal
2 Ribs horriznla - absence bucket handle
1=2 - minimal thoracic component to bent
4 Diaphragm - breathing
impaird mech effecieny
low prop high ox capc - suceptible fatige
abdo distension - splint diaphrgam - Cause RDS
Disten stom bmc - impair spont vent
5 Alv vent - 120-140mls kg min (2x adulg- WOB 1% BMR min high RR - rather larger TV
6 I;E ratio 1
7 End exp pleural pressure ~ 0
rather remain neg adult
Diffce lung vol and gas ehange
FRC 30mls kg
same adult
less stable - tend to atelectasis
FRC < CC - gas trapping small airway normal TV
AA grad inc 30mmhg v 5
increased venous admix - shunt non vent region
O2 consump - high weight bases
6-7mls kg v 3
- d/t higher BMR
O2 delivery - aided igh alveolar vent
high co
CO -> metab active
reapid inhal induction
Gas exchange reserve lower - smaller pulm bg membrane
What diffrence respiratory control neonate
Control mech< develop - espec prem baby
Period resp common
pasues 5-10s / up 5 sleep - normal
Apneoic - >20sec - a/w bradyardi - abnormal
Hypoxia response blunt hypothermi aesp prem
