ITB

Medical Complications: Overdose & Withdrawal	see below
Surgical Complications: Device & Surgery

Medical, Surgical and Device Complications can be serious, but rarely result in permanent morbidity or any mortality.

Medical Complications

• Incapacitated patients are more prone to: deep vein thrombosis (phlebitis), pulmonary embolus, pulmonary & urinary tract infections, skin breakdown and decubitus.
• The pump itself is no contraindication to use of heparin or coumadin, and does not require use of prophylactic antibiotics prior to dental work.
• Meningitis: tubing can rarely serve as a nidus in septicemia to cause abscess or meningitis.
• Intrathecal baclofen: adjustments of medication as well as device and catheter problems can be associated with overdose and withdrawal syndromes described in detail below.

ITB Overdose

OVERDOSE - SIGNS:

• DROWSINESS - PROGRESSION TO SOMNOLENCE
• CONFUSION AND COMA
• ASCENDING WEAKNESS
• SEIZURES MAY OCCUR
  • Weakness,
  • Drowsiness,
  • Dizziness,
  • Blurred Vision,
  • Headaches,
  • Hypotension,
  • Numbness,
  • Constipation,
  • Urinary Retention
  • Slurred Speech,
  • Lethargy,
  • Confusion
  • Seizures,
  • Respiratory Depression,
  • Reversible Coma
  • Death

OVERDOSE - COURSE:

• After dose change 1 - 2 hours before effect noted
• Up to 10 - 12 hours for complete lumbar effect
• Evidence of overdose may occur even later
  • LUMBAR - CEREBRAL GRADIENT
    

OVERDOSE - TREATMENT:

• REVIEW PREVIOUS SETTINGS. (if available).
• CONSIDER LUMBAR PUNCTURE FOR REMOVAL 30 - 40ml CSF (this decreases ITB gradient). If experienced - CSF can also be withdrawn via catheter access port to reduce CSF baclofen concentration. (Can access CSF by side port on pump. The mesh screen will prevent large bore needle from entering. A smaller gauge needle is required to access this port than is required for usual central refill port).
• ICU MONITORING : cardiorespiratory monitoring (vital capacity, arterial blood gas, ?ventilator support, arrhythmia), neurologic monitoring (level of arousal, seizures).
• STOP PUMP.
• Can also empty pump (Huber Needle from OR or ER available if no programmer available to stop pump) - pump automatically shuts off if empty. Empty pump by usual access port - can use template. Avoid air entry in pump reservoir.
• Support may be required for 1-2 days.
• PHYSOSTIGMINE : 1 - 2 mg intravenously over 2 minutes; may be repeated q30’ prn. (Response is usually rapid onset and brief duration.)
  • Adult dosage: 1-2mg intravenously over 5-10 minutes.
  • Pediatric dosage: 0.02mg/kg intravenously, no more than 0.5mg/minute. The dosage may be repeated at 5-10 minute intervals until a therapeutic effect is obtained or a maximum dose of 2mg is attained.
  • Caution: use of physostigmine can be associated with induction of seizures and bradycardia. It may not be effective in reversing large overdoses.
• DO NOT USE PHYSOSTIGMINE IN PLACE OF INTUBATION / VENTILATOR SUPPORT.
• Do not abruptly stop intrathecal baclofen for prolonged periods, withdrawal can occur causing seizures or death. In this situation oral baclofen can be used or the pump can be restarted at a lower dose.

ITB Withdrawal

WITHDRAWAL - SIGNS:

• return of spasticity
• return of spasms
• return of pain
• agitation
• confusion
• fever
• sweating
• tachycardia
• seizures
• death

WITHDRAWAL - COURSE:

• This can be subtle in onset or abrupt depending upon the cause of withdrawal. The manifestations will vary depending upon the rate of doseage decline and the concentration of medication one is withdrawing from. This problem can be subtle or obvious. Clinical suspicion is key to diagnosis. Withdrawal can be as a result of:
  • catheter problem (kink, disconnection, blockage or cut prevents flow to intrathecal space),
    • pump line diagnostic evauation with the injection of dye in side port to confirm and localize catheter problem causing withdrawal can occasional correct problem and result in sudden overdose
  • empty reservoir (alarm alerts patient to low reservoir; can adjust alarm to alert patient at any time before refill procedure),
  • low battery (battery life - when low the pump delivery can be erratic or stop),
  • low reservoir (as the volume in the reservoir runs low - depending upon rate and concentration of baclofen utilized - the delivery of steady state concentration can vary).

WITHDRAWAL - TREATMENT:

• Depending upon basis of withdrawal and severity the treatment may vary:
  • if due to low reservoir - end of dose and minor withdrawal - refill pump and reset reservoir alarm at higher value,
  • if due to interrupted delivery and flow of intrathecal baclofen cannot be re-established - restart oral baclofen until this problem can be corrected; (pump line diagnostics procedure itself can result in blockage being corrected, if not then surgery is required),
  • if due to low battery - replace battery and entire pump as soon as possible, there may be a 2 week window if low battery alarm on,
  • if due to empty pump - refill reservoir, but be careful because the immediate resumption of the prior steady state rate (dose) may result in an overdose type picture.