The pathophysiology of trauma in pregnancy: A review

Trauma in pregnancy: A narrative review of the current literature

INTRODUCTION

Trauma accounts for nearly half of all deaths of pregnant women. Pregnant women have distinct physiologic and anatomic characteristics which complicate their management following major trauma.

OBJECTIVE

This paper comprises a narrative review of the most recent literature informing the management of pregnant trauma patients.

DISCUSSION

The incidence of trauma during pregnancy is 6-8%. The focus of clinical assessment must be on the mother, starting with the primary survey. During airway management, clinicians should consider early intubation if necessary and utilize gastric tubes to minimize the risk of aspiration. Pregnant women experience progesterone-mediated hyperventilation, and normal PaCO2 levels may portend imminent respiratory failure. Clinicians should utilize left lateral tilt in hypotensive pregnant women to displace the uterus off the inferior vena cava. Ultrasonography is an attractive imaging modality for pregnant women which is specific for ruling in intraabdominal hemorrhage but not sufficiently sensitive to exclude this diagnosis. Clinicians should not hesitate to order computed tomography imaging in unstable patients if there is diagnostic ambiguity. Cardiotocographic monitoring simultaneously assesses uterine contractions and fetal heart rate and should last at least 4 h for pregnant women following even minor abdominal trauma if their fetus has achieved viable gestational age (approximately 24 weeks). In the event of cardiac arrest, peri-mortem cesarean section may improve outcomes for the mother and fetus alike. Unique specific complications include uterine rupture and placental abruption, which require emergent resuscitation and obstetrics consultation for definitive management. Emergency clinicians should maintain a low threshold for transfer to a tertiary care center given correlations between even isolated and relatively minor traumatic injuries with adverse fetal and maternal outcomes.

CONCLUSIONS

Trauma is a common cause of morbidity and mortality in pregnant women. Emergency clinicians must understand the evaluation and management of pregnant trauma patients.

Trauma in pregnancy clinical practice guidelines: systematic review

PURPOSE

To objectively evaluate the methodological quality and clinical heterogeneity robustness of the published clinical practice guidelines (CPGs) on the management of trauma in pregnancy.

MATERIALS AND METHODS

Pubmed, Google Scholar, UpToDate, and Scopus Database were searched. The risk of bias and quality assessment of the included CPGs were performed using "The Appraisal Of Guidelines for Research and Evaluation (AGREE II)" tool. The following points relating to the management of trauma during pregnancy were addressed: quality of evidence assessment, classification of recommendations, main causes of trauma in pregnancy, importance of correct use of seat belts, ultrasound scans and/or pregnancy test in every female of reproductive age, description of physiological changes in pregnancy, classification in primary and secondary survey, primary survey based on ABCD Approach, fetus viable based on the weeks, radiographic studies for maternal evaluation, duration of fetal monitoring, use of anti-D immunoglobulin in rhesus-D-negative pregnant trauma patients, description of dose of RhD-Ig, the way to define gestational age if it was undetermined, descriptions of obstetrical complications, use of tetanus vaccination, and timing to perimortem cesarean section (CS).

RESULTS

Six CPGs were included. Quality of evidence assessment was described in 16.7% of CPGs (1/6), while it was not reported in 83.3% (5/6). Classification of recommendations was reported in 50% (3/3) of the CPGs. Motor vehicle crash was reported as the main cause of trauma in pregnancy in all the CPGs included in the present review, despite that the importance of a correct use of seat belts was described only in the 50% (3/6). Definition of fetal viability was also different among the included CPGs; in 50% (3/6) defined a fetus viable when it from 23 weeks, 33.3% (2/6) from 24 weeks, and 16.7% (1/6) from 20 weeks of gestation. Regarding the type of fetal monitoring, 33.3% (2/6) CPGs recommended CTG assessment at least every 4 h, 16.7% (1/6) at least every 6 h, 33.3% for 24 h if there are not reassuring signs and 16.7% (1/6) did not specify the duration of monitoring. Recommendations about the use of anti-D-immunoglobulin in rhesus-D-negative pregnant were also heterogeneous: 50% (3/6) of the CPGs suggested administration in all rhesus-D-negative pregnant women, 16.7% (1/6) only according to gestational age at trauma or in case of significant abdominal trauma, and 16.7% (1/6) only in case of positive Kleihauer test while 16.7% (1/6) did not specify it. Administration of tetanus vaccination was suggested in in 33.3% (2/6) of CPGs. Finally, there were different descriptions of timing to perimortem CS: 33.3% (2/6) of CPGs claims to do CS no later than 4 min, 50% (3/6) no later than 5 min, and 16.7% (1/6) does not describe timing for CS. The AGREE II standardized domain scores for the first overall assessment (OA1) had a mean of 69%. Only three CPGs scored more than 60% and revealed a consensus agreement between the reviewers on recommending the use of these CPGs.

