Handling an on-call emergency

The information gives you pause, but you believe you can handle it with some changes in the usual trauma protocol.

“Call the Ob/Gyn, get extra shielding for the patient for X-rays, make sure the backboard is tilted 15 degrees to the left, and I’ll be right there,” you say.

Trauma is a leading cause of death and a frequent cause of injury during pregnancy, affecting 8 percent to 10 percent of all pregnancies. Prompt and effective resuscitation of the pregnant patient is the most effective way to prevent injury to the fetus. Changes in maternal physiology such as increased blood volume, cardiac output, minute ventilation, and decreased lung volume affect her response to traumatic injury. Often the increase in circulating volume will obscure signs of shock, increasing the risk of delay in resuscitation.

Overall, however, the general principles of assessing a trauma patient should be followed. During the primary survey, the emergency department physician should carefully assesses the patient’s airway, remembering that increased edema can obscure the vocal cords and that decreased gastric tone increases the risk of aspiration.

Because both mother and fetus have increased oxygen demands, a nasal cannula should be used to provide oxygen and an anesthesia team should be on standby if early intubation is needed. Two large-bore intravenous lines should be inserted and fluid replacement initiated.

If the obstetrician confirms good fetal heart rate and movement on ultrasound, fetal monitoring throughout assessment and surgery should continue because the fetus is viable (more than 24 weeks intrauterine pregnancy). The fetal heart rate will increase before the maternal vital signs, so fetal monitoring can help to detect shock response in both the fetus and the mother.

Aortocaval compression can contribute to hypotension, especially if the pregnancy has progressed beyond 20 weeks. Tipping the backboard to the left helps relieve some of this pressure until the mother can be safely moved into the left lateral decubitus position.

Immediate treatment
A secondary survey shows that the mother’s left tibiofibular fracture is grade 2 open, which is quickly dressed and splinted. An intra-articular injection of lidocaine can be used prior to relocating and reducing the ankle.

Well-monitored conscious sedation for fracture reduction in a pregnant woman is reasonable; midazolam (Versed), however, should not be used because it has been shown to be a teratogen in animal models. Lidocaine is a safe medicine during pregnancy and an intra-articular injection for closed ankle fracture reductions has been shown to be as efficacious as conscious sedation.

Issues with imaging
Although radiographic evaluation of the pregnant patient raises concerns about potential fetal exposure, necessary imaging studies should be obtained when evaluating an acutely injured patient. Both medical literature and radiation safety organizations recommend a total dose of no more than 5 rad for pregnant women. Radiation exposure can be reduced using general principles of radiation safety. Ordering only necessary testing will protect both mother and fetus.

The greatest risk to the fetus from radiation exists early during the pregnancy, during organogensis (weeks 2–8) and neural tube development (up to week 15). After week 25, the fetal central nervous system and all organ systems are relatively radioresistant, but the necessity of every radiographic study ordered should be considered.

Initial radiographic assessment of all trauma patients—including pregnant women—should include imaging of the cervical spine, chest, and pelvis. Computed tomography (CT) studies of the abdomen, pelvis, and lumbar spine should be obtained only if absolutely necessary, because these studies subject the fetus to the highest degree of radiation.

Because maternal head injury is one of the leading causes of maternal death and because a CT of the head generates only 1 rad of exposure with proper shielding, this should be done as needed. Collimation, shielding, and using alternatives to X-ray-based imaging (when available) will reduce radiation exposure to the fetus. Ultrasonography and magnetic resonance imaging (MRI )can be used when appropriate and provide no ionizing radiation to mother or fetus.

With regard to contrast, radiation-labeled and gadolinium contrasts are contraindicated, but iodinated contrast is relatively safe. Positioning the extremities away from the body for imaging will have a significant impact on radiation dose, particularly if CT of an extremity is absolutely necessary.

