UBP 5.2 (Short Form): Trauma – Obstetric Patient

Question 1

The mother is brought into the trauma suite. How is your management changed by the fact that she is pregnant?

(A 5’3”, 102 kg, 24-year-old, pregnant female (G1P0) at 36 weeks gestation is brought to the trauma suite following a motor vehicle accident. She is alert, oriented, and complaining of abdominal pain and a headache. The EMTs inform you that she hit her face on the passenger side dash when her husband rear-ended another car at about 45 miles/hour. She has not had any prenatal care and reports a history of Spina Bifida. There is a 20G IV in her right arm. Vital Signs: P = 124, R = 24, BP = 156/96 mmHg, O2 sat = 98% on non-rebreathing mask)

Answer 1

The primary goal in managing the pregnant patient is to resuscitate and stabilize the other, not only because she is the primary patient, but also because this is the most effective method for optimizing the baby’s condition.

However, recognizing that there are unique concerns associated with the pregnant patient, I would:

1. ensure left uterine displacement, keeping in mind the importance of maintaining inline stabilization of her neck during displacement
   
   • (LUD is indicated beginning at 18-20 weeks gestation);
2. recognize that the anatomic and physiologic changes of pregnancy increase the risk for –
   
   • difficult airway management, pulmonary aspiration, and thromboembolic events (once any acute coagulopathy is resolved);
3. include monitoring for fetal heart rate and uterine contractions;
4. evaluate the patient for signs of ruptured membranes, uterine rupture, and placental abruption
   
   • (signs and symptoms consistent with the last two include abdominal pain, vaginal bleeding, hypotension, and fetal compromise);
5. consider the fetal affects of narcotics and ionizing radiation; and
6. prepare for the necessity of urgent/emergent delivery of the baby, should the baby or the mother remain unresponsive to resuscitation.

Question 2

What is Rhesus isosensitization?

(A 5’3”, 102 kg, 24-year-old, pregnant female (G1P0) at 36 weeks gestation is brought to the trauma suite following a motor vehicle accident. She is alert, oriented, and complaining of abdominal pain and a headache. The EMTs inform you that she hit her face on the passenger side dash when her husband rear-ended another car at about 45 miles/hour. She has not had any prenatal care and reports a history of Spina Bifida. There is a 20G IV in her right arm. Vital Signs: P = 124, R = 24, BP = 156/96 mmHg, O2 sat = 98% on non-rebreathing mask)

Answer 2

Rhesus isosensitization occurs when delivery, miscarriage, abortion, amniocentesis, ectopic pregnancy, abdominal trauma, or external cephalic version leads to the entrance of blood from an Rh-positive baby into the circulation of an Rh-negative mother, resulting in the maternal production of IgG antibodies against the Rhesus D antigen on the baby’s red blood cells.

The passage of these IgG antibodies across the placenta can lead to Rh-disease (ranging from mild anemia to hemolytic disease of the newborn, hydrops fetalis, or stillbirth) in the current or subsequent pregnancies involving an Rh-positive fetus.

Rhesus isosensitization can be prevented by administering anti-Rh antibodies (RhoGAM) to the mother within 72 hours of a potentially sensitizing event (delivery, trauma, etc.), thereby destroying fetal Rhesus D positive erythrocytes before a maternal immune response occurs (the injected anti-Rh antibodies are removed from the maternal circulation over time).

Therefore, given this patient’s abdominal trauma, I would discuss with the obstetrician the benefits of administering RhoGAM and performing a Kleihauer-Betke test to detect and quantify the extent of fetomaternal hemorrhage (depending on the amount of fetal blood found in the maternal circulation, additional doses of RhoGAM may be required).

• Clinical Note:*
• Rh-negative mothers routinely receive RhoGAM at 28 weeks gestation, and within 72 hours after delivery. This is not necessary if the father is known to be Rh-negative (since the baby could not be Rh-positive if neither father nor mother were Rh-positive).

Question 3

Given the risk of ionizing radiation exposure to the baby, do you think a CT scan is a good idea?

