Trialing

SECTION 3

Reducing Infection Rates

Infection prevention is a major concern during pump placement, catheterization, and post-operative care. The 2017 PACC^10,12 and NACC¹⁰² recommendations include adhering to protocols for skin antisepsis, sterilization of the pump site, and maintaining strict cleanliness preoperatively, intraoperatively, and postoperatively. The use of preoperative screening protocols ^105,107 and strict skin cleansing perioperatively is recommended. Evidence supports minimizing catheter manipulation and ensuring good wound care to reduce infection rates. Use of antibiotics before, during, and after the procedure, as well as the careful management of risk factors (like smoking or obesity), is advised to further reduce infection risks^10,12.

Consensus Point 13: IDDS implanters should follow published guidelines on perioperative management of implanted devices and time medication administration optimally to prevent infection. USPSTF grade B; level of certainty moderate; evidence level IB.

Perioperative and Postoperative Management of the New Device

Perioperative education regarding surgical risk, wound and device management is crucial. Occlusive wound dressings, office follow up within 2 weeks, and judicious use of systemic opioids with IDD infusion are recommended.

Consensus Point 14: Clinicians should educate patients and their caregivers perioperatively about IDDS, the medications being administered, and potential adverse events. Clinicians also should be aware that the initial postimplant phase can be complicated by concomitant administration of systemic opioids. USPSTF grade B; level of certainty moderate; evidence level II.

Initial Pump Flow Settings

Initial flow rates are often low to ensure patient safety and avoid complications. A screening trial may be required and may provide information regarding efficacy and potential starting dose, with ziconotide being an exception. In the context of intrathecal pumps, doses may be measured in micrograms or milliliters per hour. The specific medication being administered (e.g., morphine, baclofen) greatly influences the initial flow rate. After the initial dose, flow rate is gradually increased or decreased depending on how well the drug alleviates symptoms and whether there are any side effects.

Continuous infusion is steady, low-dose continuous infusion, or microboluses to maintain consistent drug levels and is the most common intial infusion protocol. Slow flow rates with higher concentration morphine or hydromorphone may pose greater granuloma formation risk near the catheter tip^8,10,12,113.

Flex dosing and multiple flow rates, initially used for spasticity control with baclofen, has been used for analgesia during the day or nocturnal delivery^114,115,78.

Some pumps can deliver periodic single, or multiple, boluses without a continuous basal dose.

CSF velocity changes during drug bolus infusion depend on several factors, such as stroke volume, respiratory cycle, drug solution density, posture, and individual anatomical differences. These factors can alter drug dispersion and concentration^{116,117,118,119}.

Computational models suggest that low flow rates can affect CSF flow dynamics. Injection with higher latency may lead to a greater drug concentration and volume of contamination in the CSF ^97,120.

Patient activated boluses allow patients to moderate their pain management by using devices (like handheld controllers or mobile apps) to administer additional doses when needed. These doses can account for 5-20% of the total drug volume.

The use of patient activated boluses with ziconotide therapy was reported in 2010 and has become an accepted method to titrate this medication^121,122. The 2017 PACC recommendations based on the three pivotal ziconotide studies, and many years of post-FDA approval experience, suggest ziconotide dilution with preservative-free normal saline to allow dose initiation at 0.5 to 1.2 μg/d.