Evaluation Of Implantable Intrathecal Drug Delivery Port System For Treatment Of Pain In Advanced Cancer Patients

Background:Pain is one of the most fearful symptoms in advanced cancer patients,which could not only hurt the patients physically and psychologically,reduce the quality of their life,but also impose a heavy burden on their family and society.It is an important challenge for the clinicians on how to control the pain effectively.Not all cancer pain could be relieved by the principles of the World Health Organization(WHO)three-step analgesic ladder.There are still some advanced cancer patients who don't acquire adequate pain relief because of refractory pain and intolerable side-effects of systemic opioids.Intrathecal therapy(IT)has become an alternative to comprehensive medication management(CMM)for pain treatment during cancer pain therapy.Drugs are delivered to receptor sites in the dorsal horn of the spinal cord by intrathecal infusion.Morphine acts directly on pain processing center in the spinal cord,so the dose required is lower and the side effects are fewer.For neuropathic pain,the first-line drugs of intrathecal analgesia contains morphine alone or in combination with the local anesthetic bupivacaine.However the experience of using intrathecal delivery of opioids to manage refractory cancer pain is very limited in some areas,which is related to the pain mode,the expectation of analgesic effect,the life expectancy of the patients,and the cost of intrathecal drug infusion system.Cancer patients finally turned to intrathecal analgesia after they failed to escalate sequential dose of strong opioids,suffered from intolerable side effects,and nearly reach their end of life expectancy in our district.The analysis of the cost of implanted intrathecal morphine pump has been reported,but the research on the cost of implantable intrathecal drug delivery port system in the treatment of advanced cancer pain has rarely been reported.Objective:The purpose of this study was to evaluate the effect and safety of implantable intrathecal drug delivery port system with patient-controlled analgesia(PCA)electronic pump for the treatment of refractory pain in advanced cancer patients,and to count the cost of analgesia in the course of intrathecal treatment.The aim was to make a new idea and scheme for the management of pain in advanced cancer patients.Methods:A retrospective study was performed from December 2013 to December 2016.36 patients with advanced cancer pain,including 19 males and 17 females were recruited and received IT due to refractory cancer pain.All patients were treated with implantable intrathecal drug delivery port system combined with external PCA electronic pump.The drugs used were morphine and bupivacaine.It was recorded and analyzed about 1.patients demographics,general information of pain(NRS,classification,location and characteristics);2.data collected at the day before IT,the 2nd,4th,7th,14th,28th day after IT,as well as at the last observation before death,which included pain NRS,the dose of both morphine and bupivacaine used,the quality of sleep score assessed by PSQI,and the cost used of intrathecal pain management for 28 days and 56 days,the cost estimated about CMM for the same periods;3.complications associated with IT procedures,infusion devices,and drugs during treatment;4.satisfaction of patients at the period of either the whole intrathecal treatment or comprehensive drug analgesia before IT.Results:1.After implantable intrathecal drug delivery port system therapy,pain NRS decreased significantly(P<0.01)at all chosen time points compared with that before intrathecal treatment;2.The pain NRS within 14 days after intrathecal treatment was not significantly increased compared with that on the previous time point.However the pain NRS was significantly higher than that of its previous time point at 28 days after intrathecal treatment and at the last observation before death(P<0.01);3.The doses of morphine and bupivacaine in each recorded time point after intrathecal treatment were significantly higher than those at the previous time point(P<0.01);4.The sleep quality in one month after intrathecal treatment was significantly beuter than that before intrathecal treatment(P<0.01);5.After intrathecal treatment,for patients whose morphine-equivalent oral dose no more than 240mg/d,the cost of IT was significantly higher than that of CMM estimated in both 4 weeks and 8 weeks(P<0.01);however,for patients whose morphine-equivalent oral dose more than 240mg/d,the cost of IT was not significantly different compared to that of CMM estimated in 4 weeks(P>0.05),but was significantly lower than that of CMM estimated in 8 weeks(P<0.01);for all patients in the study,the cost of IT was significantly higher than that of CMM estimated in 4 weeks(P<0.05),but was not significantly different compared to that of CMM estimated in 8 weeks(P>0.05).Conclusions:1.The implantable intrathecal drug delivery port system combined with external PC A electronic pump was safe and effective in treating refractory pain in advanced cancer patients.The sleep quality of the patients was improved.Pain NRS was lower after intrathecal treatment than that of before intrathecal treatment although the NRS has obviously rising trend with the progression of cancer.The doses of morphine and bupivacaine had to be increased significantly over time in order to achieve continuous and effective pain management;2.For advanced cancer patients whose morphine-equivalent oral dose more than 240mg/d or with a relatively long life expectancy(more than 8 weeks),the implantable intrathecal drug delivery port system with PCA pump had advantages in controlling pain and was cost-effective in pain management.