PACES: CTG interpretation Flashcards
What is the normal range for foetal baseline HR on the CTG?
110-160 bpm
After how many weeks gestation can a CTG be reliably used?
32w
Recall a physiological cause of sustained foetal tachycardia on the CTG
Prematurity (the HR will fall with maturity)
Recall 3 pathological causes of foetal sustained tachycardia on the CTG
Maternal pyrexia
Hypoxia
Foetal distress
Which prescription drug can cause sustained foetal tachycardia?
Salbutamol (and other beta agonists)
Recall 2 common and 2 very concerning causes of foetal bradycardia on CTG
Common: hypotension, post-dates
Very concerning: placental abruption, uterine rupture
What HR as baseline on the CTG is indicative of impending foetal demise?
<90bpm
How do you calculate baseline variability?
Distance between highest peak and lowest trough in a 1-min segment of the CTG trace
What is normal baseline variability?
5-25 beats/ min
What is the most common cause of reduced baseline variability?
Foetal sleep
How long may reduced baseline variability last before it becomes concerning?
40 mins
How is an acceleration defined on CTG?
Rise in foetal HR >15 bpm for at least 15s
What is the expected number of accelerations on a CTG?
2 every 15 mins
What change in the CTG is most often seen with contractions?
Accelerations
How are decelerations defined on the CTG?
Fall in foetal HR of >15 bpm for more than 15 s
