Trauma in Pregnancy

Gary Davis MD, FACOG MPRI ANA Trauma and Disaster Symposium

Trauma in PregnancyLecture 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 PregnancyEpidemiology

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 PregnancyMortality 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 Mortalitywith 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

• 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 PregnancyMechanisms 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 PregnancySequence 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 PregnancyPhysical 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 PregnancyShock 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 PregnancySecondary 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 RADIATION DOSE (mrads)

Cervical spine 0.01 to 1.0 Chest 1 to 5 Extremities 0.01 Lumbar spine 600 to 1300 Pelvis 200 to 300 CT of Head < 50 CT of upper abdomen < 3000 CT of lower abdomen 3000 to 9000

Trauma in PregnancyFetal 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 PregnancyCardiotocographic 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 MonitoringInterpretation 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 PregnancyUnique 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 PregnancyUnique 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 PregnancyCriteria 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 PregnancyContraindicated Medications

ƒ Tetracyclinesƒ Chloramphenicolƒ Quinolonesƒ Salicylatesƒ Nonsteroidal antiinflammatories

Trauma in PregnancyAccepted Safe Medicationsƒ Penicillinsƒ Cephalosporinsƒ Erythromycins (except estolate)ƒ Acetominophenƒ Narcoticsƒ Hydroxyzineƒ Corticosteroidsƒ Tetanus / diphtheria toxoidƒ Tetanus immune globulinƒ Rabies vaccine & immunoglobulin

Trauma in PregnancySummary

ƒ ABC's & Primary Survey same as for other patients

ƒ Secondary survey includes assessment of uterus & fetus

ƒ Avoid maternal vena caval compressionƒ Usually need ultrasound for fetal

assessmentƒ Maternal hypovolemia needs to be

anticipated & treated aggressivelyƒ Consider early consultation with

obstetricianƒ Resuscitation & treatment of mother takes

priority over fetus