What investigations should be sent for a stable patient with a pelvic fracture?

Investigations for Stable Pelvic Fracture Patients

For hemodynamically stable patients with pelvic fractures, proceed directly to multi-phasic CT scan with intravenous contrast—pelvic X-ray can be omitted in this population. 1

Primary Imaging Investigation

• Multi-phasic CT scan with IV contrast is the gold standard for stable pelvic fracture patients, with 100% sensitivity and specificity for bone fractures 1
• The CT protocol should include arterial, portal, and delayed phases to optimally evaluate for hemorrhage or hematoma 1
• CT with 3-dimensional bone reconstructions should be obtained to reduce tissue damage during subsequent procedures, decrease operative time, and improve surgical planning 1

Laboratory Investigations

Essential blood work includes:

• Serum lactate and base deficit (via arterial blood gas) are the most sensitive markers for estimating traumatic-hemorrhagic shock extent and monitoring resuscitation response 1
• Hemoglobin and hematocrit (though these are NOT sensitive early markers of hemorrhagic shock) 1
• Point-of-care coagulation testing using Thromboelastography (TEG) or Rotational Thromboelastometry (ROTEM) for early coagulopathy detection, which allows targeted blood product resuscitation 1

Specialized Investigations Based on Clinical Findings

Genitourinary evaluation when indicated:

• Retrograde urethrogram and/or urethrocystogram with contrast CT is recommended when there is perineal hematoma or pelvic disruption on imaging 1
• These studies are critical given the intimate anatomical relationship between the bladder, urethra, and pelvic ring 2

Rectal examination and proctoscopy:

• Perineal and rectal digital examination are mandatory when rectal injury is suspected 1
• Proctoscopy is recommended if rectal examination is positive 1

Critical CT Findings to Document

When reviewing the CT scan, specifically assess for:

• Contrast extravasation (98% accuracy for identifying arterial bleeding, though absence doesn't exclude active bleeding) 1
• Pelvic hematoma size ≥500 cm³ (strongly suggests arterial injury even without visible contrast blush) 1
• Associated injuries to other organs, retroperitoneum, and bones 1

What NOT to Order

• Pelvic X-ray should be omitted in hemodynamically stable patients without pelvic instability, hip dislocation, or positive physical examination who are scheduled for CT scan 1
• The sensitivity of pelvic X-ray is only 50-68% with false negative rates of 32%, making it inadequate as definitive imaging in stable patients 1

Common Pitfalls to Avoid

• Do not rely on hemoglobin/hematocrit as early indicators of blood loss—they lag behind actual hemorrhage 1
• Remember that over 80% of stable pelvic fracture patients have additional musculoskeletal injuries requiring systematic evaluation 2
• Even in "stable" fractures, 5% will have significant bleeding, particularly if admission hematocrit ≤30%, systolic BP ≤90 mmHg, or pelvic hematoma present on CT 3
• Elderly patients warrant special consideration—they may require angiography regardless of hemodynamic status, even with mechanically stable low-risk fractures 1