SynchroMed II Drug Infusion System

SynchroMed II Drug Infusion System Models 8637-20 and 8637-40

Specifications for SynchroMed II Drug Infusion System, Models 8637-20 & 8637-40

  Model 8637-20 Model 8637-40
Battery Life 6-7 years 6-7 years
Radiopaque identifier NGP NGV
Thickness 0.78 in (19.5 mm) 1.0 in (26 mm)
Weight (empty/full) 5.8/6.5 oz (165/185 g) 6.2/7.6 oz (175/215 g)
Height 0.78 in (19.5 mm) 1.0 in (26 mm)
Displacement volume 91mL 121 mL
Diameter 3.4 in (87.5 mm) 3.4 in (87.5 mm)
Material Titanium Titanium
Capacity 20.0 mL 40.0 mL
Residual volume 1.4 mL max 1.4 mL max
Minimal flow rate .048 mL/day .048 mL/day
Pump internal fluid path volume 0.199 - 0.289 mL 0.199 - 0.289 mL
Silicone septum puncture life 500 punctures 500 punctures
Bacterial retentive filter .22 micron .22 micron
Prime volume - catheter access port (CAP) 0.14 mL max 0.14 mL max

Indications

  • Chronic infusion of Lioresal® Injection (baclofen injection) for the management of severe spasticity of spinal or cerebral origin
  • Chronic intrathecal or epidural infusion of sterile, preservative-free morphine sulfate for chronic, intractable pain of malignant and/or benign origin
  • Chronic intrathecal infusion of preservative-free ziconotide sterile solution for the management of severe chronic pain
  • Chronic intravascular infusion of chemotherapy for the treatment of cancer
  • Chronic intravascular infusion of Floxuridine (FUDR) or methotrexate for the treatment of primary or metastatic cancer

Device Longevity

Device longevity is a function of flow rate. Flow rates affect the battery voltage and motor revolutions.

Device Longevity

How SynchroMed II Works

The Medtronic SynchroMed® II Infusion System uses a catheter to deliver precise amounts of intrathecal baclofen (a muscle relaxant and antispasticity agent) directly to the intrathecal space and cerebrospinal fluid.

The intrathecal space is an ideal location for the delivery of baclofen, because spasticity begins in the nervous system. When pills are taken by mouth they have to be digested, enter the bloodstream and then cross into the fluid surrounding the brain and spinal cord (cerebrospinal fluid or CSF). Since the drug, Lioresal® Intrathecal (baclofen injection), is delivered directly into the CSF, it requires a much lower dose, which may result in significantly decreased side effects that often accompany oral medications. Additionally, the system can be programmed to deliver precise amounts of medication, allowing the therapy to be customized to meet your patient's specific needs.

Delivery Process

The pump delivers intrathecal baclofen in precise amounts based on instructions that the clinician programs into the device.

The drug enters the pump through the reservoir fill port and passes through the reservoir valve and into the pump reservoir. At normal body temperatures, pressurized gas that is stored below the reservoir expands, exerting constant pressure on the reservoir. This pressure advances drug into the pump tubing. The battery-powered electronics and motor precisely push the programmed dose out through the catheter port and into the catheter.

The peristaltic action of the pump moves the drug from the pump reservoir, through the pump tubing, check valve, catheter port, and implanted catheter, to the infusion site.

The reservoir valve prevents the drug from entering the pump reservoir when the reservoir capacity is reached. The check valve prevents the drug from passing back into the pump from the implanted catheter or catheter port.

The catheter access port (CAP) allows injection of the drug directly into the implanted catheter for drug administration and diagnostic purposes. Drug injected into the CAP bypasses the pump mechanism and goes directly through the catheter port into the implanted catheter to the infusion site.

The CAP allows entry of a 24-gauge non-coring needle to prevent accidental injection during refill procedures (which use the 22-gauge non-coring needle supplied in the refill kit).

The pump has suture loops that should be used to anchor the pump in the pocket.

 

About Baclofen

Baclofen is a structural analog of the inhibitory neurotransmitter gamma aminobutyric acid (GABA) that may exert its effects by stimulation of the GABAB receptor subtype.1

References

  1. Lioresal® Intrathecal (baclofen injection) Drug Package Insert

For more information on the indications, contraindications, warnings, and precautions for the SynchroMed programmable infusion systems, please review the device brief summaries for the SynchroMed II Drug Infusion System and the SynchroMed EL Infusion System.

ITB Therapy (Intrathecal Baclofen Therapy) is indicated for use in the management of severe spasticity. For spasticity of spinal cord origin, ITB Therapy via an implantable infusion system should be reserved for patients unresponsive to oral baclofen or those who experience intolerable CNS side effects at effective doses. Patients with spasticity due to traumatic brain injury should wait at least one year after the injury before consideration of long-term intrathecal baclofen therapy.

Indications, Safety & Warnings for ITB Therapy: Intrathecal Baclofen Withdrawal: Abrupt discontinuation of intrathecal baclofen, regardless of the cause, has resulted in sequelae that include high fever, altered mental status, exaggerated rebound spasticity, and muscle rigidity, that in rare cases has advanced to rhabdomyolysis, multiple organ-system failure, and death.

Prevention of abrupt discontinuation of intrathecal baclofen requires careful attention to programming and monitoring of the infusion system, refill scheduling and procedures, and pump alarms. Patients and caregivers should be advised of the importance of keeping scheduled refill visits and should be educated on the early symptoms of baclofen withdrawal. Special attention should be given to patients at risk (e.g., spinal cord injuries at T-6 or above, communication difficulties, history of withdrawal symptoms from oral or intrathecal baclofen).

This therapy is contraindicated in patients who are hypersensitive to baclofen. Implantation of the infusion system is contraindicated if the patient is of insufficient body size, requires a pump implant deeper than 2.5 cm, or, in the presence of spinal anomalies or active infection.

The most frequent drug adverse events vary by indication but include: hypotonia (34.7%), somnolence (20.9%), headache (10.7%), convulsion (10.0%), dizziness (8.0%), urinary retention (8.0%), nausea (7.3%), and paresthesia (6.7%). Pump system component failures leading to pump stall, or dosing/programming errors may result in clinically significant overdose or underdose. Acute massive overdose may result in coma and may be life threatening.

The most frequent and serious adverse events related to device and implant procedures are catheter dislodgement from the intrathecal space, catheter break/cut, and implant site infection including meningitis. Electromagnetic interference (EMI) and Magnetic resonance imaging (MRI) may cause patient injury, system damage, operational changes to the pump, and changes in flow rate.

Please refer to the full prescribing information and system information for details or call Medtronic at 1-800-328-0810. Rx Only. Lioresal® is a registered trademark of Novartis Pharmaceuticals Corporation.

January 2008