[Comparative study of continuous epidural analgesia versus intermittent, patient-controlled, epidural analgesia...

To assess the analgesic efficacy and the incidence of side effects of three procedures of epidural analgesia during labor.

One hundred and one nulliparous pregnant women at term with cephalic presentation were randomly allocated to 3 groups (A: 31, B: 35, C: 35). Group A was given an initial dose of 8 ml bupivacaine 0.25% (20 mg) with epinephrine 1/200,000 and 50 micrograms fentanyl followed by a continuous infusion of 8 ml/h bupivacaine 0.125% (10 mg/h) with epinephrine 1/400,000. The initial dose in group B was 10 ml bupivacaine 0.125% (12.5 mg) with epinephrine 1/400,000 and 50 micrograms fentanyl followed by a continuous infusion of 12 ml/h bupivacaine 0.0625% (7.5 mg/h) with epinephrine 1/800,000 and 12 micrograms/h fentanyl. In group C the initial dose was the same as for group A, but maintenance was provided through a patient-controlled (PCA) system with 5 ml bupivacaine 0.25% (12.5 mg) and epinephrine 1/200,000 set for a minimum interval of 1 h. If analgesia was inadequate all patients could receive top-ups of 5 ml bupivacaine 0.25% (12.5 mg) with epinephrine 1/200,000.

Quality of analgesia was similar in all three groups. We found no significant differences in level of sensory/motor blockade, hemodynamic changes, side effects or type of delivery. The total dose of bupivacaine was highest in group A, whereas group B received the higher total dose of fentanyl. The number of Apgar scores under 8 was highest in group A, although the scores rose within 5 min of delivery in all cases.

We believe that the protocol of choice is the one used with group B (initial dose of 10 ml bupivacaine 0.125% + epinephrine 1/400,000 + 50 micrograms fentanyl followed by 12 ml/h bupivacaine 0.0625% + epinephrine 1/800,000 + 12 mu cg/h fentanyl in continuous infusion). The use of PCA systems with our unscreened patients yielded no advantages over the procedure used with group B.