Template for disaster? Fatal injection
into wrong port of implanted infusion pump
From the January 15, 2004 issue
PROBLEM: Implantable infusion pumps are sometimes
used for long-term delivery of outpatient parenteral drug
therapy. For intrathecal drug therapy, common uses include
opiates to treat intractable chronic pain and baclofen to
treat spasticity associated with multiple sclerosis, cerebral
palsy, and spinal cord injuries. These pumps can accurately
deliver very small volumes over long periods of time; therefore,
concentrated medications may be used to extend the time between
each refill of medication.
One distinct advantage of intrathecally delivered opiates
is that much lower doses are needed than with other routes
of administration. For example, the parenteral to intrathecal
ratio for morphine is around 100:1. With lower doses, one
would hope the risk of adverse effects would be lessened.
However, massive intrathecal opiate overdoses have occasionally
happened during the course of filling or refilling the pumps.
The result has been a variety of adverse outcomes, including
myoclonic seizures, pulmonary edema, respiratory depression,
coma, and death.
For example, FDA has received reports of fatal overdoses
caused by the accidental intrathecal injection of concentrated
morphine while attempting to refill Medtronic SynchroMed infusion
pumps. The SynchroMed pump is a titanium device about the
size of a hockey puck. The pump is surgically implanted under
the skin in the abdomen or flank area, with a catheter that
resides in the intrathecal space. Centered on the front of
the device is a small injection port leading to a drug reservoir.
Reservoirs hold either a 10 mL or 18 mL volume and permit
the drug supply to be replenished periodically via passage
of a thin needle through the skin and into the reservoir port.
One model of the pump also has a second port located on its
periphery, which provides direct access to the intrathecal
space via the catheter (see Figure ). This catheter access
port is useful mainly for myelography, removal of cerebral
spinal fluid (CSF), and troubleshooting problems (e.g., catheter
patency). According to an FDA MedWatch report we reviewed,
attempts to refill the pump reservoir using the catheter access
port resulted in the accidental injection of concentrated
morphine into the intrathecal space. The patient died as a
result. Similar errors have been reported in the literature.1,2
Fatal errors caused by selecting the wrong port during pump
refill can happen today. In the pump's refill kit, Medtronic
supplies a template to locate the reservoir port. However,
there's also a catheter access kit with a similar-looking
template to find the side port for direct intrathecal access
(see Figure 2). If the wrong kit is used, the medication intended
for the reservoir could be injected into the intrathecal space.
Medtronic has taken a few steps to reduce the risk of an
error. The catheter access port accepts only a very thin needle,
which is included in the kit. The refill kit contains a larger
needle that will not fit through the catheter access port.
However, this safety feature will not prevent an error if
a catheter access kit is accidentally used during a refill.
If that happens, the template will locate the port with direct
access to the CSF, and the thin needle provided with the kit
will enter the port easily. Thus, medication intended for
the drug reservoir could be injected into the catheter access
port. The manufacturer also provides a cautionary pamphlet
in the refill kit with a vague picture on the cover to warn
users not to use the side catheter access port for refilling.
Written cautions appear inside the pamphlet but are easily
overlooked. A short written warning appears on the outside
cover of the catheter access kit, but it, too, may not be
seen. The templates themselves offer no warnings or differentiation
to avoid such a devastating error.
SAFE PRACTICE RECOMMENDATION: Consider the following
suggestions to reduce errors with implantable pumps.
FMEA. If you are using these devices or plan to use
them, conduct a failure mode and effects analysis (FMEA) to
determine additional ways that errors could happen and take
action to reduce the risk of patient harm.
Standardize prescriptions. Create standardized order
sets related to implanting, reprogramming, refilling, and
other possible modalities (e.g., myelography) involving implantable
pumps. Since the catheter access kit and refill kit have distinct
product numbers that are clearly visible on the packages,
consider including the kit number within the applicable order
sets to ensure distribution and use of the kit that matches
the desired function.
