Patient selection and trial methods for intraspinal drug delivery for chronic pain: a national survey

Objectives  Intraspinal drug delivery via indwelling pump is an effective means of treating refractory pain. Before a patient is selected for pump implantation, an intraspinal drug delivery trial must be performed to establish side-effects and efficacy profiles. No consensus protocol currently exists for such trials. As a preliminary step in this process, we surveyed a group of interventional pain physicians to explore attitudes on patient selection criteria, drug choice, trial techniques, and efficacy assessment. Methods  The questionnaire was sent for self-administration to 1500 interventional pain physicians, each of whom had implanted one or more Medtronic(®) implantable infusion pumps. Results  We received 205 completed surveys. Among the respondents, most were anesthesiologists (76%) and in private practice (82%). Nearly half (45%) of the respondents use the continuous intrathecal infusion technique to select patients for permanent implants. Conclusions  Trial practices vary widely in terms of patient selection, medication choice, technique, and efficacy evaluation. We hope that our findings will encourage a concerted effort to evaluate existing trial protocols in order to establish a reliable standard of care.