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A `Leaking' Synchromed® Pump
Pain 71 (1997) 109
Clinical notes
A ‘Leaking’ Synchromed Pump D.A. Cherry*, K. Eldredge Pain Management Unit, Flinders Medical Centre, Bedford Park, SA 5042, Australia Received 23 April 1996; revised version received 31 December 1996; accepted 2 January 1997
A 36-year-old woman had a Synchromed pump (a battery powered pump with an 18-ml reservoir connected to an intraspinal catheter) inserted for relief of so-called haematuria-loin pain syndrome. This syndrome is characterised by frequent microscopic haematuria associated with severe loin pain. Following significant tolerance to orally administered opioids, it was decided to treat her pain with spinally administered opioids. As this route of administration was predicted to be required for many years it was decided to implant a Synchromed pump attached to an intrathecal catheter. There had been various occasions while the patient was on oral opioids where the drugs had been stolen or lost, all with plausible stories, but none where we were able to prove conclusively that they were being misused. The pump functioned well for 30 months but there was a gradual increase in the daily morphine requirement which we were prepared to accept as being related to receptor tolerance. However the patient then reported that the pump was ‘dry’ and that she was feeling withdrawal symptoms prior to the time when we could predict that the pump needed refilling. There were suspicious needle puncture marks over the pump, but we were not able to prove that these were not due to our refilling of the pump at monthly intervals, nor due to her self administration of insulin for diabetes mellitus.
It was decided to inspect the pump to see whether the membrane was leaking but on exposure the membrane looked in excellent condition. The pump was inverted such that the refill port was inaccessible. The pump functioned perfectly for the first time for months and at reoperation to ‘inspect’ the pump again, the pump showed multiple needle puncture marks over the centre of the inferior aspect of the pump, where the patient would have thought that the refill port would be. This proved that the patient was either self draining the pump or someone else was doing it for her. The patient when initially confronted with this information, denied that she was tampering with the pump. However, when the patient was presented with the facts of the matter in the presence of her husband she did confess to draining morphine from the pump which she used parenterally herself, allegedly for pain control but more likely for the perceived secondary effects of morphine. The patient was warned not to repeat this practice or the pump would be removed. Five months later the patient presented with a cellulitis over the pump site which was obviously infected, presumably from unsterile attempts to drain the contents of the pump. The pump had to be removed and fortunately the patient did not go on to develop a more serious infection such as meningitis. In conclusion, this clinical note highlights one of the possible reasons for malfunction of implanted pumps.
* Corresponding author. 0304-3959/97/$17.00 1997 International Association for the Study of Pain. Published by Elsevier Science B.V. PII S0304-3959 (97 )0 3338-1
Clinical notes
A ‘Leaking’ Synchromed Pump D.A. Cherry*, K. Eldredge Pain Management Unit, Flinders Medical Centre, Bedford Park, SA 5042, Australia Received 23 April 1996; revised version received 31 December 1996; accepted 2 January 1997
A 36-year-old woman had a Synchromed pump (a battery powered pump with an 18-ml reservoir connected to an intraspinal catheter) inserted for relief of so-called haematuria-loin pain syndrome. This syndrome is characterised by frequent microscopic haematuria associated with severe loin pain. Following significant tolerance to orally administered opioids, it was decided to treat her pain with spinally administered opioids. As this route of administration was predicted to be required for many years it was decided to implant a Synchromed pump attached to an intrathecal catheter. There had been various occasions while the patient was on oral opioids where the drugs had been stolen or lost, all with plausible stories, but none where we were able to prove conclusively that they were being misused. The pump functioned well for 30 months but there was a gradual increase in the daily morphine requirement which we were prepared to accept as being related to receptor tolerance. However the patient then reported that the pump was ‘dry’ and that she was feeling withdrawal symptoms prior to the time when we could predict that the pump needed refilling. There were suspicious needle puncture marks over the pump, but we were not able to prove that these were not due to our refilling of the pump at monthly intervals, nor due to her self administration of insulin for diabetes mellitus.
It was decided to inspect the pump to see whether the membrane was leaking but on exposure the membrane looked in excellent condition. The pump was inverted such that the refill port was inaccessible. The pump functioned perfectly for the first time for months and at reoperation to ‘inspect’ the pump again, the pump showed multiple needle puncture marks over the centre of the inferior aspect of the pump, where the patient would have thought that the refill port would be. This proved that the patient was either self draining the pump or someone else was doing it for her. The patient when initially confronted with this information, denied that she was tampering with the pump. However, when the patient was presented with the facts of the matter in the presence of her husband she did confess to draining morphine from the pump which she used parenterally herself, allegedly for pain control but more likely for the perceived secondary effects of morphine. The patient was warned not to repeat this practice or the pump would be removed. Five months later the patient presented with a cellulitis over the pump site which was obviously infected, presumably from unsterile attempts to drain the contents of the pump. The pump had to be removed and fortunately the patient did not go on to develop a more serious infection such as meningitis. In conclusion, this clinical note highlights one of the possible reasons for malfunction of implanted pumps.
* Corresponding author. 0304-3959/97/$17.00 1997 International Association for the Study of Pain. Published by Elsevier Science B.V. PII S0304-3959 (97 )0 3338-1