Extremity Injury and Associated Problems

Extremity Injury and Associated Problems

The majority of multiply injured patients have musculoskeletal injuries. Extremity and other injuries place the patient at risk for various complications such as fat embolism, adult respiratory distress syndrome (ARDS), acute compartment syndrome and sepsis.

Pain

Pain a feeling of sever discomfort can adversely affect the outcome of an injury by becoming the primary focus of the patient and their family, impaired ventilation which causes hypoxia and pneumonia, continued immobility leading to thromboembolic events and even death. Therefore, aggressive pain control is critical in the care of multiple injury patients. Pain control can be achieved by several different methods. Fracture stabilization, whether provisional (e.g., posterior slab for extremity fracture) or definitive (external fixation for femoral fracture), will provide some pain relief. Reduction of dislocated joints significantly decreases pain. Early stabilization and restoration of alignment of fractures is an essential step in the resuscitation and pain relief of trauma patients. Unstable pelvis, acetabulum, and femur fractures are often definitively managed within the first 24 hours. These and other interventions combined with various medications including paracetamol, diclofenac, ibuprofen, and opiates (morphine, pethedine) can be used effectively to maximize patient comfort and recovery.

In other way, pain is a patient‘s essential early-warning system that an injury has occurred. It is an invaluable tool that can be used to identify injuries in the multiple-trauma patient, especially during the secondary and tertiary surveys. Painful stimuli from an injury aid in diagnosis of the problem and initiation of treatment, so that further damage of the surrounding structures can be avoided.

Extremity Injury and Hemorrhage

Extremity injuries (Figure 7.3 and Figure 7.4) can be life-threatening because of associated vascular injuries and secondary infectious complications. Vascular injuries can lead to massive hemorrhage and threaten extremity viability. Pelvic fractures or bilateral femur fractures are the two most frequent injuries that can cause bleeding of this magnitude. Usually this bleeding will be into a closed space - not immediately obvious to the examiner. For example, a femoral fracture can be associated with 2 - 3 units of occult blood loss, and closed pelvic fractures can cause even more occult blood loss resulting in hypovolemic shock. Open fractures with extensive soft tissue destruction and/or arterial injury are another problem that can be not only limb threatening, but also life-threatening because of the amount of associated hemorrhage.

After the primary survey a more deliberate secondary examination a head-to-toe search for visible injuries or deformities, including deformities of bones or joints, soft tissue bruising, and any breaks in the skin is undertaken. Indications for urgent or emergency surgery may also arise during the secondary survey. The presence of a limb threatening injury as a result of either vascular compromise, pulse less limb and condition to cause compartment syndrome should be addressed.

The Acute Compartment Syndrome

The acute compartment syndrome (Figure 7.5) exists when edema and blood accumulate within a confined osseofascial space compromising the circulation and tissues within that space. Compartment syndrome occurs after fractures of the tibia, followed by the femur and ankle. Delay in diagnosis and treatment (surgical decompression) is the most common cause of serious complications. Pain out of proportion to the clinical situation is the usual early symptom.

Acute compartment syndrome of the extremities is defined as a "condition in which increased pressure within a limited space compromises the circulation and function of the tissues within that space. With orthopedic trauma the most common cause of compartment syndrome is edema secondary to muscle injury and associated hematoma formation. Though most commonly associated with traumatic injuries, compartment syndrome can also occur as a result of a number of causes associated with trauma, burns, and prolonged limb compression. The most common fractures associated with the development of compartment syndrome are those of the tibial shaft (40%) and forearm (18%). A further 23% are caused by soft tissue injuries without fracture.

Crush Syndrome

Crush syndrome is the general manifestation of crush injury (Figure 7.6) caused by continuous prolonged pressure on one or more extremities and is commonly found in patients who have been trapped in one position for an extended period. Muscle injury secondary to ischemia causes myoglobinuria (the presence of muscle hemoglobin in the urine), which can lead to acute renal failure and subsequent profound electrolyte disturbances. The most critical treatment consists of crystalloid fluid resuscitation; a total-body fluid deficit of 15 L may occur in severe rhabdomyolysis (an acute sometimes fatal disease characterized by destructive skeletal muscle). Rhabdomyolysis must be treated with aggressive diuresis and adequate fluid replenishment, while avoiding myoglobin damage to renal structures. This may require diuretics such as mannitol, as well as alkalinizing agents (sodium bicarbonate) used to prevent myoglobin precipitation.

