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Substantial increase in healthcare costs has contributed to the development of outcomes research in the United States. Outcomes research evaluates the effectiveness of healthcare interventions in many aspects of patient care (clinical outcomes, functional health status, patient satisfaction, health-related quality of life) and reflects national trends in determining appropriateness, value, and quality of health care.1 Outcomes research in regional anesthesia has traditionally focused on clinically oriented outcomes, such as overall mortality and major morbidity (cardiovascular, pulmonary, coagulation, cognitive, gastrointestinal, immune, stress response).2 This chapter examines the currently available evidence comparing regional and general anesthesia in terms of clinically oriented outcomes. [ABSTRACT FROM AUTHOR]

There is a large variety of available routes for administration of analgesic drugs to manage postoperative pain; these include: enteral (oral, sublingual, buccal, transmucosal), rectal, parenteral [subcutaneous, intramuscular (i.m.), intravenous (i.v.)], surface (topical, transdermal), cavity (intranasal, inhalational, intra-articular), and neural (neuraxial and peripheral) routes. Table 16-1 shows the regional techniques available to manage postoperative pain. The problems associated with regional techniques generally are covered elsewhere in this book; these include technique-related issues, infection, nerve injury, systemic local anesthetic (LA) toxicity, etc. Also, it is clear that "epidural analgesia" is not a generic term. Its effects on outcome and complications may differ depending on whether epidural injections consist of opioids, LAs, or both. In addition, the insertion site for the epidural catheter (lumbar, low thoracic, or high thoracic) will significantly alter physiologic effects when LAs are used. [ABSTRACT FROM AUTHOR]

Morbidity studies concerning regional anesthesia have been published by authors in many countries. The purpose of the studies is to document the types of complications that are associated with the practice of regional anesthesia. The studies examine the causes and mechanisms leading to injury, the severity of the injury, the outcome with respect to recovery and survival, and the physician's culpability in relation to the morbid event. [ABSTRACT FROM AUTHOR]

The purpose of this chapter is to present basic medicolegal principles, to report published guidelines that establish professional standards, and to summarize recent publications concerning medicolegal issues specific to the practice of regional anesthesia. Those interested in reading a meticulous dissertation concerning the legal aspects of medicine should consult a law text covering that field of jurisprudence. One could peruse a contemporary textbook of anesthesiology; such publications devote at least one exhaustive chapter to the subject. [ABSTRACT FROM AUTHOR]

This chapter presents some of the known complications of regional anesthetics through illustrative case reports. Although the case reports are not those of actual patients, they are representative of real cases and incorporate features from actual reports or clinical experiences. Care has been taken to make certain that the depiction of presenting signs and symptoms are true to those actually reported in the literature. Reports are followed by relevant discussion, which includes our present understanding of underlying mechanisms and etiologic factors that are believed to contribute to the development of the complications. Diagnosis and management of complications are [ABSTRACT FROM AUTHOR]

Modern anesthesia is a highly predictable undertaking with a very low failure rate. The ability to produce successful anesthesia is a less important characteristic of excellent anesthetic practice than the ability to recognize and treat adverse perioperative events. Recognition of myocardial ischemia or prompt treatment of catastrophic bleeding are examples of the situations requiring careful diagnosis and calm, decisive action. This same approach should prevail when the adverse event is a neurologic complication of regional anesthesia, only there is an added difficulty. At few other times in the practice of anesthesia will a practitioner be so directly confronted with responsibility for an adverse outcome as with a complication from neural blockade, because in a sense the "smoking gun" is clearly in our hands. Additional opprobrium may stem from the common misconceptions that complication rates should be zero in the practice of anesthesiology, and that the complication would not have occurred if only a general anesthetic had been performed. [ABSTRACT FROM AUTHOR]

Performing regional anesthesia in patients with preexisting neurologic or neuromuscular disease remains controversial. Numerous anecdotal reports describe the successful use of regional techniques in a variety of neuromuscular disorders including multiple sclerosis, amyotrophic lateral sclerosis (ALS), muscular dystrophies, myotonias, and others.1 However, a study of significant size to confirm or support the safety of regional anesthesia in these patients continues to remain scarce. Specific guidelines regarding the use of regional techniques in the setting of neurologic disease are difficult to define because of these limitations. Therefore, the goal of this chapter is to review several of the more common neurologic disorders that an anesthesiologist may encounter and outline what information currently exists to help guide the use of regional anesthesia. [ABSTRACT FROM AUTHOR]

