7.3 Hemorrhagic Shock, Pelvic Ring Disruptions & Damage Control Orthopaedics
Key Takeaways
- Pelvic ring disruptions from high-energy trauma carry extreme mortality (up to 40–50% in hemodynamically unstable patients) due to massive retroperitoneal bleeding capable of sequestering 3 to 5 liters of blood from the presacral venous plexus, cancellous bony fracture surfaces, and internal iliac arterial branches.
- The Young-Burgess classification categorizes pelvic trauma by force vector: Anteroposterior Compression (APC: 'open-book'), Lateral Compression (LC: internal rotation/implosion), and Vertical Shear (VS: complete ligamentous disruption and vertical hemipelvic displacement), with APC-II/III and VS causing maximum pelvic volume expansion and life-threatening hemorrhage.
- Emergent non-invasive pelvic circumferential stabilization requires precise placement of a commercial pelvic binder or sheet centered directly over the bilateral greater trochanters and pubic symphysis (NOT over the iliac crests), closing the true pelvic volume and creating a mechanical tamponade effect.
- In severely physiologically compromised polytrauma patients presenting with the lethal triad (hypothermia, acidemia, and coagulopathy), Damage Control Orthopaedics (DCO: rapid external fixation and hemorrhage control) is prioritized over Early Total Care (ETC) to prevent fatal secondary systemic inflammatory insults ('second hit').
Hemorrhagic Shock, Pelvic Ring Disruptions & Damage Control Orthopaedics
Core Clinical Principle: High-energy disruptions of the pelvic ring represent catastrophic orthopaedic emergencies with acute mortality rates approaching 40% to 50% in hemodynamically unstable patients. The non-contained retroperitoneal space can sequester 3 to 5 liters of blood before hydrostatic pressure tamponades the bleeding. Rapid pelvic volume reduction, balanced massive transfusion resuscitation, and damage control orthopaedic strategies are mandatory to prevent fatal exsanguination and multi-organ failure.
The pelvic ring functions mechanically as a rigid, load-bearing osseoligamentous circle. A true displaced fracture or disruption at one site in the pelvic ring almost invariably implies a second break or major ligamentous rupture elsewhere in the circle.
1. Vascular Anatomy & Retroperitoneal Bleeding Sources
Pelvic hemorrhage originates from three distinct anatomical sources:
SOURCES OF PELVIC HEMORRHAGE
┌──────────────────────────────────────┬──────────────────────────────────────┐
│ Source │ Characteristics & Clinical Impact │
├──────────────────────────────────────┼──────────────────────────────────────┤
│ 1. Presacral & Pelvic Venous Plexus │ • Accounts for 85% to 90% of all │
│ (Low-pressure, high-volume) │ bleeding in pelvic ring trauma │
│ │ • Responsive to pelvic binding and │
│ │ mechanical volume reduction │
├──────────────────────────────────────┼──────────────────────────────────────┤
│ 2. Cancellous Bone Bleeding │ • Continuous bleeding from fractured │
│ (Ilium, Sacrum, Pubic Rami) │ cancellous surfaces and torn marrow│
│ │ • Controlled by rigid stabilization │
├──────────────────────────────────────┼──────────────────────────────────────┤
│ 3. Internal Iliac Arterial Branches │ • Accounts for 10% to 15% of bleeding│
│ (High-pressure pulsatile) │ • Highly lethal; requires emergent │
│ │ transcatheter angioembolization │
│ │ • Vessels: Superior gluteal, internal│
│ │ pudendal, obturator, lateral sacral│
└──────────────────────────────────────┴──────────────────────────────────────┘
The Physics of Pelvic Volume Expansion
Disruption of the pubic symphysis by just $2.5\text{ cm}$ doubles the volumetric capacity of the true pelvis. When the pelvic ring springs open (such as in "open-book" injuries), the pelvic volume expands exponentially ($V \propto r^3$), eliminating natural tissue-pressure tamponade and transforming the retroperitoneum into an expansive reservoir for rapid exsanguination.
