RESUMO
BACKGROUND: Combining neuraxial opioids and local anesthetics in acute pain results in improved duration of analgesia and reduced dosages and adverse effects. Although commonly used in intrathecal drug delivery systems (IDDS) for chronic pain, the effectiveness of this admixture has not been examined specifically in relation to patient-controlled intrathecal analgesia (PCIA). METHODS: IDDS-implanted chronic noncancer pain patients receiving opioids with bupivacaine (O + B) were randomized to receive either opioids without bupivacaine (O) or O + B in a double-blind manner, at IDDS refills, for one week and then crossed over to the other solution for another week. Primary outcome measures included numeric rating scale (NRS) pain scores before and within 30 minutes after PCIA boluses. Secondary outcome measures included average NRS scores and functional outcome measures. RESULTS: Seventeen patients were enrolled, and 16 patients completed the study. There were no differences in NRS scores before and after PCIA boluses between the O and O + B conditions, though pain scores improved significantly (average decrease in NRS scores: O 1.81 ± 1.47 vs O + B 1.87 ± 1.40, P = 0.688). No differences were noted in speed of onset or duration of analgesia. Although more patients subjectively preferred the O + B treatment, the difference was not statistically significant. No differences were noted in secondary outcome measures, with the exception of global impression of change having higher scores in O compared with O + B. CONCLUSIONS: Acutely removing bupivacaine from a chronic intrathecal infusion of opioids and bupivacaine in patients with chronic noncancer pain did not adversely affect PCIA effectiveness, nor did it affect speed of onset or duration of effect. These findings are divergent from those in acute pain and may have to do with study conditions and pain phenotypes.
Assuntos
Bupivacaína , Dor Crônica , Analgesia Controlada pelo Paciente , Analgésicos Opioides/uso terapêutico , Anestésicos Locais/uso terapêutico , Bupivacaína/uso terapêutico , Dor Crônica/tratamento farmacológico , Método Duplo-Cego , Sistemas de Liberação de Medicamentos , Humanos , Dor Pós-Operatória/tratamento farmacológicoRESUMO
OBJECTIVES: Intrathecal (IT) trial is a prognostic interventional pain management procedure employed to determine the potential success of treating intractable pain with an implantable infusion device system. There is a dearth of data regarding trials with continuous infusion of combination therapy (e.g. opioid combined with local anesthetic). The objective of the this study was to determine the overall outcomes of continuous infusion IT trials and factors influencing long-term success of IT therapy in patients with chronic intractable pain post-laminectomy. MATERIALS AND METHODS: This is a retrospective analysis of all patients with lumbar failed back surgery syndrome (FBSS) who were trialed with a combination of hydromorphone and bupivacaine with a temporary externalized IT catheter from March 2007 to June 2014. RESULTS: From a cohort of 62 patients fulfilling the inclusion criteria, 54 (87.10%) patients had successful IT trials. No significant differences were found between successful and failed trial patients with regards to age, sex, pre-trial pain numeric rating scale scores, pre-trial morphine equivalent daily dose, or trial dosages. Significant positive correlations were found between pretrial oral opioid intake and end of trial hydromorphone dose and hydromorphone dose escalation at 12 months and 24 months. CONCLUSIONS: Patients with refractory low back pain due to FBSS who underwent successful combination IT trial with hydromorphone and bupivacaine infused through a temporary IT catheter had significantly improved pain intensity scores following permanent implant. Higher pre-trial MEDD was correlated with higher trial and post-implant opioid doses and higher rates of opioid dose escalation post-implant.
Assuntos
Analgésicos/uso terapêutico , Bupivacaína/administração & dosagem , Síndrome Pós-Laminectomia/tratamento farmacológico , Hidromorfona/administração & dosagem , Injeções Espinhais/métodos , Idoso , Relação Dose-Resposta a Droga , Quimioterapia Combinada , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Tempo , Resultado do TratamentoRESUMO
BACKGROUND AND OBJECTIVES: Intrathecal (IT) drug delivery systems (IDDSs) have been valuable in managing refractory chronic cancer and noncancer pain for more than 3 decades. These devices, time tested and overall reliable, have lately been noted at this institution to cease infusing unexpectedly. If not immediately recognized and rectified, this abrupt malfunction may lead to significant patient harm. METHODS: A series of 13 patients from 1 academic center whose Medtronic SynchroMed II pumps malfunctioned from 2013 to 2015 is described. Data from the patient population with regard to variables that may increase the rate of IDDS malfunction are analyzed. The risk factors for IDDS malfunction, Medtronic-issued recalls, and current literature on IT device failure are reviewed. RESULTS: The total prevalence of device motor stall among the population of this institution is 9.03%. The incidence rate of IDDS failure is calculated at 0.04 device failures per patient per year. Increased length of time from implant was the only statistically significant (P = 0.00009) risk factor for device failure identified in this population. Dysfunction in the motor gear train was found after destructive analysis of several devices in this series. CONCLUSIONS: Higher rates of device failure are associated with the use of off-label IT drugs. However, device failure may still occur while infusing only approved medications. Implanted patients should be properly informed and educated to differentiate and recognize the critical error alarm of their device as well as the signs and symptoms of IT medication overdose and withdrawal.