Educate users. If these pumps are used, it's critical
to require special privileging and periodic competency validation
for clinicians (e.g., physicians, physician assistants, nurse
practitioners, nurses, pharmacists) involved in prescribing,
implanting, programming, dispensing, or refilling the pumps
or associated kits. All should be thoroughly oriented to the
pump's use and function, procedures for implantation, programming,
and refilling, and clearly understand the potential for life-threatening
effects if an error occurs. If low usage makes it difficult
to maintain proficiency, consider referring patients to another
provider who handles implantable pumps more frequently.
Use pumps with a reservoir port only. When appropriate
(e.g., pediatrics), implant pumps with a single port for the
drug reservoir to reduce the risk of inadvertent direct administration
of concentrated medications.
Separate the kits. Several panels on the cartons are
blank. Thus, the manufacturer's labeling does not lend itself
to easy identification and differentiation when the kits sit
on a shelf. If pumps with both ports are used, store refill
and catheter access kits in different locations. For example,
keep refill kits in a secured area like the pharmacy (some
may contain medications, baclofen for example), and catheter
access kits (without medications) in another location like
the physician's office or radiology. Also separate any refill
kits that contain different doses of medication (e.g., baclofen).
Verify correct kit and port. Follow the written procedures
provided in the manufacturer's kits for filling, programming,
and refilling the pumps. Require the clinician who will be
performing the procedure to verify the kit number with the
number on the standard order form, and to open the kit himself
so the warning messages are less likely to be overlooked.
Require use of the template in the kit to locate the port,
not just palpation. Take a "time out" and have two
clinicians (or a clinician and a patient) independently double
check the kit, template, and medication (if refilling the
pump). During refill, attempt to validate puncture into the
reservoir by aspirating the estimated volume of medication
remaining before refilling the pump. During the procedure,
inject and aspirate small amounts (3-5 mL) of the medication
into the reservoir before refilling with the entire dose.
The full volume injected should be readily aspirated and colorless.
If suspicion exists that the aspirate is not medication, a
sample can be tested with a reagent strip to determine the
presence of glucose and protein, findings that would suggest,
respectively, that cerebral spinal fluid or other body fluids
have been aspirated in error. Fluoroscopy can also be used
if location of the port is in doubt.
Provide patients with information. Since pump refills
may occasionally occur in a location where the patient's medical
records are not readily available, be sure to give the patient
an updated information card/sheet with the device manufacturer
and model number, reservoir capacity, date of last refill,
medication, concentration, programmed dose, and any other
important information. Clinicians should refer to this card
during each encounter with the patient.
Be prepared for errors. Establish written guidelines
for early recognition of an error (e.g., characteristic leg
pain, seizures, and other symptoms specific to the drug) and
prompt treatment in the event an error occurs. This may include
an immediate process for active irrigation and drainage of
the CSF, respiratory support, treatment for myoclonic seizure
activity, and small incremental doses of reversal agents as
Manufacturer changes. We have suggested changes to
the labeling and packaging of the catheter access and refill
kits, and better differentiation of the templates, to warn
practitioners about the danger of direct intrathecal injection
of medication intended for the reservoir. It would also be
helpful if the manufacturer produced a short orientation video
Figure 1. SynchroMed pump (at www.
medtronic.com). Note the catheter access port (top) and
the reservoir port (center).
Figure 2. SynchroMed templates. These clear plastic overlays
are placed over the palpated pump to help locate the correct
port. Left: The refill kit template allows only reservoir
access. Right: The catheter access kit template allows only
catheter access. Accidental use of this template when refilling
the pump has led to fatalities. (Newer design lists "SynchroMed"
on all templates.)
1. Sauter K, Kaufman HH, Bloomfield SM, et
al. Treatment of high-dose intrathecal morphine overdose.
J Neurology 1994; 81:143-46.
2. Wu CL, Patt RB. Accidental overdose of
systemic morphine during intended refill of intrathecal infusion
device. Anesth Analg 1992; 75:130-32