Dysfunctional Labor (Moulton) Flashcards
Uterus is a large smooth muscle organ composed of billions of smooth muscle cells. Each of these cells becomes a contractile element when the intracellular ionic __1__ concentration increases to trigger an enzymatic process that results in the formation of the __2__ element.
Stimulation of __3__ receptors on the plasma membrane further activates the __2__ element.
Contractions occur in localized areas during gestation but during labor the entire uterus contracts in an organized fashion. These coordinated smooth muscle cells contractions are secondary to the __4__ that activate the movement of action potentials throughout the myometrium.
1) Calcium
2) Actin-myosin
3) Oxytocin
4) Gap junctions
Relaxation of the uterus is maintained by factors that increase levels of __1__.
Contraction of the uterus is from the increase intracellular __2__ stores which promotes interaction of __3__ and __3__ causing uterine contractions
1) Cyclic adenosine monophosphate (cAMP)
2) Calcium
3) Actin and myosin
During labor, two distinct segments of the uterus are formed, the __1__ segment which actively contracts and retracts to expel the fetus and the __2__ segment along with the cervix becomes thinner & passive.
1) Upper
2) Lower
What does the cervix contain?
Collagen and smooth muscle
In labor the cervix changes from firm, intact sphincter to soft, pliable, dilatable structure. These structural changes are the result of __1__, increase in __2__, decrease in __3__, which favors increased water content.
1) Collagenolysis
2) Hyaluronic acid
3) Dermatan sulfate
In the first stage of labor, the latent phase is characterized by cervical softening and effacement occur with minimal dilation which is defined as less than __1__ cm.
The active phase starts when the cervix is dilated to __1__ cm.
1) 6 cm
For all phases of labor (except the latent phase) an abnormality may be defined as either protraction or arrest. What does each mean?
1) Protraction: Slower than normal rate
2) Arrest: Complete cessation of progress (no further dilation or descent)
An arrested latent phase implies that?
Labor has not begun
Normal limits of the latent phase in a nulliparous mother can reach up to __1__ hours.
In a multiparous mother it can reach up to __2__ hours.
1) 20 hours
2) 14 hours
Latent phase that exceed the norms is considered prolonged but the outcome of prolonged latent phase has little effect on perinatal mortality. What are some causes of prolonged latent phase?
1) Excessive use of sedatives
2) Fetal malposition
What normal daily function is recommended with prolonged latent phase as it can provide patient with relief and aid in distinction between true and false labor?
What drug can be given that will progress the patient to the active phase or will stop contractions due to the patient undergoing false labor?
1) Sleep
2) Morphine
Normal limits of the active phase in nulliparous mothers for cervical dilation is __1__?
Normal limits of the active phase in multiparous mothers for cervical dilation is __2__?
Cervical dilation of less than the norms constitutes a __3__ disorder of dilation of the active phase.
If 2 or more hours elapsed with no cervical dilation an __4__ disorder of dilation has occurred.
1) 1.2 cm/hr
2) 1.5 cm/hr
3) Protraction
4) Arrest
Normal limits of the active phase in nulliparous mothers for fetal descent is __1__?
Normal limits of the active phase in multiparous mothers for fetal descent is __2__?
Fetal descent of less than the norms constitutes a __3__ disorder of descent of the active phase.
If no change in descent/station has occurred within 1 hr an __4__ disorder of descent has occurred.
1) 1 cm/hr
2) 2 cm/hr
3) Protraction
4) Arrest
____ is defined “difficult labor” it can be used interchangeably with dysfunctional labor characterizing that labor is not progressing normally.
Dystocia
The diagnosis of dystocia should NOT be made before what has been tried?
An adequate trial of labor
__1__ refers to stimulation of uterine contraction when spontaneous contractions have failed to result in progressive cervical dilation or descent of the fetus.
This should be considered if contractions are less then __2__ in 10 minute period and/or the intensity is less than __3__ mm/Hg.
1) Augmentation
2) Three
3) 25 mm/Hg
ACOG recommends ____ in protraction and arrest disorders after assessing maternal pelvis, fetal position, station, and maternal/fetal status.
Oxytocin
The intrauterine pressure catheter (IUPC) is a soft plastic catheter placed transcervically that gives precise measurement of the __1__ of the uterine contractions in mmHg.
It require membrane to be __2__.
1) Intensity
2) Ruptured
Minimal effective uterine activity is defined as?
3 contractions in a 10 minute period averaging 25 mmHg above baseline
Montevideo Units are calculated by measuring the __1__ in mmHg in a 10 min period.
