Effectiveness of local anaesthetics with and without vasoconstrictors for perineal repair during spontaneous delivery: Double-blind randomised controlled trial

Objectiveto investigate the use of local anaesthetics, in the presence or absence of vasoconstrictors, for perineal repair during spontaneous delivery.Designdouble-blind, randomised-controlled trial.Settinga birth centre, in the city of Sao Paulo, Brazil.Participantsfrom June to December 2004, a total of 96 women were allocated into three groups (first-degree perineal lacerations, second-degree perineal lacerations or episiotomy), and treated with local anaesthesia (1% lidocaine or 1% lidocaine with epinephrine) (n=16 per treatment per group).Interventionsan initial local infiltration of the anaesthetic solution was given so that episiotomy could be carried out (5 ml) and to suture spontaneous lacerations (1 ml), followed by repeated doses (1 ml) until pain was completely inhibited.Measurements and findingsthe main outcome measurement was the volume of anaesthetic used during episiotomy and perineal suture. Our data suggest that the concomitant use of the vasoconstrictor resulted in a significantly lower average volume used in the treatment of first-degree (1 ml, 95% confidence interval (CI) 0.4–1.6) and second-degree (3.7 ml, 95% CI 1.6–5.8) lacerations (p=0.002 and 0.001, respectively). A 0.3 ml (95% CI 1.5–2.1) average decrease in anaesthetic volume was observed with episiotomy (p=0.724). The maximum volume of anaesthetic used with and without vasoconstrictor was 1–2 ml in 95% and 3–4 ml in 50% of first-degree lacerations, respectively, and 1–6 ml in 88% and 7–15 ml in 81% of second-degree lacerations, respectively. For episiotomy, the maximum dose was 15 ml, regardless of anaesthetic solution used.Key conclusionsour data confirm the hypothesis that the use of anaesthetics in conjunction with vasoconstrictors is more effective than anaesthetics alone in the repair of perineal lacerations, but not for episiotomy.