As the number of women giving birth by caesarean increases throughout most of the developed world, so too is research into postoperative pain relief for these women. Like most other post-surgical populations, the new mother needs effective pain relief so that she can mobilise early but she also has the added responsibility of needing to care for her newborn baby. There is no 'gold standard' for post-caesarean pain management; the number of options is large and the choice of method is at least partly determined by drug availability, regional and individual preferences, resource limitations and financial considerations. Most methods rely on opioids, supplemented with anti-inflammatory analgesics, nerve blocks or other adjunctive techniques. The aim of this review is to detail commonly used opioid-based methods and to review the evidence supporting non-opioid methods, when incorporated into a multimodal approach to post-caesarean pain management. Areas of promising research are also discussed.

Cell salvage in obstetric haemorrhage is now endorsed by a number of organisations. Most of the literature has focused on isolated case series and safety. We describe how cell salvage, including a quality assurance process conducted prior to clinical implementation, was introduced to our stand-alone obstetric hospital which had no previous experience of this technique. An implementation committee was established and 25 quality assurance and familiarisation cases were initially conducted. As part of this process the alpha fetoprotein, haematocrit, free plasma haemoglobin, potassium and Kleihauer tests were performed when enough blood was available for processing. Our guidelines for clinical use included women at greatly increased risk of obstetric haemorrhage and women at increased risk of haemorrhage who refused traditional transfusion. After the successful completion of this process, cell salvage was signed off for clinical use in March 2007 and was used on 51 occasions between March 2007 and July 2009. Twenty-one patients had salvaged blood re-transfused and for seven patients this was their only red blood cell replacement. The median blood loss in patients re-transfused was 3000 ml (range <500 to 8500 ml), with the median volume re-transfused 359 ml (range 60 to 1300 ml). There was one episode of unexplained hypotension associated with administration of salvaged blood. We have successfully introduced obstetric cell salvage into clinical practice. A quality assurance process prior to implementation was beneficial for the staff involved. Despite targeting a high-risk obstetric population, our re-transfusion rates are approximately 40%. No serious adverse events have been recorded. We recommend that in units that already provide intraoperative cell salvage in a non-obstetric setting, extending the service into obstetric situations should be considered. Units that routinely care for high-risk obstetric patients should also consider the introduction of such a service. Post transfusion Kleihauer testing should be performed as soon as possible in Rhesus-negative mothers who deliver a Rhesus-positive foetus, so that appropriate anti-D prophylaxis can be administered.

Prophylactic vasopressor administration is commonly recommended to reduce maternal hypotension during spinal anaesthesia for caesarean section. Metaraminol has undergone limited investigation in obstetric anaesthesia for this purpose, particularly in comparison with phenylephrine. In this multicentre, randomised, double-blind, non-inferiority study, we compared prophylactic phenylephrine or metaraminol infusions, started immediately after spinal anaesthesia, in 185 women who underwent elective caesarean section. Phenylephrine was initially infused at 50 μg.min , and metaraminol at 250 μg.min . The primary outcome was the difference in umbilical arterial pH between groups; secondary outcomes included other neonatal acid-base measures, and maternal haemodynamic changes. The mean (SD) umbilical arterial pH was 7.28 (0.06) in the phenylephrine group vs. 7.31 (0.04) in the metaraminol group (p = 0.0002). The estimated mean (95%CI) pH difference of 0.03 (0.01-0.04) was above the pre-determined lower boundary of clinical non-inferiority, and also met the criterion for superiority. Umbilical artery lactate concentration was 2.8 (1.2) mmol.l in the phenylephrine group vs. 2.3 (0.7) mmol.l in the metaraminol group (p = 0.0018). Apgar scores did not significantly differ between groups. There was a higher incidence of hypotension, defined as systolic arterial pressure < 90% baseline, in the phenylephrine group; there was a higher incidence of hypertension and severe hypertension (systolic arterial pressure > 110% and > 120% baseline, respectively) in the metaraminol group. There was no significant difference between groups in the incidence of nausea, vomiting or maternal bradycardia. We conclude that, when used as an infusion to prevent hypotension after spinal anaesthesia for elective caesarean section, metaraminol is at least non-inferior to phenylephrine with respect to neonatal acid-base outcomes.

A number of laryngeal masks are available, including both re-usable and single-use masks. Single-use laryngeal masks may decrease the risk of transmitting prion infections. We performed a single-blind randomized trial in 200 spontaneously breathing female patients under general anaesthesia with nitrous oxide, to compare a new single-use laryngeal mask, the SoftSeal™ (Portex Ltd, U.K.), with a re-usable laryngeal mask, the LMA Classic™ (Laryngeal Mask Company Ltd., Cyprus). The primary outcome was successful insertion at the first attempt. Size 4 single-use (n=99) or re-usable (n=100) laryngeal masks, inserted by experienced anaesthetists, were equivalent for successful placement at the first attempt (90% versus 91% respectively). The single-use mask was less easy to insert (47% difficult versus 9%, P<0.001). Clinical and anatomical tests of position and function were similar. The cuff pressure of the re-usable mask increased significantly compared with the single-use mask (median +10 cm versus-2 cm H 2 O, P<0.001). Forty per cent of patients allocated the single-use mask and 20% of those allocated the re-usable mask experienced sore throat at 24 hours postoperatively (P<0.05). An estimation of cost per patient use was greater for the re-usable mask. We conclude that the SoftSeal™ single-use laryngeal mask and the LMA Classic™ re-usable laryngeal mask airway are of similar clinical utility in terms of successful insertion and airway maintenance. The re-usable laryngeal mask was easier to insert and associated with less postoperative sore throat, but costs were higher.