In addition to management by a trauma team following EMST principles, this case requires additional early obstetric, neonatal and anaesthetic input. The operating theatre needs to be alerted to the possibility of the need for emergency Caesarian section. In an elderly primigravida this is likely to be a ‘precious’ pregnancy.
Other specific management issues include:
- High-flow oxygen to avoid maternal and fetal distress.
- Reduced maternal respiratory reserve with decreased FRC.
- Potential for relative difficulty in intubation
- Maternal compensation for blood loss is at the expense of utero-placental blood flow.
- Left lateral tilt to avoid aorto-caval compression.
- Transfusion should be Rhesus compatible and immunoglobulin should be given if she is Rhesus negative because of the immunological effects of minor feto-maternal haemorrhage.
- Physiological anaemia of pregnancy
- Minimise exposure to radiation – ultra-sound alternatives may be preferable. (DPL contra-indicated).
- Retroperitoneal haemorrhage, placental abruption or fetal distress may occur and premature labour may be precipitated.
- If pelvic fractures present, pelvic binders may not be suitable.
- Regular fetal monitoring is required.
- Bereavement issues in the event of an adverse fetal outcome
Some candidates wrote about trauma management in general and/or did not address the issues of abdominal trauma and hypotension in a pregnant patient.
- Airway issues
- The airway is more difficult to control.
- There is an increased risk of aspiration due to decreased gastric emptying and weakened lower oesophageal sphincter.
- Respiratory issues
- The respiratory function is impaired by decreased FRC;
- One needs to insert their chest drains higher, so as to avoid the pushed-up diaphragms
- When setting up the ventilator, one needs to keep in mind that the PaCO2 is supposed to be 30mmHg in late pregnancy.
- Circulatory issues
- The total blood volume has expanded, the cardiac output is high, and thus signs of shock will develop late.
- Vena cava compression means the patient needs to be positioned at a 30° tilt
- Neonatal and foetal welfare
- Pelvic binders are inappropriate
- Pelvic fractures may threaten the near-term foetus
- Placental abruption may result in massive haemorrhage and needs to be excluded early in the primary survey
- Foetal heart rate monitoring is essential
- Early transfer to an O&G-equipped hospital is essential
- Retroperitoneal haemorrhage from dilated pelvic veins can be difficult to assess without ultrasound
- A vaginal examination needs to be performed, looking for amniotic fluid. A pH of 7.0-7.5 will confirm this - the normal vaginal pH is much lower than that - but there are more scientific methods. A reader has pointed out that, in fact, most obstetric services would have a rapid test for premature rupture of membranes such as the Actim PROM. This specific test is based on is based on monoclonal antibodies to the insulin-like growth factor binding protein-1 (IGFBP-1) which is present in amniotic fluid (and in virtually nothing else).
- Transfusion and general haematology issues
- Rhesus-negative mothers need to receive IV immunoglobulin at least within 48 hours of the trauma
- Transfusion needs to be Rh compatible
- The pregnant trauma patient is in an even more hypercoagulable state than the normal trauma patient, and thus requires special attention to DVT prophylaxis
- Drug choices
- Antibiotic choices are limited; tetracyclines and fluoroquinolones are to be avoided
- If urgent caesarian delivery is planned, intubation drugs wil affect the foetus; thus there is need for NICU involvement for ventilation
Issues to consider in investigations and the secondary survey
- The usual barrage of blood tests remains unchanged.
- FBC, EUC, CMP LFT coags and crossmatch get sent away just as they would in any trauma patient, but the savvy candidate will mention the need for Rh blood grouping to prevent Rh isoimmunisation (where the mother is Rh negative and the foetus is Rh positive). An administration of anti-Rh IVIG can mop up any Rh-positive foetal erythrocytes which might have haemorrhaged into the maternal circulation, preventing the mother from developing her own anti-Rh antibodies (and thus preventing the haemolytic disease of the newborn). To detect foetomaternal haemorrhage, one might want to send the Kleihauer-Betke test, which looks for hfoetal haemoglobin.
- An abdominal ultrasound (FAST) is still performed, with additional focus on the uterus; uterine rupture or placental abruption need to be detected early.
- Foetal welfare can be monitored by CTG, and the O&G specialist should be invited to perfrom their own focused ultrasound to investigate the pregnancy.
- Though radiation exposure is undesirable, it is tolerated (particularly in late term pregnancy) because organogenesis has already taken place, and because the risk from ionising radiation exposure is minute in comparison to the risk of missed injuries and haemorrhage.