(A 5’3”, 102 kg, 24-year-old, pregnant female (G1P0) at 36 weeks gestation is brought to the trauma suite following a motor vehicle accident. She is alert, oriented, and complaining of abdominal pain and a headache. The EMTs inform you that she hit her face on the passenger side dash when her husband rear-ended another car at about 45 miles/hour. She has not had any prenatal care and reports a history of Spina Bifida. There is a 20G IV in her right arm. Vital Signs: P = 124, R = 24, BP = 156/96 mmHg, O2 sat = 98% on non-rebreathing mask)

Answer 3

While there are concerns about radiographic procedures leading to radiation-induced teratogenesis, the benefits to the mother of appropriate imaging usually outweigh the minimal risk to the baby.

Moreover, this risk is most significant during the first trimester and with higher levels of exposure than are typically experiened during most imaging procedures.

Concerns about ionizing radiation notwithstanding, the decision to proceed with CT scanning would more likely be based on the stability of the mother and the risks of interrupting ongoing resuscitation for the procedure, especially if it involves transferring the patient to a remote location.

While lack of fetal radiation exposure makes magnetic resonance imaging a desirable choice, the procedure takes much longer to perform than does a CT scan and would, therefore, only be appropriate for a patient that would tolerate an even longer period of interrupted resuscitation.

Question 4

She appears to be in significant pain from her abdomen discomfort, facial trauma, and possibly some rib fractures. What would you do about her pain?

(A 5’3”, 102 kg, 24-year-old, pregnant female (G1P0) at 36 weeks gestation is brought to the trauma suite following a motor vehicle accident. She is alert, oriented, and complaining of abdominal pain and a headache. The EMTs inform you that she hit her face on the passenger side dash when her husband rear-ended another car at about 45 miles/hour. She has not had any prenatal care and reports a history of Spina Bifida. There is a 20G IV in her right arm. Vital Signs: P = 124, R = 24, BP = 156/96 mmHg, O2 sat = 98% on non-rebreathing mask)

Answer 4

Recognizing that her pain could lead to pulmonary splitting (rib fractures) and reduced uteroplacental blood flow (increased circulating catecholamines; respiratory acidosis secondary to splitting),

I would attempt to control her pain utilizing intercostal nerve blocks for any identified rib fractures and the careful titration of intravenous narcotics (narcotic-induced respiratory depression must be avoided).

Moreover, I would make the obstetrician aware of any narcotic administration, so that narcotic-induced depression of fetal heart rate variability could be taken into account when interpreting the FHR tracing.

Finally, considering the effects of NSAIDs on platelet function and the fetal ductus arteriosus (should be avoided in the second half of pregnancy), I would avoid using these drugs for this pregnant patient who is at increased risk for coagulopathy secondary to occult blood loss, hypotension, significant tissue damage, uterine rupture, placental abruption, or hypothermia.

• Clinical Note:*
• Normal FHR variability, which develops around the 25^th to 27^th week of gestation, is suggestive of a normally functioning autonomic nervous system and fetal well being; absent or persistently minimal FHR variability appears to be the most significant intrapartum sign of fetal compromise. However, various factors may cause or contribute to decreased FHR variability, such as – fetal hypoxia, fetal sleep state, prematurity, fetal neurologic abnormalities, fetal tachycardia, betamethasone administration, congenital anomalies, and/or the administration of central nervous system depressants such as opioids, barbiturates, magnesium sulfate, and benzodiazepines.

Question 5

Irregular uterine contractions and significant vaginal bleeding are noted during the primary survey. The obstetrician wants to transfer her to the obstetric suite for cesarean section. The trauma team has yet to obtain additional IV access, clear her neck, or get a CT of her head. The patient appears to be stable and the obstetrician wants to transfer her now. What would you say?

(A 5’3”, 102 kg, 24-year-old, pregnant female (G1P0) at 36 weeks gestation is brought to the trauma suite following a motor vehicle accident. She is alert, oriented, and complaining of abdominal pain and a headache. The EMTs inform you that she hit her face on the passenger side dash when her husband rear-ended another car at about 45 miles/hour. She has not had any prenatal care and reports a history of Spina Bifida. There is a 20G IV in her right arm. Vital Signs: P = 124, R = 24, BP = 156/96 mmHg, O2 sat = 98% on non-rebreathing mask)

Answer 5

Considering her vaginal bleeding and the possibility of uterine rupture or placental abruption, I would agree to the transfer as soon as adequate intravenous access could be established.

