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BRITISH
MEDICAL
JOURNAL
VOLUME
291
26
OCTOBER
1985
1169
SHORT
REPORTS
Penetration
of
the
subarachnoid
space
by
fetal
scalp
electrode
Fetal
scalp
electrodes
of
various
designs
are
used
widely
for
continuous
intrapartum
fetal
heart
rate
monitoring.
Minor
lacerations
of
the
scalp
are
common,
and
1-0-4-5%
of
infants
may
develop
scalp
ulceration
or
abscess.1
2
We
describe
two
cases
in
which
there
was
penetration
of
the
subarachnoid
space
with
leakage
of
cerebrospinal
fluid
associated
with
the
use
of
a
scalp
electrode
of
the
single
helix
type.
Case
reports
Case
1-A
20
year
old
primigravida
was
admitted
in
spontaneous
labour
at
38
weeks
of
gestation.
A
fetal
scalp
electrode
was
applied
at
4
cm
cervical
dilatation
with
the
fetal
head
in
the
left
occipitoanterior
position.
Spon-
taneous
vaginal
delivery
of
a
mature
boy
weighing
3130 g
occurred
four
hours
later.
The
baby
was
in
good
condition
with
Apgar
scores
of
9
and
10
at
one
and
five
minutes
respectively.
Three
hours
after
delivery
we
noted
leakage
of
clear
cerebrospinal
fluid
from
the
scalp
electrode
site
over
the
posterior
fontanelle.
Conservative
treatment
with
a
dry
dressing,
prophylac-
tic
antibiotics,
and
nursing
of
the
baby
in
a
sitting
position
resulted
in
resolu-
tion
of
the
leak
within
48
hours
without
any
apparent
complications.
Case
2-A
20
year
old
primigravida
was
admitted
in
spontaneous
labour
at
39
weeks.
A
fetal
scalp
electrode
was
applied
at
3
cm
cervical
dilatation
with
the
fetal
head
in
the
right
occipitoanterior
position.
Spontaneous
vaginal
delivery
of
a
mature
girl
weighing
3050
g
occurred
seven
hours
later.
The
baby
was
in
good
condition
with
Apgar
scores
of
9
and
10
at
one
and
five
minutes.
Routine
examination
after
birth
disclosed
leakage
of
clear
fluid
from
the
electrode
site
over
the
right
parietal
bone,
2-5
cm
behind
the
posterior
edge
of
the
anterior
fontanelle.
As
in
case
1
there
was
rapid
resolution
of
the
leak
(in
this
case
within
24
hours)
without
any
neurological
complications.
The
position
of
the
injury
suggested
that
there
had
been
penetration
of
both
bone
and
dura
resulting
in
the
leak.
.s
+
..
...
...s
d-w
{N
o
m
..
..
Fetal
scalp
hair
and
tissue
entrapped
between
electrode
wire
and
plastic
body
of
device.
Comment
Penetrating
injuries
of
the
skull
may
lead
to
infection
and
meningi-
tis
and
to
intracranial
haemorrhage
due
to
vascular
injury.
There
may
be
a
long
term
risk
of
epilepsy
due
to
cortical
injury
and
scarring.
In
each
of
these
two
cases
the
electrode
was
applied
without
difli-
culty
by
an
experienced
midwife
In
one
the
application
was
unsatis
factory
as
it
was
over
the
posterior
fontanelle,
but
in
the
other
the
application
was
in
an
ideal
position
over
the
panietal
bone.
Our
staff
have
reported
several
instances
of
difficulty
in
removing
these
elecc
trodes,
and
we
think
that
the
injuries
were
sustained
during
removal
rather
than
application.
There
are
two
important
design
features
of
the
single
helix
elec
trode
which
contribute
to
the
difficulty
of
removal.
Firsty,
the
attachment
of
the
helical
electrode
wire
close
to
the
perimeter
of
the
plastic
body
causes
the
axis
of
rotation
of
the
electrode
to
be
indeter-
minate
and
variable
during
both
application
and
removal.
Secondly,
the
narrow
angle
of
insertion
of
the
electrode
wire
into
the
plastic
body
creates
a
wedge
within
which
fetal
scalp
hair
and
tissue
may
become
entrapped
(figure).
The
effect
of
these
design
features
is
such
that
any
traction
applied
to
the
electrode
during
its
removal
may
cause
the
wire
to
straighten
and
thereby
increase
its
potential
depth
of
penetration.
Any
oscillating
rotation
which
may
be
used
to
free
the
electrode
carries
the
risk
of
deeper
penetration
of
the
tip
through
the
fetal
scalp.
