Nasal versus Epidural Fentanyl for Patient Controlled Analgesia after Caesarean Section

Fentanyl is a morphine-like pain relieving drug used for pain relief after caesarean section. In our institution most patients have "patient-controlled epidural analgesia" (PCEA) following routine or emergency caesarean section. PCEA allows the patient to give themselves small doses of drug safely by pressing a button on a pump whenever the pain is more than they find acceptable. However, not all women are suitable for an epidural. In some other cases, the epidural is removed straight after the operation because of concern about infection or bleeding risks, sometimes the epidural catheter falls out early on. Pain relief in these cases is usually provided with oral medications and/or an intravenous patient controlled analgesia pump (PCIA). Recently a patient-controlled analgesia pump has been made that allows a patient to give themselves a pain relieving drug, for example fentanyl, as a nasal spray; this method is called "patient-controlled intranasal analgesia" or PCNA. The aim of this study is to compare PCEA and PCNA, to see whether PCNA could be a reliable alternative method of pain relief after caesarean section. This study will compare two methods of pain relief after caesarean section. Patients will, over two consecutive 18 hour time periods, self-administer epidural fentanyl for one period and intranasal fentanyl for the other. The order in which the fentanyl is used will be randomised (i.e. based on a toss of a coin), so each patient may receive either epidural or nasal fentanyl first. After 18 hours, this will changed around. However, to "blind" the study (a means of making sure the results are more reliable), patients will be given both an epidural and a nasal patient controlled analgesia pump; they will be asked to press both each time they need some more medication; and they will not be told which one contains fentanyl (the other will contain saline solution, a "placebo". This means patients will be unaware as to whether the fentanyl is being given into the epidural or the nose. At regular intervals during the 36 hours of the study, patients will be asked about pain relief, side effects (for example, feeling sick or drowsy), recovery from the operation and satisfaction. Patients will also receive regular paracetamol tablets for pain relief, and other tablet pain relief is available if required. In all other respects, patients will be looked after routinely. Because we also want to know what the blood levels of fentanyl are, we need to take a series of small blood samples at 8 times during the 36 hours of the study period. The age, weight and general well-being of the baby will also be assessed. This will include a painless clinical examination of the baby's alertness. The entire examination should not take more than 10 minutes and will be performed by a paediatrician or anaesthetic research doctor. This will take place at the end of the first study period (at about 18 hours after operation).