Traumatic Amputation

Traumatic amputation and near-amputation (surgical removal of limb or part of the limb) are severe open fractures (Figure 7.7). Pressure to control bleeding is important as are expeditious antibiotic and tetanus prophylaxis for any open fracture. Reimplantation, especially with certain hand injuries, and salvage (rescue from loss) of near-amputation may be possible, if this can be completed within the first several hours of injury. Crush injuries, prolonged ischemia time, severe trauma elsewhere in the limb, serious systemic injury, advanced age, and underlying medical conditions are factors decreasing the likelihood of successful salvage. Emergency surgery is recommended to examine the affected area, to perform surgical debridement, and to gain control of bleeding. In rare cases amputation is undertaken to stop bleeding in a mangled extremity. This can be life-saving and can reduce the wound and injury burden in a multiply injured person. More commonly, salvage is attempted with provisional or definitive stabilization of fractures. Oftentimes, external fixation is used as a rapid means of stabilizing fractures in patients who are critically ill and under resuscitated. External fixation can generally be performed in several minutes with minimal surgical trauma. Serial debridement and later definitive fixation (versus amputation) can be done after discussions with the patient and other subspecialists. Amputation is occasionally necessary for massive crush injury, vascular injury, or progressive soft tissue infection.

Fat Embolism

Fat embolism is a well-known complication of skeletal trauma and surgery involving instrumentation of the femoral medullary canal and after long bone fracture. Embolism is the blocking of an artery by a mass of material, usually a blood clot, air or fat, preventing the flow of blood. Fat embolism syndrome (FES) is a physiologic response to fat within the systemic circulation. Fat embolism represents capillary endothelial breakdown, causing pericapillary hemorrhagic exudates that are most apparent in the lungs and brain. The Pathophysiology of FES is unclear, but it probably involves two processes: the embolization of fat and "bone marrow debris;' which can mechanically obstruct the capillaries of end organs, and the triggering of a systemic inflammatory response.

The clinical manifestations of FES include respiratory, neurologic, hematologic, and cutaneous signs and symptoms. The presentation of FES can be gradual, developing over 12 to 72 hours, or fulminant (dangerous disease which develops rapidly) leading to acute respiratory distress and cardiac arrest. Signs include

• Petechial rash: Petechiae is small red spot which does not go white when pressed, caused by bleeding under the skin in fat embolism usually present on the conjunctiva, oral mucosa, and skin folds of the neck and axilla.
• Diffuse alveolar infiltrates
• Hypoxemia Pao2,<70 mm Hg, FlO2, 100%
• Confusion
• Fever >38°C
• Heart rate> 120 beats/min
• Respiratory rate >30

Management of fat embolism

• Follow ABCDE
• Treatment consists of early recognition, oxygen administration, and maintenance of intravascular volume. With appropriate fluid management, adequate ventilation, and the prevention of hypoxemia, the outcome is usually excellent.
• Patients at risk for developing FES should be monitored with pulse oximetry, and tracheal intubation and mechanical ventilation should be instituted before respiratory failure.
• Fixation of long bone fractures also helps decrease the incidence of fat embolism syndrome.

Anesthetic Consideration for Extremity or Musculoskeletal Trauma

• Anesthetic management for emergency and trauma patient should be considered for managing extremity trauma. Induction and maintenance drug and dose recommendations used for abdominal trauma surgery are used to orthopedic trauma surgical procedures (Table 7.1 and Figure 7.8).

• Life-threatening and limb-threatening musculoskeletal injuries are addressed emergently. These include patients with massive hemorrhage from pelvic fracture or multiple long-bone fractures, arterial injury in an extremity, and compartmental syndrome. In these situations, orthopedic management contributes to resuscitation and promotes viability of life and limb.
• Communication between the surgeon and the anesthesia team regarding the rationale for surgery and the plan of treatment is very important. This will facilitate patient safety and expedite the procedure.
• During positioning we have to be cautious for spinal cord injury, analgesia to reduce pain during movement and slight traction when moving extremity should be considered.
• The choice of spinal (regional) or general anesthesia depends on patient preference, ability of the patient to provide informed consent, confidence and expertise of the anesthetist in performance of regional anesthesia, duration of the procedure, surgical preference, and presence or absence of contraindications
• Muscular relaxation of the patient is necessary for reductions to be performed safely. Closed reductions, in which the dislocation is manually manipulated without surgery, are possible in most cases. Some dislocations are most safely undertaken in the operating room under general anesthesia. This permits muscular paralysis and promotes safe airway management.
• Anesthetic management for amputation requires preliminary emotional and psychological support.
• During anesthesia, the patient should be kept warm, and emergence shivering must be avoided to maximize perfusion.
• The time for tourniquet application should be noted and inform the surgeon every hour.
• The importance and preparation of blood prior to administering anesthesia as these procedures may bleed torrentially