External Ventricular Drain

Department of Neurosurgery, Hospital Sultanah Aminah
1 August 2007

Outline
• Introduction
• Indications
• Types of EVD system
• Insertion of external ventricular drainage
• Drain management
• Pitfalls
• Complication
• Rules and facts
• Conclusion

Introduction
• An External Ventricular Drainage
(EVD) is the temporary drainage
of cerebrospinal fluid (CSF) from
the fluid filled cavities of the brain
(lateral ventricles) to a closed
collection system outside the
body.

Indications
• To relieve raised intracranial
pressure (ICP).
• To divert infected CSF
• To divert bloodstained CSF
following neurosurgery /
haemorrhage.
• To divert the flow of CSF
• For ICP monitoring
• For Irrigation?

Copyright ©2003 American Academy of Pediatrics
The direction of irrigation and drainage of the ventricular system

Types of EVD system
• New ventricular catheter
– New catheter placed into the ventricle through a
small hole (burr hole) made in the skull
– The new catheter is tunnelled under the scalp,
and connects to an external drainage system
– This system does not have a pressure valve so
drainage depends upon gravity.
• Externalisation of existing shunt system
– Externalised at the distal end and connected to
an external drainage system.
– This shunt system will contain a pressure valve,
which controls the amount of drainage from the
ventricles.

External drainage system
• The system has several components:
•A self-sealing sampling &
injection port.
•To provide access to
the catheter.
•An anti reflux drip/collection
chamber.
•To observe CSF
drainage.
•A drainage bag.
•To enable on-going
collection of CSF.
•A pressure scale mounting
panel or a tape measure.
•To facilitate accurate
positioning.

Types of ventricular
catheter
• Ventricular Catheter 8F
• Antiseptic EVD-Catheters

INSERTION OF EXTERNAL VENTRICULAR
DRAINAGE

Drain Management:
Positioning of Drain
• The system must be positioned
accurately, to ensure desired amount of
CSF
1. The level of the ventricles must be
estimated:
2. The midpoint of this line is the zero point for the
EVD system.

The difference in height between the patient’s
ventricles and the drip chamber creates both
a pressure gradient and a safety valve.

The height of the drip
chamber equates to the
pressure inside of the head or
intracranial pressure (ICP).
This pressure must be reached before any CSF will drain into the drip chamber

Drain Management:
Positioning of Drain
• Neurosurgeons will specify and
prescribe a drain height post-
operatively and that the drain
height is to be either:
– Maintained OR
– Altered, to drain a certain amount
of CSF an hour.
The flow chamber of the EVD system must be aligned
at the cm mark prescribed by the neurosurgeon
(initially this is generally 10cm).

Position of EVD System
The position of drain should be indicated on the patient’s fluid chart

Drain Management:
Drainage
• Once the drain is connected and positioned
an initial assessment of CSF drainage
should be made. (To ensure CSF is draining
at the correct rate.)
• Subsequently hourly checks should be
made of:
– Amount of drainage.
• To ensure CSF drainage rate is as prescribed.
• A sudden increase in drainage may result from
inaccurate zeroing of the drain or could signify a
rise in ICP.
• A decrease in drainage could also indicate
inaccurate zeroing of the drain or that the tubing
may be kinked, blocked, disconnected or the ports
are closed

Drain Management:
Drainage
• Subsequently hourly checks
should be made of:
– Colour of CSF - should be
colourless.
• Bloodstained CSF could indicate blood
in the ventricles
• Cloudy CSF may indicate the
presence of an infection
– Exit site.
• To ensure CSF is not leaking.

Drain Management:
Drainage
• An approximate guide to CSF drainage
• CSF drainage must be observed regularly
(having the flow chamber facing the nurse at
the bedside will ensure regular observation),
and recorded hourly on the ICU chart.
CSF is produced continuously by the choroid plexus of the two
lateral ventricles at a rate of approximately 20-25ml per hour, or
500mls per day (Hickey, 1997)

Drain Management:
Drainage
• Drainage of more than 50mls/hour is
considered excessive, however this
may be acceptable in patients with
gross hydrocephalus
• The presence of blood may indicate
haemorrhage.
• The sudden presence of blood in the
EVD must be reported to a
neurosurgeon immediately

Drain Management:
Drainage
• Description the colour of CSF
– 1. Clear and colourless
– 2. Xanthocromic – discoloured CSF
usually yellow, orange or brown
due to the breakdown of RBC’s
from previous haemmorhage
– 3. Blood stained – as a result of
recent haemmorhage or surgery
CSF may also be described as turbid (cloudy) which
occurs due to the presence of increased WBC’s as a
result of CNS infection e.g. Meningitis.

