Cardiotocograph Flashcards
Aside from CTG, how else can you monitor baby?
pinard stethoscope
List two complications of fetal hypoxia?
perinatal death
hypoxic ischaemic encephalopathy
cerebral palsy
List three maternal factors associated with fetal hypoxia
hypotension epidural or spinal respiratory disease cardiac disease diabetes smoking infection drugs alcohol thyroid disease
List two placental factors associated with fetal hypoxia
placental abruption cord accidents infection chorioamnionitis pre-eclampsia
List three fetal causes of hypoxia
instrumental delivery cord prolapse malpresentations infection anaemia prematuryity haemorrhage congenital anomalies
What are the four features of fetal heart rate?
baseline rate
baseline variability
presence/absence of accelerations
presence/absence of decelerations
What are reassuring baseline rates for CTG?
110-160 bpm
What are abnormal/worrying baseline HR?
<100
>180
What is normal baseline variability?
5 to 25 bpm
What is abnormal baseline variability?
<5 bpm for >50 mins
>25 bpm for >25 mins
Are accelerations reassuring or not?
reassuring! the absence of them is abnormal.
15 bpm for 15 sec or more
When is variable deceleration concerning?
lasting more than 60 sec
failure to return to baseline
biphasic W shape
What is a normal/non concerning cause of variable deceleration?
cord compression
Which type of deceleration is most indicative of fetal hypoxia?
late deceleration
List two causes of decreased variability
sleep
fetal hypoxia
drugs
List one drug that can cause decreased varability
opiates
magnesium sulphate
List one cause of fetal tachy?
fetal hypoxia
chorioamnionitis
List two factors associated with high risk pregnancy?
meconium stained liquor
fever
intrauterine growth restriction
Explain the compensating mechanisms for hypoxia
reduced myocardial workload + reduced movement to conserve energy. No accelerations. Release of catecholamines which increase HR, promote peripheral vasoconstriction (to divert blood to vital organs), and promote glycogenolysis to increase energy supply.
What are the signs of decompensation on CTG?
loss of baseline variability (reduced oxygen to brain)
myocardia hypoxia and acidosis- unstable baseline
What is a pneumonic to remember the patterns of CTG changes in response to hypoxia?
ABCDE
Accelerations disappear
Baseline FHR increases
Compensated stress (stable basline FHR and normal variability)
Decompensation (unstable baseline and changes in varaibility)
End stage (Step ladder pattern due to myocardial failure)
Are early decelerations normal?
physiological- head compression, resolves when contraction ends
What is shouldering?
umbilical cord compression- fetus not hypoxic, compensating well. Variable deceleration
What are concerning features of variable decelerations?
> 60 sec
biphasic shape
no shouldering
reduced baseline variability
What do late decelerations indicate?
utero-placental insufficiency
List two causes of late decelerations?
maternal hypotension
pre-eclampsia
uterine hyperstimulation
