CTG Flashcards
What is the normal variability on the baseline rate?
Should be over 5bpm
What is the normal baseline rate for a CTG?
110-160 bpm
How long is the variability allowed to be less that 5bpm for it to be
1) nonreassuring
2) abnormal
1) over 40mins
2) over 90mins
What does the acronym DRC BRVADO stand for
Define Risk - high or low Contractions Baseline Rate Variability Accelerations Decelerations Overall impression
How do you read how many contractions?
How many in 10 big squares (10 mins)
Eg 3 in 10
What is considered prolonged bradycardia?
What are the causes?
Less than 80 for over 3 mins
Cord compression
Spinal/epidural
Maternal seizure
Rapid foetal descent
What is the most common cause of reduced variability for less than 40 mins?
The foetus is sleeping
Define an acceleration..
Increase from baseline for over 15 bpm for over 15 seconds
Are accelerations reassuring or non reassuring?
Reassuring
What is the physiology behind early decelerations?
Pathological or not?
It occurs during a contraction and stops when contraction stops.
It is caused by increased foetal intracranial pressure causing increased vagal tone
Not pathological
What is a variable deceleration?
What is it often caused by?
No relation to contractions
Cord compression
More likely in those with decreased amniotic fluid
What is a late deceleration?
What might this indicate?
Begins at the peak of a uterine contraction and recover after contraction ends
Lack of blood flow to foetus therefore potential hypoxia or acidosis
For “overall impression” what would the three categories be?
Normal
Suspicious
Pathological
What features do you need for suspicious or pathological?
Suspicious- one nonreassuring
Pathological - two non reassuring or one abnormal
What are typical decelerations?
Less that 60bpm for less than 60 seconds