Drain Management:
Drainage
• The drainage tubing must be checked for patency at
the beginning of each shift and again at regular
intervals thereafter.
• Observe the tubing to establish whether or not the
level of CSF in the tube is oscillating
• If the level is not oscillating the flow chamber may be
dropped to below the foramen of Monro for a brief
period only to check whether CSF drains into the
chamber.
• Once this has been observed the flow chamber must
be re-aligned to prevent over-drainage of CSF.
• If at any time an EVD appears to be blocked, a
neurosurgeon must be contacted immediately as it
may be necessary to flush the system

Drain Management:
Clamping The EVD
• It may be necessary to clamp the
system for short periods.
• An example of such an occasion is
during the moving and handling or
repositioning of patients.
• It must be clamped for no more than
30 minutes at a time.
• Following administration of the drug
(intrathecal antibiotics) the EVD must
be clamped for 60 minutes to allow for
absorption of the drug

When moving or
repositioning the patient
• Clamp drain
• Re-zero drain
• Unclamp drain immediately

Drain Management
• In children, to clamp the drain if:
– Moving their child
– If their child is crying excessively.
• To prevent over drainage of CSF.
• The drain should not be clamped for longer
than 1 hour.
• This to minimise risk of blocked catheter
and to prevent raised intracranial pressure.

Drain Management:
Intracranial Pressure
• It is possible to monitor
intracranial pressure through the
ventricular catheter using a
continuous closed monitoring
system with a non-flush
transducer device.
• Careful technique and handling
is essential to prevent infection.

Drain Management:
To obtain a CSF specimen
• Clean injection port on EVD system
• Insert syringe into port
• Slowly withdraw 2 mls of CSF,
remove syringe & discard
• Insert second syringe into port
• Slowly withdraw 2 mls of CSF
• Place CSF into each universal
specimen container
• Open clamps on drainage system
close to injection port

Drain Management:
To administer intrathecal
antibiotics:
• Prepare drugs using aseptic non-touch technique
• Clean injection port on EVD system
• Slowly withdraw 2 mls of CSF, remove syringe &
discard
• Insert syringe containing the antibiotic into injection
port
• Inject antibiotic according to manufacturer’s
guidelines
• Remove syringe
• Insert syringe containing 0.9% sodium chloride into
port & gently flush catheter with 2mls 0.9% sodium
chloride
• Remove syringe
• Keep drainage system clamped for one hour only

Drain Management:
Exit Site Care
• If exit site is dry it should be dressed with a sterile
dressing.
• Change the dressing weekly unless contaminated.
• The dressing should be changed if it becomes
contaminated with CSF or blood.
• If the exit site is oozing it should be dressed with
sterile gauze pads and surgical tape.
• A microbiological swab may need to be taken for
culture & sensitivity.
• Check exit site hourly for:
– Redness
– Inflammation
– Oozing of blood
– Leakage of CSF
• Loop catheter once at exit site under dressing.

Drain Management:
CSF Sampling
• CSF samples should be taken:
– Every 24 hours, according to
microbiological advice, until the
CSF is sterile/infection free
– Every 72 hours for infection free
CSF

Drain Management:
Removal of the Drain
• Once the patients’ clinical condition and neurological
status has stabilised, instructions may be given to
raise or clamp the EVD prior to removal.
• The patient’ neurological status must be closely
monitored during the period when the drain is
clamped or raised
• The EVD is removed by a neurosurgeon using strict
aseptic technique. The skin must be sutured at the
insertion site and an occlusive dressing applied.
• The catheter tip must be sent for culture.
• On removal of the EVD the patients’ neurological
observations must be monitored closely.
• It is recommendation of the people reviewing these
guidelines that neuro observations be recorded
hourly for 4 hours, then reduced once the patients’
condition is stable.

