6: Complications of L&D Flashcards
risk factors of preterm labor (PTL)
preterm ROM; chorioamnionitis; multiple gestations; uterine anomalies such as a bicornuate uterus; previous preterm delivery; maternal prepregnancy weight less than 50 kg; placental abruption; maternal disease including preeclampsia, infections, intra-abdominal disease or surgery; and low SES.
prematurity increases risk of
respiratory distress syndrome (RDS) or hyaline membrane disease, intraventricular hemorrhage, sepsis, and necrotizing enterocolitis
only tocolytic FDA approved in the US
ritodrine—a beta-mimetic agent
many others are used
ritodrine and terb doses
Ritodrine is given as continuous IV therapy, whereas terbutaline is usually given as 0.25 mg SC, loaded Q 20 min × 3 dosages, and then Q 3 to 4 h maintenance
how does hydration act as a tocolytic?
decreases levels of ADH, the octapeptide synthesized in the hypothalamus along with oxytocin. Because ADH differs from oxytocin by only one amino acid, it may bind with oxytocin receptors and lead to contractions.
why does terbutaline have a black box warning?
may cause maternal death and cardiac events, including tachycardia, transient hyperglycemia, hypokalemia, cardiac arrhythmias, pulmonary edema, and myocardial ischemia
Mg sulfate dosing
loaded as a 6-g bolus over 15 to 30 minutes, and then maintained at a 2- to 3-g/hour continuous infusion. A slower infusion should be used in the case of renal insufficiency because magnesium is cleared via the kidneys.
risks at toxic levels of magnesium (> 10 mg/dL)
respiratory depression, hypoxia, and cardiac arrest, pulmonary edema
risks at magnesium levels less than 10 mg/dl
Deep tendon reflexes (DTRs) are depressed
adverse effects of indomethacin
premature constriction of the ductus arteriosus, pulmonary hypertension, and oligohydramnios secondary to fetal renal failure.
increased risk of necrotizing enterocolitis and intraventricular hemorrhage in extremely premature fetuses that had been exposed to indomethacin within 48 hours of delivery
Oxytocin antagonists can also be used as tocolytics, including
atosiban
preterm ROM vs premature ROM (PROM)
preterm ROM: before week 37
PROM: ROM occurring before the onset of labor
may occur together: PPROM
prolonged rupture of membranes if ROM lasts longer than 18 hours before delivery
most common concern of PROM
chorioamnionitis
test for ROM
pooling, nitrazine test, ferning, U/S, Amnisure test, tampon test
the vault is composed of what 5 bones?
can do what during labor?
two frontal, two parietal, and one occipital
the bones of the vault are not fused and can undergo molding to conform to the maternal pelvis in contrast to the bones of the face and base
factors associated with breech presentation
complications?
previous breech delivery, uterine anomalies, polyhydramnios, oligohydramnios, multiple gestation, PPROM, hydrocephaly, and anencephaly
complications: prolapsed cord, head entrapment
types of breech: frank, complete, incomplete/footling
frank: “folded”; flexed hips and extended knees
complete: “compact”; flexed hips, but one or both knees are flexed as well, with at least one foot near the breech
incomplete/footling: one or both of the hips not flexed so that the foot or knee lies below the breech in the birth canal.
three management options for breech
external cephalic version of the breech (manipulation into a vertex presentation), trial of breech vaginal delivery, and elective cesarean delivery
compound presentation
watch out for ?
tx is different for UE and LE
fetal extremity presenting alongside the vertex or breech
risk of umbilical cord prolapse
UE may be gently reduced
LE is considered footling/incomplete and calls for c section
types of breech: frank, complete, incomplete/footling
frank: “folded”; flexed hips and extended knees
complete: “compact”; flexed hips, but one or both knees are flexed as well, with at least one foot near the breech
incomplete/footling: one or both of the hips not flexed so that the foot or knee lies below the breech in the birth canal.
OP vs OT position, which one more common to deliver vaginally?
While OP position fetuses deliver vaginally in about 50% of cases, OT position fetuses rarely deliver vaginally in the OT position and must rotate to either OA or OP to deliver vaginally.
(may try to rotate manually or operatively with vacuum/forceps, otherwise C section)
etiologies of prolonged FHR decelerations include
preuterine (maternal PE, MI, AFE, seizure, epidural) uteroplacental (abruption, tetanic contraction, rupture) or postplacental (cord prolapse/compression, vasa previa)
prolonged deceleration vs bradycardia
prolonged decel: FHR below 100-110 bpm for >2 minutes
bradycardia: >10 minutes
C section if FHR decelerations are due to
cord prolapse, placenta previa, abruption
management of prolonged FHR deceleration
left or right lateral decubitus position (to reduce IVC compression)
oxygen via face mask
if maternal hypotension: aggressive IV hydration and ephedrine
Tetanic uterine contraction is treated with
nitroglycerin, usually administered via a sublingual spray, and/or terbutaline
maneuvers for shoulder dystocia
McRoberts, suprapubic pressure, Rubin maneuver, Wood’s corkscrew maneuver, deliver of the posterior arm/shoulder
then: generous episiotomy, Zavanelli maneuver, symphysiotomy
risk factors for shoulder dystocia
fetal macrosomia (weight over 4,000 g), preconceptional and gestational diabetes, previous shoulder dystocia, maternal obesity, postterm pregnancy, prolonged second stage of labor, and operative vaginal delivery.
Rubin maneuver
pressure on an either accessible shoulder toward the anterior chest wall of the fetus to decrease the bisacromial diameter and free the impacted shoulder
Wood’s corkscrew maneuver
pressure behind the posterior shoulder to rotate the infant and dislodge the anterior shoulder.
McRoberts maneuver
sharp flexion of the maternal hips that decreases the inclination of the pelvis increasing the AP diameter can free the anterior shoulder
Pregnant patients commonly have BPs around
90/50 mm Hg
Associated complications of uterine rupture
prior uterine scar from myomectomy or C section, uterine fibroids, uterine malformations, obstructed labor, and the use of oxytocin/PGEs
uterine rupture may present how?
management?
“popping” sensation or sudden abdominal pain, fetus may be palpable in the extrauterine space, there may be vaginal bleeding, and commonly the fetal presenting part is suddenly at a much higher station than previously
immediate cesarean delivery and exploratory laparotomy.
Management of a Pregnant Patient with Seizures or in Status Epilepticus
Assess and establish airway and vital signs including oxygenation
Assess FHR or fetal status
Bolus magnesium sulfate, or give 10 g IM
Bolus with lorazepam 0.1 mg/kg, 5.0–10.0 mg at no more than 2.0 mg/min
Load phenytoin 20 mg/kg, usually 1–2 g at no more than 50 mg/min
If not successful, load phenobarbital 20 mg/kg, usually 1–2 g at no more than 100 mg/min
Laboratory tests include CBC, metabolic panel, AED levels, and toxicology screen
If fetal testing is not reassuring, move to emergent delivery
BPs much lower than the 80/40 mm Hg range is unusual and can lead to poor maternal and uterine perfusion. Common etiologies?
vasovagal events, regional anesthesia, overtreatment with antihypertensive drugs, hemorrhage, anaphylaxis, and AFE
tx of maternal hypotension
aggressive IV hydration and adrenergic medications to constrict peripheral vessels, and increase both the preload and the afterload.
consider Benadryl and epinephrine should be considered for a possible anaphylactic reaction
Vertex malpresentations include
face, brow, compound, and persistent OP.
If there is no sign of resolution of the FHR deceleration in 4 to 5 minutes, the patient should either be
delivered vaginally or moved to the OR for cesarean.
