Transcript 19. obgyn

Trauma in Pregnancy
Gary Davis MD, FACOG
MPRI
ANA Trauma and Disaster Symposium
Trauma in Pregnancy
Lecture Objectives
ƒ Correlate anatomic and physiologic
changes of pregnancy with effects of
trauma
ƒ Prioritze trauma management of the
mother and the fetus
ƒ Recognize specific trauma
complications related to pregnancy
Trauma in Pregnancy
Epidemiology
ƒ Trauma is the most frequent cause of death in
women under 35 years of age
ƒ Blunt trauma complicates 6 to 7 % of all
pregnancies
ƒ Main etiologies :
–Assaults
–Motor vehicle crashes (MVC's)
–Falls
Physical Assault During Pregnancy
ƒ Occurence rate while pregnant : 17 %
ƒ MVA’s or falls occur in 7% of pregnancies
ƒ 29 % or more of pregnant patients report abuse
when questioned directly
Minor Trauma in Pregnancy
4 to 10 % complication rate, due to :
–Placental abruption
–Premature labor
–Premature rupture of membranes
Trauma in Pregnancy
Mortality Statistics
ƒ Pregnant patients with major truncal injuries :
–24 % maternal mortality rate
–61 % fetal mortality
ƒ Pregnant patients with trauma induced
hemorrhagic shock have greater than 80 % rate
of unsuccessful outcome
ƒ General principle : treatment of the mother takes
precedence over treatment directed at the fetus
(the fetus' best chance is with resuscitation of the mother)
Fetal Mortality Rates
maternal shock : 80 % fetal mortality
Fetal Mortality
with major trauma :
15 to 40 %
with minor trauma :
1 to 4 %
Gunshots to the uterus : 80 %
Stab wounds to uterus : 40 to 50 %
Physiologic Changes During Pregnancy
• There are three sexes—male , female, and
pregnant.!!!!
Genitourinary Tract
• Both uterus and bladder become abdominal
organs
• Renal enlargement and hydronephrosis
• Increased GFR and urinary output
• Increased uterine blood flow
Non-gravid uterus—60cc/minute
Term uterus ---- 600cc/minute
Gastrointestinal Tract
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GI motility decreases
Prolonged gastric emptying
Gastric fluid more acidic
If you think about an NG tube—do it
Uterine enlargement reduces GI injury from
blunt trauma, but “crowding” causes penetrating
trauma to be more complex
Cardiovascular System
• Cardiac output starts to increase in first
trimester, up to 50% above baseline in second
trimester
• Blood volume increases 50%
( blood volume at term-six liters)
• RBC mass increases 10-15 %
(dilutional anemia up to 10%)
• Maternal heart rate increases to 90 bpm
• Widening of pulse pressure
Pulmonary
• Increase minute ventilation
• Increased tidal volume
• Increased oxygen consumption
• Reduced functional residual capacity
• PCO2 decreases to 30-36 mmHG
Hematologic Indices
anemia from dilution (Hct between 32-34)
• Fibrinogen and factors VII,VIII,IX & X increase
• Fibrinogen levels 400-450 mg/dl
• White count 13,000- 18,000
• A gravid patient is in hyper coagulable state !!!
Trauma in Pregnancy
Mechanisms of Injury
ƒ Blunt trauma
–Can rupture uterus
–Uterus & amniotic fluid may act to protect
fetus
–Can exert indirect shearing effects
ƒ Penetrating trauma
–Uterus acts to protect other viscera
–Uterine wall can absorb much of energy
of projectiles
–Compaction of organs may lead to
complex injuries
Uterus at 3 months
Uterus at 7 months
Effects of Burn Trauma in Pregnancy
ƒ < 20 % TBSA burn : usually no
increased risk of complications
ƒ > 30 % TBSA burn : often causes early
labor
ƒ > 40 % TBSA burn : high fetal
mortality
ƒ > 60 % TBSA burn : high maternal
mortality
Trauma in Pregnancy
Sequence of E.D. Care
ƒ Diagnostic and treatment priorities are the
same as for other patients
–ABC's
–Restore blood volume
–Complete secondary survey
–Decide if radiographic or lab studies needed
–Provide definitive trauma management
ƒ Don’t hesitate to all obstetrician !!!
(concentrate glory –spread blame!!!)
Trauma in Pregnancy : Uterine Fundal
Height with Advancing Gestation
Uterine Fundus Position
Gestational Age
Feels enlarged on pelvic exam
8 weeks
Pelvic brim
12 weeks
Halfway between umbilicus and
pelvic brim
16 weeks
At umbilicus
20 weeks
# of cm above the umbilicus
20 + # of cm above umbilicus
is the # of weeks
Thoracic Injuries
• The Gravid uterus may elevate the diaphragm
• Thoracostomy tubes should be inserted one or
two intercostal spaces higher than the usual,
(fifth intercostal space—mid axillary line), and
after careful digital exploration.
Lateral positioning to avoid vena caval compression
Trauma in Pregnancy
Physical Exam (cont.)
ƒ Additional secondary survey abdominal exam
components in the pregnant patient :
–Measure fundal height (mark on abdomen)
–Listen for fetal heart tones (may need Doppler)
–Palpate for fetal movement
–Assess for uterine contractions & irritability
–Assess fetal position
–Consider ultrasound !!!!!