Drain Management:
Removal of the Drain
• The EVD should remain in situ for no longer
than 10 days.
• After this time the entire system should be
removed or changed in theatre??
• Pre-operatively the nurse may be asked to
clamp the drain for a specified time prior to
surgery.
• If the patient’s condition deteriorates due to
clamping pre-operatively, unclamp the drain
and contact the neurosurgical team.
• Post operatively assess the patient and
dress the exit site.

Fluid and Electrolyte
Balance
• Cerebrospinal fluid (CSF) losses should be
replaced ml/ml unless otherwise indicated.
• The losses are usually replaced with
intravenous 0.9% sodium chloride.
• Oral sodium chloride can be used.
• Cerebrospinal Fluid (CSF) losses and
intravenous fluid replacement should be
recorded hourly on a fluid balance chart and
reviewed every shift by the nurse in charge.

If there is no CSF in
chamber:
• Observe for movement of CSF
in system
• Ensure system is not clamped or
kinked
• Lower chamber momentarily
below head level
• Call doctor, may need to
aspirate the system.

If a catheter becomes
disconnected:
• Clamp catheter close to patient
• Place end in sterile
wrapping/container
• Lie patient down
• Thoroughly clean exposed tip using a
sterile alcohol impregnated swab &
connect a new system aseptically
• Record event in patient’s health care
records & inform the doctor

To repair a split catheter:
• Put on apron and perform a ward aseptic
procedures hand wash
• Open new drainage system and put on sterile gloves
• Assemble new drainage set closing clamps
• Remove last 3-way tap on drainage set
• cleans the exposed catheter end
• Using sterile scissors cut just above the split
• Insert EVD connector into the catheter lumen
• Connect new system
• Check connections
• Position system as prescribed by the neurosurgeon
• Release clamps on new system & those close to the
patient

If a catheter appears to be
blocked:
• Exclude damage to the EVD
system
• Lower drain & observe for CSF
movement
• Change EVD
• The EVD to be aspirated.
– *All EVD’s may be aspirated
including those with a valve.

To aspirate an EVD:
• Clamp catheter close to patient
• Lie patient down
• Put on apron & perform a clinical hand wash
• Open new drainage system and put on sterile gloves
• Assemble new drainage set closing clamps
• Remove last 3-way tap on drainage set
• Cleans the catheter connection
• Disconnects the old system & cleans the exposed
catheter end
• Insert syringe into end of catheter
• Release the clamps close to the patient
• Very gently attempt to aspirate CSF
• If the aspiration has been unsuccessful the EVD
should be flushed.

To flush the EVD:
• The doctor should draw up 1-2mls of 0.9% sodium
chloride into a syringe
• Insert syringe into the exposed end of catheter
• Release the clamps close to the patient
• Gently attempt to inject the sodium chloride
• Continue after aspirating and/or flushing by:
– Discard syringe
– Connect new system
– Check connections
– Release clamps on new system & those close to the
patient
– Gradually lower system to check for drainage
– Position system as instructed by the neurosurgeon

Complication
• Inadequate drainage of CSF may cause the ventricles
to enlarge with subsequent rises in ICP
• This may occur if:
– 1. The EVD system is placed too high above the level of
the foramen of Monro thus minimising CSF drainage.
– 2. CSF drainage is obstructed. This may occur if the
tubing is kinked or inadvertently clamped, the three way
tap is turned the wrong way, the drainage bag is full or
tissue/thick CSF blocks the system.
• Excessive drainage of CSF may also occur if the
system is placed too far below the level of the foramen
of Monro.
• This excessive drainage may cause the ventricles to
collapse and pull the brain tissue away from the dura.
This can cause tearing of the blood vessels and result
in a subdural or subarachnoid haemorrhage (Bracke et.
Al., 1978).

Complication
• Tentorial herniation may be caused by either
excessive or insufficient drainage of CSF.
Symptoms include:
– • Severe headache
– • Lethargy
– • Drowsiness
– • Irritability
– • Apnoea
– • Sluggish pupillary responses
– • Abnormal reflexes
– • Pronator arm drift
– • Changes in BP and heart rate
• All of the above signs and symptoms require
prompt intervention

Complication
• The symptoms of excessive drainage
include:
– • Sweating
– • Tachycardia
– • Headache
– • Nausea
• If drainage is insufficient the patient
will develop signs of increased
intracranial pressure with changes in
conscious level.