During procedures, fluoroscopy should be used judiciously. The image intensifier should be as close to the patient as possible to minimize radiation dose. The surgeon should be prepared to use bone plates if multiple fluoroscopy images would be required for fracture reduction and intramedullary nailing.

In the operating room
Published literature supports deferring elective orthopaedic or other procedures until the post-partum period. Reducing a grade 2 open tibiofibular fracture, however, is not an elective procedure.

Although general anesthesia is low-risk for the pregnant patient, its use can result in issues of delayed gastric emptying, edema that can contribute to a more difficult intubation, and a slightly increased risk of spontaneous abortions and low birth weight. In studies to date, regional anesthesia has been found to be safe and effective.

The anesthesia team must meticulously record input and output, because the increase in circulating volume during pregnancy will obscure signs of shock and increase the risk of delay in resuscitation. They must also ensure that maintenance of oxygenation during the procedure remains a high priority, because functional reserve capacity (pulmonary reserve), is decreased in pregnancy.

Place the patient in the left lateral decubitus position on the operating table, with lead shielding both above and below her pelvis and abdomen. If the procedure cannot be performed with the patient in the lateral decubitus position, a bump or wedge can be placed under the right hip and the operating table tilted to the left to minimize aortocaval compression. Intraoperative mechanical prophylaxis can be used, with pregnant trauma patients who do not have bilateral injuries.

Antibiotic prophylaxis and analgesics
Patients, including pregnant women, with open fractures should receive intravenous cephazolin in the emergency department and postoperatively, in accordance with standard protocols. According to the U.S. Food and Drug Administration, cephalosporins are considered safe to use during pregnancy and dosing does not need to be adjusted. If the patient is allergic to penicillin, clindamycin can be used, also without dose adjustment. Gentamicin and penicillin could be used safely, but changes in dosing and dosing interval are required for the pregnant trauma patient.

Fetal monitoring should continue after surgery, assuming that both the patient and the fetus do well. Narcotic medications and acetaminophen are generally considered to be the safest pain medications to administer during pregnancy, but should be used in moderation. The patient can be discharged with a codeine derivative analgesic, such as hydrocodone. Non-steroidal anti-inflammatories should be avoided, due to the potential for birth defects and premature closure of the ductus arteriosus. Aspirin is also discouraged, because of the increased risk of bleeding.

Anticoagulation therapy
Because pregnancy is a relative hypercoagulable state, both prophylaxis and treatment of known thrombi should be undertaken with vigilance. If possible, mechanical prophylaxis should be used while the patient is hospitalized. Warfarin, which crosses the placenta and may contribute to teratogenicity, is not safe in the pregnant patient, and aspirin is not as effective as low molecular weight heparins. Low molecular weight heparin is reported to be a safe and effective option for prophylaxis and treatment in pregnancy.

No consensus exists regarding length of treatment in pregnant patients for the prevention of deep venous thrombosis (DVT) and pulmonary embolism; one prospective study of DVT prophylaxis in blunt trauma patients excluded pregnant patients from enrollment. Until the patient can mobilize well and for no less than 4 weeks, she should be treated with low molecular weight heparin. If DVT is suspected, ultrasound surveillance should be used.

Susan V. Bukata, MD, and Julie A. Switzer, MD, are members of the AAOS Women’s Health Issues Advisory Board. Caleb J. Behrend, MD, is a resident member of the AAOS.

Putting sex in your orthopaedic practice
This quarterly column from the AAOS Women’s Health Issues Advisory Board and the Ruth Jackson Orthopaedic Society provides important information for your practice about issues related to sex (determined by our chromosomes) and gender (how we present ourselves as male or female, which can be influenced by environment, families and peers, and social institutions). It is our mission to promote the philosophy that male and female patients may experience and react to musculoskeletal conditions differently; when it comes to patient care, surgeons should not have a one-size-fits-all mentality. This column was edited by Laura L. Tosi, MD, and Elizabeth A. Arendt, MD.

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