Open AccessEffects of Flow Rate Modifications on Reported Analgesia and Quality of Life in Chronic Pain Patients Treated with Continuous Intrathecal Drug Therapy
Author(s) -
Perruchoud Christophe,
Eldabe Sam,
Durrer Anne,
Bovy Michèle,
Brookes Morag,
Madzinga Grace,
Garner Fay,
Batterham Alan M.,
Menoud Carole,
Jacobs Myriam,
Gulve Ash,
Buchser Eric
Publication year - 2011
Publication title -
pain medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.893
H-Index - 97
eISSN - 1526-4637
pISSN - 1526-2375
DOI - 10.1111/j.1526-4637.2011.01088.x
Subject(s) - medicine , visual analogue scale , quality of life (healthcare) , adverse effect , anesthesia , crossover study , chronic pain , physical therapy , alternative medicine , nursing , pathology , placebo
Objective. We compared the analgesia and the quality of life of a constant daily dose of intrathecal drug administered at different flow rates in patients treated for chronic pain. We postulate that the quality of the analgesia, at the same daily dose, will show an infusion rate dependent pattern with decreased pain at higher flow rates. Patients. Twenty consecutive patients on stable intrathecal treatment were included in a double‐blind three‐period crossover study where the same daily dose was administered at single, double, and quadruple flow rates in a randomized sequence. Outcomes Measures. The mean daily pain score and the quality of life (EuroQol measure of health outcome [EQ‐5D]) were measured following each flow rate change, after 1 week of stabilization. Results. Visual analog scale (VAS) scores remained unchanged with all flow rates. Compared with the lowest flow rate, the EQ‐5D index decreased with double and even more with quadruple flow rate, suggesting a clinically relevant worsening of the health state with higher flow rates. Adverse events were equally distributed in all groups. Conclusion. Pain VAS did not significantly change with flow rate. This is consistent with preclinical data showing very limited increase in drug distribution in the cerebrospinal fluid with much larger flow rate augmentation. However, the quality of life decreased consistently as the flow rate increased. This was entirely due to a worsening of the pain and anxiety dimension of the EQ‐5D questionnaire, caused presumably by a slight increase in pain rather than adverse events. We suggest that at higher flow rates increased drug dilution results in a decreased effect at the receptor site.