Managing the injured pregnant trauma patient can be anxiety inducing, as one needs to manage two patients at once amidst the altered physiology of pregnancy. The good news is that there are more similarities than differences when managing a pregnant trauma patient. Trauma in pregnancy is surprisingly common, affecting 7% of all pregnancies. This means that if you work in an Emergency Department, you will manage an injured pregnant patient at some point. Trauma is responsible for the highest number of maternal deaths when obstetric causes are excluded. In most countries, motor vehicle accidents are the commonest type of trauma, and are also responsible for the highest number of fetal deaths. Intimate partner violence, is the second most common cause, which we should always be careful to exclude in women presenting following trauma to the ED.
So how do we look after our two patients? Is it double the trouble? It’s a big topic which will be split over three posts. First, let’s begin with resuscitation of the severely injured pregnant trauma patient.
How would you manage this case?
A young woman, in her second trimester of pregnancy, presents following an motor vehicle collision. She was not wearing a seatbelt. She arrives in the ED brought by basic life support crew, who have immobilised her on a spine board. She is diaphoretic, tachypnoiec and appears grey. She is alert but anxious, complaining of chest and abdominal pain. Initial vitals are: Sats 82% on room air, HR 120 BPM, BP 80/60.
You need a multi-disciplinary team. Call for help early.
The principles of major trauma resuscitation still apply. Manage her initially as you would manage any other critically injured patient. The primary survey focuses on identifying life threatening injuries and complications and managing them.
Resuscitate the mother as your priority. All resuscitative efforts are focused on her initially, regardless of the gestational age of the fetus. Improving the mother’s oxygenation and perfusion will improve fetal oxygenation and perfusion.
The pregnant trauma patient is a physiologically and anatomically difficult airway. Prepare well and be meticulous.
Administer supplemental oxygen if required, aiming for oxygen sats of 95-98%.
Fetal loss is high when maternal shock is present. Identify the cause of the maternal shock and treat. Obtain good vascular access and activate your massive transfusion protocol early. Administer O negative blood until the mother’s Rh status is known to avoid Rhesus iso-immunisation.
The pregnant patient has an increased circulating blood volume. This means that she loses more of her blood volume to manifest hypotension than if she were not pregnant. It is easy to underestimate blood loss in a pregnant patient. Hypotension in the pregnant trauma patient is end-stage shock.
Pregnant women were excluded from trials studying the efficacy of Tranexamic acid (TXA) in trauma patients. It classified as a category B drug in pregnancy, meaning that no animal studies have shown adverse outcomes with its use, but no human studies exist. TXA crosses the placenta. Despite the lack of published research, TXA may be of benefit in bleeding, seriously injured pregnant patients.
The management of haemorrhage is to stop the haemorrhage. The indications for operative control of bleeding still apply to pregnant trauma patients as they do to non-pregnant patients. Pelvic fractures can bleed heavily due to the engorged pelvic veins. Signs of peritonism can be unreliable in pregnancy, so have a low threshold to investigate abdominal pain further.
Shock should always be considered due to haemorrhage first, but bear in mind the presence of aortocaval compression by the uterus and its effects on the mother’s haemodynamics. After 20 weeks of pregnancy, the IVC is commonly compressed by the uterus, and the aorta may be compressed in severe cases. This can cause a 20% drop in SV and Cardiac output, reducing perfusion to maternal organs, especially the placenta. This reduction in perfusion may be critical in an injured patient. Furthermore, the fetus may be hypoxic due to reduced placental perfusion even though the mother may appear normotensive. Remember to perform manual uterine displacement in all pregnant trauma patients over 20 weeks gestation.
Avoid vasopressors wherever possible. They are associated with worse outcomes in all trauma patients. Furthermore, they produce vasoconstriction of the placental bed, increasing the risk of fetal hypoxia.
Traditionally it is recommended to tilt the patient left lateral. This can be difficult to accomplish while resuscitative measures are underway.
An easier way is to keep her supine, and displace the uterus off the IVC, by either pulling the uterus from the left, or standing on the right side and pushing the uterus towards the left. Pushing from the right side is easier to do than pulling from the left, especially if it needs to be done for long periods.
The gravid uterus displaces the diaphragm upwards. Intercostal catheters should therefore be placed 1-2 intercostal spaces higher than normal to avoid inadvertent intra-abdominal placement.
Injured pregnant women should never be denied adequate analgesia. Opiates are safe in pregnancy. Anti-tetanus toxoid is also safe in pregnancy.
As soon as feasible, an obstretic ultrasound should be done to determine to determine fetal viability. The gestational age at which the fetus is considered viable varies between countries: most guidelines consider viability from 23-24 weeks. In LMICs, fetal viability may be considered to be more than 28 weeks, depending on the available resources to look after preterm infants.
If the gestational age is below than 23-24 weeks, no external fetal monitoring is advised, and further management is focused on optimising the mother. If the gestational age is more than 24 weeks, cardiotocographic monitoring is advised to monitor fetal well-being and to monitor for uterine contractions, provided that monitoring does not interfere with maternal resuscitation and care.
Resuscitative hysterotomy is indicated in cardiac arrest and should be done as soon as possible to ensure the best outcome to the mother and fetus. It is primarily done to improve return of spontaneous circulation in the mother by improving venous return and cardiac output by eliminating aortocaval compression by the gravid uterus. It also improves pulmonary mechanics by reducing pressure on the diaphragm by the abdominal contents and reduces oxygen demand. Resuscitative hysterotomy should therefore be considered from 23 weeks gestation. If there is no time to obtain an accurate gestation, feel for the height of the uterine fundus. If it is above the umbilicus, the fetus is more than 20 weeks gestation.
Principles of major trauma resuscitation still apply.
Resuscitation and stabilisation of the mother always takes priority over fetal well-being. Fetal outcome can be optimised with good maternal resuscitation.
Perform manual uterine displacement in pregnant trauma patients over 20 weeks.
In viable pregnancies, perform external fetal monitoring.
Consider resuscitative hysterotomy in patients more than 23 weeks gestation.