Fetal heart rate monitoring Flashcards

1
Q

late decels

characteristics, likely cause, and mgmt

A

characteristics
>15bpm drop lasting 15sec ( or <15bpm drop, if also reduced variability (<5bpm)
>uniform/ repetitive
»slow onset from mid to end of contraction, lowest point is >20sec after peak of cx contraction started, recovers after Cx finished

likely cause
hypoxia (the longer the late decel, the worse)

management
Consult

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2
Q

what is a prolonged decel

A

Drop in baseline FHR >90 sec - 5min

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3
Q

what are reasons for reduced variability

A

fetus sleeping (most common- but shouldn’t be for longer than 40mins)
fetal acidosis (due to hypoxia) –more likely if there are also late decels
fetal tachycardia
drugs- opiates, mg sulphate
preterm
congenital heart abnormalities

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4
Q

variable decels

A

characteristics
repetitive or intermittant depth / duration
usually with a contraction- typically rapid onset and recovery
- may / may not have shouldering

likely cause
with shouldering- normal physiological response- cord compression
if no shouldering- could indicate fetus becoming hypoxic

mgmt
assess for any “ complicated features-“
if no complicated features, generally assume baby is having eustress and coping ok
if variable decels are persistent consider changing position / more monitoring

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5
Q

complicated variable decels

A

features that indicate liklihood of fetal hypoxia

  • rising baseline or fetal tachycardia
  • reducing baseline variability
    -slow return to baseline after cx
  • large amplitude of decel i.e. drop by 60bpm, or to 60bom, or lasting longer than 1min
  • presence of smooth post decel overshoots
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6
Q

what is shouldering?
What does it indicate

A

HR accelerates at start of cx, then rapidly decelerates, then rapidly accelerates.

Presence indicates fetus is not hypoxic and adapting to reduced blood flow (usually cord compression)

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7
Q

definition of deceleration

A

abrupt decrease in FHR baseline >15bpm for >15 sec

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8
Q

CTG - definition of normal baseline variability

A

“minor fluctuations in baseline FHR- occur 3-5cycles / min

6-25bpm

‘reassuring baseline’ is >5

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9
Q

Definition of acceleration

A

> 15bpm increase in baseline, lasting >15 sec
Normal and reassuring to have accelerations (although unclear whether there is an issue if there is absence of accelerations )
preterm accelerations smaller

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10
Q

What is a sinusoidal CTG pattern

A

indicators:
smooth wave like pattern, 2-5 cycle / min
no accels/ decels in 20mins
no variability

Indication
severe fetal hypoxia or anaemia, maternal or fetal haemorrhage
CONSULT

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11
Q

what is management of abnormal CTG

A

? Checking maternal pulse/attach maternal probe if not recorded by toco
? Checking positioning of CTG transducer
? Maternal position change to increase utero-placental perfusion and/or alleviate cord
compression
? Continuing or commencing continuous EFM
? Identification of any reversible cause of the abnormality and initiation of appropriate action
(e.g. correction of maternal hypotension, cessation of oxytocin infusion* and/or acute tocolysis
for excessive uterine activity)
? Consideration of fetal blood sampling
? Escalation of care

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12
Q

what is a bradycardia
what does this mean

A

fall in FHR baseline for >5mins

LIKELY to be associated with significant fetal compromise
IMMEDIATE management

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13
Q

what is a normal reassuring CTG

A

Baseline btn 110-160
variability present (6-25)
2 accelerations in 10-20mins (>15bpm, for >15sec)
no decels

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14
Q

what is most important aspect of CTG

A

variability –> fluctuating 5-25bpm over 10-20 sec

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15
Q

what is increased variability?

A

> 25

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16
Q

what is reduced variability

A

3-5bpm

17
Q

what is absent variability

A

<3 bpm

18
Q

how do we identify baseline FHR

A

rate in absence of both movements + cx

19
Q

how do we define baseline bradycardia- what are possible reasons?

A

<100bpm, lasting >10mins

reasons
hypoxia
drugs
congenital
hypotehermia

20
Q

how do we define tachycardia - what are possible reasons?

A

> 160bpm for more than 10mins

maternal fever
fetal infection
hypoxia
prem babies (<34wks) - normal

21
Q

when can you use Dawes redman

A

Antenatal only- NOT intrapartum

22
Q

Early decels -

characteristics, likely cause, and mgmt

A

characteristics
15bpm drop, for 15 sec
uniform / repetitive
slow early onset in cx, slow return to bsaeline by end of cx

Likely cause
head compression, pethadine, sleep trace

how do we interpret this
- this classifies as “non reassuring / “suspicious” / “abnormal but unlikely to be compromising”)

23
Q

uterine hypertonus / hypersystole

A

cx lasting >2mins
or cx occuring within 60seconds of each other

without FHR ABNORMALITY

24
Q

uterine hyperstimulation

definition
referral
mgmt

A

either uterine tachysystole (>5cx:10) or hypertonus (>2mins or <60sec rest between)
AND FHR abnormalities

Referral
CONSULT

mgmt
- Reduce / cease oxytocin
- continuous monitoring / stay with woman
- consider tocolytic + urgent delivery

25
Q

uterine tachysystole

A

> 5 contractions in 10mins
without FHR abnormalities

26
Q

when is Dawes- Redman appropriate

A

> 28 wks
AN only (not intrapartum)

27
Q

when can you start using continuous CTG

A

> 26 wks

28
Q

what is moderate bradycardia, what is abnormal bradycardia?

A

moderate-100-109bpm
abnormal <100bpm

29
Q

what is moderate tachycardia?
what is abnormal tachycardia

A

moderate: 160-180bpm
abnormal >180bpm

30
Q

intermittant auscultation
protocol

A

1st stage-
every 15-30mins
listen for at least 1min
record as single rate, and any accelerations /decels heard

2nd stage
every 5mins (or every cx)
listen for 30-60 sec from end of cx

listen to maternal pulse hourly (at least)

31
Q

What are risks associated with fetal scalp electrodes
what are contraindications

A

bruising / scratching baby’s scalp
risk of infection to mum / baby, or from mum to baby

contraindicated- HIV, herpes, hepatitis

32
Q

what does the evidence say about CTG use in low/high risk pregnancy

A

CTG associated with
* signficiant decrease in neonatal seizures
* increase of CS / operative birth
* no difference in perinatal death / cerebral palsy

NOT recommended for low risk women

33
Q

what is normal preterm baseline

A

higher than term

34
Q

what is normal baseline for post term fetus

A

90-100 bpm (as parasympathetic system is maturing)