Tag Archives: pregnancy

Trauma In Pregnancy 1: Introduction

February 13, 2017 The Trauma Pro Leave a comment

Trauma in the pregnant patient is scary, but thankfully not very common. About 1 in 15 pregnant women sustain some type of significant injury. About half are from car crashes (most commonly if unrestrained), and 25% each are from assault (frequently domestic) and falls. Unfortunately, trauma is the leading cause of non-obstetric fetal death.

What makes this type of trauma problematic is two-fold, literally. First, you have two patients. And second, neither one has “normal” physiology. The mother has made numerous adaptations to accommodate the pregnancy, and the fetus is essentially a small parasite, totally dependent on her.

Let’s look at the impact of some of the more important maternal adaptations:

Total blood volume increases by about one liter. This would seem to be good, but since it is mainly dilutional with no real increase in total RBCs, and this is coupled with a lower mean blood pressure. Trauma professionals can easily underestimate blood loss.
Going into the third trimester, the uterus can compress the IVC when the mother is lying supine. but it is quite frequently forgotten. One of the first maneuvers when you suspect an advanced pregnancy is to bump the patient to her left. Do this even if the blood pressure is normal.
The pelvic veins are huge. Disruption from pelvic fractures or penetrating injury can lead to massive bleeding.
The stomach is probably full, and under pressure from below. This increases aspiration risk in women who have decreased mental status or need intubation.

And don’t forget the fetus:

The fetal/placental/uterine complex is one large, non-compressible unit with multiple shear planes within it. Blunt force will stress those planes, and may result in disruption of the uterus from pelvic veins (massive bleeding), or separation of the placenta from the uterus (abruption).
The fetus is totally dependent on the mother for survival, but the placenta will protect the mother first, shutting down fetal circulation if she becomes hypotensive or hypoxic.
The baby was designed to come into this world at full term. We have developed the technology to sustain life in smaller and more premature babies. The magic number of weeks keeps slowly decreasing, but preemie survival without complications is a challenge.

Tomorrow, we’ll move on and get to the fun stuff, predicting outcome after trauma in pregnancy.

Pharmacy

Enoxaparin And Pregnancy

July 15, 2016 The Trauma Pro Leave a comment

Pregnant women get seriously injured, too. And pregnancy is an independent risk factor for deep venous thrombosis. We reflexively start at-risk patients on prophylactic agents for DVT, the most common being enoxaparin. But is it safe to give enoxaparin during pregnancy?

Studies have looked at drug levels in cord blood when the mother is receiving enoxaparin, and none has been found. No specific bleeding complications have been identified, either. So from the baby’s standpoint, administration is probably safe.

However, there are two other issues to consider. In a study looking at the use of enoxaparin for prophylaxis in women with a mechanical heart valve, 2 of 8 women (and their babies) died. Both suffered from clots that developed and blocked the valves. Most likely, the standard dose of enoxaparin was insufficient, so monitoring of anti-Factor Xa levels must be done.

The other problem lies in the multi-dose vial of Lovenox (Sanofi-Aventis). Each 100mg vial contains 45mg of benzyl alcohol, which has been associated with a fatal “gasping syndrome” in premature infants. The individual dose syringes do not have this preservative.

Bottom line: It is probably safe to give enoxaparin to pregnant women after trauma. However, it is unclear if the dose needs to be increased to achieve adequate prophylaxis. Only consider using this medication after consultation with the patient’s obstetrician, and use only the individual dose syringes. Otherwise fall back to standard subcutaneous non-fractionated heparin (even though it is a Category C drug by FDA; it is still considered the anticoagulant of choice during pregnancy).

General