Pregnancy and Trauma -

Pregnancy and Trauma

1. Physiological Changes in Pregnancy Relevant to Trauma

A. Cardiovascular Changes

✅ Increased Blood Volume (40-50%) → Delayed signs of hemorrhagic shock.

✅ Increased Cardiac Output (30-50%) → May mask hypovolemia early.

✅ Supine Hypotension Syndrome → Compression of IVC by gravid uterus (from 20 weeks).

📌 Clinical Implication: Even with normal BP, significant blood loss may have occurred.

B. Respiratory Changes

✅ Increased O₂ Consumption (~20%) → More prone to hypoxia.

✅ Decreased FRC (by 20%) → Rapid desaturation during apnea.

✅ Compensated Respiratory Alkalosis (PaCO₂ ~ 30 mmHg).

📌 Clinical Implication: Early oxygenation and ventilation are critical; pregnancy worsens hypoxia in trauma.

C. Hematological & Coagulation Changes

✅ Hypercoagulable State → Increased risk of DVT/PE.

✅ Increased Fibrinogen & Clotting Factors (VII, VIII, X).

📌 Clinical Implication: Higher risk of thromboembolism, requiring DVT prophylaxis in ICU.

D. Gastrointestinal Changes

✅ Delayed Gastric Emptying → High risk of aspiration.

✅ Reduced Lower Esophageal Sphincter Tone → Increased GERD.

– Peritoneal Changes in Late Pregnancy:

– The peritoneum stretches significantly by the third trimester, reducing sensitivity to peritoneal irritation.

– Even with traumatic hemoperitoneum, abdominal tenderness may be absent due to decreased peritoneal sensitivity.

– Blunt Trauma & Organ Injury:

– The spleen is the most commonly injured organ, similar to nonpregnant blunt trauma patients.

📌 Clinical Implication: Always assume full stomach → Use rapid sequence induction (RSI) with cricoid pressure.

2. Trauma Resuscitation in Pregnancy (ED Management)

The primary principles remain Airway, Breathing, Circulation, Disability, Exposure (ABCDE) with maternal stabilization as the priority.

– Radiation Exposure vs. Diagnosis:

– Fear of radiation should not delay establishing the correct diagnosis.

– Rhesus (Rh) Blood Type & Immunoglobulin:

– Patient’s Rh status should be determined.

– Rh immunoglobulin dosage depends on gestational age:

– <12 weeks: 150 mcg

– >12 weeks: 300 mcg

– Higher doses may be required in massive blunt-force trauma with significant feto-maternal hemorrhage.

– Kleihauer-Betke test is used to assess fetal blood in maternal circulation and determine additional Rh immunoglobulin needs.

– Test detects hemorrhage above 5 mL, but iso-immunization can occur at just 0.01 mL.

– Blood Pressure Management:

– Permissive hypotension should be avoided in pregnant trauma patients.

– Central Venous Access & Thoracostomy:

– Femoral vein catheterization should be avoided due to vena cava compression risk from the uterus.

– Thoracostomy tube placement should be 1–2 intercostal spaces higher in late pregnancy due to diaphragm elevation (by ~4 cm).

– Laparotomy in Pregnancy:

– Indications for laparotomy remain the same as in nonpregnant trauma patients.

– Laparotomy alone is not an indication for cesarean section.

– Uterus should be handled with care to prevent vascular compromise.

– With adequate resuscitation, the fetus should tolerate surgery well.

– An obstetric clinician should be present during surgery in preterm pregnancies.

– Medications & Prophylaxis in Pregnancy:

– Tetanus toxoid is safe during pregnancy.

– Standard antibiotic prophylaxis is acceptable, but the following should be avoided due to teratogenicity:

– Aminoglycosides, quinolones, metronidazole, and sulfonamides**

– Enoxaparin or heparin can be used for venous thromboembolism (VTE) prophylaxis as they do not cross the placenta.

A. Airway & Breathing

🔹 Early intubation → Avoid maternal hypoxia.

🔹 Anticipate difficult airway → Edematous airway, increased risk of failed intubation.

🔹 Preoxygenation is critical → Desaturation occurs rapidly.

🔹 Use smaller ETT (6.0-6.5 mm) due to mucosal edema.

📌 Key Point: Apneic oxygenation & cricoid pressure should be used to minimize desaturation and aspiration.

