In order to comply with guidance from the National Institute for Health and Clinical Excellence (NICE) [1], Birmingham Women's Hospital changed their standard practice for caesarean section (CS) in November 2011, by changing the intrathecal opioid component of spinal anaesthesia from fentanyl to 300 μg diamorphine. This provided an opportunity to conduct impact audits of both the effect of this change on length of hospital stay, and the effect of introducing 8 mg ondansetron peri-operatively to counteract the side-effects of nausea [2] and pruritis [3].

Data were prospectively collected for sequential elective and emergency CS carried out between Monday and Thursday for a period of seven weeks, immediately before and after the change of practice. The time of hospital discharge was recorded from the mother's discharge summary letter. Follow-up of side-effects was undertaken 24 h after surgery.

Our data (Table 3) revealed a significantly shorter hospital stay in women receiving intrathecal diamorphine compared with those receiving intrathecal fentanyl, confirming additional financial and patient benefits in addition to the longer duration of postoperative analgesia and reduced opioid requirement in the first 24 h found previously [4].

Table 3. Comparison of intrathecal fentanyl, diamorphine and the effect of ondansetron. Values are proportion or mean (SD)
 Fentanyl (n = 112)Diamorphine (n = 101)Diamorphine + 8 mg ondansetron (n = 100)
  1. a

    p < 0.0001; unpaired t-test.

Time to hospital discharge; h74 (41)56 (20)a 

Prophylactic ondansetron decreased the prevalence of vomiting and pruritus after CS, but was associated with an increase in the prevalence of nausea. Considering the cost, potential safety issues (its manufacturers recommend avoiding its use during pregnancy and breastfeeding) and lack of apparent demonstrable benefit, we suggest that an anti-emetic other than ondansetron should be offered, if required during caesarean section.

  1. No external funding and no competing interests declared.


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