Determination of pH or lactate in fetal scalp blood in management of intrapartum fetal distress: randomised controlled multicentre trial.

OBJECTIVE: To examine the effectiveness of pH analysis of fetal scalp blood compared with lactate analysis in identifying hypoxia in labour to prevent acidaemia at birth. DESIGN: Randomised controlled multicentre trial. SETTING: Labour wards. PARTICIPANTS: Women with a singleton pregnancy, cephalic presentation, gestational age >or=34 weeks, and clinical indication for fetal scalp blood sampling. INTERVENTIONS: Standard pH analysis (n=1496) or lactate analysis (n=1496) with an electrochemical microvolume (5 mul) test strip device. The cut-off levels for intervention were pH <7.21 and lactate >4.8 mmol/l, respectively. MAIN OUTCOME MEASURE: Metabolic acidaemia (pH <7.05 and base deficit >12 mmol/l) or pH <7.00 in cord artery blood. RESULTS: Metabolic acidaemia occurred in 3.2% in the lactate group and in 3.6% in the pH group (relative risk 0.91, 95% confidence interval 0.61 to 1.36). pH <7.00 occurred in 1.5% in the lactate group and in 1.8% in the pH group (0.84, 0.47 to 1.50). There was no significant difference in Apgar scores <7 at 5 minutes (1.15, 0.76 to 1.75) or operative deliveries for fetal distress (1.02, 0.93 to 1.11). CONCLUSION: There were no significant differences in rate of acidaemia at birth after use of lactate analysis or pH analysis of fetal scalp blood samples to determine hypoxia during labour. TRIAL REGISTRATION: ISRCT No 1606064.

Epidural analgesia with sufentanil during labor and operative delivery.

BACKGROUND: It has been argued that by adding an opioid to the local anesthetic drug used for epidural analgesia during childbirth, one can reduce the risk of operative delivery. Objective. In a population-based observational study, to evaluate the effect of adding an opioid to a local anesthetic drug on the risk of instrumental delivery or cesarean section. DESIGN: Comparison of delivery units adding/not adding opioid to the local anesthetic for epidural analgesia in labor. SETTING: All deliveries using epidural analgesia in Sweden during 1992-96 were evaluated on the basis of information stored at the Medical Birth Registry, the National Board of Health and Welfare, Stockholm. METHOD: A questionnaire was sent to all delivery units (n=61), as well as to the Head of corresponding Anesthesiology Department in each hospital, requesting information regarding the period when opioids (sufentanil) were first added to the local epidural analgesic. Parturients given epidural analgesia were divided into three time-related groups: those delivered before the introduction of opioids (n=34,071), when opioids were first added (n=7,236), and since the introduction of opioids (n=44,384). Odds ratio (OR) with 95% confidence interval (CI) was used to assess the effect of sufentanil versus no sufentanil, on the risk of operative delivery. The parturients were stratified for year of delivery, age, and parity. Main outcome measures. Instrumental delivery, cesarean section, length of stay in hospital post partum. RESULTS: A significant reduction was observed in the incidence of instrumental delivery (OR 0.72; 95% CI 0.68-0.76). A similar though less pronounced effect was evident concerning the risk of cesarean section for nulliparae (OR 0.79; 95% CI 0.72-0.88) but not for multiparae (OR 0.93; 95% CI 0.80-1.07). Fewer women with an opioid added to the local anesthetic spent more than 4 (or more than 7) days in hospital post partum, compared with those given epidural analgesia without an opioid. CONCLUSION: When added to the local anesthetic used for epidural analgesia, as in Sweden during the last 5 years, opioids appear to reduce the incidence of instrumental delivery and cesarean section and also the post partum hospital stay.