Question | Answer |
Preterm birth | 20-37 weeks after first day of last menstrual |
Second leading cause of neonatal mortality | preterm |
mortality rate after 23 weeks | 84% |
Survival with preterm improves with | each week that labor is delayed |
Look at fetal development slide | slide 9 |
Most common causes of preterm death | Most common is resp distress but others include patent ductus arteriosus, intravent hemm, and necrotizing enterocolitis |
There is a decline in morbitidy between | 32-36wks |
Look at table 1 for risk factors of preterm | slide 12 |
Describe etiologic sequelae for preterm | A person can have allergy or mulptiple preg, uterine abnormalities or polyoligohydraminos or uterine distension that leads to: amiochorion decidua->inflam->prostglandin synth->preterm |
What is the most consistent risk factor for preterm | Hx of preterm delivery bc that suggests a genetic contribution |
What hormone cut down on preterm births by 1/3 | Progesterone |
S/S preterm labor | Findings of persistent uterine contractions ( 4 in 20 minutes)
Intermittent abdominal cramping
Menstrual-like cramping
Pelvic pressure
Backache
Increase in vaginal discharge
Vaginal spotting or bleeding |
What confirms preterm labor | Cervical dilation of 2cm or effacement of 80% confirms preterm labor |
5 criteria to begin tocolytic therapy | Gestational age between 20 and 34 weeks
Fetal weight less than 2500 grams
Absence of fetal distress
No clinical signs of infection
Weighing maternal vs Fetal risk of tocolytic therapy |
Tocolytic | Anticontraction |
Contraindications to stopping labor - 6 reasons for contraindication of long term inhibition | Fetal death
Fetal anomalies incompatible with life
Fetal distress that warrants immediate delivery
Chorioamnionitis
Severe hemorrhage
Severe chronic and/or pregnancy induced HTN |
Relative contraindiction to stopping labor | Cervical dilation > 4cm, ruptured membranes, SGA fetus and maternal cardiac disease |
Treatment/delay tactics for preterm labor | Bedrest
Hydration
Tocolytic therapy |
2 kinds of tocolytic therapies | PRROM and chorioamnitis |
General MOA tocolytics and types available | Promote uterine relaxation by interfering with myometrial contraction- reduce free Ca or Beta adrenergi. Most reduce free Ca. |
How do beta adrenergics work as tocolytics | Beta-adrenergic agents promote intracellular storage of calcium by interfering with adenylyl cyclase, which in turn perpetuates an increase in cAMP |
How do Ca and Mg work as tocolytics | Magnesium and Calcium antagonists act by inhibiting the influx of calcium through the cell membrane |
Mag sulfate dose and MOA | Anatgonizes intracell Ca.
4-6g loading with 2-4g every hour after |
Terbutaline (Bricanyl)dose and MOA | Beta 2 agonist sympamimetic that decreases intracell Ca. 0.25-0.5mg SC Q3-4 hrs |
Ritodrine (Yutopar) dose and MOA | Beta 2 agonist sympamimetic that decreases intracell Ca.
0.05-0.35mg per minute IV |
Nifedipine/procardia dose and MOA | CA channel blocker.
5-10mg SL Q15-20 min to a max of 4x. Then 10-20mg Q4-6 hours |
Indomethacin dose and MOA | Prostoglandin and cyclooxygenase inhibitor.
