In a pregnant trauma patient, should she be placed in left lateral decubitus (or left tilt) rather than right side, and how critical is this positioning?

Pregnant Trauma Patient Positioning

In a pregnant trauma patient with a gravid uterus at or above the umbilicus (≥20 weeks gestation), keep the patient SUPINE and perform continuous manual left uterine displacement rather than placing her in left lateral tilt—this is critically important because left lateral tilt severely compromises the effectiveness of any resuscitation efforts while manual displacement maintains optimal hemodynamics without sacrificing procedural access. 1, 2

Why LEFT (Not Right) Displacement Matters

• The gravid uterus compresses the inferior vena cava and aorta when the patient lies supine, reducing venous return by up to 30% and potentially causing complete cardiovascular collapse. 2 The anatomic position of these vessels means displacement must be to the LEFT to relieve this compression. 1

• Manual left uterine displacement produces coronary perfusion pressures of approximately 20 mm Hg compared to only 5 mm Hg with left lateral tilt positioning (P<0.05) in animal models. 2 This represents a four-fold improvement in critical perfusion pressure.

The Critical Positioning Algorithm

For Conscious, Stable Pregnant Trauma Patients (>20 weeks):

• Position the patient in full left lateral decubitus position OR use left lateral tilt to prevent aortocaval compression. 1 This applies when the patient is awake, hemodynamically stable, and not requiring active resuscitation. 1

• If the patient must remain supine for procedures (imaging, examination, surgery), use manual left uterine displacement or left lateral tilt of at least 15°. 1, 3, 4, 5 However, recognize that 15° tilt may be inadequate beyond 26 weeks gestation based on simulation data. 6

For Unstable or Arrested Pregnant Trauma Patients (≥20 weeks):

• Place the patient fully SUPINE on a firm surface—never use left lateral tilt during active resuscitation or CPR. 1, 2 This is the single most important positioning principle.

• Assign a dedicated team member to perform continuous two-handed manual left uterine displacement throughout the resuscitation. 1, 2 The technique involves either:

  • Standing on the patient's LEFT side and cupping/lifting the uterus upward and leftward, OR
  • Standing on the patient's RIGHT side and pushing the uterus upward and leftward 1

• The rescuer must avoid pushing downward, which would worsen inferior vena cava compression rather than relieve it. 1

Why This Positioning Is Critically Important

Hemodynamic Impact:

• Left lateral tilt of >30° still allows inferior vena cava compression to occur, and the heart shifts laterally during tilt, making chest compressions significantly less effective. 1

• Left lateral tilt reduces correct compression depth rate by 19% and correct hand position rate by 9% compared to supine positioning, yielding only about 10% of normal pregnancy cardiac output. 2

• Manual left uterine displacement compared to 15° left lateral tilt results in significantly less hypotension and lower vasopressor requirements during cesarean delivery in non-arrest patients. 1

Practical Advantages of Manual Displacement Over Tilt:

• Easier airway management access 1
• Easier defibrillation access 1
• Patient remains on firm surface for optimal chest compressions 1
• No risk of patient sliding off an inclined surface at >30° tilt 1

When Positioning Becomes Critical

• The uterus reaches the umbilicus at approximately 20 weeks gestation—this is when aortocaval compression becomes clinically significant. 1, 2 If the fundus is palpable at or above the umbilicus, positioning interventions are mandatory. 1

• In morbidly obese patients where uterine size is difficult to assess, attempt manual left uterine displacement if technically feasible. 1

Additional Critical Considerations for Trauma Resuscitation

• Establish IV access ABOVE the diaphragm immediately, as inferior vena cava compression renders lower extremity access ineffective. 2

• Pregnant patients desaturate within 1-2 minutes of apnea due to 20% decreased functional residual capacity and 20-40% increased oxygen consumption. 2 Provide 100% oxygen and anticipate rapid desaturation. 1

• If return of spontaneous circulation is not achieved within 4 minutes in a patient ≥20 weeks gestation during cardiac arrest, begin perimortem cesarean delivery at the bedside. 2 This relieves aortocaval compression and improves maternal resuscitation—it is performed for the MOTHER, not primarily for fetal salvage. 2

Common Pitfalls to Avoid

• Never use left lateral tilt during active CPR or resuscitation requiring chest compressions—this is the most critical error. 2 The compromise in compression quality far outweighs any theoretical hemodynamic benefit.

• Do not assume 15° tilt is adequate for all gestational ages—simulation studies suggest this may only normalize hemodynamics up to 26 weeks, and term pregnancy may require 28° or more. 6 Manual displacement is superior across all gestational ages.

• Do not delay necessary radiographic imaging or procedures due to positioning concerns—use manual displacement to maintain hemodynamics while performing essential interventions. 3, 4

• Recent evidence in non-laboring, non-anesthetized term pregnant women suggests that in the ramped (head-elevated) position, left lateral tilt may not be necessary for maintaining cardiac output. 7 However, this applies only to elective positioning in stable patients, not trauma or resuscitation scenarios.