2. Pelvic Ring Classifications: Young-Burgess & Tile Systems
The Young-Burgess classification categorizes pelvic injuries based on the direction of applied kinetic force vectors, directly predicting bleeding risk and associated visceral injury:
YOUNG-BURGESS PELVIC CLASSIFICATION
┌────────────┬─────────────────────────────┬───────────────────┬──────────────┐
│ Mechanism │ Skeletal & Ligament Pattern │ Hemodynamic Risk │ Associated │
├────────────┼─────────────────────────────┼───────────────────┼──────────────┤
│ APC-I │ Symphysis diastasis <2.5 cm;│ Low │ Rare │
│ (Antero- │ SI ligaments intact │ │ │
│ posterior) ├─────────────────────────────┼───────────────────┼──────────────┤
│ │ Symphysis >2.5 cm; anterior │ High hemorrhage │ Bladder / │
│ APC-II │ SI & sacrotuberous torn; │ risk (venous + │ urethral │
│ ("Open- │ posterior SI intact │ bone surfaces) │ injury │
│ Book") ├─────────────────────────────┼───────────────────┼──────────────┤
│ │ Complete SI disruption; │ CATASTROPHIC │ Massive shock│
│ APC-III │ bilateral sacroiliac joint │ Highest arterial │ (Arterial │
│ │ dislocation (open book) │ injury rate │ transection) │
├────────────┼─────────────────────────────┼───────────────────┼──────────────┤
│ LC-I │ Impacted sacral crush on │ Low │ Mild pain │
│ (Lateral │ side of impact; stable │ │ │
│ Compres- ├─────────────────────────────┼───────────────────┼──────────────┤
│ sion / │ Crescent iliac wing fracture│ Moderate │ Bladder/bowel│
│ Implosion) ├─────────────────────────────┼───────────────────┼──────────────┤
│ LC-II/III │ LC on impact side + "wind- │ High hemorrhage │ Visceral │
│ │ swept" APC on opposite side │ and crush risk │ perforation │
├────────────┼─────────────────────────────┼───────────────────┼──────────────┤
│ VS │ Complete disruption of │ CATASTROPHIC │ Severe shock,│
│ (Vertical │ anterior & posterior ring; │ Massive arterial │ sciatic nerve│
│ Shear) │ gross vertical hemipelvic │ and venous │ avulsion, L5 │
│ │ displacement (fall from ht) │ disruption │ nerve palsy │
└────────────┴─────────────────────────────┴───────────────────┴──────────────┘
The Tile Classification (Stability-Based)
- Tile Type A: Stable ring (avulsion fractures, isolated pubic ramus fracture).
- Tile Type B: Partially stable (rotationally unstable, vertically stable; B1 open-book, B2 lateral compression).
- Tile Type C: Completely unstable (rotationally and vertically unstable; complete disruption of posterior sacroiliac complex).
3. Emergency Nursing Assessment & Critical Safety Warnings
EMERGENCY PELVIC ASSESSMENT PROTOCOL
┌────────────────────────────────────────────────────────────────────────────┐
│ 1. HEMODYNAMIC TRIAGE: Hypotension (SBP < 90), tachycardia (HR > 120), │
│ pale cool skin, delayed capillary refill (> 3s), base deficit < -6. │
└─────────────────────────────────────┬──────────────────────────────────────┘
│
▼
┌────────────────────────────────────────────────────────────────────────────┐
│ 2. CAUTION: SINGLE GENTLE PELVIC STABILITY CHECK ONLY │
│ Apply gentle manual inward compression over anterior iliac crests ONCE. │
│ CRITICAL WARNING: NEVER REPETITIVELY "SPRING" OR ROCK THE PELVIS! │
│ Repeated manipulation dislodges fresh clots and causes re-bleeding. │
└─────────────────────────────────────┬──────────────────────────────────────┘
│
▼
┌────────────────────────────────────────────────────────────────────────────┐
│ 3. INSPECT PERINEUM, GENITOURINARY & RECTUM │
│ • Flank / scrotal ecchymosis (Destot sign, Earle sign) │
│ • Blood at the urethral meatus, high-riding prostate, or rectal tear │
│ • DO NOT INSERT A FOLEY CATHETER if urethral injury is suspected! │
└────────────────────────────────────────────────────────────────────────────┘
4. Emergency Pelvic Binder Application: The Greater Trochanter Rule
Non-invasive pelvic circumferential compression is the most effective first-line emergency intervention to reduce true pelvic volume, stabilize bone ends, and promote retroperitoneal clot tamponade.
Anatomic Placement: The Greater Trochanter Rule
PELVIC BINDER PLACEMENT RULES
┌────────────────────────────────────────────────────────────────────────┐
│ CORRECT PLACEMENT: │
│ • Center the binder directly over the BILATERAL GREATER TROCHANTERS │
│ and the PUBIC SYMPHYSIS (the widest prominence of the hip). │
│ • Compresses the femoral heads into the acetabula, closing the ring. │
├────────────────────────────────────────────────────────────────────────┤
│ FATAL PLACEMENT ERROR: │
│ • Placing the binder high around the ILIAC CRESTS / ABDOMEN. │
│ • Creates a cantilever fulcrum that forces the posterior ring wider │
│ open and fails to close the true pelvic volume, worsening bleeding. │
└────────────────────────────────────────────────────────────────────────┘
- Adjunctive Lower Limb Maneuver: Internally rotate the lower extremities and tape the knees/feet together (unless hip fractures are present) to further close the pelvic ring.
- Skin Care Monitoring: Monitor skin under the binder; loosen or adjust every 24 to 48 hours under orthopaedic supervision to prevent full-thickness pressure necrosis over bony prominences.
