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 apparent risk (e.g. spinal cord injuries at T-6 or above, communication difficulties, history of withdrawal symptoms from oral or intrathecal baclofen). Consult the technical manual of the implantable infusion system for additional postimplant clinician and patient information.
User instructions - Comply with all product instructions for initial preparation and filling, implantation, programming, refilling, and accessing the catheter access port (if present) of the pump. Failure to comply with all instructions can lead to technical errors or improper use of implanted infusion pumps and result in additional surgical procedures, a return of underlying symptoms, drug withdrawal symptoms, or a clinically significant or fatal drug underdose or overdose.
Implantation and system management - Implantation and ongoing system management must be performed by individuals trained in the operation and handling of the infusion system and must be in compliance with procedures described in the appropriate technical instructions. Inadequate training or failure to follow instructions can require surgical revision or replacement, and result in a clinically significant or fatal drug underdose or overdose.
Calculating catheter volume - Use the catheter length recorded at implant or catheter revision when calculating catheter volume. The actual implanted catheter length and catheter model number are required to accurately calculate catheter volume. A universal value does not exist that can be used as a substitute for this knowledge. An inaccurate catheter volume calculation can result in a clinically significant or fatal drug underdose or overdose.
Contrast medium (pumps with a catheter access port) - Do not inject any contrast medium into the pump reservoir. Injecting contrast medium into the pump reservoir can impair pump operation.
Refill - Patients must return to the clinic for refills at the prescribed times. Failure to return to the clinic for refills at the prescribed times can result in the actual flow rate of the pump being less than expected, resulting in a loss of or change in therapy, which may lead to a return of underlying symptoms, drug withdrawal symptoms, or a clinically significant or fatal drug underdose. Failure to return at the prescribed times can also damage the pump, requiring surgical replacement.
Refill kit components – Use the appropriate Medtronic refill kit during all refill procedures for Medtronic implantable infusion pumps. Using components other than Medtronic components or a kit other than the appropriate refill kit can damage Medtronic components, requiring surgical revision or replacement, and allow drug leakage into surrounding tissue, resulting in loss of or change in therapy, which may lead to a return of underlying symptoms, drug withdrawal symptoms, or a clinically significant or fatal drug underdose or overdose.
Injection error during a pump refill procedure - Be certain you are accessing the reservoir fill port when injecting fluids into an implanted pump. ALWAYS:
- identify the pump model and reservoir volume.
- identify the location of the reservoir fill port.
- Avoid pocket fill, i.e. improper injection of medication into the subcutaneous tissue (see below)
- Avoid inadvertent injection into the catheter access port (see below)
- use the instructions, noncoring needles, appropriate template edge, and other accessories provided in the appropriate kit.
- verify the location of the reservoir fill port during needle insertion according to the instructions provided AND using other medical procedures as appropriate.
- refer to the drug labeling for indications, contraindications, warnings, precautions, adverse events, and dosage and administration information.
Pocket fill is the improper injection of refill medication into the subcutaneous tissue, which includes the pump pocket. The injection of drug into the subcutaneous tissue can lead to an acute systemic overdose, which can be fatal. After a pocket fill, the pump reservoir will become empty sooner than anticipated, and this may cause underdose symptoms and/or baclofen withdrawal syndrome, which can be fatal. If it is suspected or known that all or part of the drug was injected into the pocket during the refill procedure, monitor the patient closely for signs and symptoms of overdose in an appropriate facility for a sufficient amount of time or until the symptoms have resolved. Refer to the refill kit manual or the Indications, Drug Stability, and Emergency Procedures for SynchroMed and IsoMed Implantable Infusion Systems Reference Manual for emergency procedures associated with drug underdose and overdose. Refer to the drug product information label for specific drug underdose and overdose symptoms and methods of management.
Inadvertent injection into the catheter access port may result in a clinically significant or fatal drug overdose. If it is suspected or known that all or part of the drug was injected into the catheter access port during the refill procedure, monitor the patient closely for signs and symptoms of overdose in an appropriate facility for a sufficient amount of time or until the symptoms have resolved. Refer to the catheter access port kit manual or the Indications, Drug Stability, and Emergency Procedures for SynchroMed and IsoMed Implantable Infusion Systems Reference Manual for emergency procedures associated with drug overdose. Refer to the drug labeling for specific drug overdose symptoms and methods of management.
