Obstetric Analgesia and Anesthesia

Abstract

SAFE obstetric analgesia and anesthesia needs no special pleading nowadays. Briefly its advantages are: (1) it is humane; (2) the mothers feel better and regain their strength more quickly (in fact they do not lose their strength); (3) the babies, if anything, do better, and (4) more mothers willingly undertake the bearing of children when there is a prospect of painless delivery. Its disadvantages are: (1) it is troublesome and time-consuming for the obstetrician and (2) it requires more nursing care. Clinically, labor with modern analgesia and anesthesia is quite different from labor conducted without pain-relieving drugs. The underlying physiology is the same. We still have the three stages of labor: the first stage, from the beginning of labor until the cervix is dilated; the second stage from the dilatation of the cervix until the baby is born; and the third stage, from then until the after-birth is delivered. For the dilatation of the cervix, uterine contractions, or first-stage pains are necessary. For the birth of the baby the uterine contractions must be augmented by the abdominal muscles and the diaphragm, or else by outside aid from the obstetrician. The separation of the placenta is brought about by the contraction of the uterus and the after-birth is expelled by the uterine contractions plus the contractions of the abdominal and respiratory muscles and the obstetrician's aid. During this stage and afterwards, we must have contractions of the uterine muscles to stop hemorrhage. The problem then of the obstetrical anesthetist varies with the different stages. In the first stage one tries to prevent the pain that accompanies strong uterine contractions, reaching the sensorium, without interfering with the force or frequency of the uterine contractions. If you push the analgesics too far you stop all progress and if you do not use enough, the patient feels the pains. This narrow zone between too much and