Postpartum contractions

The uterus of a nonpregnant woman usually is mildly stimulated by meperidine. Administered before an oxytocic, meperidine does not exert any antagonistic effect. Therapeutic doses given during active labor do not delay the birth process in fact, the frequency, duration, and amplitude of uterine contraction sometimes may be increased. The drug does not interfere with normal postpartum contraction or involuntary contraction of the uterus, and it does not increase the incidence of postpartum hemorrhage. 

Ergonovine and methylergonovine both increase the strength, duration, and frequency of uterine contractions and decrease the incidence of uterine bleeding. They are given after the delivery of the placenta and are used to prevent postpartum and postabortal hemorrhage caused by uterine atony (marked relaxation of the uterine muscle). 

Carboprost has been used successfully to control postpartum bleeding that was secondary to loss of uterine tone and where the myometrium was unresponsive to oxytocin, ergonovine, or methylergonovine. Given intramuscularly, carboprost causes an almost immediate and sustained uterine contraction. Clinical experience has shown that the use of this agent has saved many women from operative interventions (including hysterectomy) to control postpartum hemorrhage. 

It increase force, frequency and duration of uterine contractions. It is used to control and prevent postpartum haemorrhage. It is also used to prevent uterine atony after cesarean or instrumental delivery. 

Ox ocin is a nonapeptide which is structurally related to vasopressin. It stimulates rhythmic uterine contractions and is widely used by intravenous infusion of a diluted solution to induce labour and to treat postpartum bleeding. In large doses, it may cause relaxation of vascular smooth muscle causing hypotension in patients with cardiac disease or who are dehydrated. It has water-retaining properties and when given for prolonged periods to patients whose intake is electrolyte-free it causes overhydration and hyponatraemia. This may result in convulsions in the newborn with the risk of cerebral damage. 

Before delivery, oxytocin is usually administered intravenously via an infusion pump with appropriate fetal and maternal monitoring. For induction of labor, an initial infusion rate of 0.5-2 mU/min is increased every 30-60 minutes until a physiologic contraction pattern is established. The maximum infusion rate is 20 mU/min. For postpartum uterine bleeding, 10-40 units are added to 1 L of 5% dextrose, and the infusion rate is titrated to control uterine atony. Alternatively, 10 units of oxytocin can be administered by intramuscular injection after delivery of the placenta. 

Ergometrine and oxytocin differ in their actions on the uterus. In moderate doses oxytocin produces slow generalised contractions with full relaxation in between ergometrine produces faster contractions superimposed on a tonic contraction. High doses of both substances produce sustained tonic contraction. It will be seen, therefore, that oxytocin is more suited to induction of labour and ergometrine to the prevention and treatment of postpartum haemorrhage, the incidence of which is reduced by its routine prophylactic use (generally i.m.). 

In an in vitro experiment using uterine muscle strips from 10 consenting parturients undergoing cesarean section, therapeutic concentrations of propofol had no effect on isometric tension developed during contraction of the muscle (68). However, higher than therapeutic concentrations did reduce the peak muscle tension that developed. These results confirm that propofol is free of this adverse effect, which is a known cause of postpartum bleeding after the use of volatile anesthetic drugs. 

Indications Postpartum blood vacuity contracting cold. Retention of lochia, retention of placental fragments, and numerous other postpartum complaints associated with malign blood retained in the lower abdomen and then possibly thrusting here and there, chronic endometritis, puerperal infection, and trichomonas vaginitis... 

Routine management after delivery of the placenta, uterine atony, and hemorrhage Antepartum to initiate or improve uterine contractions postpartum to produce uterine contractions in third stage of labor, control of postpartum bleeding and hemorrhage... 

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