The potential for significant occult blood loss and massive hemorrhage would make transferring this patient without sufficient intravenous access very dangerous (one 20G IV is inadeqate in the setting of rapid blood loss from uterine rupture or placental abruption), especially since the establishment of intravenous access would become increasingly difficult with worsening hypovolemia.

Moreover, if possible, I would delay the transfer until the primary survey could be completed (Airway, Breathing, Circulation, Disability, Exposure).

Finally, I would be continuously monitoring the fetal heart rate and uterine contractions throughout the process, as deterioration in the baby’s status would affect my management of the situation.

While clearance of her cervical spine and a head CT would potentially be beneficial, I would not delay an emergent cesarean section for these interventions.

Question 6

The patient is being transferred to the obstetric suite for urgent cesarean section. Would you encourage her to hyperventilate during transport?

(A 5’3”, 102 kg, 24-year-old, pregnant female (G1P0) at 36 weeks gestation is brought to the trauma suite following a motor vehicle accident. She is alert, oriented, and complaining of abdominal pain and a headache. The EMTs inform you that she hit her face on the passenger side dash when her husband rear-ended another car at about 45 miles/hour. She has not had any prenatal care and reports a history of Spina Bifida. There is a 20G IV in her right arm. Vital Signs: P = 124, R = 24, BP = 156/96 mmHg, O2 sat = 98% on non-rebreathing mask)

Answer 6

Despite the fact that she is complaining of a headache following head trauma, I would NOT recommend hyperventilation unless I thought her intracranial pressure (ICP) was elevated enough to place her at risk for brain stem herniation and other methods of ICP reduction proved unsuccessful.

While hyperventilation to a CO2 of 25-30 mmHg may be helpful in reducing intracranial pressure, it can also exacerbate cerebral ischemia by inducing cerebral vasoconstriction.

Moreover, hyperventilation can lead to reduced maternal cardiac output, decreased blood pressure, and increased uteroplacental vasoconstriction, all of which may result in compromised uteroplacental blood flow, placing the baby at increased risk.

Therefore, I would preferentially employ other methods of ICP reduction, always keeping in mind that the mother is my primary patient and that optimizing her condition is the most effective way to maintain the health of the baby.

Question 7

Can you explain the difference between spina bifida occulta and spina bifida cystica?

(A 5’3”, 102 kg, 24-year-old, pregnant female (G1P0) at 36 weeks gestation is brought to the trauma suite following a motor vehicle accident. She is alert, oriented, and complaining of abdominal pain and a headache. The EMTs inform you that she hit her face on the passenger side dash when her husband rear-ended another car at about 45 miles/hour. She has not had any prenatal care and reports a history of Spina Bifida. There is a 20G IV in her right arm. Vital Signs: P = 124, R = 24, BP = 156/96 mmHg, O2 sat = 98% on non-rebreathing mask)

Answer 7

Spina bifida occulta describes a condition where there is abnormal or incomplete formation of the midline structures over the back without herniation of meninges or neural elements.

Spina bifida cystica, on the other hand, describes a condition where failed fusion of the neural arch is associated with herniation of the meninges alone (meningocele) or both the meninges and neural elements (myelomeningocele).

Spina bifida occulta occurs in 5-36% of the population, usually affects a single vertebra (typically L5 or S1), remains asymptomatic, and does not involve underlying spinal cord anomalies.

Rarely, the abnormality is more extensive, involving more than one vertebra.

This variant, sometimes referred to as occult spinal dysraphism, is often associated with:

1. cutaneous manifestations over the site of the defect (i.e. tuft of hair, skin dimple, hyperpigmented area, and cutaneous lipoma);
2. underlying spinal cord abnormalities, such as tethered cord (abnormal attachment of the spinal cord to a structure in the lumbar spine; associated with a low-lying conus medullaris);
3. neurologic deficits of the lower limbs, bladder, and bowel; and
4. scoliosis.

A meningocele, the most rare form of spina bifida cystica, is usually asymptomatic and associated with a normal spinal cord.

A myelomeningocele, however, is often associated with a tethered cord, hydrocephalus, scoliosis, and neurologic deficits of the lower limbs, bladder, and bowel.