Background: To compare analgesic therapy with acetaminophen (PCM) in combination with opioids due to pain (semiquantified by score analysis) between women after elective caesarean section (CS) or urgent CS.

Material and Methods: In a monocenter, prospective clinical comparatice observational study over two years at the Department of Obstetrics at a German University Hospital, women were treated with opioid (unretarded piritramide) boluses, patient-controlled opioid analgesia (piritramide-PCA) and acetaminophen for drug escape medication (PCM). The consumption of acetaminophen and opioids was quantifed. Postoperative pain was assessed by numerical rating scale (NRS).

Results: After institutional approval, 352 consecutive women undergoing elective CS (n=179) or urgent CS (n=173) were enrolled in the study.

Total amount of the opioid (piritramide) was equal in both groups on the day (d) of CS (bolus: elective (el.) 9.09±4.52; non-elective (urgent=ur.) 8.88±4.89 / PCA pump: el.: 33.44±15.16; ur.: 31.09±15.42). On the first postoperative day, 15.6 % of the el. and 18.5 % of the ur. CS patients needed a bolus, 65 % of the CS patients out of el. and 55 % out of the ur. group used the PCA pump, respectively. On the second post-Op day, the patients only required PCM. The total amount of PCM was significantly higher in the elective CS group (el.: 9.48+2.12 vs. ur.: 8.69+2.27; p<0.001). On the 2nd post-Op day the PCM doses were equal in both groups: el.: 3.61 + 0.90 vs. ur.: 3.48 + 1.04 (n.s.). In addition, on the same day, NRS of the el. group was significantly lower (p<0.001).

Discussion: Because of the half-life of priritramide, the pain-reducing effect cannot be an effect of piritramide but rather of PCM, which was administered alone on the 2nd postoperative day. PCM can not be considered as an analgesic drug, because both groups received on 2nd post-Op day equal doses of PCM. PCM could be considered as a placebo from an analgesic point of view with placebos having the best effect in case of helplessness and anxiety. In the elective CS group, there are more patients with trait anxiety, which increases the pain perception. A state of higher anxiety remains to be discussed as the cause of the better effect of PCM in the elective group.

This is in accordance with the previous literature, which assumes a better pain reduction in clarified patients. The elective group is clarified also because of the higher state anxiety level.

Conclusion: Because of the huge problem of chronic post-surgical pain after caesarean section caused by insufficient pain medication and neglected screening for anxiety, the increased consumption of PCM as an indicator for anxiety should remind of necessary subsequent care for the distress in operated women.