While there are may reasons for pump failure to include but not limited to, battery end of life, internal computer failure, rotor failure, catheter failure a new failure has been identified, inability to re-expand the diaphragm at the time of a refill.

Materials and Methods

Personal Experience

Results

Recently 2 patients had Medtronic EL pumps that could not be refilled. The first patient's problem developed over a period of 3 refills, each successive one becoming more difficult until the last refill the diaphragm could not be expanded.

The next patient had a similar experience in that the refill prior to failure was very difficult to achieve requiring extreme pressure to expand the diaphragm and the on return refill visit the diaphragm could not be expanded at all.

Both patients were long standing to the practice and had been refilled numerous times by the same staff without difficulty. They both were on stable doses of medication without any recent changes.

The medication in both pumps was a compounded mixture of low concentration fentenyl / bupivicave, and morphine / clonidine respectively. The same pharmacy had compounded the mixture for 5 and 2 years for these patients.

The fear of injury is of major concern for the patients. The pressures used for refill were so great there was concern of internal failure of the pumps. Even with an extension tubing in place the risk of inadvertent dislodgment of the needle form the center port and subcutaneous infusion of medication was a consideration.

Since both pumps could not be refilled the patients underwent emergent pump replacement without sequela.

Conclusions

Any difficulty in achieving a pump refill should be cause for close monitoring of the patient and if need be replacement of the pump.