Infectious complications may occur after any regional anesthetic techniques, but are of greatest concern if the infection occurs around the spinal cord or within the spinal canal. Possible risk factors include underlying sepsis, diabetes, depressed immune status, steroid therapy, localized bacterial colonization or infection, and chronic catheter maintenance. Bacterial infection of the central neural axis may present as meningitis or cord compression secondary to abscess formation. The infectious source for meningitis and epidural abscess may result from distant colonization or localized infection with subsequent hematogenous spread and central nervous system (CNS) invasion. The anesthetist may also transmit microorganisms directly into the CNS by needle/catheter contamination through a break in aseptic technique or passage through a contiguous infection. An indwelling neuraxial catheter, although aseptically sited, may be colonized with skin flora and consequently serve as a source for ascending infection to the epidural or intrathecal space. [ABSTRACT FROM AUTHOR]

This chapter discusses major injuries such as paraplegia caused by epidural, caudal, and spinal anesthetic techniques. [ABSTRACT FROM AUTHOR]

Interest in interventional pain management is on the rise, as indicated by an increased enrollment into the anesthesiology pain fellowship programs in North America.1 The prevalence of treatment-related complications has also increased, as suggested in a recent Closed Claims study.2 In this chapter, we discuss sympathetic, visceral, and somatic blocks frequently used in the management of chronic pain. To understand how complications arise, it is necessary to review the anatomy and techniques of the blocks, which can be used for diagnostic or therapeutic purposes. It is also important to understand some of the unique drugs used in this setting (e.g., neurolytic agents and corticosteroids). In general, procedure-related damage can result from needle insertion, misplacement or unanticipated spread of the drug, drug toxicity, injection of the wrong substance, or from an idiosyncratic reaction. Postblock physiologic changes may also add to complications. [ABSTRACT FROM AUTHOR]

Catheters for prolongation of nerve blocks were first used in the 1940s, when ureteral lacquered silk catheters were applied in continuous caudal (sacral) analgesia,1,2 continuous subarachnoid block,3 and continuous lumbar epidural block.4 Thereafter, there has been a steady development in plastic material technology and polyethylene and polyvinyl catheters have been followed by presently used nylon (polyamide), polyurethane, and Teflon (tetrafluoroethylene) catheters. Still today, there seems to be no universally ideal catheter material, and the material, design, and diameter of regional anesthesia and analgesia catheters are chosen according to the specific requirements associated with the various blocks. Overall, the catheter material is such that in a case of resistance or obstruction, the catheter must not break.5 For example, an epidural catheter should advance into and through the needle rather than flex excessively when resistance is encountered, and yet still bend and deflect off tissue.6 The deflection property has been solved in some of the epidural catheters by a "soft" and flexible steel coil extension of the tip (e.g., Arrow Flextip®). An intrathecal catheter should be soft, relatively thin, and resistant to kinking. However, a brachial plexus catheter has to be relatively stiff and blunt. In addition to acceptable tissue compatibility, the catheter must also withstand the destructive (solubilizing) action of the neurolytic drug solutions administered through the catheters, such as 6%-10% phenol or 100% ethanol. [ABSTRACT FROM AUTHOR]

