Trauma and Pregnancy

OVERVIEW

• leading cause of non-obstetric maternal mortality -> also has a high chance of fetal loss
• ATLS approach (primary and secondary survey) including safe transport to trauma centre with obstetric care.
• 80% of women who survive haemorrhagic shock experience fetal death

Additional issues:

• anatomical and physiological changes of pregnancy
• pregnancy specific complications
• foetal issues

ANATOMICAL AND PHYSIOLOGICAL CHANGES IN PREGNANCY

Airway

• aspiration risk
• potentially difficult intubation (narrow airway, oedematous, bleeds easily, increased risk of CICV)
• may require: RSI with skilled staff, in-line stabilisation and have DA equipment

Breathing

• smaller FRC due to gravid uterus, high O2 consumption -> decreased apnoeic supply
• physiological respiratory alkalosis, with comp metabolic acidosis -> a PaCO2 of 35-40 may already indicate respiratory failure
• give additional high flow oxygen – target higher SaO2 due to fetal requirements
• if intubated – controlled ventilation
• fetus may not tolerate permissive hypercapnoea due to increasing acidosis

Circulation

• physiologically lower SBP and DBP, lower SVR, increased HR and increased CO – must be taken into account on evaluation
• physiologic anaemia and increased blood volume – may lose 1.2 – 1.5 L of blood volume before showing signs of hypovolaemia
• avoid aortocaval compression syndrome – keep in L lateral position or manually displace the uterus
• Rh compatible transfusions. Rh neg mothers will need Ig for the immunological risk of fetomaternal haemorrhage -> – Rh Ig for all Rh D negative women within 72 hours
• ECG changes: L axis, flat or inverted T waves, ectopics
• FAST scan/USS can be difficult c/o gravid uterus
• give blood early

Others

• radiology: remember foetal exposure but do what needs to be done (more care in first trimester)
• uterus is extra-pelvic from week 12
• cephalad movement of bowel

PREGNANCY SPECIFIC ISSUES

• monitor baby (CTG)
• place chest drains slightly higher than normal c/o cephalad movement of diaphragm
• Kleihauer-Betke test can detect fetal blood in maternal circulation (can estimate volume of transplacental haemorrhage)
• look for: retroperitoneal haemorrhage / placental abruption / foetal distress / premature labour / AFE / DIC / uterine rupture
• pelvic binders in pelvic fracture may be unsuitable

FOETAL ISSUES

• Call for help early – O&G, paeds and anaesthetics
• continuous foetal monitoring with CTG (depending on gestational age, > 20 weeks)
• intrauterine resuscitation: foetal oxygenation dependent on mothers oxygenation/ventilation and CO / uterine perfusion
• maternal compensation for blood loss is at the expense of uteroplacental flow

References and Links

LITFL

• Trauma Tribulation 006 — Trauma And Pregnancy
• Trauma Tribulation 007 — Trauma and Pregnancy Redux