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 0.048 mL/day 0.048 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 intrathecal or epidural infusion of sterile, preservative-free morphine sulfate for chronic, intractable pain
  • Chronic intrathecal infusion of preservative-free ziconotide sterile solution for the management of severe chronic pain
  • Chronic infusion of Lioresal® Injection (baclofen injection) for severe spasticity of spinal or cerebral origin
  • 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 pump is an implantable, battery-powered device that stores and dispenses the prescribed medication directly to the cerebrospinal fluid around the spinal cord. This process occurs according to instructions programmed by the clinician. As a result, effective pain relief is achieved using much smaller doses than are used in orally administered analgesics ( approximately 1/300 of an oral morphine dose)1,2 which may reduce the frequency of side effects as well.

Delivery Process

The pump delivers the prescribed medication in precise amounts based on the 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 directly into the implanted catheter for drug administration and diagnostic purposes. Fluid 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.

 

References

  1. Lamer TJ. Treatment of cancer-related pain: When orally administered medications fail. Mayo Clinical Proc 1994;69:473-80.
  2. Levy, R. Implanted Drug Delivery Systems for Control of Chronic Pain. Chapter 19 of Neurosurgical Management of Pain. New York, NY: Springer-Verlag; 1997.