Complication : INFECTION
• Maintenance of a closed system is essential, and
IRRIGATION OF THE EVD SHOULD ONLY BE
PERFORMED IF ABSOLUTELY NECESSARY and
must encompass a strict aseptic technique
• A three minute preparation of the injection port with a
povidone iodine solution (betadine) must be
performed prior to withdrawal of CSF for sampling or
injection of intrathecal antibiotics
• An occlusive dressing e.g. Primapore, Is applied over
the insertion site and changed only when soiled or
loose using a strict aseptic technique.
• The site must be observed for signs of infection
whenever the dressing is removed.

Complication : INFECTION
• Scalp dressings are often difficult to apply
and maintain, and it is essential that the
ventricular catheter and EVD tubing are free
from traction and kinks.
• Observe the EVD for evidence of CSF
leakage.
• Leakage is suspected if the dressing is wet,
and a neurosurgeon must be informed.
• It can also occur at any connection ports
throughout the system and a routine check
of these must be made at least once per
shift.

Complication : External ventricular
drain malposition.
Narenthiran G, White BD. Department of Neurosurgery, Queen’s Medical
Centre, Nottingham
• 1-year period (14 February 2003 - 13
February 2004)
• All external ventricular drains (EVD) are
inserted in operating theatre
• 84 patients had insertion of EVDs (frontal,
parietal and occipital) and 13 of them had
more than one EVD
• 8 of the 13 were for malposition of EVD
• 9.5% complication from malposition of EVD
with a minimum complication rate for
insertion of EVD being 15.5%.

Antibiotic Prophylaxis of
Ventriculostomy
Poon et al. Acta Neurochir 1998;71:146-148.
• 228 patients
• Randomized to single-dose or
prolonged prophylaxis
(ampicillin-sulbactam)
• Lower rate of extracranial and
intracranial infections after
prolonged prophylaxis

Cefepime vs. Ampicillin/Sulbactam and
Aztreonam as antibiotic prophylaxis in
neurosurgical patients with external
ventricular drain: result of a prospective
randomized controlled clinical trial
• 255 eligible patients
• Group A employed Cefepime 2G 12 hourly and Group B
employed dual antibiotics as Ampicillin/Sulbactam 3 g 8
hourly and Aztrenam 2 g 8 hourly
• There was no statistically significant difference in
cerebrospinal fluid (CSF) infection rate with 14 patients
(11·5%) in group A (Cefepime prophylaxis) and eight
patients (6·0%) in group B (dual prophylaxis with
Ampicillin/Sulbactam and Aztrenam) had CSF infection
(P = 0·18).
• There was also no statistical significant difference between
wound infection rate happened in eight patients (6·6%) in
Group A and three patients (2·3%) in Group B (P = 0·17).
• Single board spectrum antibiotic prophylaxis with
Cefepime was an effective alternative regimen for
neurosurgical patients with an EVD in situ.
W. S. Poon FRCSEd Division of Neurosurgery, Prince of Wales
Hospital, Chinese University of Hong Kong

Antibiotic Prophylaxis for External
Ventricular Drains in Neurosurgical
Patients
• Intravenous cephalothin (1g 6-hourly for 24 hours)
was the antibiotic of choice
• External ventricular drains were removed after five
days and replaced if further monitoring or CSF drain-
age was required
• Twelve patients with EVDs were identified in first 6
months and 15 patients with EVDs were identified in
the 6 months following implementation of the
protocol.
• Positive CSF Gram-stains were found in 3/12 (25%)
patients in the pre-protocol group and in 0/15(0%) in
the post-protocol group
• Statistically significant improvement in compliance
with antibiotic prescription and reduction in the
incidence of positive CSF cultures
M. A. LUCEY, J. A. MYBURGH
Intensive Care Unit, The St. George Hospital, Sydney, NEW SOUTH WALES

Infection and Intracranial Pressure Monitors
Risk Factors and Antibiotic Prophylaxis
Rebuck et al. J Neurol Neurosurgery Psych 2000;69:381-384
• Review of 215 patients
• Infection rate 7.5%
• Not influenced by prophylaxis
• Risk Factors (RR, 95% CI)
– Monitoring > 5 days 4.4 (1.3 - 11.9)
– Ventriculostomy 3.4 (1.0 - 10.7)
– CSF leak 6.3 (1.5 - 27.4)
– Concurrent infection 3.4 (1.2 - 9.5)
– Serial device placement 4.9 (1.7 - 13.8)

