Extra-dural analgesia in obstetrics and gynaecology.

There are many advantages to be derived from the use of extra-dural block in obstetrics and gynaecology. In the past many anaesthetists have been reluctant to make use of the method owing to the difficulty in accurately locating the extra-dural space, but with advances in technique this has been overcome and there has been a great increase in the use of this form of analgesia in recent years. One of the great advantages in maternity work is that there is a minimal upset of metabolism and the drug does not pass the placental barrier so that the foetus is quite unaffected. While in operative gynaecology where the patient must be in the Trendelenburg position, the weight of the bowels on the unparalysed diaphragm does not interfere with the respiratory exchange, and consequently bleeding is much reduced. The technique must be considered under four headings, operative gynaecology, therapeutic relief of such conditions as phlegmasia alba dolens, Caesarean section and normal labour.