The analgesic efficacy of patient-controlled ropivacaine instillation after cesarean delivery

To assess the efficacy and safety of wound instillation of ropivacaine, whe n administered via a patient-controlled elastometric pump, 50 term parturie nts undergoing cesarean delivery were enrolled into this prospective, place bo-controlled, double-blinded study. In all cases, a standard spinal anesth etic was administered. After the surgery, a multihole 20-gauge epidural cat heter (B. Braun, Melsungen, Germany) was placed above the fascia such that the tip was sited at the point that demarcated 50% of the length of the sur gical wound. Thereafter, the catheter was connected to the elastometric pum p. According to a computer generated randomization schedule, the pump was f illed with either ropivacaine 0.2% (Ropivacaine Group) or an equal volume o f sterile water (Control Group). Postoperatively, patient-controlled analge sia was administered via the elastometric pump. During the first 6 postoper ative hours, a coinvestigator administered "rescue" morphine (2 mg, IV). Th ereafter, "rescue" dipyrone (1 g) was administered on patient request. In a subset of 10 patients, blood ropivacaine levels were assessed. Compared wi th the Control Group, significantly fewer patients in the Ropivacaine Group received "rescue" morphine (92% vs 48%, respectively) (P < 0.01). The tota l "rescue" morphine administered during the first 6 postoperative hours was 2 +/- 3 mg vs 10 +/- 5 mg (P < 0.01) for the Ropivacaine and Control Group s, respectively. Patient-generated resting pain scores were similar between the groups. However, pain scores generated after coughing and leg raise we re significantly (P < 0.04) less in the Ropivacaine Group. More patients in the Ropivacaine Group than in the Control Group described their analgesia as good or excellent. In the subset of patients (n = 10) studied, unbound r opivacaine blood levels were below the toxic threshold (600 ng/mL). However , blood ropivacaine accumulation was noted. All patients stated that the el astometric pump was easy to use. Ropivacaine wound instillation via an elas tometric pump is a simple technique that provides safe and effective analge sia after cesarean delivery.