We
think
that
this
is
the
most
likely
mechanism
for
the
penetration
of
the
parietal
bone
in
case
2.
In
view
of
these
potentially
serious
injuries
we
believe
that
the
use
of
the
single
helix
scalp
electrode
should
be
abandoned
in
favour
of
either
the
double
helix
or
Copeland
pattern,
whose
design
features
prevent
the
type
of
injuries
that
we
describe.3
1
Ashkenazi
S,
Metzker
A,
Merlob
P,
Ovadia
J,
Reisner
SH.
Scalp
changes
after
fetal
monitoring.
Arch
Dis
Child
1985;60:267-9.
2
Okada
DM,
Chow
AW.
Neonatal
scalp
abscess
following
intra-partum
fetal
monitoring:
prospective
comparison
of
two
spiral
electrodes.
Am
J
Obstet
Gynecol
1977-;127:875-8.
3
Department
of
Health
and
Social
Security.
Helical
foetal
scalp
electrodes.
DHSS
Safety
Information
Bulletin
1985;
No
21.
(Accepted
17July
1985)
Department
of
Obstetrics
and
Gynaecology,
North
Manchester
General
Hospital,
Crumpsall,
Manchester
MS
ORB
D
S
SHARP,
MB,
MRCOG,
consultant
obstetrician
J
M
COURIEL,
MB,
MRCP,
consultant
paediatrician
Correspondence
to:
Mr
Sharp.
Exchange
transfusion
and
quinine
concentrations
in
falciparum
malaria
We
were
asked
to
admit
a
patient
with
an
80%
falciparum
parasitaemia,
hyperventilation,
and
tachycardia.
From
her
description
she
sounded
moribund,
so
we
decided
to
do
an
exchange
transfusion
as
soon
after
admission
as
possible.
Case
history
In
1985
a
white
woman
aged
38
was
referred
with
falciparum
malaria
and
a
parasitaemia
of
80%,
hyperventilation,
and
tachycardia
after
a
holiday
in
Kenya.
She
had
had
fever
for
two
weeks,
followed
by
confusion
and
deafness,
before
her
husband
called
the
doctor.
She
was
drowsy
and
very
weak.
Temperature
was
39-5'C,
heart
rate
127/min,
respiratory
rate
24/min,
weight
82
kg,
blood
urea
concentration
45-3
mmol/l
(273
mg/100
ml),
bilirubin
31
jurnol/l
(1.8
mg/100
ml),
and
platelet
count
19x
103/mm3.
Ten
units
of
blood
were
cross
matched
and
a
two
hour
infusion
of
500
mg
base
quinine
dihydrochloride
(6.1
mg/kg)
in
500
ml
isotonic
saline
started
on
admission
to
the
intensive
care
unit
at
2130.
A
colleague
confirmed
that
the
parasitaemia
was
about
70%,
so
an
exchange
transfusion
was
begun
three
hours
after
admission
(at
0030)
in
an
attempt
to
save
the
patient's
life.
The
blood
was
transfused
into
a
vein
in
the
right
antecubital
fossa.
Because
of
difficult
peripheral
venous
access
a
right
subclavian
cannula
was
inserted
and
7
units
of
blood
(3-5
1)
withdrawn
over
130
minutes
before
the
cannula
blocked
(table).
During
this
time
7
units
of
stored
donor
blood
were
transfused,
followed
by
2
units
of
fresh
frozen
plasma
and
6
units
of
platelets
to
replenish
clotting
factors.
After
the
exchange
we
rechecked
the
parasitaemia
in
the
blood
taken
on
admission
and
found
it
to
be
22%.
Haemoglobin
concentration
changed
little
during
the
procedure
(from
85
to
81
g/l).
The
7
units
of
blood
showed
a
steadily
decreasing
parasitaemia
(from
26%
to
5%)
and
plasma
quinine
concentration
(18-2
to
6-5
mmol/l;
5-9
to
21
jsg/ml).
The
patient
became
more
alert
during
the
procedure.
Whole
blood
exchange
(7
units)
over
two
hours
Unit
of
blood
Parasite
count
in
Quinine
concentration
Time*
withdrawn
unit
(%)
in
unit
(mmol/l)
0045
1
26
18-2
0100
2
19
13
9
0125
3
14
12-3
0140
4
10
9-2
0155
5
8
9-5
0230
6 7
7-7
0240
7
5
6-5
*Exchange
began
at
0030.
Conversion:
SI
to
traditional
units-Quinine:
1
mmol/l
z
0-32
,ug/ml.
