Trauma in Pregnancy

1. Trauma in Pregnancy Dr N du Plessis Dept of Obstetrics and Gynaecology March 2013

2. Introduction • Unique challenge – evaluation of pregnant trauma patient • Two patients potentially at risk • Influence of pregnancy-related anatomic and physiological changes

3. Four groups • Injured unaware of pregnancy • All pregnant till proven otherwise • Teratogenic effects • Gestation < 26 weeks • Maternal resus primary • Gestation > 26 weeks • 2 patients • Perimortem state • Early C/S: maternal resus, fetal survival

4. Incidence and etiology of trauma in pregnancy • Major contributor to maternal mortality worldwide • USA leading cause of pregnancy-associated maternal deaths • Two-thirds: MVA. Other: domestic violence, assaults, suicide. • Pregnancy risk factor for being assaulted • SA - ↑ incidence of trauma and violence

5. Anatomy • Uterine enlargement • 12w, 20w, 36w • Uterine wall • Amniotic fluid • Placenta • Descent of fetal head • Upward displacement • GIT • Diaphragm • On XR

6. Pregnancy-related changes • Cardiovascular system - ↑ CO, from 1st trimester, ↑↑ 20 weeks - HR ↑ 15 beats/min - BP: ↓ 10mmHG, nadir @ 26 weeks, ↑ to pre-pregnancy values @ term - ↓systemic vascular pressure - maternal hemorrhage compensated for by fetal distress (rather than tachy and hypotension) - supine hypotension syndrome (30 degree tilt after 20 w) - loss of 30% blood volume before symptomatic NB

7. Pulmonary system - By 20 weeks:↓ FRC and ↑ in tidal volume - No changes: FEV1 and respiratory rate - Respiratory alkalosis due to physiological hyperventilation→↓ PaCO2, ↑PaO2 and ↓ bicarbonate concentration

8. Haematological system - Plasma volume ↑ 45% (6-8w), physiological anaemia – dilution effect - Hb 10,5 g/dL - WCC 6 000 – 16 000 (1st and 2nd trimester), 20 000 – 30000 (peripartum) - Fibrinogen concentration > 200mg/dL

9. Gastrointestinal system - gastric aspiration: ↑ intra-abdominal pressure, relaxation of lower esophageal sphincter → early gastric decompression • Neurological/ CNS • Enlarged pituitary: susceptible to shock • Pre-eclampsia mimic head injury • Changes in need for anesthetic drugs • Renal system - glomerular hyperfiltration – reduction in normal plasma creatinine (35 – 40 mmol/L)

10. Cardiopulmonary resuscitation • External chest compression more difficult - ↓chest compliance • Hand position on sternum • Above center – accommodate upward displacement of the diaphragm by gravid uterus • Not effective (2nd and 3rd trimester): aortacaval compression, ↓cardiac output • C/Section required to perform effective CPR – within 4-5 minutes

11. Assessment and resuscitation • Penetrating trauma • Similar management • Better prognosis than gun shot wound • Fetus at greater risk with enlarged uterus • Indication for laparotomy unchanged, well tolerated

12. Blunt trauma • #1: evaluate and resus mother • Assess and monitor fetus • Secondary survey of mother • Definite care: standard trauma protocols • Remember • NG tube • O2 • Positioning (spinal injury excluded) • Signs of maternal hemorrhage (fetal distress) • Avoid vasopressors • Rhesus typing • Radiographic studies

13. Burns • Fetus: fluid loss, hypoxemia and sepsis • Hospitalize • smoke inhalation, electrical burns, burns of both hands and feet, > 10% surface area involved and full-thickness burns • Add 5% if anterior abdomen is involved • O2, wound care, tetanus toxoid

14. Resuscitation during pregnancy • Call for help – multi-disciplinary team • Involvement of Obstetrician • Displace uterus laterally and left if above umbilicus • Initiate ABC’s (CAB) • Differentiate between obstetric and non-obstetric causes • Estimate gestational age • Uterine fundus ≥ 4 finger breadths above umbilicus, at 4 min, perimortem C/Section • Defibrillation – for adult defib, remove fetal monitoring equipment

15. Fetus • Document gestational age and heart auscultation • Factors predicting mortality and morbidity: hypoxia, infection, drug effects and preterm delivery • First trimester • 13 – 24 weeks • > 24w: supine hypotension, neurodevelopmental delay and preterm birth • 3rd trimester neurodevelopment: • Primary disease process • Surgical complications • Anesthetic agents • Anesthetic management (respiratory support)