Changing drug or decreasing drug concentrations - Rinse the reservoir twice between solutions when changing drug or decreasing drug concentrations in the pump reservoir. A significant amount of drug may be present in the pump reservoir after emptying the pump. This residual volume cannot be removed by emptying the pump. Rinsing the reservoir between solutions minimizes the amount of drug in this residual volume but does not eliminate it. Failure to account for residual drug in the pump reservoir can result in a concentration that is different than intended and a clinically significant or fatal drug underdose or overdose. Program a bridge bolus after rinsing the reservoir twice. The bridge bolus advances the remaining old drug (the drug left in the pump tubing, catheter access port, and catheter after emptying and refilling the pump) to the catheter tip at the prior flow rate.
Refer to "Performing a reservoir rinse" on page 18 of this manual. Refer to the programming guide for bridge bolus procedures.
Connections - Firmly secure all connections. Failure to secure connections can allow drug to leak onto the surrounding skin and may result in inadequate therapy or infection.
Reservoir fill port injections - Do not use excessive force when accessing the reservoir fill port. Excessive force can result in damage to the needle or pump requiring surgical revision or replacement, and leakage into surrounding tissue, resulting in loss of or change in therapy, which may lead to a return of underlying symptoms, drug withdrawal symptoms, or a clinically significant or fatal drug underdose or overdose.
Intrathecal therapy - For intrathecal therapy, use ONLY a preservative-free sterile solution indicated for intrathecal use. Nonindicated fluids containing preservatives or endotoxins can be neurotoxic in intrathecal applications. Using nonindicated fluids can result in adverse events including, but not limited to, extreme pain, cramps, seizures, and death.
Drug information - Refer to the drug labeling for indications, contraindications, warnings, precautions, dosage and administration information, and screening procedures. Refer to the drug labeling for specific drug underdose or overdose symptoms and methods of management. Failure to refer to the drug labeling can result in inappropriate patient selection and management, inadequate therapy, intolerable side effects, or a clinically significant or fatal drug underdose or overdose. Consider the possibility of a drug error if the patient experiences unusual side effects. Failure to do so can result in misdiagnosis of patient symptoms.
Mixing drugs - The effects that drug mixtures have on pump operation are unknown. Drugs can precipitate when mixed. These precipitates can inhibit pump flow or block the catheter, resulting in loss of therapy or a clinically significant or fatal drug underdose.
Drug interaction and side effects - Inform patients of the appropriate warnings and precautions regarding drug interactions, potential side effects, and signs and symptoms that require medical attention, including prodromal signs and symptoms of inflammatory mass. Failure to recognize the signs and symptoms and to seek appropriate medical intervention can result in serious patient injury or death.
Drug overdose symptoms and management - Refer to the emergency procedures included at the end of this manual and the drug labeling for specific drug overdose symptoms and methods of management.
Drug underdose/overdose - Inform patients and caregivers of the signs and symptoms of a drug underdose and overdose. Inform patients and caregivers:
- to be aware and report any unusual signs or symptoms at anytime during or after a refill or catheter access port procedure.
- to be alert for any burning sensations in the area of the pump pocket during their refill or catheter access port procedure.
- to especially watch for signs of underdose and overdose.
- to stay alert for signs or symptoms that may indicate changes to their prescribed drug concentration or programmed dose.
- to seek emergency assistance as necessary. Refer to the refill kit or catheter access port kit manual or the Indications, Drug Stability and Emergency Procedures for SynchroMed and IsoMed Implantable Infusion Systems Reference Manual for emergency procedures associated with drug underdose and overdose.
Failure to recognize these signs and symptoms and to seek appropriate medical intervention can result in serious patient injury or death.
Patient travel - Patients should notify their clinicians of any travel plans. Clinicians need this information to coordinate patient care and pump refills and help prevent a loss of or change in therapy, which may lead to a return of underlying symptoms, drug withdrawal symptoms, or a clinically significant or fatal drug underdose.