Monitoring Complex Labour Flashcards
What can cause a complex labour think? MOTHERS
Meconium Oxytocin Temperature Hyperstimulation/Haemorrhage Epidural Rate of progress Scar
100-109 beats as baseline is considered as…
non-reassuring (continue usual care if variability is normal and there are no variable or late decelerations)
160-180 beats as baseline is considered as…
NO OTHER NON- REASSURING features and no maternal tachycardia or pyrexia – continue (uncomplicated tachycardia)
<100 beats or >180 as a baseline is considered as …
abnormal
How can the sympathetic system have an influence on the baseline rate.
Increase in heart rate through direct nerve impulses and indirectly through catecholamine release
How can the parasympathetic system have an influence on the baseline rate.
decrease heart rate through the release of acetylcholine
5-25 beats in variability is considered as…
normal
5 beats for >30mins but < 50mins
non-reassuring
5 beats for >50mins
abnormal
25 beats
(salutatory)
25 beats ) for >15mins but <25mins
non-reassuring
Name 3 associated factors that could influence the variability of a CTG
Fetal sleep – cycling indicative of an intact CNS Maternal opiates Fetal hypoxia Pre-existing fetal brain damage Cardiac arrhythmia
What is suspected with reduced variability in conjunction with tachycardia and decelerations?
high suspicion of fetal hypoxia
Name the basic characteristics of sinusoidal traces
- Stable baseline of 120-160bpm with regular sine-wave oscillations
- Amplitude of 5-15bpm
- Frequency of 2-5 cycles/minute
- Reduced or absent baseline variability
- No accelerations
What can a Smooth or typical – rounded, symmetric in shape in trace indicate?
fetal thumb sucking,
some narcotics,
fetal anaemia secondary to rhesus isoimmunization
What can a Jagged or atypical – saw-tooth trace indicate?
fetal hypoxia and acidosis, sudden loss of fetal blood volume – fetomaternal haemorrhage
What are Accelerations?
An Increase of at least 15 beats for at least 15 seconds
When is Accelerations more frequent?
Occurs most frequently during fetal activity
–Generally a sign the baby is healthy
–Absence in an otherwise normal CTG is not indicative of acidosis
What are Decelerations?
Drop in the FHR of at least 15beats for at least 15 seconds
What are the two types of deceleration?
reflex and effect of hypoxia on myocardium
Reflex – low levels of O2 as a result of…
placental bed perfusion impairment – compression of uterine vessels
•Head compression
•Cord compression which increases stimulation of vagus nerve (parasympathetic nervous system),
what is the effect of hypoxia on heart?
Severe or prolonged shortage of O2 may affect myocardium which ceases to contract efficiently and the FHR falls
Name 4 characteristics of early decelerations
-Uniform
–Repetitive
–Starts at beginning of contraction and returns to baseline by the end of the contraction
–Nadir of deceleration corresponds to peak of contraction
– head compression(Relatively rare – only in late 1st and 2nd stage of labour)
Name the characteristics of Variable decelerations.
-Vary in shape, form and timing
–Most common >85%
–Classified as concerning and un-concerning
Name the characteristics of un-concerning variable decelerations
last <60 sec & <60 bpm
have shoulders
Name the characteristics of concerning variable decelerations
Lasts >60 sec, decreased variability within deceleration
•Failure to return to baseline, biphasic
•No shouldering
What is considered as a reassuring variable decelerations ?
Variable decelerations with no concerning characteristics for <90mins
What is considered as a Non-reassuring variable decelerations ?
Variable decelerations with no concerning characteristics for >90mins
Variable decelerations with concerning characteristics with <50% contractions for >30mins
Variable decelerations with concerning characteristics with >50% contractions <30mins
What is considered as a Abnormal variable decelerations ?
Variable decelerations with concerning characteristics with >50% contractions for >30mins (less if maternal or fetal risk factors – vaginal bleeding or significant meconium)
Name four characteristics late decelerations
Occurs mid to late in contraction
Nadir at least 20 seconds after peak of contraction
Return to baseline after contraction ceased
Similar shape to contraction
Related to hypoxaemia, hypercarbia and acidosis
Placental insufficiency
What is considered as Non-reassuring late deceleration?
With >50% contractions and <30mins (no maternal or fetal risk factors – mec or bleeding)
What is considered as Abnormal late deceleration?
With >50% contractions and >30mins
How long does a Prolonged decelerations or acute hypoxia last for?
lasts at least 3mins
Name the 4 types of ways to manage a prolonged deceleration
Exclude placental abruption, uterine rupture and cord prolapse
May be secondary to uterine hyperstimulation or tonic contraction or hypotension
Give IV fluids and stop oxytocin or give tocolytic
What is the Rule of 3s?
3mins – call for help
6mins – prepare for transfer to theatre
9mins – in theatre
12mins – have started LSCS
FUN FACT!!!
Always abnormal but action dependent on cause and assessment of CTG before and after incident
What is considered as a NORMAL DR C BraVADO ?
All features reassuring
What is considered as a SUSPICIOUS DR C BraVADO ?
1 feature non-reassuring and 2 features reassuring*
What is considered as a PATHOLOGICAL DR C BraVADO ?
1 feature pathological OR 2 features non- reassuring*
What are 8C’s of physiological approach to CTG interpretation?
Clinical picture Cumulative uterine activity Cycling of FHR Central organ oxygenation Catecholamine surge Chemo- or baroreceptor mediated decelerations Cascade Consider the next change on the CTG trace
What is subacute hypoxia?
Defined as when the HR spends more time decelerating than at the baseline
Iatrogenic cause = uterine hyperstimulation
What are the steps to a evolving hypoxia ?
Normal CTG decelerations loss of accelerations catecholamines released raising baseline reduced variability baseline instability terminal bradycardia fetal demise
what does Acidaemia mean?
low blood pH
what does Acidosis mean?
low blood and tissue pH
What does Base Excess/Deficit mean?
measure of how much buffer has been used
What does Hypoxia?
low O2 levels in tissues
What does Hypoxaemia mean?
low O2 tension in blood (low pO2)
What does Metabolic acidosis mean?
low blood pH and high base excess due to the accumulation of CO2 and H+ ions using up buffers
What does Respiratory acideamia mean?
low blood pH due to the accumulation of CO2
What does Low pH and a normal BE cause?
respiratory acidaemia (accumulation of CO2 through impaired gas exchange)
What does Low pH and an abnormal BE cause
combined respiratory and metabolic acidaemia (accumulation of CO2 through impaired gas exchange and the build up lactate and H+ ions through anaerobic metabolism)
what does it mean If there is a large arterial – venous difference in pH?
acidaemia is likely to have occurred in the 2nd stage or if LSCS before full dilation an acute event or cord compression
what does it mean If there is a small arterial – venous difference in pH?
acidaemia is likely to be longstanding
