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MANAGEMENT OF SECOND-STAGE LABOR. The onset: full dilatation of the cervix bear down descent of the presenting part the urge of defecate uterine contraction & expulse force. MANAGEMENT OF SECOND-STAGE LABOR. Duration -50 min in nulliparous
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MANAGEMENT OF SECOND-STAGE LABOR • The onset: full dilatation of the cervix • bear down descent of the presenting part the urge of defecate • uterine contraction & expulse force
MANAGEMENT OF SECOND-STAGE LABOR • Duration -50 min in nulliparous 20 min in multiparous -become abnormally long :a contracted pelvis a large fetus impaired expulsive effort from conduction analgesia or intense sedation
MANAGEMENT OF SECOND-STAGE LABOR • Fetal heart rate -low risk: 15 min high risk: 5 min -slowing of the FHR : due to fetal head compression : reduce placental perfusion : recovery after the contraction and expulsive effort cease
-descent of the fetus :obstruct umbilical cord blood flow (tighten loop or cord neck) ->uninterrupted maternal expulsive effort can be dangerous to the fetus -maternal tachycardia in second stage :common, must not be mistaken for a normal FHR
MANAGEMENT OF SECOND-STAGE LABOR • Maternal expulsive efforts -bearing down: reflex and spontaneous but, does not employ expulsive force and coaching is desirable -leg: half-flexed deep breath & breath held exert downward pressure -She should not be encouraged to “push” beyond the time of completion of each uterine contraction
-Gardosi(1989): squatting or semi-squatting using a specialized pillow -> shortens second labor -in increasing bulging of the perineum :encouragement is very important -> FHR is likely to be slow -feces is frequently expelled perineum begins to bulge , tense and glistening scalp may be visible
MANAGEMENT OF SECOND-STAGE LABOR • Preparation for delivery -the dorsal lithotomy posiyion : increase the diameter of the pelvic outlet : using leg holder and stirrup ->result in spontaneous tear or fourth degree -not strapped into the stirrup : allowing quick flexion of the thighs back onto the abdomen -> shouder dystocia -vulvar and perineal cleansing : sterile drape and gowning, gloving
SPONTANEOUS DELIVERY • Delivery of the head -”crowning: : encirclement of the largest head diameter by the vulvar ring -unless episiotomy ; spontaneous laceration -It is now clear that an episiotomy will increase the risk of a tear into the external anal sphincter and the rectum -unless episiotomy. anterior tears involving the urethra and labia are mush more common
SPONTANEOUS DELIVERY • Ritgen maneuver - By the time the head distends the vulva and perineum enough to open the vaginal introitus to a diamater of 5 cm or more - one hand: a towel-draped, gloved hand may be exert forward pressure on the chin of the fetus through the perineum just in frint if the coccyx the other hand: exerts pressure superiorly against the occiput
SPONTANEOUS DELIVERY • Delivery of shoulder -the occiput : turns toward one of the maternal thigh fetal head: transverse position external rotation: bisacromial diameter had rotated into the anterioposterior dimeter of the pelvis -sucking the nasopharinx or checking for a cord -downward traction : ant. shoulder under the pubis upward movement: post. shoulder is delivered
-the rest of the body almost always follows the shoulder without difficulty -prolonged delay : more tracton pressure on the fundus -traction should be exerted only in the direction of the long axis of the infant, for if applied obliquely it causes bending of the neck and stretching of the bradhial plexus
SPONTANEOUS DELIVERY • Clearing the nasopharynx -prevent of aspiration of amnionic fluid, debris, blood -the face: quickly wiped nares and mouth : aspirated • Nuchal cord -after head dilevered, ascertain the umbilical cord -occur 25%, ordinarily do no harm -drawn down or cut (too tightly)
SPONTANEOUS DELIVERY • Clamping the cord -between two clams: 4 or 5cm and later 2 or 3cm from the fetal abdomen -timing of cord clmaping :after delivery, the infant is placed at the level of vagina for 3 min, the fetoplacental circulation is not occluded :80 ml of blood – shift to the fetus (50 mg of Fe) :after first clearing the airway (30 secend) -> then clamps the cord
MANAGEMENT OF THE THIRD STAGE -after delivery of the infant, the height of fundus and its consistency are ascertained -No massage is practiced -the hand is simply rested on the fudus frequency : become atony and filled with blood
MANAGEMENT OF THE THIRD STAGE • Signs of the placental separation 1. uterus : globular, firmer the earliest sign 2. a sudden gush of blood 3. uterus : rise in the abdomen because the placenta passes down 4. the umbilical cord protruded out of the vagina. indicating that the placenta has descended -usually within 5 min, sometimes within 1min