It should be greater than __2__ for at least two hours.
1) Peaks of contractions
2) 200
What is the only FDA approved medicine for labor stimulation due to inadequate uterine contractions?
Pitocin (oxytocin injection)
__1__ refers to a disparity between the size of the maternal pelvis & the fetal head that precludes vaginal delivery.
It causes a failure of __2__.
__3__ women who present in labor with an unengaged head indicates an increased likelihood.
1) Cephalopelvic disproportion
2) Descent
3) Nulliparous
____ and ____ shaped pelvises have a good prognosis for delivery.
Gynecoid and Anthropoid
Presentations other than vertex __1__ position are considered to be abnormal in the laboring patient.
Fetal head usually enters and engages the maternal pelvis in __2__ position but then rotates to __1__.
1) Occiput anterior
2) Occipitotransverse
What occurs when the head fails to rotate and flex into the OA position and may be caused by Cephalopelvic disproportion, altered pelvic architecture (Android or platypelloid pelvis), or relaxed pelvic floor (epidural)?
Persistent Occipitotransverse Position
A persistent OT position with arrest of descent for a period of 1 hr or more is known as __1__.
Arrest occurs because of the deflexion that occurs with persistent OT positions resulting in the __2__diameter (11cm) to becomes the presenting diameter.
1) Transverse arrest of descent
2) Occipitofrontal
If pelvis is adequate, infant is not macrosomic, and contractions are inadequate what is the management for the Persistent Occipitotransverse Position?
If pelvis is inadequate or infant deemed to be macrosomic proceed with?
1) Oxytocin and induce rotation manually or with Kielland forceps
2) Cesarean section
Course of labor in the Occipitoposterior position is usually normal however the __1__ stage may be prolonged and it may be associated with considerably more __2__ discomfort.
1) Second
2) Back
Macrosomia is defined as the fetus weighing __1__?
Large for gestational age is when the birth weight equals to or greater than the __2__ for a given gestational age.
1) 4500 g
2) 90%
What may cause enlargement of the head that makes vaginal delivery impossible and is usually seen by ultrasound?
Hydrocephalus
__1__ or __2__ can result in a dystocia secondary to enlarged fetal abdomen.
__3__ is most common cause of this.
1) Fetal ascites
2) Enlargement of fetal organs (liver)
3) Immune hydrops (Rh isoimmunization)
Macrosomia can lead to damage to the nerves of the brachial plexus especially?
This results in what upper arm palsy?
1) C5 and C6
2) Erb-Duchenne paralysis
Klumpke paralysis is a lower arm palsy caused by damage to?
C8 and 1st thoracic nerve
What maternal risks are caused by macrosomia?
Postpartum hemorrhage and significant vaginal lacerations
____ is defined as a delivery that requires additional obstetric maneuvers following failure of gentle downward traction on the fetal head to effect delivery of the shoulders.
Shoulder dystocia
Shoulder dystocia is caused by the impaction of the anterior fetal shoulder behind the maternal __1__ or the impaction of the posterior shoulder on the __2__.
__3__ can be seen which is retraction of the delivered fetal head against the maternal perineum.
1) Pubic symphysis
2) Sacral promontory
3) Turtle sign
Which palsy is more common?
Which is more common with shoulder dystocia?
1) Erb’s palsy
2) Klumpke’s palsy
In the management of shoulder dystocia, the McRoberts Maneuver induces what movements of the maternal hips?
1) Hyperflexion
2) Abduction
In the management of shoulder dystocia, __1__ pressure may dislodge the impacted anterior shoulder.
However you do NOT want to apply __2__ pressure.
1) Suprapubic
2) Fundal
In the management of shoulder dystocia, when using the Rubin maneuver you want to place pressure on an accessible shoulder to push it toward the ____ of the fetus to decrease the bisacromial diameter and free the impacted shoulder.
Anterior chest wall
In the management of shoulder dystocia, when using the Wood’s corkscrew maneuver you want to apply pressure ____ in order to rotate the infant and dislodge the anterior shoulder.
Behind the posterior
__1__ maneuver for shoulder dystocia is the last resort maneuver where the fetal head is manually returned to its prerestitution position and slowly replaced in the vagina by steady upward pressure.
Delivery is then done by?
1) Zavanelli
2) Emergent cesarean section
Shoulder dystocia is an obstetric emergency, what teams should be called for help?
The initial maneuvers used are?
1) Anesthesiologist and NICU
2) McRoberts and suprpubic pressure