CONCLUSION

There is clinical heterogeneity in some of the most relevant aspects of the management of pregnant women with trauma. The findings from this systematic review highlight the need for up to date and shared guidelines promoted by the main body societies in order make management of pregnant women with trauma homogenous.

Neonatal minimal invasive management of a prenatal gunshot trauma: case report

Background

Prenatal penetrating gunshot trauma represents a challenging scenario for healthcare providers. Trauma is the leading non-obstetric cause of morbidity and mortality during pregnancy, and even though rare, firearm injuries have the most fatal outcomes and higher fetus mortality rates. Understanding the mechanism of injury in order to identify the possible injuries and adequate management is essential. In this paper, we discuss the case of a newborn with prenatal gunshot trauma, the treatment used, and the outcome of conservative and minimally invasive management.

Case presentation

We present the case of a male newborn, 37 weeks of gestational age and weighing 3050 g, delivered through an emergency cesarean section with prenatal gunshot trauma. Two skin wounds were found, one in the arm and another in the left thoracic region. The patient presented with respiratory distress, bilateral pneumothorax, and pneumoperitoneum, requiring high-frequency mechanical ventilation and the placement of bilateral thoracic drains. The pneumoperitoneum was attributed to pulmonary barotrauma, with no suspicion of abdominal hollow viscera lesion. A right thoracoscopy was performed after 24 h of conservative management for the removal of the foreign body. Both the mother and the baby had a positive outcome, with no further treatment needed.

Conclusions

For the improvement in the result of trauma events, an adequate intervention and coordinated efforts from multidisciplinary clinical and surgical teams are required. For gunshot wounds, entry, trajectory, the final position of the bullet, and pathological findings in images need to be analyzed before taking the patient to the operative room. Chosen with strict selection criteria, some patients could benefit from conservative management.

Guidance for Evaluation and Management of Blunt Abdominal Trauma in Pregnancy

Blunt abdominal trauma is the leading type of traumatic injury in pregnancy, with motor vehicle crashes, falls, and assault being the most common etiologies. Several adverse outcomes can occur in pregnancy, including placental abruption, preterm labor and preterm delivery, uterine rupture, and pelvic fracture. Understanding and integration of key anatomic and physiologic changes in pregnancy are key when evaluating a pregnant trauma patient. Pregnant women should be managed in a medical center with the ability to provide adequate care to both trauma patients-the pregnant woman and fetus. Multiple clinical providers are usually involved in the care of pregnant trauma patients, but obstetric providers should play a central role in the evaluation and management of a pregnant trauma patient given their unique training, knowledge, and clinical skills. An algorithm for management of trauma in pregnancy should be used at all sites caring for pregnant women. An alignment of policies within each system optimizes appropriate triage, integration of care, management, and monitoring of pregnant trauma patients and their fetuses. Ensuring effective protocols for prehospital and hospital treatment, as well as thorough training of involved health care providers, is essential in ensuring that optimal care is provided.

Guidelines for the Management of a Pregnant Trauma Patient

OBJECTIVE

Physical trauma affects 1 in 12 pregnant women and has a major impact on maternal mortality and morbidity and on pregnancy outcome. A multidisciplinary approach is warranted to optimize outcome for both the mother and her fetus. The aim of this document is to provide the obstetric care provider with an evidence-based systematic approach to the pregnant trauma patient.

OUTCOMES

Significant health and economic outcomes considered in comparing alternative practices.

EVIDENCE

Published literature was retrieved through searches of Medline, CINAHL, and The Cochrane Library from October 2007 to September 2013 using appropriate controlled vocabulary (e.g., pregnancy, Cesarean section, hypotension, domestic violence, shock) and key words (e.g., trauma, perimortem Cesarean, Kleihauer-Betke, supine hypotension, electrical shock). Results were restricted to systematic reviews, randomized control trials/controlled clinical trials, and observational studies published in English between January 1968 and September 2013. Searches were updated on a regular basis and incorporated in the guideline to February 2014. Grey (unpublished) literature was identified through searching the websites of health technology assessment and health technology-related agencies, clinical practice guideline collections, clinical trial registries, and national and international medical specialty societies.

VALUES

The quality of evidence in this document was rated using the criteria described in the Report of the Canadian Task Force on Preventive Health Care (Table 1).

