CTG Masterclass

AVMA Annual Clinical Negligence Conference 2012

Professor Tim Draycott, Consultant ObstetricianHealth Foundation Improvement Science Fellow

Birth care not always easy

Introduction

• Cerebral Palsy – Pattern of injury– Relationship with low Apgar score

• Standard of care– Intermittent Auscultation– Electronic Fetal Monitoring

• Interpretation• Action required

• Cases

Low Apgars and CP

• Base Excess ≤12 likely to be normal

• Apgar score <7– Odds ratio for CP after low (<7) Apgar

scores at 5 minutes in tern infants is 3.72– Proportion of CP in the population that

could be attributed to a low Apgar score (<7) at 5 minutes is 10.9%

– At least 50% of Low Apgar scores could be prevented with better care

Recurring Themes

• Failure to perform EFM

• Failure to recognise CTG abnormalities

• Failure to respond to CTG abnormalities:

• Fetal blood sampling• Expedite delivery

Cerebral Palsy

Proportion CP

Spastic Diplegic 26%

Hemiplegic 35%

Ataxic 4%

Athetoid (Dyskinetic)

7-15%

Spastic Tetraplegic 18-20%

..and Clinical Negligence

Proportion CP

Intrapartum

Spastic Diplegic 26% <1%

Hemiplegic 35% 0%

Ataxic 4% 0%

Athetoid (Dyskinetic)

7-15% 80%

Spastic Tetraplegic

18-20% 45% +

Clinical Negligence

• Standard of care

• Breach in duty of care– Midwives– Obstetricians– Paediatricians

• Did that breach cause the injury ?

Causation

• Athetoid Dyskinetic Cerebral Palsy– Acute profound hypoxia

• Spastic Tetraplegic Cerebral Palsy– Chronic partial ischaemia

Athetoid CP

• Profound acute hypoxia - ‘lack of oxygen’

– Uterine Rupture– VBAC

– Cord Prolapse

– Abruption

Hypoxia

• Oxygen sensitive parts of body

– Kidneys

– Heart

– Brain

MRI findings

• Areas of brain with high metabolic rate

– Deep grey matter• Posterior parts of lentiform nuclei• Ventro-lateral nuclei of thalami• Hippocampus

MRI

Spastic Tetraplegic CP

• Mechanism of injury less established

• Prolonged period of mild – moderate hypotension– Cord Compression– Head Compression

• Watershed areas of brain

Chronic Partial Ischaemia

• Low blood pressure in cerebral arteries

• Perfusion at peripheries reduced

• Lawn Sprinkler

MRI Findings

Intrapartum

• Monitoring fetal heart rate in labour– Intermittent Auscultation– Cardiotocograph

• Baseline rate• Baseline variability• Accelerations• Decelerations

• Introduction only

Intermittent Auscultation

• Normal Labour– The RCOG EFM guideline recommends:

• In the active stages of labour, intermittent auscultation (IA) should occur after a contraction, for a minimum of 60 seconds, and at least.

– every 15 minutes in the first stage – every 5 minutes in the second stage

• Failure to perform IA as above is substandard care

When to change to EFM ?

Cardio-tocography

• Abdominal palpation

• Maternal pulse

• Name/number/time/paper speed

• Technically adequate

• Documentation (actions & opinion)

• Interpret in light of clinical setting

Reassuring CTG

• 4 Features: – Baseline rate

110-160– Baseline

variability - 5bpm or more

– Accelerations– No

decelerations

Intrapartum

• Standard of care– NICE EFM May 2001

– NICE Intrapartum Guideline Sept 2007

– Pre 2001 – FIGO guidance published in 1987

NICE EFM

Coalface

Reassuring Non- reassuring AbnormalBaseline rate(bpm)

110 – 160 100 – 109161 - 180

<100>180

Comments:-

Variability(bpm)

5 bpm or more <5 for 40 mins ormore but <90 min

< 5 for 90 mins ormore

Comments:- CTG onfor 60 mins so far

Accelerations Present None Comments:-

Decelerations None EarlyVariableSingle prolongeddeceleration up to 3mins

Atypical variableLateSingle prolongeddeceleration > 3mins

Comments:-Unprovokeddecelerations

Opinion Normal CTG(All f our f eaturesreassuring)

Suspicious CTG(One non-reassuringfeature)

Pathological CTG(two or more non-reassuring or one ormore abnormal f eatures)

Dilatation Not assessed Comments:- Not contracting Contractions ….:10

Action Urgent transfer to tertiary unit and review by senior obstetrician

Date ……………………… Time………………… Signature………………………………………………. Status………………………….

Classification

Actions - Suspicious

Action - Pathological

NICE IP ‘Guide’line

New Sticker

Antenatal Sticker

Dr C BRAVADO

• Discuss risk• Contractions

• Baseline Rate• Accelerations• Variability• Accelerations• Decelerations

• Outcome

However……….

• DrCBravado not consistent with:– Electronic Fetal Monitoring

Guideline, published in 2001– NICE Intrapartum Guideline in 2007

• Therefore its use is substandard care

Breach of Duty

• Assessment of CTG

• Classification into NICE category

• Documentation, each hour

• Appropriate action for CTG category

Causation – CP Template

• Fetal, umbilical arterial cord, or very early neonatal blood: pH <7.00 & base deficit >12 mmol/l

• Severe or moderate neonatal encephalopathy in infants >34 weeks

• Spastic quadriplegic or dyskinetic CP

• Exclusion of other identifiable causes

CP Template contd

• Sentinel hypoxic event

• Sustained fetal bradycardia or poor variability in the presence of late or variable decelerations

• Apgar scores of 0-3 beyond 5 minutes (previously <7).

• Onset of multi-system involvement within 72 hours of birth.

Causation and timing

• Paediatric expert

• Use of umbilical artery base excess: Algorithm for the timing of hypoxic injury

Ross and Gala. Am JOG. 2002

– >10% infants born with Base Excess ≥16 will have cognitive defects at 1 yr

– Almost all infants born with base excess ≤ 12 are normal

Timing of Injury

• Normal Labour• Fetus enters labor with a base excess of –2

mmol/L– 1 mmol/L per 3 to 6 hours in normal first stage of

labour– 1 mmol/L per hour of second stage

• Abnormal CTG– 1 mmol/L per 30 minutes with repetitive typical

severe variable decelerations– 1 mmol/L per 6 to 15 minutes in subacute fetal

compromise– 1 mmol/L per 2 to 3 minutes with acute, severe

compromise (eg, terminal bradycardia)

Timing

• A guide, not an exact science

• At what time would delivery have avoided injury ?

• Work backwards through trace

• Intermittent Auscultation

Pitfalls

• Cord Gas better than expected– Venous sample– Complete cord compression

• MRI– Other causes

• Chronic Partial – May not have sentinel event

Conclusion

• Breach of duty of care– Use NICE EFM & IP Template– Action also defined by national

guidance

• Causation– ACOG & International consensus

template

Problem ?

• 50% adverse outcomes preventable with better care

CESDI – 4th Annual Report. 1997CEMD – Why Mothers Die. 1998

CEMACH – Saving Mothers Lives 2007

• UK Apgar <7 at 5 mins• Ranges from 0.4% of term infants to

1.96%• 5 fold variation !

Neonatal Outcomes

5’ Apgar p=0.00042 (Chi2 test for trend)

HIE p=0.0176 (Chi2 test for trend)

National Results

Thankyou

• www.prompt-course.org

• tdraycott@gmail.com