TNCC Musculoskeletal and Surface Trauma 2 — Questions and Answers
Question 1: A patient with a closed femur fracture is at risk for significant hemorrhage. The estimated blood loss from a single femur fracture is approximately:
- 200-500 mL
- 500-750 mL
- 1,000-1,500 mL (Correct answer)
- 2,500-3,000 mL
Correct answer: 1,000-1,500 mL
A closed femur fracture can result in 1,000-1,500 mL of blood loss into the thigh compartment, representing a significant source of hemorrhagic shock.
Fracture-associated hemorrhage is a significant and sometimes underappreciated source of blood loss in trauma. Estimated blood loss by fracture site: humerus 250-500 mL, tibia 500-1,000 mL, femur 1,000-1,500 mL, and pelvis 1,500-3,000+ mL. The femur is surrounded by large muscle compartments (quadriceps, hamstrings, adductors) with rich blood supply. A closed fracture disrupts nutrient vessels, periosteal vessels, and the surrounding muscle vasculature. Bilateral femur fractures can produce 2,000-3,000 mL of hemorrhage — enough for Class III-IV shock. Open fractures may lose even more as the compartment effect is lost. This is why femur fractures require early traction splinting (which reduces the thigh compartment volume, provides tamponade, and reduces pain) and monitoring for hemorrhagic shock signs. Blood transfusion should be anticipated.
Question 2: A trauma patient presents with a pale, cool, pulseless right lower leg after a knee dislocation. The nurse's priority is:
- Apply ice and elevate the extremity
- Document the findings and continue the secondary survey
- Notify the physician immediately for emergent vascular assessment — limb-threatening vascular injury is likely (Correct answer)
- Obtain bilateral ankle-brachial indices
Correct answer: Notify the physician immediately for emergent vascular assessment — limb-threatening vascular injury is likely
A pulseless extremity after knee dislocation suggests popliteal artery injury, which occurs in 20-40% of knee dislocations. This is a limb-threatening emergency requiring immediate intervention.
Knee dislocation has the highest rate of associated vascular injury of any extremity dislocation, with popliteal artery injury occurring in 20-40% of cases. The popliteal artery is relatively fixed as it passes through the adductor hiatus and the soleal arch, making it vulnerable to stretch, intimal tear, or complete disruption when the tibia displaces on the femur. A pale, cool, pulseless limb indicates critical limb ischemia — the 'golden period' for limb salvage is approximately 6-8 hours of warm ischemia before irreversible muscle necrosis occurs. Immediate actions: notify the surgeon for emergent vascular assessment (CT angiography or surgical exploration), reduce the dislocation if not already reduced, and document serial neurovascular checks. The peroneal nerve (common fibular nerve) is injured in 25-35% of knee dislocations, causing foot drop.
Question 3: The six P's of compartment syndrome include all of the following EXCEPT:
- Pain out of proportion to injury
- Pulselessness
- Purulent drainage (Correct answer)
- Paresthesia
Correct answer: Purulent drainage
The six P's of compartment syndrome are Pain (out of proportion), Pressure (tense compartment), Paresthesia, Paralysis, Pallor, and Pulselessness. Purulent drainage is a sign of infection, not compartment syndrome.
Compartment syndrome occurs when pressure within a closed muscle compartment exceeds capillary perfusion pressure, compromising tissue blood flow. The six P's are: (1) Pain — out of proportion to the injury, especially with passive stretch of muscles in the affected compartment (the earliest and most reliable symptom); (2) Pressure — the compartment feels tense and firm on palpation; (3) Paresthesia — numbness or tingling from nerve ischemia; (4) Paralysis — inability to move digits/muscles in the compartment (late finding); (5) Pallor — from compromised blood flow; (6) Pulselessness — loss of distal pulses (very late finding, indicates irreversible damage is likely). It is critical to understand that pulselessness is a LATE sign — compartment syndrome should be diagnosed and treated (fasciotomy) well before pulses are lost. Diagnosis is primarily clinical, supported by compartment pressure measurement (normal <10 mmHg; fasciotomy indicated when within 30 mmHg of diastolic pressure).