BENEFITS, HARMS, AND COSTS

This guideline is expected to facilitate optimal and uniform care for pregnancies complicated by trauma. Summary Statement Specific traumatic injuries At this time, there is insufficient evidence to support the practice of disabling air bags for pregnant women. (III) Recommendations Primary survey 1. Every female of reproductive age with significant injuries should be considered pregnant until proven otherwise by a definitive pregnancy test or ultrasound scan. (III-C) 2. A nasogastric tube should be inserted in a semiconscious or unconscious injured pregnant woman to prevent aspiration of acidic gastric content. (III-C) 3. Oxygen supplementation should be given to maintain maternal oxygen saturation > 95% to ensure adequate fetal oxygenation. (II-1B) 4. If needed, a thoracostomy tube should be inserted in an injured pregnant woman 1 or 2 intercostal spaces higher than usual. (III-C) 5. Two large bore (14 to 16 gauge) intravenous lines should be placed in a seriously injured pregnant woman. (III-C) 6. Because of their adverse effect on uteroplacental perfusion, vasopressors in pregnant women should be used only for intractable hypotension that is unresponsive to fluid resuscitation. (II-3B) 7. After mid-pregnancy, the gravid uterus should be moved off the inferior vena cava to increase venous return and cardiac output in the acutely injured pregnant woman. This may be achieved by manual displacement of the uterus or left lateral tilt. Care should be taken to secure the spinal cord when using left lateral tilt. (II-1B) 8. To avoid rhesus D (Rh) alloimmunization in Rh-negative mothers, O-negative blood should be transfused when needed until cross-matched blood becomes available. (I-A) 9. The abdominal portion of military anti-shock trousers should not be inflated on a pregnant woman because this may reduce placental perfusion. (II-3B) Transfer to health care facility 10. Transfer or transport to a maternity facility (triage of a labour and delivery unit) is advocated when injuries are neither life- nor limb-threatening and the fetus is viable (≥ 23 weeks), and to the emergency room when the fetus is under 23 weeks' gestational age or considered to be non-viable. When the injury is major, the patient should be transferred or transported to the trauma unit or emergency room, regardless of gestational age. (III-B) 11. When the severity of injury is undetermined or when the gestational age is uncertain, the patient should be evaluated in the trauma unit or emergency room to rule out major injuries. (III-C) Evaluation of a pregnant trauma patient in the emergency room 12. In cases of major trauma, the assessment, stabilization, and care of the pregnant women is the first priority; then, if the fetus is viable (≥ 23 weeks), fetal heart rate auscultation and fetal monitoring can be initiated and an obstetrical consultation obtained as soon as feasible. (II-3B) 13. In pregnant women with a viable fetus (≥ 23 weeks) and suspected uterine contractions, placental abruption, or traumatic uterine rupture, urgent obstetrical consultation is recommended. (II-3B) 14. In cases of vaginal bleeding at or after 23 weeks, speculum or digital vaginal examination should be deferred until placenta previa is excluded by a prior or current ultrasound scan. (III-C) Adjunctive tests for maternal assessment 15. Radiographic studies indicated for maternal evaluation including abdominal computed tomography should not be deferred or delayed due to concerns regarding fetal exposure to radiation. (II-2B) 16. Use of gadolinium-based contrast agents can be considered when maternal benefit outweighs potential fetal risks. (III-C) 17. In addition to the routine blood tests, a pregnant trauma patient should have a coagulation panel including fibrinogen. (III-C) 18. Focused abdominal sonography for trauma should be considered for detection of intraperitoneal bleeding in pregnant trauma patients. (II-3B) 19. Abdominal computed tomography may be considered as an alternative to diagnostic peritoneal lavage or open lavage when intra-abdominal bleeding is suspected. (III-C) Fetal assessment 20. All pregnant trauma patients with a viable pregnancy (≥ 23 weeks) should undergo electronic fetal monitoring for at least 4 hours. (II-3B) 21. Pregnant trauma patients (≥ 23 weeks) with adverse factors including uterine tenderness, significant abdominal pain, vaginal bleeding, sustained contractions (> 1/10 min), rupture of the membranes, atypical or abnormal fetal heart rate pattern, high risk mechanism of injury, or serum fibrinogen < 200 mg/dL should be admitted for observation for 24 hours. (III-B) 22. Anti-D immunoglobulin should be given to all rhesus D-negative pregnant trauma patients. (III-B) 23. In Rh-negative pregnant trauma patients, quantification of maternal-fetal hemorrhage by tests such as Kleihauer-Betke should be done to determine the need for additional doses of anti-D immunoglobulin. (III-B) 24. An urgent obstetrical ultrasound scan should be undertaken when the gestational age is undetermined and need for delivery is anticipated. (III-C) 25. All pregnant trauma patients with a viable pregnancy who are admitted for fetal monitoring for greater than 4 hours should have an obstetrical ultrasound prior to discharge from hospital. (III-C) 26. Fetal well-being should be carefully documented in cases involving violence, especially for legal purposes. (III-C) Obstetrical complications of trauma 27. Management of suspected placental abruption should not be delayed pending confirmation by ultrasonography as ultrasound is not a sensitive tool for its diagnosis. (II-3D) Specific traumatic injuries 28. Tetanus vaccination is safe in pregnancy and should be given when indicated. (II-3B) 29. Every woman who sustains trauma should be questioned specifically about domestic or intimate partner violence. (II-3B) 30. During prenatal visits, the caregiver should emphasize the importance of wearing seatbelts properly at all times. (II-2B) Perimortem Caesarean section 31. A Caesarean section should be performed for viable pregnancies (≥ 23 weeks) no later than 4 minutes (when possible) following maternal cardiac arrest to aid with maternal resuscitation and fetal salvage. (III-B).