Trauma in Obstetrics

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Trauma in Obstetrics
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Trauma in Pregnancy

• Major physiologic changes
• Altered anatomical relationships
• Signs and symptoms of injury may be altered
• Treatment priorities are the same
• Usually the best treatment for the fetus is the
  best treatment for the mother

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Trauma in Pregnancy

• Resuscitation and stabilization may need to be
  modified to accommodate the altered physiologic
  and anatomic changes of pregnancy
• 2 patients
• Consult OB/GYN early
• Dont withhold X-rays (10 rads or more are
  teratogenic

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Priorities

• A. Airway
• B. Breathing
• C. Circulation

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Trauma in Pregnancy

• Physical trauma complicates 1/12 of pregnancies
• Trauma is the 1 cause of non Obstetrical
  maternal deaths
• Serious retroperitoneal bleeding following blunt
  abdominal trauma is more common in pregnant women
  as opposed to non pregnant

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Trauma in pregnancy

• Bowel injuries are less common in pregnant
  patients as opposed to non pregnant patients
• The presence of vaginal bleeding and uterine
  hypertonicity is presumptive evidence of
  placental abruption

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Objectives

• A. Oxygen requirements
• B. Blood replacement requirements
• C.Proper patient positioning
• D.Significance of fetal monitoring
• E. Vaginal bleeding

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Anatomic and Physiologic Alterations of Pregnancy

• The Uterus is an intra pelvic organ until the
  twelfth week of gestation
• At 20 weeks the uterus is at the umbilicus
• At 36 weeks the uterus is at the costal margins
• In the last 2-8 weeks the fetal head descends to
  become engaged in the pelvis

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Anatomic and Physiologic Alterations of Pregnancy

• Intestinal tract is displaced upward and
  posterior
• As gestation continues the uterus becomes more
  vulnerable as the walls thin and there is less
  protection by amniotic fluid
• Thromboplastin and plasminogen activator can be
  released with trauma to the placenta and uterus

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Hemodynamics

• Cardiac Output- Increases 1-1.5 L per minute by
  10 weeks (Vena cava compression in the supine
  position can decrease CO by 30-40)
• Heart Rate- Increases up to 15-20 beats per
  minute at term

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Hemodynamics

• Blood Pressure- 5-20mmHG decrease (maximum in the
  second trimester) Returns near normal at term
• Some women may exhibit profound hypotension in
  the supine position, turn patient to the left
  lateral decubitus position

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Hemodynamics

• Venous pressure- CVP is variable in pregnancy,
  the response to volume is the same as in the non
  pregnant state, (venous hypertension in the lower
  extremities is normal during the third trimester)

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Hemodynamics

• EKG- There may be a left axis shift of about 15
  degrees
• Flattened or inverted T waves in leads III, AVF
  and the precordial leads may be normal
• Ectopic beats are slightly increased in pregnancy-

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Blood Volume and composition

• Plasma volume is increased and reaches its
  maximum at about 34 weeks (40-50 above
  pre-pregnant levels)
• RBC volume increases but not as much as the
  plasma volume resulting in a lower hematocrit
  (the so called physiologic anemia of pregnancy)

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Volume

• Late pregnancy hematocrit of 31-35 is normal
• Overall blood volume is up 50
• With hemorrhage a healthy pregnant women may
  lose 30-35 of their blood volume before
  exhibiting symptoms

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Blood composition

• WBC- can be up to 20,000
• Fibrinogen and other clotting factors are
  elevated
• Prothrombin and partial thromboplastin times may
  be shortened
• Bleeding and clotting times are unchanged

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Blood composition

• Albumin falls (2.-2.8g/dl)
• Serum osmolarity remain at about 280mOsm/L
• A pregnant women is twice as likely as a non
  pregnant women to develop a DVT or PE (adding
  trauma to this increases the likelihood

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Respiratory

• Respiratory rate is unchanged
• Tidal Volume is increased by 40
• Residual volumes fall
• PCO2 pf 30mmHg is normal
• Hyperventilation of pregnancy
• Chest X-ray shows increased lung markings and
  prominent pulmonary vessels

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Gastrointestinal

• Gastric emptying is greatly prolonged (Pregnant
  women all have full stomachs)
• The uterus may shield the intestines
• The liver and spleen are unchanged

