Complications of Labor Flashcards
Definition of preterm labor?
Regular uterine contractions occurring at least q10min resulting in cervical change prior to 37 weeks.
What is the weight threshhold for Low Birth Weight (LBW)?
Very Low Birth Weight (VLBW)?
<2500g=LBW
<1500g=VLBW
Between what two weeks gestation does survival rate increase by 5% each day?
Between 25-26 weeks.
There is an association with preterm labor and what 3 genital tract colonizations?
- Group B Strep
- Neisseria gonorrhoeae
- Bacterial Vaginosis organisms
What can be done to stop or attempt to slow contractions to avoid Preterm labor?
Tocolytic therapy (also an epidural can avoid pushing).
Tocolytic therapy can be used up to how many weeks gestation?
34 wks
What is the ultimate goal of tocolytic therapy?
Short term use to permit corticosteroid treatment to aid fetal lung maturation and allow potential transfer to NICU prepared facility.
What are the 6 tocolytic therapies available?
- Ethanol
- Magnesium
- Calcium-Channel Blockers
- Beta-Adrenergic Agonists
- Prostaglandin Synthetase Inhibitors
- Methylxanthines
How does methylxanthines (aminophylline) produce tocolysis?
Phosphodiesterase inhibitor which increases cAMP, causes uterine muscle relaxation.
What is an example of a Calcium Channel Blocker used in tocolytic therapy?
Nifedipine
What are maternal side effects of Nifedipine use?
- Hypotension, tachy, dizzy, palpitations, flushing
- Myocardial depression
- Hepatic dysfunction
- Postpartum hemorrhage
- Decrease UBF=fetal hypoxemia
Why do calcium channel blockers increase risk of post-partum hemorrhage?
Uterine atony refractory to oxytocin and prostaglandin F-a2
What are two examples of Prostaglandin Synthetase Inhibitors?
- Indomethacin
2. Sulindac
MOA of indomethacin and sulindac?
Decrease cyclooxygenase which decreaes prostaglandins
What are maternal side effects of indomethacin and sulindac?
- Nausea
- Heartburn
- Transient dec. bleeding aggregation (bleeding)
- Primary Pulm HTN
What are fetal side effects of indomethacin and sulindac?
- Crosses placenta
- Premature closure of ductus arteriosus
- Persistent fetal circulation
- Renal impairment- oliguria.
How does magnesium produce tocolysis?
Competes with Ca++ to decrease contractility by activating adenylcyclase and increasing cAMP
If magnesium therapy is performed for tocolysis, how would your anesthetic plan change?
Use decreased doses of DNMBA and NDNMBA.
MAC decreases
What is normal serum mag treatment range?
4 to 7mg/100ml
At what serum mag levels are toxicity signs seen?
8-10 loss of deep tendon reflexes.
10-15 Resp depression and Wide QRS/PR interval.
20+= cardiac arrest
What is treatment for magnesium toxicity?
Calcium Gluconate or CaCL
What are examples of Beta Adrenergic Agonists used for tocolytic therapy?
Terbutaline and ritodrine
How do terbutaline and ritodrine cause tocolysis?
Increase cAMP causes uterine relaxations
What are side of effects of terbutaline and ritodrine?
- N/V
- Anxiety/restlessness
- Hyperglycemia, hypokalemia, acidosis
- Tachy, arrhythmias, dec PVR, dilutional anemia,
- Pulmonary edema
Risk factors involved in beta adrenergic agonist therapy and pulmonary edema?
- Undiagnosed CHF/LV dysfunction
- Infection
- Hypokalemia
- Tocolysis >24hrs
- Multiple gestations
- Concomitant mag therapy
How much does fetal mortality risk change in twins vs singleton pregnancy?
5-6x increase in twins (because of increase in risk of prematurity)
What are 5 maternal consequences of multiple gestation pregnancies?
- CV- Increased CO earlier on.
- Heme- Increased incidence of anemia
- Resp- Dec TLC, dec FRC, inc closing capacity
- Metabolic- Inc oxygen consumption, inc metabolic rate
- Reproductive- Larger uterus=aortocaval compression, greater aspiration risk.
Preterm labor occurs in approx how many multiple gestation pregnancies?
40-50%
What LA is preferred for twin births and why?
2 Chloroprocaine 3% because of rapid onset.
What medication can be given to provide uterine relaxation for internal manipulation of fetus(es)?
Nitroglycerine 100mcg (max 500).
What are 5 signs of uterine rupture?
- Sudden abd pain
- Vaginal bleeding
- Hypotension
- Cessation of labor
- Fetal distress
What is the most reliable sign of uterine rupture?
Fetal distress
What are 9 risk factors of uterine rupture?
- Previous uterine surgery
- Trauma
- Multiparity
- Uterine anomaly
- Oxytocin
- Placenta percreta
- Tumors
- Macrosomia
- Malposition
What abnormal presentation is an absolute indication for c-section?
Transverse lie
What presentation has greatest chance of uncomplicated spontaneous vaginal delivery?
Vertex presentation with flexed c spine and anterior occiput.
What are the three variations of breech?
- Complete breech (both feet first)
- Incomplete breech ( 1 foot first, 1 foot up)
- Frank Breech (butt first).
What are the complications associated with post-maturity gestation (beyond 42 weeks)?
Dec uteroplacental blood flow.
Umbilical compression.
Meconium staining of amniotic fluid.
Macrosomia and shoulder dystocia
How long of a window of time before fetal compromise with a prolapsed umbilical cord?
10 minutes
What anesthetic management would you take with intrauterine fetal demise?
Epidural, IV analgesia, remember to ruleout coagulopathy as cause of demise
What is most common cause of intrauterine fetal demise?
Cord accidents (prolapse, cord length, entanglement, torsion)
What does the acronym VEAL CHOP Mean?
(V) Variable Decels= (C) Cord Compression
(E) Early Decels= (H) Head Compression
(A) Accelerations= (O) OK or Oxygen
(L) Late Decels= (P) Placental Insufficiency
