Trauma in Obstetrics

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

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 Don’t withhold X-rays (10 rads or more are teratogenic

Priorities A. Airway B. Breathing C. Circulation

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

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

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

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

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

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

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

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)

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-

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)

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

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

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

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

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

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

Endocrine Pituitary gland gets 30-50% heavier during pregnancy Shock may cause Sheehan’s syndrome(pituitary necrosis)

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

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

Initial Assessment Primary survey ABC’s Supplemental oxygen (re-breather mask If ventilation is required mild hyperventilation Crystalloid fluid resuscitation and early blood product administration

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

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%

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

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

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

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

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)

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

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

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

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

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

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

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

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

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