50-100mg rectal then 25-50mg orally Q6hr |
6 Potential complications with mag sulfate | pulmonary edema, profound hypotension, profound musc paralysis, maternal tetany, cardiac arrest, respiratory depression |
8 potential complications with beta adrenergics | hypokalemia, hyperglycemia, hypotension, pulmonary edema, arrythmia, cardiac insufficiency, myocardia ischemia, maternal death |
3 potential complications with indomethacin | renal failure, hepatitis, GI bleed with chronic use |
potential issue with nifedipine | transient hypotension |
Antenatal corticosteroids - why are they used, at what time period, MOA, what kind of timeframe is best for benefits | Use: Reduce risk and severity of RDS
Time: 24 – 34 weeks gestation
MOA: Corticosteroids promote fetal lung maturation by inducing production of surfactant
Optimal benefits: within 7 days of delivery |
Why are preterm babies more vulnerable to depressant effect of anesthesia? (5 reasons) | Dec protein for drug binding– drug affinity by the protein that is present
Higher levels of bilirubin, which may compete for protein binding
Greater drug access to the CNS due to incomplete blood-brain barrier
dec ability to metabolize and excrete drug |
What do preterms have a higher incidence of at delivery | Higher incidence of acidosis during labor and delivery |
Is anesthesia harmful or beneficial to preterms | Its better, there have been less deaths perinatally when given anesthesia |
Review 37.1 in text | 37.1 |
5 reasons for antepartum hemm | Abortion
Ectopic gestation
Placenta previa
Abruptio placenta
Vasa previa |
3 reasons for intrapartum hemm | Uterine rupture
Splenic or hepatic rupture
Some sources include abruptio placenta as being intrapartum hemorrhage
*may also be related to antepartum mechanisms |
6 reasons for postpartum hemm | Placental implantation abnormalities
Uterine inversion
Uterine atony
Retained placenta
Lacerations
Ischiorectal hematoma |
14 risk factors for hemm | Elderly gravida
Macrosomia
Previous uterine surgery
Abnormal fetal presentation
Difficult delivery
Tocolytics
Antepartum problems
Grand multipariety
Placental abnormalities
Maternal trauma
Uterine infection
prev hemm
forcep/vacum
obesity dm p |
Abruptio placentae accounts for... | 31% OF ALL THIRD TRIMESTER BLEEDING |
Abruptio placentae defined | SEPARATION OF THE PLACENTA FROM THE DECIDUA BASALIS BEFORE DELIVERY OF THE FETUS |
Abruptio placentae incidence | OCCURS IN ABOUT 1.3 % OF ALL PREGNANCIES (& INCREASING) WITH THE MAJORITY OCCURING AT LESS THAN 36 WEEKS GESTATION
IT RECURS IN 9% OF THOSE WITH PREVIOUS ABRUPTION |
Clinical diagnosis of abruptio placentae | Dx with U/S
PAINFUL VAGINAL BLEEDING
PORT WINE - NON-CLOTTED BLOOD
BLOOD LOSS OFTEN CONCEALED
All of these lead to fetal death |
7 s/s abruptio placentae | Painful vaginal bleeding
Uterine tenderness/Back pain/Abdominal pain
Fetal distress
High frequency contractions
Uterine hypertonus (tetanic contraction)
Preterm labor
Dead fetus |
9 risk factors for abruptio placentae | MATERNAL COCAINE USAGE
CIGARETTE SMOKING & ALCOHOL
CHRONIC HYPERTENSION
PREECLAMPSIA
SHORT UMBILICAL CORD
MULTIPLE BIRTHS
UTERINE ABNORMALITIES/PREVIOUS HISTORY OF PLACENTAL ABRUPTION
TRAUMA
HYPERTENSION |
Grading of abruptio placentae | ASYMPTOMATIC(Grade 0)
Vag bleeding with or w/o uterine tetany, no sign of maternal shock or fetal distress(Grade1)
Ext vag bleeding, no shock, but fetal distress is present(Grade 2)
+maternal shock, fetal demise, and coagulopathy may be present(Grade 3 |
Management of abruptio placentae | EVALUATION
HYPOVOLEMIA
COAGULOPATHY
MONITORING - CVP/A-LINE ?
