CARDIOTOCOGRAPHY Flashcards
Contributory factors to fetal morbidity and mortality following CTG
- CTG technique/equipment
- Errors of interpretation of CTG
- Failure to act upon suspicion of pathological CTG
- Fetal blood sampling
- CTG and blood sampling–other
T/F: Staff tasked with CTG interpretation must have evidence of annual training
T
T/F: Key management decisions should not be based on CTG alone
T
Monitoring tool to identify hypoxia
`Cardiotocograph
T/F: CTG during labour is associated with reduced rates of neonatal seizures
T
T/F: increase in caesarean sections and instrumental vaginal births with CTG in labour
T
T/F: with CTG there is no clear differences in cerebral palsy, infant mortality or other standard measures of neonatal wellbeing.
T
CTG pattern with stress
- Hypoxia begins with deceleration
- Acceleration disappear
- Baseline HR increases
CTG pattern with compensated stress
- Stable baseline
- normal variability
- deceleration deeper and wider
CTG pattern with decompensation
- Unstable Baseline
- changes in variability
4features of fetal heart rate
- Baseline rate
- Baseline variability
- Presence or absence of decelerations (and concerning characteristics of variable decelerations if present)
- Presence of accelerations
T/F: If there is a stable baseline fetal heart rate between 110and 160beats/minute and normal variability, continue usual care as the risk of fatal acidosis is low
T
T/F:The presence of fetal heart rate accelerations, even with reduced baseline variability, is generally a sign that the baby is healthy
T
Normalbaseline rate is
110 – 160 bpm
T/F: Baseline HR is gestation dependent
T
Non reassuring baseline rate are –and –
baseline bradycardia and baseline tachycardia
Baseline bradycardia is
100 - 109 bpm
Baseline tachycardia is
160 - 179bpm
AbnormalHR
<100 bpm
>180 bpm
Acceleration is
Increase in FHR above baseline of at least 15bpm for at least 15seconds
T/F: Absence of FHR acceleration is a good predictor of fetal metabolic acidemia or hypoxic injury
F. Poor predictor
Single most helpful method of assessing a fetus
Variability
T/F: Represents integrated activity of the autonomic nervous system
T
T/F: Tends to be reduced during spells of quiet sleep
T
Abnormal variability is
Reduced variability with decelerations
low or high baseline rate
Normal variability
Between 5 and 25 bpm
Increased variability
> 25 bpm
Reduced variability
2 - 5 bpm
Absent variability
< 2 bpm
Types of variability
Normal, increased, reduced and absent
Deceleration is
Drop in baseline of at least 15bpm, lasting at least 15 seconds
Types of decelerations
early, late and variable
A temporary decrease in fetal heart rate below the baseline
Deceleration
T/F: Deceleration may be obvious (deep and broad) or subtle (shallow)
T
Fetal autonomic response to changes in intracranial pressure and/or cerebral blood as a result head compression in labour.
Early deceleration
reflex fetal response to transient hypoxemia during uterine contraction
Late deceleration
fetal autonomic reflex response to mechanical compression of the umbilical cord
Variable deceleration
No Concerning characteristics with variable decelerations are –, –, – and –
- lasting less than 60seconds
- baseline variability maintained within the deceleration
- shouldering
- V shape
Concerning characteristics with variable decelerations
- lasting more than 60seconds
- reduced baseline variability within the deceleration
- failure to return to baseline
- biphasic (W) shape
- no shouldering
T/F: Shallow decelarations are more ominous compared to deep decelarations
T
Rare and associated with fetal anaemia and hypoxia.
Sinusoidal pattern
A regular oscillation of the baseline long-term variability resembling a sine wave
Sinusoidal pattern
Characteristics of sinusoidal pattern
- a smooth undulating pattern
- 3-5cycles per minute
- Amplitude 5-15bpm
- No acceleration
- Persist at least 20 minutes
How long should a CTG trace be stored
- 25 years
- In cases where there is concern that the baby may experience developmental delay, photocopy CTG traces and store them indefinitely in case of possible adverse outcomes.
T/F: Antenatal CTG can be performed from 24 weeks
F. Not done prior to 26 weeks
T/F: Computerised CTG is not appropriate for intrapartum fetal monitoring
T.
NOT appropriate for intrapartum fetal monitoring. It is not valid if the woman is experiencing regular uterine contractions, or when she is in the latent phase of labour. It can be used prior to the administration of Propess, but not after it has been administered.
T/F: A short-term variation (STV) value of less than 3ms is strongly linked to the development of metabolic acidemia and impending intrauterine death
T
Dawes Redman Criteria
DRC met =
Normal CTG
Criteria can be met as early as 10minutes and CTG discontinued before 20minutes
DRC not met –
continue CTG for full 60minutes
Codes for why criteria not met
5 maternal indications for intrapartum CTG
Antepartum haemorrhage
Significant meconium
Oxytocin use
Suspected chorioamnionitis, sepsis
PET ( severe HTN , proteinuria)
5 fetal indications for intrapartum CTG
Cord presentation
Abnormal presentation – breech, transverse
Fetal growth restriction
Deceleration heard on IA
Suspicious CTG is
2 normal features plus one non reassuring feature
Features of a non reassuring CTG
- Baseline of 100 - 109 or 161 -180
- Variability of <5bpm for 30 mins or >25bpm for 15 mins
- Read up the decelerations
Features of pathological CTG
- Baseline below 100 or > 180
- Variability of <5bpm for 50 mins or >25bpm for 25 mins
- Read up the decelerations
