Introduction
Trauma is a major cause of morbidity and mortality worldwide, responsible for 8% of all deaths. In the United States, it is the leading cause of death for individuals younger than 30 years. Anesthesia and acute pain management for trauma victims can be very challenging to anesthesiologists, critical care physicians, and surgeons. Inadequate treatment of acute pain can potentiate the stress response associated with trauma and may lead to the development of chronic pain syndromes in the long term. The prevalence of chronic pain after orthopedic trauma varies among published series. One study found that 37% of orthopedic trauma patients complained of moderate to severe pain 6 months after the injury. In a separate series, this rate was doubled (73%) at 7 years after lower extremity (e.g., calcaneus and distal tibial fractures) orthopedic trauma. Regional anesthesia (RA) has been shown to improve acute pain control and decrease the development of chronic pain. However, it is still underused in orthopedic trauma for several reasons, including the emergent or urgent nature of the surgery, lack of resources and infrastructure, the challenges associated with polytrauma (e.g., multiple surgical sites, contaminated wounds, and spine fractures), and the concern of delaying a diagnosis of acute compartment syndrome (ACS).
Options
RA can be used in the setting of orthopedic trauma for intraoperative anesthesia, postoperative analgesia, or both. RA includes neuroaxial techniques (spinal and epidural), plexus blocks, and peripheral nerve blocks. RA may also be used as part of a multimodal pain regimen. The choice of medication, dose, route, and duration of therapy should be individualized. RA should be used only after careful consideration of the risks and benefits for the individual patient. The selected technique should reflect the individual anesthesiologist’s expertise, as well as the capacity for its safe application in each practice setting.
Evidence
Potential of Regional Anesthesia for the Orthopedic Trauma Patient
Traditional endpoints used to measure the effect of RA on patients’ outcomes include morbidity and mortality and postoperative analgesia. Spinal and epidural anesthesia has been shown to decrease mortality and postoperative pulmonary complications in patients with hip fractures. RA also provides better pain control when compared with systemic narcotics in different practice settings. Chelly and colleagues found that lumbar plexus blocks reduced morphine requirements and were associated with earlier recovery of unassisted ambulation in patients undergoing open reduction and internal fixation of acetabular fractures. Advantages of regional techniques include providing site-specific analgesia and avoidance of narcotic-induced side effects. These side effects include but are not limited to sedation, nausea and vomiting, itching, and respiratory depression. Avoiding systemic sedation in polytrauma patients makes it easier to monitor the mental status of patients with head injuries. The possibility of avoiding management of a difficult airway may offer an advantage in some cases based on the individual circumstances of each case. RA may also decrease intraoperative blood loss, decrease the incidence of deep venous thrombosis, and increase range of motion for the injured extremity, which may lead to a better functional outcome. Whether RA decreases the incidence of postoperative cognitive dysfunction is questionable. Some studies support this hypothesis and others do not.
Patient-centered outcomes (e.g., patient satisfaction, quality of recovery, and health-related quality of life) are also improved with the use of RA when compared with general anesthesia. RA can reduce the length of stay in the postanesthesia care unit and the hospital length of stay. This is especially important in patients with isolated extremity injuries who can have surgery performed as an outpatient or with a short hospital stay. Trauma patients admitted to the intensive care unit can also benefit from RA in terms of reduced pain scores, increased comfort, and decreased length of stay in the intensive care unit.
The use of RA on the battlefield in recent military conflicts facilitated transport of soldiers from the hospital field with extensive trauma to the extremities. This work suggests that the use of RA as an early intervention reduces pain and injury-related complications. In addition to the short-term benefits of acute pain control, early treatment of injuries to the extremities has potential long-term benefits including reduction in the incidence and severity of chronic pain sequelae such as chronic regional pain syndrome and posttraumatic stress disorder. Despite these known benefits, RA techniques have been underused in trauma patients, especially during the early phase of injury. One study reports that up to 36% of patients with acute hip fractures in the emergency department received no analgesia and even fewer patients were considered for regional nerve blocks. The perioperative use of RA for orthopedic trauma is no exception. Side effects and the potential risk for complications after RA are often cited as reasons to avoid regional techniques.
There are numerous studies that have been unable to show a benefit of RA in orthopedic trauma patients. One study concluded that epidural analgesia was not associated with reducing narcotic requirements or hospital lengths of stay after repair of a posterior wall fracture of the acetabulum. Patients who received popliteal blocks for open reduction and fixation of ankle fractures experienced a significant increase in pain between 12 and 24 hours when compared with their counterparts who received general anesthesia alone. Koval et al followed up 641 hip fracture patients and found that the anesthetic technique (general versus regional) was not associated with improvement in functional recovery at 3, 6, and 12 months after surgery, respectively. Foss and colleagues found that superior analgesia with epidural analgesia after hip fracture surgery did not translate into enhanced rehabilitation.