- when placenta has separated, ascertain uterus firmly ->mother: bear down , incease abdominal pressure if fail or impossible: pressure on the fundus propel the detached placenta
MANAGEMENT OF THE THIRD STAGE • Delivery of the placenta -traction in the umbilical cord must not be used to pull the placenta out of the uterus -the uterus is lifted cephalad with the abdominal hand. This maneuver was stopped as the placenta passes through the introitus -if the membranes start to tear, they are grasped with a clamp and removed by gentle traction
MANAGEMENT OF THE THIRD STAGE • Manual removal of placenta -the placenta will not separate promptly (preterm) -there is brisk bleeding and the placenta cannot be delivered -> manual removal -proof of this practice has not been established and most obstetricians await spontaneous placental separation unless bleeding is excessive
MANAGEMENT OF THE THIRD STAGE • “Fourth stage” of labor -the hour immediately following delivery is critical and it has been designated by some as the “fourth stage of labor” -postpartum hemorrhage uterine atony observation of vaginal excessive bleeding -check vital sign every 15 minutes for the first hour
OXYTOCIN AGENT -after placenta delivery, the primary mechanism by which hemostasis is vasoconstriction produced by a well-contracted myometrium -oxytocin (Pitocin, Syntocinon) ergonovine maleate (Ergotrate) methylergonovine maleate (Methergine)
OXYTOCIN AGENT • Oxytocin -the synthetic form of the octapeptide oxytocin -not effective by mouth -half-time of IV : 3 minutes -before delivery : the uterus is sensitive to oxytocin ->so violently as to kill the fetus ruptued itself after delivery these dangers no longer exist
OXYTOCIN AGENT • Cardiovascular effects -deleterious effect: IV injetion of a bolus decreased maternal BP (5 unit) decreased arterial BP ->increased cardiac output -not be given IV as a large bolus dilute solution by continuous IV infusion IM in a dose of 10 unit -direct injection of uterus (trasnvagina or abdomen) :also proven effective
OXYTOCIN AGENT • Antidiuresis -water intoxication: maternal convulsion -continuous IV inj (20 unit) : decreased urine flow -not in electrolyte-free aqueous dextrose solution : normal saline or lactated Ringer solution -need for high dose of oxytocin : concentration should be increased rather than increasing the rate flow of a more dilute solution
OXYTOCIN AGENT • Ergonovine and methylergonovine -an alkaloid from lysergic acid -effects :use IV, IM , PO :powerful myometrial contraction :persist for hours :sensitivity of uterus is very great :the response is sustained with little tendency toward relaxation
-But, sometimes induce severe hypertension :also colvulsion or cadiac arrest (Browning(1974)) -because of the frequency of hypertension, do not use these alkaloids routinely
OXYTOCIN AGENT • Oxytocics after delivery -standard practice :20 unit of oxytocin per liter :a rate of 10 ml/min after delivery of placenta for a few minutes until the uterus remains firmly contracted and bleeding is controlled :transfer to postpartum unit ->rate is reduced to 1 to 2 ml/min
LACERATIONS OF THE BIRTH CANAL • First-degree: fourchette, perineal skin, vaginal mocasal membrane • Second-degree: fascia and muscle of the perineal body usuallu extend upward on one or both sides of the vagina • Third-degree: involve the anal sphincter • Fourth-degree: rectal mocosa expose the lumen of the rectum involve the region of the urethra
EPISIOTOMY AND REPAIR • Purposes of episiotomy - easier to repair postoperative pain is less healing improved -prevented pelvic relaxation (cystocele, rectocele urinary incontinence) -but, increased incidence of anal sphincter and rectal tears
EPISIOTOMY AND REPAIR • Timing of episiotomy -early : bleeding late : laceration -when the head is visible during a contraction to a diameter of 3 to 4 cm
EPISIOTOMY AND REPAIR • Midline versus mediolateral episiotomy
EPISIOTOMY AND REPAIR • Timing of the repair of episiotomy -after the placenta has been delivered • Technique -hemostasis and anatomical restoration without excessive suturing are essential -suture material: 3-0 chromic catgut
EPISIOTOMY AND REPAIR • Fourth-degree laceration -approximate the torn edges of the rectal mucosa with muscularis sutures placed approximately 0.5 cm apart -this muscular layer then is covered with a layer of fascia -stool softener, prophylactic antimicrobials -enema should be avoided
EPISIOTOMY AND REPAIR • Pain after episiotomy -ice pack aerosol sprays containing a local anesthesia -If pain is severe or persistent :vulvar, paravaginal or ischioractal hematoma or perineal hematoma