BLOOD LOSS
AGENTS FOR GENERAL ANESTHESIA |
5 fetal risks with IUGR | Major fetal risk: hypoxia
Fetal distress and intrauterine fetal death occur more frequently with abruption than placenta previa
15% to 25% of perinatal deaths occur secondary to abruption
RDS is the most common neonatal complication. |
How many births are complicated with abruption due to IUGR | As many as 50% of deliveries complicated by abruption |
Look at slide with clinical staging of blood loss | Slide 84 |
7 complications with IUGR | UTERINE ATONY
POST PARTUM BLEEDING
COAGULOPATHY WITH DIC
ACUTE RENAL FAILURE
PITUITARY NECROSIS
C/S HYSTERECTOMY
ANEMIA |
Most common cause of DIC | abruption |
coagulopathy occurs in ---% of all placental abruptions | 10% |
Explain DIC with abruption | Separation of placenta causes a release of thromboplastin into the circulation, which in turn triggers the extrinsic coagulation cycle and there is an increase in fibrin degradation products and decrease in platelets |
Lab of choice for placental abruption | FDP |
COUVELAIRE UTERUS : define, risk of coagulopathy,associated with, things to expect | IT IS A WIDE SPREAD EXTRAVASATION OF BLOOD INTO THE MYOMETRIUM
AS MUCH AS 4L OF BLOOD HAS BEEN CONCEALED
THE MORE CONCEALED BLOOD THE HIGHER RISK OF COAGULOPATHY
ALWAYS ASSOCIATED WITH ABRUPTIO PLACENTA
HYSTERECTOMY AND MASSIVE BLOOD LOSS TO BE EXPECT |
Placenta previa: incidence and definition | ACCOUNTS FOR ABOUT 22 % OF THIRD TRIMESTER BLEEDING
OCCURENCE IS ABOUT 3.6 per 1000 PREGNANCIES
IMPLANTATION OF THE PLACENTA IN THE LOWER UTERINE SEGMENT IN ADVANCE OF FETUS |
6 risk factors for placenta previa | PREVIOUS C/SECTION
MULTIPARIETY
ADVANCED MATERNAL AGE
LARGE PLACENTA
PREVIOUS UTERINE SURGERY
CIGARETTE SMOKING |
Diagnosis of placenta previa | PRESENTING PART PALPATION IN UPPER UTERINE SEGMENT
ULTRA SOUND ANALYSIS,ABDOMINAL,TRANSVAGINAL
MRI
“RARE CIRCUMSTANCES DOUBLE SET UP IN OPERATING ROOM”
“PAINLESS VAGINAL BLEEDING” |
Placenta previa: uncommon effects and rate of fetal death | Blood loss is not concealed
Shock is not common
Rare DIC unless massive blood loss (Dilutional thrombocytopenia)
Fetal mortality is 4-8% (complications of prematurity)
Fetal distress is UNCOMMON |
3 anesthetic considerations for placenta previa | “Double set-up” for dx, vaginal delivery or possible cesarean delivery
Cesarean delivery for an elective hemodynamically stable parturient
Cesarean delivery for actively bleeding parturient for emergency cesarean delivery (hemodynamically unstable) |
3 reasons placenta previas are still at risk for intra and post operative blood loss | Obstetrician may cut into placenta during uterine incision
After delivery, the lower uterine segment implantation site does not contract as well as the normal fundal implantation site
Patients with placenta previa are risk for placenta accreta |
Vasa previa defined and when it should be suspected | The velamentous insertion of the cord where fetal vessels transverse the fetal membranes ahead of the fetal presenting part.
Suspect: whenever bleeding occurs with ROM, particularly if the rupture is accompanied by FHR decelerations or bradycardia |
Is vasa previa bad for mom | It poses no risk |
2 things vasa previa is associated with | Also associated with multiple gestation (triplets)
It is associated with one of the highest fetal mortality rates (50% to 75%) of any complications of pregnancy |
Fetal blood loss with vasa previa | 250ml |
Occurance of vasa previa | Rare occurrence (1 in 2000 to 3000) deliveries |
5 risks of getting vadsa previa | Multiple pregnancies
Women with low riding placentas
Placenta previa
Bi-lobed placenta
Pregnancy from in-vitro fertilization |