Indications, Safety, and Warnings
It’s important for the healthcare provider to be familiar with all
indications, warnings, and precautions for this device.
Draining and monitoring of cerebrospinal fluid (CSF) flow from the
lateral ventricles or lumbar subarachnoid space is indicated in
selected patients to:
- Reduce intracranial pressure (ICP), eg, pre-, intra-, or
- Monitor CSF chemistry, cytology, and
- Provide temporary CSF drainage in patients with
infected cerebrospinal fluid shunts.
Monitoring of intracranial pressure (ICP) is indicated in selected
- Severe head injury
- Subarachnoid hemorrhage graded
III, IV, or V preoperatively
- Reyes syndrome or similar
- Miscellaneous problems when drainage is to be used
as a therapeutic maneuver.
Monitoring can also be used to evaluate the status pre- and
postoperatively for space-occupying lesions.
Intracranial pressure monitoring with a ventricular or lumbar
catheter is contraindicated in patients receiving anticoagulants or
who are known to have a bleeding diathesis. The use of a ventricular
catheter is contraindicated if scalp infection is present. A patient
undergoing external drainage and monitoring must be kept under
continuous, close supervision. The use of a ventricular or lumbar
drainage catheter, or a Duet™ EDMS, is contraindicated where trained
personnel are not available to supervise monitoring and drainage on a
The use of a lumbar catheter for drainage and monitoring of
cerebrospinal fluid is not recommended for patients with
non-communicating hydrocephalus; where lumbar puncture is
contraindicated; in the presence of large intracranial mass lesions,
tumors, hematomas, or cysts; in the presence of infections in the
surrounding area which includes the skin, subcutaneous tissue, bone
and the epidural space; and patients who have demonstrated blockage of
cerebrospinal fluid to the subarachnoid space due to trauma, hematoma,
fracture or tumor. The use of a lumbar catheter under these conditions
for external drainage and monitoring is at the discretion of the physician.
Monitoring pressure from the lumbar subarachnoid space can be done
only in instances where lumbar puncture does not pose a danger to the patient.
Warnings & Precautions
- Failure to appropriately adjust the rate of CSF outflow
through the external drainage system may result in potentially
serious injury to the patient.
- Patients undergoing external
drainage and/or intracranial pressure monitoring must be kept under
constant supervision in an intensive care unit staffed with trained
personnel familiar with the use of intracranial and lumbar pressure
- Improper vigilance or improper
drainage system setup can lead to overdrainage or underdrainage and
potentially serious injury to the patient. Intracranial and lumbar
pressure monitoring has been associated with intracranial infection,
meningitis and ventriculitis. This hazard has been quoted at less
than 1% to more than 5%. The risk of infection is probably
influenced both by the number of times a system is opened and by the
duration of the monitoring. Prolonged steroid therapy can also
increase the risk of infection.
- It is possible that the
puncture of the ventricle or the opening of the dura will result in
an intracranial hemorrhage.
- It is possible that if too much
CSF is removed from the ventricles, either during a drainage
procedure or when the ventricle is first punctured, the ventricle
may collapse and occlude the catheter.
- It is possible that
the monitoring system may give a false pressure reading either due
to a pressure line becoming clogged or kinked or from an air bubble
lodged in the system. An incorrect pressure reading may lead to the
wrong therapy being given to the patient. The irrigation of the
catheter or the performance of a Volume Pressure Relationship (VPR)
study may induce pressure waves in the patient. For this reason,
irrigation or VPR studies should be done only by, or on the order
of, a physician.
- In order to minimize the possibility of
infection, meningitis or ventriculitis, several steps should be
observed. First, the injection sites should always be cleaned with
alcohol and the alcohol allowed to dry before a needle is inserted
into them. Second, sterile technique should be observed in setting
up the system and in the placement of the catheter. Third, subgaleal
tunneling of the ventricular catheter should be approximately one to
- In order to avoid possible cracking of the Luer
connectors after cleaning with alcohol, allow to air dry completely
prior to connecting the system.
- Leakage from the system,
which can result from damaged system components or improper use or
handling, can potentially result in overdrainage, the need to
replace the drainage system and/or other complications to the
- In order to ensure against ventricular collapse and
the possible consequence of tentorial herniation, always perform a
drainage maneuver against a positive pressure head on the order of
20 cm H2O or 15 mm Hg. In addition, when the ventricle or lumbar
subarachnoid space is first punctured during the insertion of the
catheter, care should be taken so as little CSF as possible is
- A double suture tie with silk suture should be used to
secure the ventricular or lumbar catheter to the connection fitting.
Check to ensure that the connection is tight prior to use.
- Whenever irrigation of the catheter or the performance of the
VPR is decided upon, great care must be used so that pressure waves
are not initiated. Only a small volume of saline should ever be
injected into the ventricular system, and this only done by, or on
the order of, a physician. In general, in monitoring intracranial
pressure, one should always be aware of the waveform on the
oscilloscope. If the waveform begins to dampen out, it is important
that the entire monitoring system be examined. Ensure that the line
to the patient is not kinked and that all air bubbles or blood or
other debris are removed from the system.
- Ascertain that
the transducer is on the same level as the patient’s ventricular
system to ensure the proper reference level in the manometer tube
for use in calibration procedures. Pressure monitoring with the
manometer may result in overdrainage of the ventricles.
- Infections, particularly meningitis, ventriculitis, and wound
- Overdrainage, leading to:
- Permanent neurological deficit
- Frequent punctures of the brain to insert the ventricular
catheter can predispose to intracerebral hemorrhage and edema
leading to a further rise in Intracranial Pressure (ICP).
- Poor recording of ICP will result if the catheter, patient line
or other components of the monitoring system become clogged with
blood clots, brain tissue fragments, or fibrinous debris.
- Ventricular wall collapse, in small patients, resulting in
obstruction of the catheter and predisposing to tentorial
herniation. It is therefore important to avoid excessive release of
CSF before the system catheter is attached to the patient line.
- Limiting the duration of monitoring from a single site to less
than five days will reduce the infection rate.
If monitoring must continue past five days, consider inserting a new
catheter at a fresh site and changing the entire system.
Important Safety Information
This therapy is not for everyone. Please
consult your physician. A prescription is required. For more
information, please contact us at 1-800-468-9710.
For further information, please call
Medtronic NT at 1-800-468-9710, or contact your Medtronic NT sales representative.
Caution: Federal (USA) law restricts this device to sale by or on
the order of a physician. Refer to product package insert for
instructions, warnings, precautions and complications.