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Urinary tract

• GFR and renal blood flow increase during
  gestation
• BUN and Creatinine are about half non pregnant
  levels
• Physiologic dilation of the renal calyxes,pelves
  and ureters
• Creatinine clearance increased to 150

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Endocrine

• Pituitary gland gets 30-50 heavier during
  pregnancy
• Shock may cause Sheehans syndrome(pituitary
  necrosis)

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Neurologic

• Ecclampsia is a condition that may mimic a head
  injury
• If a seizure occurs make sure the patient is
  evaluated for ecclampsia

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Initial assessment

• Position patient to avoid supine hypotension
  unless spinal injury is suspected
• Left lateral positioning is preferred
• If transport is needed displace uterus to left
  and elevate right hip

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Initial Assessment

• Primary survey
• ABCs
• Supplemental oxygen (re-breather mask
• If ventilation is required mild hyperventilation
• Crystalloid fluid resuscitation and early blood
  product administration

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Initial assessment

• Blood is shunted away from the uterus in a
  hypotensive state
• The gravida can lose up to 35 of her blood
  volume before tachycardia, hypotension, and other
  signs of hypovolemia occur
• The fetus may be in shock and the mother appear
  stable

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Initial assessment

• Avoid vasopressors because these further reduce
  uterine blood flow
• 2 large bore lines (14-16 gauge) fluid should be
  LR or NS replace at 3-1 for estimated blood loss
• O2 saturations above 90

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Initial Assessment

• With gun shot wounds to the abdomen exploration
  is mandatory
• Stab wounds to the abdomen may be able to be
  observed in selected cases

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Secondary Assessment

• Uterine irritability
• Fundal height and tenderness
• Fetal heart rate and movement
• Pelvic exam ( look for bleeding, premature
  dilation, rule out ROM by fern and nitrazine if
  indicated

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Secondary Assessment

• If possible place patient on fetal monitor to
  assess contractions and fetal heart rate
  reactivity
• With any trauma an ultra sound exam is required
  to look for placental separation and possibly to
  obtain biophysical profile

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Secondary Assessment

• Ultrasound can be useful for determining
  gestation age, placental location, fetal status,
  amniotic fluid volume, and fetal position

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Monitoring

• Mother-BP, pulse, CVP if needed, respiratory
  rate, pulse oximeter
• Fetus-preferentially continuous fetal and uterine
  monitoring
• Placental abruptions can be seen 24-48 hours
  following trauma( if contractions are present
  Abruptio placenta is more likely)

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Monitoring

• If no contractions are present and the fetal
  heart rate is reassuring ACOG recommends 2-6
  hours of monitoring
• If less than 20 weeks monitoring may not be
  needed as long

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Definitive care

• Uterine rupture can present in massive shock with
  hemorrhage to a patient with minimal symptoms
• Signs of uterine rupture on radiologic exams can
  be extended fetal extremities, abnormal fetal
  presentations, or free intraperitoneal air

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Definitive care

• If uterine rupture is suspected immediate
  surgical exploration is necessary
• Abruptio placenta is the leading cause of fetal
  death after blunt trauma
• Signs of abruption- Irritable uterus, tetanic
  contractions, tenderness, enlarging uterus

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Definitive care

• Other signs of abruptio- bleeding, Consumptive
  coagulopathy, maternal shock, pain
• Retroperitoneal hemorrhage can be massive after
  blunt trauma or pelvic fracture

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Definitive care

• Remember Rh sensitization (Kleihauer-Betke)
• Administration of Rho gam (D immunoglobin within
  72 hours
• Tetanus prophylaxis is the same as in the non
  pregnant patient

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Definitive care

• Perimortem cesarean delivery is unlikely to
  produce a living fetus if the mother has been
  dead for more than 20 minutes

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Summary

• Recognize the effect of anatomic and physiologic
  changes
• Vigorous shock therapy
• Recognize the unique spectrum of potential
  injuries
• Stabilize the mother first because the fetuses
  life is dependant on the mother integrity

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Summary

• Fetal heart rate monitoring should be maintained
  during resuscitation and after stabilization
• Less than 20 weeks gestation the fetus is non
  viable so treat the mother
• Do not withhold diagnostic X-rays
• Get an Obstetrician fast

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Summary

• Changes in vital signs can occur relatively late
  so the patient may be worse off than the vitals
  indicate
• Ultrasound will miss an abruption less than 30
  so be clinically aware