–Pelvic exam : CAUTION : if any possibility of
placenta previa (this may be manifested by bright red
painless vaginal bleeding in the 3rd trimester)
Placenta
Previa
Trauma in Pregnancy : Precautions
Regarding Placenta Previa
ƒ If the patient is known or suspected to have
a placenta previa, then speculum or digital
vaginal exam is CONTRAINDICATED in the
emergency dept. due to the risk of causing
uncontrollable bleeding
ƒ In this situation, vaginal exam should occur
only in the operating room or delivery suite
where an emergency C-section could be
done
Trauma in Pregnancy
Shock Considerations
ƒ Because of the elevated blood volume and compensatory
mechanisms, up to 35 % of blood volume can be lost in
the pregnant patient before signs of hypovolemia
(tachycardia, hypotension) occur
ƒ Uterine blood flow is reduced earlier, so the fetus may be
"in shock" before the mother shows signs
ƒ So early aggressive fluid treatment is important for
pregnant patients
ƒ Vasopressors (alpha effect) should be avoided because
they reduce uterine blood flow
Trauma in Pregnancy
Secondary Survey and Radiographic Studies
ƒ Should utilize same priorities and
treatment procedures in the pregnant
patient as for other trauma patients
–Only exception is peritoneal lavage may
need to be done supraumbilically and via
open procedure if late pregnancy
ƒ Radiographs and other studies should
be ordered by same criteria (usually
need to add ultrasound of abdomen)
Fetal Exposure to X-Rays
ƒ Exposure < 5000 to 10,000 millirads (mrads)
yields little additional risk
ƒ Abdominal shielding decreases exposure 75 %
ƒ Radiation effects based on fetal age :
–0 to 1 week (implantation) : death or no effect
–2 to 7 weeks (organogenesis) : teratogenesis ; this is
the highest risk period
–8 to 40 weeks : less effect but growth disturbances or
CNS dysfunction possible
Estimated Radiation Dose to
the Ovaries from Radiographs
FILM TYPE
Cervical spine
Chest
Extremities
Lumbar spine
Pelvis
CT of Head
CT of upper abdomen
CT of lower abdomen
RADIATION DOSE (mrads)
0.01 to 1.0
1 to 5
0.01
600 to 1300
200 to 300
< 50
< 3000
3000 to 9000
Trauma in Pregnancy
Fetal Monitoring
ƒ Usually should get abdominal
ultrasound to assess uterus and fetus
for trauma
ƒ Should undertake fetal heart rate
monitoring as early as possible
–Both rate and relationship to uterine
contractions should be followed
ƒ Generally obstetrical consultation
should be obtained
Trauma in Pregnancy
Cardiotocographic Monitoring
ƒ Consists of fetal cardiac activity detected by Doppler, &
measurement of uterine activity
ƒ Fetal distress is a sensitive indicator of maternal shock
ƒ Should monitor at least 4 hours for minor trauma
ƒ Should monitor at least 24 hours for :
–Major trauma
–Vaginal bleeding
–Uterine tenderness
–Uterine contractions
–Ruptured memebranes
Cardiotocographic Monitoring
Interpretation of Findings
ƒ If > or = 8 uterine contractions per hour :
–10 % had adverse pregnancy outcome
ƒ If < 8 uterine contractions per hour :
–(during first 4 hours) : no adverse outcomes
ƒ Signs of fetal distress :
–Bradycardia ( < 110 bpm)
–Tachycardia ( > 160 bpm)
–Late decelerations
–Loss of beat to beat variability
–Sinusoidal (speeding then slowing) heart rate patterns
Trauma in Pregnancy
Unique Complications
ƒ Rh isoimmunization
–Can occur in Rh negative mother even
with mild trauma
–If suspected, patient should receive Rh
Immunoglobulin (Rho-Gam) IM within 72
hours (300 micrograms per 30 ml.
estimated materno-fetal blood exchange)
Trauma in Pregnancy
Unique Complications (cont.)
ƒ Amniotic fluid embolism
–Can occur from blunt trauma
–Manifests as disseminated intravascular
coagulation (DIC) or bleeding or shock
ƒ Abruptio placentae
–Leading cause of fetal death after blunt trauma
–May have dark red vaginal bleeding
– May have uterine tenderness, uterine rigidity, maternal
shock
–If separation involves 25 % of placental surface, premature
labor may begin
–Ultrasound is best diagnostic test (also for placenta previa)
Abruptio
Placentae
Pelvic fractures
with bone
penetration of
fetal calvarium
Trauma in Pregnancy
Criteria for Admission
ƒ Same criteria as for other trauma patients, plus
:
–Vaginal bleeding
–Uterine contractions or "irritability"
–Abdominal pain, tenderness, or cramps
–Hypovolemia
–Changes in fetal heart tones or rates
–Leakage of amniotic fluid
ƒ Additional admission consideration is for fetal
monitoring
Trauma in Pregnancy
Contraindicated Medications
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Tetracyclines
Chloramphenicol
Quinolones
Salicylates
Nonsteroidal antiinflammatories
Trauma in Pregnancy
Accepted Safe Medications
ƒ Penicillins
ƒ Cephalosporins
ƒ Erythromycins (except estolate)
ƒ Acetominophen
ƒ Narcotics
ƒ Hydroxyzine
ƒ Corticosteroids
ƒ Tetanus / diphtheria toxoid
ƒ Tetanus immune globulin
ƒ Rabies vaccine & immunoglobulin
Trauma in Pregnancy
Summary
ƒ ABC's & Primary Survey same as for other patients
ƒ Secondary survey includes assessment of uterus &
fetus
ƒ Avoid maternal vena caval compression
ƒ Usually need ultrasound for fetal assessment
ƒ Maternal hypovolemia needs to be anticipated &
treated aggressively
ƒ Consider early consultation with obstetrician
ƒ Resuscitation & treatment of mother takes priority
over fetus