Paracervical Pudendal Nerve Block for Obstetric Analgesia

Abstract

SUMMARY

Paracervical and pudendal blocks may be used to provide obstetric analgesia for the first and second stages, respectively. The advantages of these two techniques are: (a) simplicity and ease of application; (b) lack of sedation or drowsiness in the mother; (c) no increase in the duration of the first and second stages, and (d) no decrease in the ability of the mother to bear down in second stage.

The disadvantages of these techniques are: (a) an unpredictable incidence of fetal bradycardia and acidosis with PCB; (b) the risk of maternal toxicity from vascular absorption of the local anaesthetic; (c) the risk of direct injection into the fetus; and (d) a variable degree of successful analgesia with either technique.

The safest local anaesthetic for either type of block is 2-chloroprocaine. Meticulous attention to anatomical landmarks and sterility are important.

Careful monitoring of both the fetus and the mother should be instituted prior to using these blocks and continued until after delivery.

Both paracervical and pudendal nerve blocks should be used in obstetrics only when other forms of analgesia are unavailable or inappropriate.