Blunt Trauma In Pregnancy

BLUNT TRAUMA IN PREGNANCY

AUTOMOBILE ACCIDENTS

Trauma affects 6-7% of pregnancies in the U.S. 60 - 67% related to automobile accidents.

Fetal mortality after maternal blunt trauma is 34 - 38%. The two major causes of fetal death after maternal blunt trauma are: Maternal shock/death, and placental abruption.

The pregnant trauma patient presents a unique challenge because care must be provided for two patients, the mother and the fetus. It is vital that the nurse know and understand the anatomical and physiological changes that occur during pregnancy. She must be aware of these changes, and how they can mask or mimic injury, and very importantly that fetal distress or loss can occur even when the mother has incurred no abdominal injuries.

Regardless of the apparent severity of injury in blunt trauma, all pregnant women should be evaluated in a medical setting.

Only viable fetuses are monitored, because no obstetric intervention will alter the outcome of a pre-viable fetus. Determination of fetal viability is subject to institutional variation: an estimated gestational age of 20 - 26 weeks and an estimated fetal weight of 500g. Are commonly used thresholds of viability. Therefore, patients who have minor trauma and who are at less than 20 weeks gestation do not require specific intervention or monitoring. All pregnant women beyond 20 weeks' gestation should undergo a minimum of 4 - 24 hours, and in some cases as long as 48 hours of monitoring. Fetal distress may be the first sign of maternal hemodynamic compromise and fetal distress, and to identify possible placenta abruption.

Resuscitation of the more serious trauma patient must focus on the mother because the most common cause of fetal death is maternal shock or death. It is important to remember that the mother will maintain her vital signs at the expense of the fetus. Because plasma volume is increased by 50% and the mother is able to shunt blood away from the uterus, maternal shock may not manifest itself until maternal blood loss exceeds 30%.

Initial ABC assessment:

Airway and breathing: All pregnant trauma patients should receive supplemental oxygen, because the fetus is extremely sensitive to hypoxia and because the oxygen reserve is significantly diminished in the pregnant patient.

Because the heavy uterus may compress the great vessels when a pregnant women is supine, causing a decrease in blood pressure, thus a decrease in stroke volume, and consequently a decrease in uterine blood flow, the patient should be placed on her side, if she must lay supine, place a small pillow under one hip, this will tilt the uterus off the inferior vena cava, improving blood flow throughout the woman's body and to the placenta.

Survival of the fetus depends on adequate uterine perfusion and delivery of oxygen. Uterine circulation has no auto-regulation system, uterine blood flow is directly related to maternal blood pressure. To maximize uterine perfusion and oxygenation to the fetus supplemental oxygen and IV fluids are administered and continued until hypovolemia, hypoxia, and fetal distress resolve.

In general, pregnancy does not affect the decision to intubate, although the risk of aspiration is increased - related to decreased gastric tone, delayed gastric emptying, and cephalad displacement of intra-abdominal organs. The use of medications for rapid-sequence intubation in pregnancy is not will studied, however no absolute contraindications exist.

If a chest tube is placed, enter the chest 1 or 2 interspaces higher than usual, because the diaphragm is elevated during pregnancy.

Circulation:.

Rule out occult sources of bleeding, because maternal blood flow is maintained at the expense of fetal blood flow.

If blood is needed on an emergency basis, use Rh-negative blood unless the patients's Rh status is known.

After initial stabilization, other maternal injuries are evaluated, and fetal heart tones are assessed by Doppler or ultrasonography.

Secondary assessment

Physical:

The findings of the physical examination in the pregnant woman with blunt trauma are not reliable in predicting adverse obstetric outcomes. Nurses must be aware of pregnancy induced physiologic changes when making assessments. For example, The pregnant woman's blood volume increases to provide exchange of nutrients, oxygen and waste products within the placenta and as a reserve for blood loss at birth. Therefore maternal blood pressure does not accurately reflect uterine perfusion or fetal injury. Pregnant women can lose up to 30% (2L) of their blood volume before their vital signs change. The nurse must also recognize that significant blood loss can occur in the uterine wall or retroperitoneal space without external bleeding.

Compared with nonpregnant persons who experience trauma, pregnant women have a higher incidence of serious abdominal injury but a lower incidence of chest and head injuries. Maternal pelvic fractures, particularly in late pregnancy, are associated with bladder injury, urethral injury, retroperitoneal bleeding, and fetal skull fracture. After 12 weeks of gestation, the maternal uterus and bladder are no longer exclusively pelvic organs and are more susceptible to direct injury.

Abdominal examination:

.Inspect for ecchymosis, especially across the lower abdomen, which may indicate a possible seatbelt injury.

Palpate for uterine contractions or tenderness. Occasional uterine contractions are the most common finding after trauma in pregnant women. In 90% of the cases this usually resolves within a few hours. Note that because of peritoneal stretching in the third trimester decreases the density of afferent pain fibers, abdominal tenderness may be masked.

Sterile speculum examination:

Perform these in the absence of vaginal bleeding:

Test the fluid for pH and ferning. A pH of 7 indicates amniotic fluid. Vaginal secretions are more acidic, with a pH around 5.

Examine for vaginal lacerations, or bone fragments, which signify and