CTG Analysis Flashcards
1
Q
Framework for analysing CTG?
A
DR C BRAVaDO
- DR ➔ Determining risk of the pregnancy
- C ➔ Contractions
- BR ➔ Baseline rate (110-160 bpm)
- A ➔ Accelerations
- Va ➔ Variability
- D ➔ Decelerations
- O ➔ Overall impression
2
Q
How do you describe contractions?
A
- X in 10 (how many contractions in a ten-minute period)
- Around 3-4 in 10 occurs in labour
- > 5 in 10 is concerning for uterine
hyperstimulation
- Duration (last around 40-50s)
- Intensity (Assessed on palpations)
3
Q
What is the normal range for baseline rate?
A
110-160 bpm
4
Q
What does foetal tachycardia (>160) indicate?
A
- Chorioamnionitis (infection)
- Foetal hypoxia
- Foetal anaemia
- Premature
- Neonatal hyperthyroidism (child born to Graves mother, TRAbs pass through placenta)
5
Q
What does foetal bradycardia (<110) indicate?
A
- Post-date gestation
-
Prolonged severe bradycardia (<80 for at least 3 mins):
- Cord prolapse
- Cord compression
- Epidural/Spinal anaesthesia
- Maternal seizure
6
Q
What is an acceleration?
A
- An abrupt increase of 15 bpm in baseline rate which remains elevated for >15 seconds
- Presence of accelerations is reassuring
- Accelerations occurring alongside uterine contractions is a sign of a healthy foetus.
- The absence of accelerations with an otherwise normal CTG is UNIMPORTANT
7
Q
What is variability?
A
- Variation of foetal heart rate from one beat to the next (e.g. one beat 120, next 130)
- A healthy foetus will constantly be adapting its heart rate in response to changes in its environment. (reactive)
8
Q
What is a normal range for variability?
A
5-25 bpm change per beat (either up or down)
9
Q
What causes reduced variability?
A
- Foetal sleeping (should not last longer than 40 mins)
- Foetal acidosis/hypoxia
- Maternal opiates and benzos
10
Q
What conservative measure can relieve a reduced variability
A
Re-position the mother
11
Q
What are decelerations?
A
- An abrupt decrease in baseline rate of 15 bpm which remains decreased for >15 seconds
- in the case of reduced variability, the decels may be shallow
12
Q
What do early decels represent?
A
- ↓ baseline rate start when the uterine contraction begins and
- Rapid recovery when uterine contraction stops.
- This is due to increased foetal intracranial pressure causing increased vagal tone.
13
Q
What do variable decels represent?
A
- ↓ baseline rate with a variable recovery phase.
- They are variable in their duration and may not have any relationship to uterine contractions
- Usually caused by cord compression
14
Q
What do late decels represent?
A
- Late decelerations begin at the peak of the uterine contraction and recover after the contraction ends (the whole time the uterus is contracting, the baby has shit blood flow)
- Indicates decreased uteroplacental blood flow
- Maternal hypotension
- Pre-eclampsia
- Uterine hyperstimulation
15
Q
What are prolonged decels?
A
- A prolonged deceleration is defined as a deceleration that lasts more than 2 minutes:
- If it lasts between 2-3 minutes it is classed as non-reassuring.
- If it lasts longer than 3 minutes it is immediately classed as abnormal.
