扬州大学：《妇产科学》课程教学课件（PPT讲稿）17 胎儿监护 Fetal Surveillance During Labor 3/3

Fetal HeartRatePatternsPeriodic Fetal HeartRate ChangesThree kinds of responses to uterine contractionsDeceleration: The FHR decreasesin responseto uterine contractions.Decelerations may beearly,late,variable or mixed.All except earlydecelerations are abnormalSAAM八八EAm手0nunBn儿eamnsFigure10-3,EalydoceemNoeththedceutarts and ench with the ulesaM-NHhea

Fetal Heart Rate Patterns Periodic Fetal Heart Rate Changes Three kinds of responses to uterine contractions ◼ Deceleration: The FHR decreases in response to uterine contractions. Decelerations may be early, late, variable or mixed. All except early decelerations are abnormal

Nonreactivefetal heart rate tracingPlacing an artificial larynx with 120 dB of sound onthe maternal abdomen in the vicinity of the vertex,acousticstimulation can be used to try to induce FHR-accelerationsA response of greater than 15 bpm lasting at least 15seconds can ensures the absence of fetal acidosisThe chance of acidosis occurring in the fetus who failsto respond to such stimulation is about 5o%

Nonreactive fetal heart rate tracing ◼ Placing an artificial larynx with 120 dB of sound on the maternal abdomen in the vicinity of the vertex, acoustic stimulation can be used to try to induce FHR￾accelerations ◼ A response of greater than 15 bpm lasting at least 15 seconds can ensures the absence of fetal acidosis ◼ The chance of acidosis occurring in the fetus who fails to respond to such stimulation is about 50%

Late DecelerationsChange the maternal position from supine to left orright TateralGive oxygen by face mask, this can increase fetalPoz by 5 mmHgStop any oxytocic infusionInject intravenously a bolus of tocolytic drug torelieve uterine tetary.Monitor maternal blood pressureOperative delivery should be considered for fetaldistress when fetal acidosis is present or when latedecelerations are persistent in early labor and thecervix is insufficiently dilated

Late Decelerations ◼ Change the maternal position from supine to left or right lateral ◼ Give oxygen by face mask, this can increase fetal Po2 by 5 mmHg ◼ Stop any oxytocic infusion ◼ Inject intravenously a bolus of tocolytic drug to relieve uterine tetary. ◼ Monitor maternal blood pressure ◼ Operative delivery should be considered for fetal distress when fetal acidosis is present or when late decelerations are persistent in early labor and the cervix is insufficiently dilated

Fetal Tachycardia心动过速Prolonged periods of tachycardia areusually associated with elevatedmaternal temperature or an intrauterineinfection, which should be ruled out. Theacid-base status is usually normalIn general, fetal tachycardia occurs toimprove placental circulation when thefetus is stressed

Fetal Tachycardia心动过速 ◼ Prolonged periods of tachycardia are usually associated with elevated maternal temperature or an intrauterine infection, which should be ruled out. The acid-base status is usually normal ◼ In general, fetal tachycardia occurs to improve placental circulation when the fetus is stressed

ABNORMALFETALHEARTTRACING1.Alterpositionto leftorrightside2100%0,byfacemask3Discontinueoxytocin4.Ruleoutcordprolapse5.Performfetal scalp stimulation6.ConsiderTerbutaline25mgsubcutaneouslyProlongedImprovedfetalPersistentabnormalpatternsdecelerationcondition具宝Fetal scalpbloodpHConsiderimmediateContinue monitoringdelivery(considerfetal oxygen saturationtesting-see text)pH≥7.25PH≤7.20ContinuedConsider immediatedeliverysurveillanceFigure 10-6. Algorithm for the management of an abnormal heart tracing during fetalmonitoring

MeconiumThe presence of meconium in theamniotic fluid may be a sign of fetaldistressEarly passageLate passgeManagement

Meconium ◼ The presence of meconium in the amniotic fluid may be a sign of fetal distress ◼ Early passage ◼ Late passge ◼ Management

EarlypassageEarlypassage occursany timepriorto rupture of themembranes and is classified as light or heavy,basedon its color and viscosityA.light meconium: Light meconium is lightlystained yellow or greenish amniotic fluid. It isnot associated with poor outcome.B.Heavy meconium:Heavy meconium is darkgreen or black and usually thick and tenacious.It is associated with lower 1- and 5- minuteApgar scores and is associated withthe riskofmeconiumaspiration

Early passage ◼ Early passage occurs any time prior to rupture of the membranes and is classified as light or heavy, based on its color and viscosity • A. light meconium: Light meconium is lightly stained yellow or greenish amniotic fluid. It is not associated with poor outcome • B. Heavy meconium: Heavy meconium is dark green or black and usually thick and tenacious. It is associated with lower 1- and 5- minute Apgar scores and is associated with the risk of meconium aspiration

LatepassgeLate passage usually occurs during thesecond stage of labor, after clearamniotic fluid has been noted earlierLate passage, which is most oftenheavy,is usually associated with someevent, e.g: umbilical cord compressionor uterine hypertonus, late in laborthat causes fetal distress

Late passge ◼ Late passage usually occurs during the second stage of labor, after clear amniotic fluid has been noted earlier ◼ Late passage, which is most often heavy, is usually associated with some event, e.g: umbilical cord compression or uterine hypertonus, late in labor that causes fetal distress

ManagementAmnioinfusion:it candecrease in meconium-relatedrespiratorycomplicationsperhaps as a resultof thedilutional effect of the infused fluidManner:Infuse a bolus of up of up to 8oo ml of normal salineat a rate of 10-15 ml/minute over a period of 50 to 80minutes.This is followed by a maintenance dose of 3ml/minutes until deliveryOverdistentionof the uterine cavity can be avoided bymaitaining the baseline uterine tone in the normalrange and at less than 2OmmHg

Management ◼ Amnioinfusion: it can decrease in meconium-related respiratory complications perhaps as a result of the dilutional effect of the infused fluid ◼ Manner: ◼ Infuse a bolus of up of up to 800 ml of normal saline at a rate of 10-15 ml/minute over a period of 50 to 80 minutes. This is followed by a maintenance dose of 3 ml/minutes until delivery ◼ Overdistention of the uterine cavity can be avoided by maitaining the baseline uterine tone in the normal range and at less than 20mmHg

Fetal BloodSamplingManner:Blood is obtained fromthefetus by placing an amnioscopetransvaginally against the fetal skull.sourCervicalmucusisremovedwith cottonFigure10-5,Technique offetal scalpblood sampling via an amnioicope,Afiermukingall stab incision in the fetal scalp, theblood is drawn off through a long capillary tubeswabs.Siliconegreaseisappliedto theskull forblood beadformation.A 2x2-mm lancet is used for a stab incision and a drop of blood is aspiratedinto alongheparinized glasscapillarytubeFetal blood PH correctly predictsneonataloutcome 82% of thetime,asmeasured by the Apgar score .Thefalse-positive nate is about 8 %,andthe false-negative about 10%

Fetal Blood Sampling ◼ Manner: Blood is obtained from the fetus by placing an amnioscope transvaginally against the fetal skull. Cervical mucus is removed with cotton swabs. Silicone grease is applied to the skull for blood bead formation. A 2Х2- mm lancet is used for a stab incision , and a drop of blood is aspirated into a long heparinized glass capillary tube ◼ Fetal blood PH correctly predicts neonatal outcome 82% of the time , as measured by the Apgar score . The false-positive nate is about 8 %, and the false-negative about 10%