Risk of Regional Anesthesia
Deep venous thrombosis prophylaxis is often used in trauma patients. This practice often complicates the decision to use RA, especially a neuraxial technique. The major concern is the development of spinal or epidural hematoma in this setting. Patients receiving postoperative epidurals for lower extremity surgery must be followed up closely for the development of ACS. Patients undergoing tibial fracture fixation who received a postoperative epidural were four times as likely to develop neurologic complications or missed compartment syndrome compared with those receiving only narcotics. Epidural analgesia increases local blood flow secondary to sympathetic blockade and can lead to increased swelling of an injured limb. The concern about masking or delaying the diagnosis of ACS is often cited as a reason to avoid RA in the setting of orthopedic trauma.
ACS commonly develops in traumatized patients with distracting or neurologically inhibiting injuries. Physicians must have a high degree of suspicion when treating these patients. Time to diagnosis is the most important prognostic factor in these patients. Insufficient understanding of the natural history and limited evaluation of signs and symptoms primarily account for delays in diagnosis. Risk factors for development of ACS include male gender, age younger than 35 years, and tibial shaft fractures.
ACS is a result of two factors occurring in isolation or simultaneously: an increase in the contents of an enclosed space (e.g., bleeding) and/or a decrease in the volume of the space (e.g., tight cast). Compartment syndrome occurs when the interstitial pressure within the compartment exceeds the perfusion pressure at the level of the capillary beds. Elevated intracompartmental pressure (ICP) leads to increased pressure at the venous end of the capillary beds, causing increased hydrostatic pressure and a further increase in ICP, eventually leading to arteriolar compression. Loss of the perfusion pressure gradient results in the onset of ischemia and, ultimately, cellular anoxia and death.
Clinical Diagnosis
Compartment syndrome is, for the most part, a clinical diagnosis. It is a diagnosis made over time, assessing the evolution of signs and symptoms, rather than a diagnosis made in isolation. Serial examinations should always be performed, preferably, by the same experienced examiner. The classic P s described in compartment syndrome are pain, paresthesia, paralysis/paresis, pulselessness, and pallor. Although all have a role in the diagnosis of compartment syndrome, the constellation of signs and symptoms and overall clinical picture is more important than the presence or absence of any particular finding. Overall, the absence of symptoms is more useful in excluding ACS than the presence of symptoms is for diagnosing ACS.
Compartment Pressure Monitoring
ICP monitoring is a controversial component in evaluating the patient with suspected ACS. Normal resting ICP is around 8 mm Hg in adults and slightly higher (13 to 16 mm Hg) in children. A number of different techniques have been described for ICP monitoring including “the slit catheter,” the side portal needle (Stryker needle), and a regular 18-gauge needle with a setup similar to an arterial line. When techniques were compared, no significant difference was found between compartment pressures measured by slit catheters and side portal needles. Compartment pressures also vary by location, both within normal compartments and in relation to an injury.
Areas of Controversy
The major area of concern is whether delaying or masking the diagnosis of ACS precludes the use of RA. Should it be used, provided certain conditions are met and certain guidelines are followed? Specifically, does RA by itself mask or delay the pain associated with ACS, or is it the dosage of RA or of any modality of analgesia that is implicated? Finally, how much postoperative pain should trigger clinical suspicion for the diagnosis of ACS, and is this pain different in nature from acute postoperative pain?
The debate about whether RA delays the diagnosis of ACS in the setting of orthopedic trauma is old. It will continue as long as we do not have class I or II evidence that would support or refute either side of the debate. ACS is a rare event that, unfortunately, does not lend itself to randomized clinical trials to define whether it is associated with the use of regional techniques.