B. Circulation

🔹 Maternal hemorrhagic shock signs are delayed → Look for fetal distress as an early sign!

🔹 Left Uterine Displacement (LUD) → Tilt patient 15-30° left to relieve aortocaval compression.

🔹 Massive Transfusion Protocol (MTP) → 1:1:1 ratio of RBC:FFP:Platelets if bleeding.

📌 Key Point: Uterine rupture & placental abruption are major life-threatening causes of hemorrhage.

C. Fetal Considerations in Trauma

Placental Abruption (40-50% of major trauma cases) → Monitor via continuous fetal heart rate (FHR).

• Uterine Rupture → More common in previous C-section patients.

– Fetal Heart Tone (FHT) Detection:

– At 20 weeks gestation, FHTs can be auscultated using a stethoscope.

– Before 20 weeks, a Doppler device is required.

– FHTs can be detected as early as 12 weeks gestation, with a normal range of 110–160 bpm.

– Fetal Distress & Monitoring:

– Tonometry is the most accurate method to assess fetal distress.

– Early fetal hypoxia → tachycardia(increased heart rate).

– Prolonged hypoxia → bradycardia(low heart rate due to reduced arterial oxygen content).

– Fetal distress is indicated by a sustained FHT below 120 bpm.

📌 Key Point: Fetal distress precedes maternal deterioration → Always monitor FHR via continuous CTG.

3. Anesthetic Considerations in Pregnant Trauma Patients

A. General Anesthesia (GA) Considerations

✅ Rapid Sequence Induction (RSI) is mandatory → High aspiration risk.

✅ Propofol or Ketamine induction → Etomidate can be considered in unstable patients.

✅ Early extubation if possible to prevent ICU complications.

📌 Key Point: Ketamine is preferred in unstable trauma patients due to its hemodynamic stability.

B. Regional Anesthesia Considerations

✅ Epidural/SAB generally safe if no coagulopathy or head injury.

✅ Avoid in major trauma with hypotension, coagulopathy, or placental abruption.

✅ Spinal anesthesia may cause severe hypotension in hypovolemic patients.

📌 Key Point: In polytrauma or unstable patients, GA is preferred over regional anesthesia.

4. ICU Management of Pregnant Trauma Patients

A. Hemodynamic Support

• Avoid excessive crystalloid resuscitation → Use balanced transfusion strategies.

• Vasopressors → Phenylephrine preferred (maintains uteroplacental perfusion).

B. Ventilation & Oxygenation

• Target SpO₂ > 95% and PaO₂ > 70 mmHg (to prevent fetal hypoxia).

• Permissive hypercapnia is NOT allowed → Aim for PaCO₂ ~ 30 mmHg.

C. DVT Prophylaxis

• LMWH prophylaxis unless contraindicated (active bleeding or surgery).

D. Fetal Monitoring & Obstetric Consultation

• Continuous CTG monitoring if viable fetus (>24 weeks).

• Urgent OB-GYN involvement for fetal distress or emergency C-section.

📌 Key Point: In maternal cardiac arrest >4 min, perimortem C-section (PMCS) should be performed within 5 min.

MCQs (Multiple Choice Questions)

1. What is the earliest sign of maternal hypovolemia in pregnancy?

A) Hypotension

B) Tachycardia

C) Fetal distress

D) Reduced urine output

Answer: C) Fetal distress

2. Which induction agent is preferred for GA in a hemodynamically unstable pregnant trauma patient?

A) Propofol

B) Ketamine

C) Midazolam

D) Sevoflurane

Answer: B) Ketamine

3. Which vasopressor is preferred in pregnant trauma patients?

A) Dopamine

B) Phenylephrine

C) Epinephrine

D) Dobutamine

Answer: B) Phenylephrine

Viva Questions & Model Answers

1. What are the most common causes of maternal trauma?

• Motor vehicle accidents, falls, domestic violence.

2. Why is left uterine displacement (LUD) important?

• Prevents aortocaval compression, maintains venous return and cardiac output.

3. What are the fetal considerations in maternal trauma?

• Fetal distress is an early warning sign of maternal hypovolemia.

4. When is perimortem C-section (PMCS) indicated?

• If maternal cardiac arrest occurs for >4 minutes with viable fetus >24 weeks.