Results
We initially selected 80 patients, of whom 11 were excluded after their caesarean section. Reasons for drop-out were: four patients because of BMI ≥ 35, three patients because they refused the prescribed medication doses after caesarean section, two patients because of ketamine administration during their caesarean section and two patients because of failed spinal analgesia. At the end, a total of 69 patients were included in the study and randomly allocated into two groups: 35 patients in the ropivacaine group, and 34 in the placebo group (Figure 1). Patient’s baseline characteristics were comparable among the two groups (Table 1). As primary outcome, the morphine consumption (mean ± standard deviation) was significantly reduced by 8.05 mg (P value = 0.047) in the ropivacaine group compared to the placebo group, with respectively 21.52 mg ± 21.56, and 29.57 mg ± 22.38 morphine consumption (Table 2). For secondary outcomes no significant differences were observed in pain evaluated by VAS comparing the ropivacaine group to the placebo group, except for pain at mobilisation 6 hours after caesarean section. Pain by VAS at mobilisation 6 hours after surgery was 3.90 ± 2.66 in the ropivacaine group and 5.36 ± 2.55 in the placebo group (P value = 0.03) (Figure 2). Pain by VAS at rest 6 hours after surgery (ropivacaine 2.73 ± 1.98 vs. placebo 3.79 ± 2.43 (P value = 0.08)), at rest 12 hours after surgery (ropivacaine 3.53 ± 2.19 vs. placebo 3.67 ± 2.46 (P value = 0.07)) and at mobilisation 48 hours after surgery (ropivacaine 3.14 ± 2.09 vs. placebo 4.13 ± 2.24 (P value = 0.06)) showed a trend toward significance in favour of ropivacaine. No significant differences were observed for the incidence of adverse effects (post-operative nausea/vomiting and pruritus) (Figure 3). No significant differences were observed for time of first ambulation (Table 3). No pump failure or infection sites were observed. No breastfeeding problems were observed during hospitalisation.