FIGURE 2.

Per-subject 6-month accuracy ratios (n = 65 patients). Details of 4 subjects with 6-month ratios farthest from 1.0 (circled values) are described from the top of graph downward. Ratio = 1.24. Five refills of 20-mL pain pump with per-visit ratios ranging from 1.13 to 2.5, observed delivery volumes of 10.6, 2.4, 1.0, 2.2, and 11.6 mL. During this period, 2 adverse events of drug toxicity/adverse effects were reported (nausea and vomiting, and peripheral edema). Ratio = 1.14: 2 refills of 40-mL spasticity pump per-visit ratios of 0.93 and 1.31, observed delivery volumes of 4.0 and 6.8 mL. Twenty-nine days after implantation, catheter dislodgment was reported. Pump programmed to minimum rate and catheter replacement was carried out prior to 6-month visit. Ratio = 1.11: 2 refills of 40-mL pain pump, per-visit ratios of 1.14 and 1.07, observed delivery volumes of 39.8 and 31 mL. Eleven days after implantation, the patient reported increased pain. Magnetic resonance imaging confirmed no inflammatory mass, and radiographs confirmed catheter tip location at T11-T12. Ratio = 0.88. Two refills of 40-mL spasticity pump during the 6-month period, per-visit ratios of 0.93 and 0.71, observed delivery volumes of 27 and 7.0 mL. Following the 6-month visit, the patient experienced muscle spasms. The intrathecal baclofen dosage was increased at 4 consecutive visits.