The Effect of Continuous Lumbar Epidural Analgesia on the Acid‐base Status of Maternal Arterial Blood During the First Stage of Labour

Summary The maternal arterial acid‐base status and arterial lactate concentrations were measured in parturient women before the onset of clinically detectable labour, at the beginning of the active phase of labour and at full dilatation of the cervix. Of the patients studied, 43 were provided with continuous lumbar epidural analgesia, and 30 were managed conventionally. Epidural analgesia was associated with less alteration in acid‐base status during the first stage of labour than was seen in suitable controls. The possible cause of this finding is discussed briefly.