1. Review common concerns in orthopedic trauma patients

Orthopedic trauma patients are some of the most challenging cases for the anesthesiologist to manage, secondary to multiple coexisting injuries, associated comorbidities, potential for multiple surgeries, and increased incidence of complications (Table 24.1). On presentation, the stabilization of the trauma patient remains the primary concern, with focus on hemodynamic maintenance and multifocal injuries assessment. The use of a tourniquet and the need of cement implantation during surgery may add further complexity to the management. Additionally, the pain experienced by trauma patients can be from multiple locations, of varying severity, and if not treated appropriately may predispose the patient to other morbidities such as chronic postsurgical pain syndrome (CPSP). Chronic postsurgical pain syndrome occurs in 10 to 50% of individuals after common operations, including orthopedic procedures, with 2 to 10% of these patients developing severe chronic pain [1].

2. Describe how to best control pain in trauma patients

Falling far behind elective surgery patients, trauma patients have been the last group of patients to have sophisticated applications of pain management applied. Timely, aggressive, and adequate multimodal approaches to pain control should be the goal for all trauma patients, after the initial hemodynamic resuscitation and stabilization. Reliance on opioid monotherapy is, unfortunately, still the most common form of analgesia for trauma patients.

The multimodal approach improves analgesia by combining both centrally and peripherally acting agents, opioids, and non-opioid medications (Table 24.2). At present, few studies have investigated the use of aggressive analgesia in combat and/or trauma patients. Decreased pain intensity and improved pain relief were shown to occur in soldiers with major combat injuries that were treated with multimodal analgesia and interventions, including regional nerve blocks [2]. Non-opioid medications provide analgesia with an opioid-sparing effect, while reducing pain with movement and opioid side effects [3]. Non-steroidal anti-inflammatory drugs (NSAIDs) are frequently not administered to trauma patients in the perioperative period due to concern for their side effects. Most data on side effects are from randomized, controlled trials or data resources of patients with chronic pain, and therefore long-term NSAID use. Safety of the short-term perioperative use of NSAIDs is less well studied. Animal studies indicate negative effects of NSAIDs on fracture healing, but only with long-term use. The data in humans are contradictory. Short-term use of NSAIDs is presumably not harmful for fracture healing. The presence of other risk factors for delayed fracture healing should be taken into account when using NSAIDs in patients with fractures [4–5].

The early use of regional anesthesia can be especially beneficial to the orthopedic trauma patient and might have a far larger impact on the patient outcomes than previously assumed (Table 24.3) [6–7]. Continuous epidural or paravertebral analgesia is routinely used in trauma patients with rib fractures. They decrease patient morbidity by decreasing pulmonary, cardiovascular, and gastrointestinal complications. Continuous peripheral nerve blocks (CPNBs) of the upper or lower extremity can also be performed for treatment of pain. Perineural catheters can remain for long periods of time, as the reported incidence of clinically relevant infection is <1% [8]. However, when utilizing local anesthetics, it is important to distinguish the need for anesthetic effects and analgesic effects. Unless anesthesia is required, analgesic doses should be employed to minimize motor and sensory decrements. Renewed mobility, as soon as possible with existing injuries, is beneficial and should be the goal of any analgesic regimen.

3. Discuss the controversy of compartment syndrome and regional anesthesia

Compartment syndrome is a condition in which swelling and increased pressure within a closed muscle compartment compromises the circulation and results in ischemia and muscle necrosis. The injury is considered ischemic in nature, although the nerve injury appears to not be from a total lack of blood supply, since pulses are often present until the very late stages. This ischemic pain is in addition to the pain associated with the initial injury and is of a different nature. This is possibly due to the significant acidosis as well as other factors in the area of ischemia.

Every year, more than 200,000 people are diagnosed with acute compartment syndrome in the United States. Compartment syndrome can be caused by fractures, crush injuries, soft tissue trauma, intramedullary nailing, prolonged limb compression (e.g., cast), and reperfusion injuries. Risk factors for the development of compartment syndrome are as follows:

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  male gender

  
  
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  history of drug use

  
  
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  type of injury

  
  
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  use of cast or intramedullary nailing

  
  
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  prolonged elevated positioning

The majority of cases result from tibial shaft fractures (40%), soft tissue tibial traumas (23%), and forearm fractures (18%) [9–10]. The incidence of acute compartment syndrome is 4.3% in tibial shaft fractures, 3.1% with diaphyseal forearm fractures, and 0.25% in distal radius fractures [9].

It is thought that postoperative pain control, especially regional anesthesia, may mask the symptoms of compartment syndrome and delay diagnosis. Since unrecognized and untreated compartment syndrome can result in permanent nerve damage within eight hours, caution must be entertained when the possibility exists. While a long-acting anesthetic block may mask the diagnosis of a developing compartment syndrome, the potential for masking a developing compartment syndrome with perineural analgesia is controversial. Mar et al., in a comprehensive review of all cases of acute compartment syndrome associated with regional anesthesia, found that in most cases the symptoms suggestive of compartment syndrome had been present for many hours, but had been ignored and assumed to be related to the regional anesthesia technique [11–12]. A common theme in published case reports is one of a patient with stable therapeutic analgesia, who suddenly experiences a significant increase in pain. Similar scenarios should raise the suspicion of compartment syndrome. Close and frequent follow up is imperative if an anesthetic or analgesic block is placed in an orthopedic trauma patient. Recent military experiences report successful uses of regional techniques in trauma patients, provided that a high index of suspicion, ongoing patient assessment, diligent nursing care, and compartment pressure measurements are utilized [13–14].

Due to the low incidence of compartment syndrome, it is nearly impossible to evaluate the safety of regional anesthesia in this population with prospective, randomized studies. However, the number of case reports is increasing. Cometa et al. described a successful diagnosis of compartment syndrome due to breakthrough pain, despite a well-functioning continuous peripheral nerve block [15]. Kucera and Boezaart reported two cases of ischemia due to a tight cast with a CPNB analgesia in place [16]. Another case involves a 45-year-old female smoker, with a history of diabetes mellitus and hypertension who presented with increasingly cold, cyanotic, and painful fingers in her right hand [16]. She developed necrotic lesions of her 4th and 5th fingers accompanied by severe ischemic type pain. A continuous C7 cervical paravertebral block was placed and, despite dense sensory and motor blockade, she reported excruciating pain. Although this case was not secondary to trauma, it illustrates the fact that ischemic pain was still present and identified despite anesthetic blockade.

Often regional analgesia is denied to patients with orthopedic injuries. It should be emphasized that missed compartment syndrome occurs and has been documented in patients on PCA, without a regional block. A report of four cases of tibia nailing with delayed diagnosis of compartment syndrome, in patients with IV PCAs, illustrates that it is not the type of analgesia that may delay diagnosis. Having a non-sedated patient who can communicate, and has an analgesic but not anesthetic block, may actually help identify developing compartment syndrome.

Diligent care and close observation is the key to early diagnosis of this potentially serious complication [16]. A system of detection should involve anesthesiologists, orthopedic surgeons, trauma surgeons, and nurses in the post-anesthesia care unit (PACU) and in the ward. Education must stress that the traditional symptoms, such as a loss of pulses, associated with the development of acute compartment syndrome are unreliable. Serious consideration should be given to the use of inter-compartment pressure monitoring. Additionally, protocols for perioperative monitoring of the patients at risk must be developed and data reviewed at a minimum of two-hour intervals.