Chapter 16 CTG - PowerPoint Presentation

Slide1

Chapter 16 CTG

Dr

Areefa

AlbahriSlide2

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FHR as a screening test

Intrapartum

FHR monitoring is a

screening test

that provides information to alert the clinician that a true test for

fetal

welfare assessment needs to be performed,

eg

:

An atypical variable (pathological feature)

fetal

blood sampling should be performedSlide3

3

FHR evaluation

Dr C Bravado



ALSO

DR –

d

etermine the

r

isk

C –

c

ontractions

Bra –

b

aseline

ra

te

V –

v

ariability

A –

a

ccelerations

D –

d

ecelerations

O –

o

verall assessment (followed by a management plan)Slide4

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FHR Monitoring on admission in labour

??? Electronic FHR monitoring

??? Doppler auscultation

???

PinardsSlide5

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Who should have continuous electronic FHR monitoring?

Antenatal risk factors

Prematurity

Pre-

eclampsia

/

eclampsia

Diabetes

Growth restriction

Non-reassuring antenatal

fetal

welfare assessment

Multiple pregnancy

MalpresentationSlide6

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Who should be have continuous electronic FHR monitoring?

Intrapartum

factors

Syntocinon

Meconium

Epidural

Suspicious FHR on auscultation

Prolonged rupture of the membranes

Prematurity

Previous C/SSlide7

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Practice Recommendations for intermittent auscultation

Healthy women with uncomplicated

labour

IA with

Pinards

/Doppler recommended

Active

labour

- after contraction for at least 60 seconds & at least

every 15mins 1

st

stage

every 5mins 2

nd

stage

Continuous EFM is recommended if:

Baseline < 110 or >160bpm;

Decelerations or

intrapartum

risk factors developSlide8

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Categorization

of FHR FeaturesSlide9

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Baseline rate

Normal = 110 – 160bpm

Bradycardia

(moderate) = 100 – 109bpm

Bradycardia

(abnormal) = < 100

bpm

Tachycardia (moderate) = 161 – 180

bpm

Tachycardia (abnormal) = >180

bpm

(RCOG)

Variability

Greater than 5bpm and less than 25bpm

Increased variability is often seen following an acute hypoxic event. Slide10

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Baseline RateSlide11

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Baseline Bradycardia

Bradycardia (moderate) = 100 – 109bpm

Bradycardia (abnormal) = < 100 bpm

Rare

Consider the cause if this is a sudden event – ? prolonged decelerationSlide12

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Causes of Baseline Tachycardia

Excessive fetal movement

Maternal dehydration

Prematurity

Maternal fever

Maternal or fetal stress causing adrenaline release

ChorioamnionitisSlide13

13Slide14

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Causes of Reduced Variability

= 5bpm fetal sleep or quiet state

Maternal medications – Morphine, Pethidine etc

Fetal hypoxia – depressing the CNS

Fetal anomalies

Fetal Cardiac ArrhythmiasSlide15

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Sinusoidal

Wave like pattern of 3 – 5 oscillation / min ranging between 5 – 15 beatsSlide16

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Decelerations

Early

Late

Variable – typical and atypical

ProlongedSlide17

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Early

Repetitive from one contraction to another

Recovery to baseline is always at the end on the contraction

Caused by vagal nerve stimulationSlide18

18Slide19

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Late Decelerations

Repetitive from one contraction to the next (3 or more)

Recovery to baseline is late, well after the end of the contraction

More ominous when associated with minimal variability &



baseline

Reflects a change in placental ability to adequately meet fetal needs

May indicate the presence of fetal hypoxia and acidosis

Often signifies fetal decompensation

Slide20

20Slide21

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The Fetal Heart Rate – Late decelerations

Lates represent fetal hypoxia and are related to an interruption in

O

2

supply at cardiac level

Reduced O

2

leads to stimulation of chemoreceptors

Results in activation of the cardiac centres in the brainstem

SA node is effected and the FHR slows.

With the prolonged hypoxia, myocardium is effected causing further decrease in the FHR and hypotension

Recovery is slower

as the myocardium gradually reoxygenatesSlide23

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Variable Decelerations

Repetitive or intermittent

Rapid

sudden fall in FHR

Often rapid recovery

Reflect some degree of umbilical cord impingement

Often seen when liquor volume is

Slide24

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Shoulders

Baseline Rate

Typical variablesSlide25

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1cm per min

Baseline Rate

OvershootSlide26

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Prolonged Decelerations

FHR falls for > 3 minutes

Usually associated with an acute insult - Top up, VE,



Syntocinon

FHR pattern before and in recovery indicates fetal tolerance - not the deceleration itself

Should be managed vigorouslySlide27

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Suspicious FHR Pattern: What should you do?

Maternal

Position

Dehydration

Infection

Hypotension

?V.E/bedpan

Vomiting/vasovagal

Analgesia/Drugs

Mechanical

Poor quality CTG

Maternal pulse

Transducer site

FSE

Oxytocics

Prostaglandins

Slide28

Typical variable decelerations

Typical variable decelerations occur in response to interment cord compression

and

are commonly seen during the second stage of

labour

. They are quick to recover to the normal baseline, have normal variability, last less than 2 minutes and have evidence of

shouldering

, which is a normal physiological response to intermittent cord compression.Slide29

Atypical variable decelerations

These decelerations can be an indicator of hypoxia and have some or all of

the following features:

Loss of acceleration (shouldering) before and after deceleration

Delayed recovery

back to baseline

Rebound

tachycardia – caused by catecholamine release in response to stress

Loss of variability/change in baseline rate.Slide30

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