Epidural Analgesia
In 2008 Mar and colleagues published a comprehensive review of the reports of ACS associated with postoperative analgesia (i.e., epidural/spinal, peripheral nerve blocks, and intravenous patient-controlled analgesia [IV-PCA]) after orthopedic and nonorthopedic surgery. A total of 28 case reports and case series referred to the influence of analgesic technique on the diagnosis of ACS, of which 23 discussed epidural analgesia. Some of the cases described gluteal ACS related to a prolonged lithotomy position in urologic surgery. In 32 of 35 patients, classic signs and symptoms of ACS were present while the epidural infusion was still running. However, the significance was not recognized until the epidural infusion had been stopped. A delay occurred in the diagnosis in three cases. All three had dense motor blocks. The conclusion of the authors was that “there is no convincing evidence that patient-controlled analgesia opioids or regional analgesia delay the diagnosis of compartment syndrome provided patients are adequately monitored.” Johnson and Chalkiadis reviewed pediatric and adolescent cases of ACS associated with epidural analgesia. They identified warning signs that should trigger clinical suspicion for the diagnosis, including increased analgesic requirements, pain remote from the surgical site, paresthesia, pain on passive movement of the extremity involved, swelling, and decreased perfusion of the painful site. The authors suggested a clinical pathway for management of patients at high risk for the development of ACS. Table 56-1 summarizes the case reports associated with epidural analgesia in the setting of orthopedic surgery.
Report | Patient Demographics | Procedure | Local Anesthetic Used | Presentation |
---|---|---|---|---|
Hailer and colleagues | 43-yr-old female | TKA | Ropivacaine and sufentanil (no dose details) | Paraesthesia, swelling, pain, increased analgesic requirements |
Kumar and colleagues | 46-yr-old female | TKA | NS | Increased pressure, swelling, pain once epidural removed |
71-yr-old male | THA | NS | Pain 16 hr after epidural removed. Tense, firm, tender, swollen buttock | |
55-yr-old male | Hip resurfacing arthroplasty | NS | Pain 4 hr after epidural removed | |
72-yr-old male | TKA | NS | Foot drop, paralysis, buttock swelling | |
Haggis and colleagues | 69-yr-old female | TKA revision | NS | No pain. Tight, swollen calf |
53-yr-old male | TKA | NS | Pain, cold, pulselessness, swelling | |
48-yr-old female | TKA | NS | Swelling, foot drop | |
49-yr-old female | Bilateral TKA | NS | Pain, foot drop | |
61-yr-old male | TKA | NS | Pain, paralysis, paraesthesia, tight swollen calf | |
Bezwada and colleagues | 60-yr-old male | Bilateral TKA | Bupivacaine and fentanyl (no dose details) | Weakness, paralysis, swelling, numbness |
Somayaji and colleagues | 39-yr-old male | THA | Bupivacaine 0.125% and fentanyl | Pain after epidural stopped; paralysis, paraesthesia |
Pacheco and colleagues | 47-yr-old male | TKA | NS | Back pain once epidural stopped, then buttock pain |
71-yr-old male | TKA | NS | Foot drop, paraesthesia once epidural stopped | |
Tang and Chiu | 62-yr-old female | TKA | Bupivacaine 0.125% | Decreased capillary return (POD 2), no pain, calf swelling |
Dunwoody and colleagues | 14-yr-old male | Triple osteotomy, left hip | Bupivacaine 0.1% and fentanyl | Pain, worse pain on movement |
7-yr-old male | Ilazarov frame to the left femur | Bupivacaine 0.25% and fentanyl | Decreased pulse, calf spasm | |
Kontrobarsky and Love | 70-yr-old male | Ankle fusion | Bupivacaine 0.125% | Buttock pain |
Nicholl and colleagues | 65-yr-old male | THA revision | Morphine | Pain, pain with passive stretch, swelling, tenderness |
Price and colleagues | 16-yr-old male | Distal femur and proximal tibial osteotomy | Fentanyl | Discomfort, numbness, and increased pressure |
Seybold and Busconi | 18-yr-old male | Scapular fasciocutaneous-free flap graft | NS | Swelling, rigid compartment; pain after epidural was stopped |
Morrow and colleagues | 18-yr-old male | Bilateral femoral IM nail | Bupivacaine 0.2% and fentanyl | Unilateral paresis and anesthesia |
Strecker and colleagues | 45-yr-old male | Free fibular flap | Bupivacaine 0.125% at 10 mL/hr | Pain after the epidural was stopped on POD 1. Pain, swelling of the donor site, and dysesthesia on the planter surface of the foot |
Ross | 6-yr-old female | External fixation midshaft tibia | 15 mL bupivacaine; 0.25% of caudal epidural | Pain 7 hr postoperative; nonresponsive IV opioids |
Llewellyn and Moriarty | NS | Tibial osteotomy | NS | Audit concluded that occurrence of compartment syndrome does not appear to be masked by the presence of working epidural |
Whitesides * | 15-yr-old male | Proximal tibial osteotomy | NS | NS; however, the patient developed ACS on one side |
23-yr-old male | Repair of ligamentous injury of the knee and closed reduction of spiral fracture of the tibia and fibula | NS | NS; however, the patient developed ACS |