16. Increased vascularity and blood flow • Dilated pelvic vasculature → ↑ risk retroperitoneal haemorrhage from abdominal and pelvic trauma • Blood flow to uterus 600ml/min • Fetal oxygenation dependent on uterine blood flow, no autoregulation • Also reduced from vasoconstriction (drugs), maternal hypercarbia an hypocarbia

17. Changes in abdomen • Pregnant women sustain abdominal trauma more easily • Enlarged uterus protects against visceral injury from lower abdominal penetrating injuries and shields retroperitoneal structures • Penetrating injuries above uterus – likely to injure bowel • Rebound tenderness and guarding less prominent

18. Respiratory support • Liberal oxygen supplementation • Anoxia develops sooner • Oxygen saturation > 95%, if < do blood gas (PaO2, PaCO2). • Favourable placental oxygenation when PaO2 > 70mmHg • Early intubation • Airway edema • Difficult to secure airway, risk of aspiration • Cricoid pressure • Chest tube – remember diaphragm elevate

19. Volume replacement • Two large bore IV lines • Prefer volume replacement, vasopressors can reduce uterine blood flow

20. Caesarean delivery NB • Urgent delivery if imminent maternal death • CPR not successful within 4 minutes • Stable mother, non-reassuring CTG • During laparotomy, gravid uterus prevents adequate surgery for injuries • Perimortem C/Section optimum survival of fetus and mother if within 4 min • Irreversible brain damage after 4-6min • Pregnant pt anoxic sooner • Effective resuscitation with empty uterus • Improved fetal survival with shorter time to delivery

21. Uterine rupture • Sharp or blunt trauma • Late second and third trimester • Signs and symptoms: shock, non-reassuring CTG, fetal death, uterine tenderness, peritoneal irritation, vaginal bleeding, palpable fetal parts • Fortunately rare • Early recognition and appropriate resus

22. Placental abruption • Incidence varies with different degrees of abdominal trauma • Direct abdominal trauma, uterine and abdominal tenderness, vaginal bleeding (clots), non-reassuring CTG, premature labour • Position of placenta can influence symptoms • NB – clinical diagnosis • Monitoring for 48 hours: delayed abruptio, preterm labour

23. Fetomaternal haemorrhage • More common in anterior placenta • Complications: fetal anemia, chronic asphyxia, fetal death, maternal iso-immunization • Administration of anti-D immune globulin in all Rh-negative mothers after abdominal trauma • Kleihauer-Betke test

24. Preterm labour and premature rupture of membranes • Consider and manage appropriately • Potential consequence of trauma during pregnancy; • Maternal injury or death • Fetal injury or death • Pregnancy complications • Any complications of trauma as in non-pregnant women

25. Influence of gestational age • First trimester – uterus protected in pelvis • Risk if maternal hypotension, serious pelvic injury (direct injury of fetus, uterus, placenta, uterine vessels)

26. Influence of trauma severity • Poor predictors of fetal outcome: maternal hypotension, non-reassuring fetal heart pattern, direct injury to the uterus/fetus, maternal death, maternal coma, high injury severity score • Highest risk – mother with life-threatening trauma: hypovolemic shock, coma, emergency laparotomy • Minor trauma < 5% pregnancy loss • Delivery remote from trauma – still significant risk of preterm birth, low birth weight, abruptio NB

27. Prevention • Prenatal care include education about correct seat belt use, evaluation for presence of domestic violence (begins/increase during pregnancy/peripartum) • Lap belt - under uterus, over middle portion of clavicle • Decreased force transmission through uterus • Airbags safe. Sternum 10cm away from dashboard or steering wheel containing airbag • Multiple tools to detect presence of domestic violence, substance abuse • Additional risk factors: young age, drug or alcohol use

28. Summary and Recommendations • Anatomic and physiological changes related to pregnancy impact the evaluation and management of the pregnant trauma patient • Initial evaluation – stabilize mother • Treatment and diagnostic imaging as needed • Displace uterus to the left • Empty uterus to save mother’s life

29. Summary and Recommendations • After excluding catastrophic trauma, determine whether obstetric complications. Important symptoms: contractions, vaginal bleeding, abdominal pain • Abruptio irrespective of severity of trauma • Fetal viability – monitoring and uterine monitoring for signs of preterm labour and abruption (continuous for 4 hrs, then up to 48hrs) • Anti-D immune globulin administration to unsensitized Rh-negative women after abdominal trauma • Screen for domestic violence

30. Thank you