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Brachial Palsy:Prediction & Prevention.
Raphi Pollack, MDCM, FRCSC.
Bikur Cholim Hospital,
Jerusalem.
Outline
• History
• Natural history
• Risk Factors
• Prevention strategies
• Conclusions
History
Smellie 1764 Erb 1874 “delivery paralysis” related to
“moderately energetic manipulation by the obstetrician”
Significance of Brachial Palsy
• Complication of birth trauma
• Major cause of neonatal morbidity
• “Fetal-physician” risk
• Accounts for 4.2% of OBS litigation
8
7
9
4
5
6
3
2
1
Roots
Trunks
Cords
Nerves
ANATOMY OF THE BRACHIAL PLEXUS
UlnarMedianRadial
7
8
9
5
Lateral PosteriorMedial
4
6
Upper Middle Lower
1
2
3
Clinical Syndromes
• Erb Palsy– C5, C6 root avulsion– Upper trunk plexopathy– Arm Adduction & internal rotation– Elbow extended & forearm pronated– “Waiters tip” position– +/- Horner syndrome
Clinical Syndromes
• Flail arm– Injury to entire plexus
• Klumpke palsy– Lower trunk (C8, T1) injury– Poor grasp, proximal function preserved
Electrodiagnosis
• Nerve conduction studies– Changes in amplitude of motor & sensory response
• Electromyography– Study of motor unit potential
• Technically difficult in the neonate• Insights into pathogenesis
Electrodiagnosis:Timing of Injury
• Fibrillations• Onset = 12-21 days• Peak = 35 days
• Conduction abnormalities : Sensory• Onset = 5-6 days• Peak = 10 days
• Conduction abnormalities : Motor– Onset = 2-4 days– Peak = 7 days
Incidence of Brachial Palsy
• 0.5-3 per 1000 births
• Gilbert et al (1995) 1.5/1000 births
• 5420 cases annually in USA
• 180 cases annually in Israel
Natural History
• Important to understand burden of disease– Contrast with clavicular #
• Resolution – how often ?– Michelow HSC (1994) 92% resolved– Bager (1997) 49% resolved
• 22% severely impaired
– Eng (1996) 22% resolved• 78% long term disabilities
Pathogenesis
Excessive downward traction.
Vs.
In-utero insult.
In- utero insult
• Koenigsberger (1980)– EMG evidence of prenatal injury
• Dunn & Engle (1985)– Bicornuate uterus– Bb skeletal deformities, muscle atrophy,
brachial palsy– EMG findings
In-utero insult : The Evidence
• 1,611 cases of OBP
• 47% of all OBP do not involve shoulder dystocia
• 60/1,611 cases of OBP Cesarean delivery
• Ascertainment bias ??
• Excessive traction at time of CS ?? Gilbert (1999)
In-utero insult : Natural History
• Gherman (1998) 40 cases of OBP.
• OBP in absence of SD : high persistence.
• OBP in presence of SD : low persistence.
• Suggests pathogenetic heterogeneity.
Brachial Palsy: Risk Factors
• Shoulder dystocia (OR=76.1)• Neonatal birthweight• Instrumental vaginal delivery• Breech presentation (OR=5.6)• Gestational DM (OR=1.9)• Prior infant with brachial palsy
Brachial Palsy & Neonatal BW
4001- 4500
> 4500
2.4
21
0
5
10
15
20
25
OR
Brachial Palsy & Instrumental Delivery
2.73.7
18.3
0
2
4
6
8
10
12
14
16
18
20
OR
Vacuum LFD MFD
Highest Risk of Brachial Palsy
Maternal Diabetes Mellitus&
BW > 4500 Gms.&
Instrumental Vaginal Delivery
OR = 52
Pts. At Highest Risk for OBP
100 pts
92 ptsnormal
8 pts OBP
Birth Trauma: Recurrence Risk
• Baskett (1995)• Shoulder dystocia over 10 yrs. (N=254)• Recurrent shoulder dystocia = 1/93 (1.1%)• 0/8 cases of OBP in setting of prior OBP• Al-Qattan (1996)• 16/49 (33%) cases of recurrent OBP
OBP: Negative associations
• Prematurity (OR = 0.8)
• IUGR (OR = 0.9)
• Cesarean delivery (OR = 0.2)
• No factors were entirely protective
Prevention Strategies
• Manipulation of BW– Tight control in DM
• Risk stratification– Identification of the macrosomic fetus– Elective induction– Elective Cesarean delivery
Murphy’s Law: First Corollary
“Nothing is as simple as it first seems”
Prevention Strategies
• Must be broad based.
• Most OBP cases are not predictable.– BW < 4000 Gms.– Not associated with DM.
• Perlow (1996) 19% of OBP predictable.
• Skillful management of shoulder dystocia.
Fetal Macrosomia: Diagnosis
• MacDonald measurement (SFH)
• Maternal estimation
• Sonographic EFW
• All techniques limited
Fetal Macrosomia: Induction of Labor
• Inclusion EFW > 4000 Gms. @ 38 wks.
• RCT.
• Induction (N=134).
• Expectancy (N=139).
• Power to detect 15% change in CS rate.
Gonen 1997.
Fetal Macrosomia: Induction of Labor
InductionExpectancy
Time to delivery (d)-3.2
BW (Gms.)40624132 *
C/S for CPD1918
Shoulder Dystocia56
Brachial Palsy02
Fetal Macrosomia:Elective Cesarean Delivery
• Decision analysis model.
• Three policies compared.– No sonographic EFW.– C/S for EFW > 4000 Gms.– C/S for EFW > 4500 Gms.
Rouse 1996.
Fetal Macrosomia:Elective Cesarean Delivery
Intervention # C/S performed / OBP prevented
Cost /
OBP prevented
C/S for EFW > 4000 Gms. 2,345 $4,900,000
C/S for EFW > 4500 Gms. 3,695 $8,700,000
Fetal Macrosomia:Elective Cesarean Delivery
• 4000 Gms. Threshold– Would increase C/S rate by 50%– Reduces OBP by 31%– Costs $4,900,00 per OBP prevented– Leads to 1 maternal death per 3.2 OBP cases
prevented– Cannot be justified medically or economically Rouse, 1996
Conclusions
• Beware of macrosomic infants
• Avoid midpelvic deliveries in macrosomics & GDMs
• Manage Shoulder Dystocia– Don’t rush– Avoid excessive traction
Practical Advice
Avoid poor judgment…
Judgment comes from experience…
Experience comes from poor judgment.
Jeanty
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