Maternal and neonatal side-effects of remifentanil patient-controlled analgesia in labour.

BACKGROUND: Remifentanil has been suggested as an ideal opioid for patient-controlled analgesia (PCA) in labour, but the safety profile has not been established. The aims of this preliminary prospective observational study were to investigate the maternal side-effects and early neonatal effects, and to assess the placental transfer of remifentanil PCA during labour. METHODS: Women with no known obstetric complications or contraindication to remifentanil were recruited (n=50). Remifentanil was administered at a bolus dose of 0.5 microg kg(-1) and a lockout period of 2 min. A visual analogue scale was used to assess pain, nausea and itching. Maternal observations were recorded hourly and fetal heart rate trace was assessed every 2 h. Umbilical cord gases, 1 and 5 min Apgar scores and neurological evaluation of the neonate were recorded. Maternal venous blood and umbilical artery and vein cord blood samples were collected for analysis of remifentanil concentration. RESULTS: Fifty women enrolled in the study (24 multiparous, 26 primiparous). There was no evidence of cardiovascular instability or respiratory depression. Pain scores decreased significantly, but there was no significant change in nausea after initiating the PCA. A statistically significant increase in itching was found to be clinically mild and 22 women were slightly drowsy (95% confidence interval [CI], 30-58.7%) but alert to voice. Ten fetal heart rate traces demonstrated changes in the first 20 min, but did not require intervention (95% CI, 10-33.7%). The median 1 and 5 min Apgar scores were 9. The mean umbilical cord gases and neurological examination were within normal limits. Maternal vein and umbilical vein cord samples demonstrated placental transfer of remifentanil, and small amounts were detected in umbilical artery samples. CONCLUSIONS: At the bolus dose used remifentanil PCA has an acceptable level of maternal side-effects and minimal effect on the neonate. Remifentanil crosses the placenta and appears to be either rapidly metabolized or redistributed in the neonate.

An unexpectedly difficult intubation following repeated endoscopy.

A 67-year-old man required an urgent laparotomy for a bleeding gastric ulcer. He had undergone three upper gastrointestinal endoscopies over five days since admission to hospital. Tracheal intubation was unexpectedly difficult due to marked supraglottic oedema as well as unfavourable upper airway anatomy. A fibreoptic intubation through a laryngeal mask airway was performed with difficulty. The management of this case of difficult intubation following repeated endoscopy is presented.

A comparison of pethidine and remifentanil patient-controlled analgesia in labour.

We conducted a double-blind randomised controlled trial comparing the efficacy of analgesia during labour of remifentanil and pethidine. Nine women were randomised to receive an i.v. bolus of remifentanil 0.5 microg.kg(-1)with a lockout period of 2 min and eight women were randomised to receive a bolus of pethidine 10 mg with a lockout period of 5 min. A visual analogue scale (VAS) scoring system was used to assess the level of pain hourly throughout the first and second stages of labour and a score was recorded within half an hour of delivery for the level of pain overall throughout labour (post delivery score). The study was terminated after 17 subjects, on agreement with the local ethics committee, due to concern with the poor Apgar scores in the pethidine group. With the data available, we demonstrated significantly lower mean hourly and post delivery VAS scores for pain in the remifentanil group (P < 0.05). The 1 and 5 min Apgar scores were significantly lower in the pethidine group compared with the remifentanil group (P < 0.05). This preliminary study suggests that remifentanil may have a use as patient-controlled analgesia for women in labour.