Bedside external ventricular drain
placement for the treatment of acute
hydrocephalus
B. Z. Roitberg; N. Khan, British Journal of Neurosurgery,15,(4 ),2001,324 - 327
• 103 consecutive cases over one year
• Short tunnel ventriculostomy was performed at the
bedside in the neurosurgical intensive care unit
• Long-term care included meticulous site care by a
dedicated NSICU nurse, daily cultures and
prophylactic antibiotics
• The average duration of EVD was 10.7 days (range
1-28 days).
• There was one case of positive cerebrospinal fluid
(CSF) culture. Additional complications included one
small intraparenchymal hematoma and two cases of
EVD disconnection.
• There was no correlation between the duration of
EVD and infection

External ventricular drain infections are
independent of drain duration:
An argument against elective revision
• A retrospective study of 199 patients with
269 EVDs
• 21 CSF infections.
• Acinetobacter accounted for 10 (48%) of
these infections
• The duration of drainage was not an
independent predictor of infection
• Multiple insertions of EVDs was a
significant risk factor
• Second and third EVDs in previously
uninfected patients were more likely to
become infected than first EVDs
Cheng H. Lo, Departments of Neurosurgery and Intensive Care, The Alfred
Hospital Melbourne, Australia

Failure of regular external ventricular drain
exchange to reduce cerebrospinal fluid
infection: result of a randomised controlled
trial
• 103 patients requiring external ventricular drains for
more than five days and with no evidence of
concurrent CSF infection were studied
• The patients were randomised to regular change of
ventricular catheter (every five days) and no change
unless clinically indicated.
• The CSF infection rates were 7.8% for the catheter
change group and 3.8% for the no change group,
respectively
• Regular changes of ventricular catheter at five day
intervals did not reduce the risk of CSF infection
• A single external ventricular drain can be employed
for as long as clinically indicated.
Dr W S Poon, Division of Neurosurgery, Department of Surgery, Prince of
Wales Hospital, The Chinese University of Hong Kong

Can a regular change of external ventricular drainage
(EVD) prevent cerebrospinal fluid infection in patients
with intracranial hemorrhage?
• 50 patients per treatment group
• Most of the patients needed EVD treatment because
subarachnoid hemorrhage (SAH) without (42
patients) and with (15 patients) intraventricular
hemorrhage
• Randomly assigned to the treatment groups
(changing or non-changing group)
• The infection rate in the changing group was 18%
and clearly higher than in the non-changing group,
infection rate of 8%, although this difference was not
statistically significant (p=0,23).
• Regular changes of external ventricular drainage in
patients with intracranial hemorrhage cannot lower
infection rates. On the contrary, we observed higher
infection rates when EVD was changed on a
regular basis in these patients.
C. Mayer, Neurochirurgische Universitätsklinik , Klinikum der Universität
Regensburg, German

Antibiotic-impregnated
shunt catheters
• Retrospectively reviewed all pediatric patients
undergoing CSF shunt insertion over a 3-year period
• 147 pediatric patients underwent 325 shunting
procedures.
• 181 (56%) shunts were placed with non-impregnated
catheters prior to October 2002.
• 144 (44%) shunts were placed with antibiotic-
impregnated shunt catheters after October 2002
• Followed for 6 months after surgery
• Sixteen (9%) patients with non-impregnated
catheters experienced shunt infection
• Three (2%) patients with antibiotic-impregnated
catheters experienced shunt infection within the 6-
month
Daniel M Sciubba MD, George I Jallo MD
Department of Neurological Surgery, Johns Hopkins University, Baltimore, USA
p = 0.025.

Conclusion
• Maintain sterility when handling EVD
• Accurate charting of amount and pattern of
drainage
• To convert to internal CSF diversion system
as early as possible
• Single broad spectrum antibiotics as
prophylaxis is useful to prevent CSF
infection
• Regular change EVD does not change CSF
infection rate
• Antibiotic-impregnated shunt catheters may
lower CSF infection rate

External Ventricular Drain

Recomendados

Recomendados

Más contenido relacionado

La actualidad más candente

La actualidad más candente (20)

Destacado

Destacado (6)

Similar a External Ventricular Drain

Similar a External Ventricular Drain (20)

Último

Último (20)

External Ventricular Drain