Question 4: A patient has a degloving injury of the forearm with significant soft tissue loss. The appropriate wound management includes:
- Primary wound closure with sutures in the trauma bay
- Wound irrigation, debridement of devitalized tissue, moist sterile dressing, and surgical consultation (Correct answer)
- Application of a dry dressing without irrigation to prevent hypothermia
- Immediate skin grafting in the emergency department
Correct answer: Wound irrigation, debridement of devitalized tissue, moist sterile dressing, and surgical consultation
Degloving injuries require thorough irrigation, careful debridement of nonviable tissue, moist sterile dressings to protect the wound bed, and surgical consultation for definitive management.
Degloving injuries involve shearing separation of skin and subcutaneous tissue from the underlying fascia, disrupting perforating blood vessels and creating large areas of potentially nonviable tissue. Initial management follows wound care principles: (1) Copious irrigation with warm sterile saline to remove debris and reduce bacterial contamination. (2) Careful assessment of tissue viability — degloved skin may appear viable but have compromised perfusion; fluorescein or clinical assessment guides decisions. (3) Debridement of clearly nonviable tissue. (4) Moist sterile dressing to protect the wound bed (moist wound healing promotes granulation). (5) Tetanus prophylaxis and antibiotics as indicated. (6) Surgical consultation for definitive management — options include reapplication of degloved skin (if viable), split-thickness skin grafting, rotational or free flaps, or staged reconstruction. Primary closure is inappropriate for wounds with significant tissue loss or contamination.
Question 5: Which splinting principle is MOST important when immobilizing a fractured extremity?
- Splint the joint above and below the fracture site (Correct answer)
- Apply the splint as tightly as possible to prevent any movement
- Straighten all angulated fractures before splinting
- Splint over clothing to save time
Correct answer: Splint the joint above and below the fracture site
Proper splinting requires immobilizing the joint above and the joint below the fracture site to prevent movement at the fracture and reduce pain, bleeding, and further injury.
The fundamental splinting principle is to immobilize the joint above AND the joint below the fracture to prevent any movement that could worsen injury, increase hemorrhage, damage nerves or vessels, or convert a closed fracture to open. For example, a tibial fracture requires immobilization of both the knee and ankle. Additional principles include: assess and document neurovascular status (pulses, sensation, motor function, capillary refill) before AND after splinting; pad bony prominences; splints should be snug but not tight enough to compromise circulation; generally splint in the position found unless there is neurovascular compromise (then gentle realignment to restore pulses); remove jewelry from the affected extremity; apply cold packs for swelling; and elevate when possible. Circumferential rigid casts are avoided in acute trauma due to swelling risk. Reassess neurovascular status frequently after splint application.
Question 6: A patient with an open (compound) fracture of the tibia has bone protruding through the skin. Which action should the nurse avoid?
- Covering the wound with a moist sterile dressing
- Administering IV antibiotics within one hour
- Pushing the bone back beneath the skin surface (Correct answer)
- Assessing distal neurovascular status
Correct answer: Pushing the bone back beneath the skin surface
Exposed bone should never be pushed back into the wound, as this introduces skin flora and environmental contaminants into the deep tissues and bone, increasing the risk of osteomyelitis.
Open fractures are orthopedic emergencies because the communication between the fracture and the external environment creates high infection risk. The exposed bone has been contaminated by skin flora and environmental bacteria. Pushing it back beneath the skin would drive this contamination deep into the wound and medullary canal, dramatically increasing osteomyelitis risk. Correct management includes: (1) photograph the wound for surgical planning before dressing; (2) remove gross contamination; (3) irrigate gently; (4) cover with a moist sterile dressing; (5) splint to prevent further contamination and tissue damage; (6) administer IV antibiotics within one hour (typically a first-generation cephalosporin; add an aminoglycoside for severe contamination, and penicillin for farm injuries); (7) tetanus prophylaxis; (8) urgent surgical consultation for formal irrigation and debridement in the OR. Gustilo-Anderson classification (Types I-IIIC) guides management based on wound size, contamination, and soft tissue/vascular involvement.
TNCC Musculoskeletal and Surface Trauma 2
A patient with a closed femur fracture is at risk for significant hemorrhage.
The estimated blood loss from a single femur fracture is approximately: