Flashcards in Monitoring Complex Labour Deck (53)
What can cause a complex labour think? MOTHERS
Rate of progress
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 ...
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...
5 beats for >30mins but < 50mins
5 beats for >50mins
25 beats ) for >15mins but <25mins
Name 3 associated factors that could influence the variability of a CTG
Fetal sleep – cycling indicative of an intact CNS
Pre-existing fetal brain damage
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
What can a Smooth or typical – rounded, symmetric in shape in trace indicate?
fetal thumb sucking,
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
•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
–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
Name the characteristics of concerning variable decelerations
Lasts >60 sec, decreased variability within deceleration
•Failure to return to baseline, biphasic
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)