5. Hemorrhagic Shock Resuscitation & Massive Transfusion Protocols
BALANCED MASSIVE TRANSFUSION PROTOCOL (MTP)
┌──────────────────────────────────────┬──────────────────────────────────────┐
│ Resuscitation Component │ Clinical Target & Rationale │
├──────────────────────────────────────┼──────────────────────────────────────┤
│ 1. Balanced Blood Ratio │ • 1 : 1 : 1 ratio of PRBCs, FFP, and │
│ (Damage Control Resuscitation) │ Platelets (prevents coagulopathy) │
├──────────────────────────────────────┼──────────────────────────────────────┤
│ 2. Tranexamic Acid (TXA) │ • 1 g IV bolus over 10 min within │
│ (CRASH-2 Protocol) │ 3 hours of trauma, then 1 g / 8 hr │
├──────────────────────────────────────┼──────────────────────────────────────┤
│ 3. Permissive Hypotension │ • Target SBP 80–90 mmHg / MAP 60–65 │
│ (Prior to surgical hemostasis) │ until surgical hemostasis achieved │
├──────────────────────────────────────┼──────────────────────────────────────┤
│ 4. Calcium Replacement │ • 1 g IV Calcium Chloride for every │
│ (Antidote to Citrate Toxicity) │ 4 units of blood (target Ca > 1.1) │
└──────────────────────────────────────┴──────────────────────────────────────┘
6. Angioembolization vs. Preperitoneal Pelvic Packing (PPP)
When pelvic binding and MTP fail to stabilize hemodynamics, the trauma team selects a definitive hemostasis pathway:
- Transcatheter Angiography & Embolization (TCAE): Performed in Interventional Radiology (IR). Indicated for hemodynamically stabilized patients with contrast extravasation ("blush") on CT, selectively embolizing bleeding branches of the internal iliac artery.
- Preperitoneal Pelvic Packing (PPP) & External Fixation: Performed in the operating room for patients with severe refractory hypotension who cannot travel safely to IR. A midline suprapubic incision opens the space of Retzius; laparotomy pads are packed directly into the retroperitoneal pelvic space, and a pelvic external fixator or C-clamp is deployed.
7. Damage Control Orthopaedics (DCO) vs. Early Total Care (ETC)
In severe polytrauma, the timing of definitive fracture surgery is dictated by the patient's physiological reserve to avoid triggering a fatal "Second Hit" systemic inflammatory response:
DCO VS. EARLY TOTAL CARE (ETC)
┌──────────────────────────────────────┬──────────────────────────────────────┐
│ Early Total Care (ETC) │ Damage Control Orthopaedics (DCO) │
├──────────────────────────────────────┼──────────────────────────────────────┤
│ • Definitive internal fixation │ • Rapid, temporary external fixation │
│ (ORIF, IM nailing) within 24 hours │ and hemorrhage control (< 2 hours) │
│ • INDICATED ONLY IN PHYSIOLOGICALLY │ • INDICATED IN UNSTABLE / BORDERLINE │
│ STABLE PATIENTS │ POLYTRAUMA PATIENTS │
└──────────────────────────────────────┴──────────────────────────────────────┘
The Lethal Triad & Physiological Stratification
DCO is mandatory if the patient exhibits any parameters of the Lethal Triad:
- Hypothermia: Core Body Temperature $< 35.0^\circ\text{C}$
- Acidosis: Arterial $\text{pH} < 7.25$, Serum Lactate $> 2.5\text{ mmol/L}$, or Base Deficit $< -6\text{ mEq/L}$
- Coagulopathy: $\text{INR} > 1.5$, $\text{aPTT} > 60\text{ s}$, or Platelets $< 50,000/\mu\text{L}$
STAGED DCO SURGICAL PHASES
┌─────────────────────────┐ ┌─────────────────────────┐ ┌─────────────────────────┐
│ PHASE 1: OR (< 2 Hours) │ ──> │ PHASE 2: ICU RESUSCITATE│ ──> │ PHASE 3: DEFINITIVE FIX │
│ Rapid external fixator │ │ Rewarming, reversal of │ │ Staged conversion to │
│ pelvic packing, debride │ │ acidosis & coagulopathy │ │ ORIF / IM nail (Day 5–8)│
└─────────────────────────┘ └─────────────────────────┘ └─────────────────────────┘
A 34-year-old construction worker arrives in the trauma bay following a 25-foot fall with a suspected Young-Burgess APC-III ('open-book') pelvic disruption. When applying an emergency commercial pelvic binder, where must the orthopaedic trauma nurse position the center of the device?
During the secondary survey of a polytrauma patient with an unstable pelvic ring fracture, what critical clinical precaution must the orthopaedic nurse enforce regarding physical examination of the pelvis?
A polytrauma patient with a vertical shear pelvic fracture and bilateral femur fractures is in hemorrhagic shock with a temperature of 34.2°C, arterial pH 7.18, serum lactate 4.8 mmol/L, and INR 2.1. Why is Damage Control Orthopaedics (DCO) with temporary external fixation indicated over Early Total Care (ETC) definitive internal fixation?
Which anatomical vascular structure is responsible for the vast majority (approximately 85% to 90%) of retroperitoneal hemorrhage in high-energy pelvic ring disruptions?