Date Published: November 21, 2011
Publisher: Hindawi Publishing Corporation
Author(s): Janice J. Wu, Loreto Lollo, Andreas Grabinsky.
Regional anesthesia is an established method to provide analgesia for patients in the operating room and during the postoperative phase. While regional anesthesia offers unique advantages, as shown by the recent military experience, it is not commonly utilized in the prehospital or emergency department setting. Most often, regional anesthesia techniques for traumatized patients are first utilized in the operating room for procedural anesthesia or for postoperative pain control. While infiltration or single nerve block procedures are often used by surgeons or emergency medicine physicians in the preoperative phase, more advanced techniques such as plexus block procedures or regional catheter placements are more commonly performed by anesthesiologists for surgery or postoperative pain control. These regional techniques offer advantages over intravenous anesthesia, not just in the perioperative phase but also in the acute phase of traumatized patients and during the initial transport of injured patients. Anesthesiologists have extensive experience with regional techniques and are able to introduce regional anesthesia into settings outside the operating room and in the early treatment phases of trauma patients.
Compressing peripheral nerves over an extended period of time to cause profound analgesia distal to the site of compression is a historical method of regional anesthesia described in the 16th century by the French military surgeon Ambroise Parē (1510–1590). Dominique Jean Larrey (1766–1842), surgeon-in-chief in Napoleon’s army, described his observation of cold injury on nerve function and its analgesic effect on soldiers during amputations.
One of the advantages of early utilization of regional anesthesia is to reduce intravenous opioid requirements in order to adequately relieve pain. A functioning peripheral nerve block, using a long-acting local anesthetic with fast onset time, attenuates the stress response to injury, and reduces the incidence of untoward dose-related opioid side effects including respiratory depression, increased sedation, confusion, pruritus, and nausea . Additional benefits demonstrated in patients receiving peripheral nerve blocks in the pre-hospital setting include safer transport and a decreased need for their medical supervision and in the setting of mass casualties, a stable, comfortable, and awake patient allows for decreased staffing .
The disadvantages of regional analgesia are technical complexity of the procedure and the training and repetition required to achieve and maintain proficiency in regional techniques. Regional anesthesia is an invasive procedure with risks of infection, nerve injury, and procedure-specific risks such as vascular injury, pneumothorax, local anesthetic toxicity, infection, or possibly masking a compartment syndrome in extremity injuries. While for some patients with extensive extremity injuries multiple continuous catheter techniques can be utilized, often these patients require systemic analgesics and sedation, which may be more reasonable than regional techniques in some instances.
There have been anecdotal reports about regional anesthesia techniques successfully being utilized by European emergency physicians in the field. In Europe, where physicians and often anesthesiologists are utilized in the emergency medicine systems and are brought by ambulance to the scene of an accident, those physicians often utilize their skills and experience of regional techniques in the acute trauma care setting. In addition, the recent experiences of the military have shown promising results in trauma patients with the early use of regional anesthesia, especially continuous catheter techniques, after injury and during transport. It is likely that this experience will be transferred into the civilian sector in the coming years, including continuous catheters for longer-term analgesia. It is important for anesthesiologists to take the lead in adapting regional anesthesia techniques outside of the operating room environment and introduce them into the emergency room and prehospital care setting.