The major trend in the provision of anesthesia services to pregnant women over the past 25 years has been the increasing use of regional anesthetic techniques for labor and operative delivery.1 According to the latest report on Confidential Enquiries into Maternal Deaths in the United Kingdom, at least 80% of cesarean deliveries are now performed under regional block.2 The report highlights that the likelihood of dying from anesthesia is now 1 per 100,000 cesarean deliveries, more than 30 times less than it was during the 1960s. This reduction in mortality is clearly associated with the increased use of regional anesthesia, to which no deaths were attributed in this triennium. 2 This was not always the case, and it is only 15 years since deaths resulting from regional anesthesia in the United States were evenly divided between local anesthetic toxicity and high spinal/epidural anesthesia.3 In contrast to regional anesthesia, the safety of general anesthesia remains unchanged since 1982-1984, and the risk of death attributable to general anesthesia is now estimated to be 1 death per 20,000 cesarean deliveries.2 Death is only the tip of the morbidity iceberg, however, and obstetric regional anesthesia was the source of more than one-third of anesthesia malpractice insurance claims in the United States during the 1980s and 1990s.4,5 Obstetric anesthetists must be familiar with the differential diagnosis of postpartum injuries to be able to recognize rare but potentially life-threatening complications of regional anesthesia. Such injuries may be intrinsic to labor and delivery or they may result directly or indirectly from obstetric or anesthetic intervention.6 [ABSTRACT FROM AUTHOR]

In the first edition of "Complications in Regional Anesthesia," Broadman1 produced a chapter that essentially reported a synopsis of all of the complications that were available at that time in the English-language literature that were associated with the placement of regional blocks in infants and children, and the limited safety record associated with caudal block placements. The caudal block safety record was based on three moderately sized series, 750-7800 blocks, which had been safely performed by anesthesiologists that are now recognized authorities in the field of pediatric regional anesthesia.2-4 All of the potential problems or complications associated with the placement of regional anesthesia blocks at the time of the first writing were unfortunately derived from single case reports. [ABSTRACT FROM AUTHOR]

Intravenous regional anesthesia (IVRA) of the limb was first described by Bier in 1908.1 The original technique involved the surgical exposure of, and direct injection of local anesthetic into, an antecubital vessel, of an exsanguinated and isolated upper limb, thereby rendering the tissue below the applied tourniquet insensitive to pain. IVRA is a simple and effective method of providing anesthesia to peripheral tissues that anatomically have a blood supply which can be occluded by a pneumatic cuff. The technique in use today consists of the placement of a catheter in a suitable vein before exsanguination of the surgical site by gravity or compression, the inflation of a pneumatic double tourniquet, and the injection of a local anesthetic into the venous system of the isolated limb. Serious IVRA-related complications are rare and can be classified as drug and tourniquet related.2 [ABSTRACT FROM AUTHOR]

This chapter will discuss peripheral nerve blocks (PNBs) of the lower extremity. There are relatively few reports about complications associated with the use of PNBs in general and also about the mechanisms of injury after nerve blockade and methods to prevent them. [ABSTRACT FROM AUTHOR]

Epidural anesthesia was first reported by Sicard and Cathelin in France, in 1901.1 Whereas continuous techniques were pioneered by Hingson et al.2 and Tuohy,3 Dawkins4 and Bromage5 established lumbar epidural anesthesia as the gold standard for the management of labor pain. As these techniques evolved, undesirable effects became apparent; those that were repeatedly seen were judged to be side effects of the technique, and were accepted as an expected and predictable part of practice. Less common, more serious outcomes may be considered complications; these events may result in significant morbidity or mortality if left unchecked. Anesthesiologists should take great care to identify those patients at risk of developing serious complications, and must make risk-benefit evaluations in determining the suitability of a particular technique. In some cases in which the absolute risk may be difficult to quantify, and the outcome may be potentially catastrophic, the practitioner may exclude an entire subset of the patient population (e.g., the anticoagulated patient and the risk of epidural hematoma). There are a multitude of factors that can lead to adverse epidural usage outcomes. Safety in clinical practice is a complex system, which is beyond description within the confines of this paragraph. However, careful patient selection and adherence to established guidelines form the cornerstones of complication prevention. [ABSTRACT FROM AUTHOR]

Spinal anesthesia celebrated its first centennial in 1998 and still is one of the centerpieces of modern regional anesthesia. August Bier from Germany was the first to publish a report of the first successful spinal anesthesia with cocaine on his friend and assistant Hildebrandt. Since then, spinal anesthesia has gained worldwide popularity and an impressive safety record. However, the history of complications of spinal anesthesia is as old as the method itself.1 The very first spinal anesthetics were followed by postdural puncture headaches (PDPHs) as Bier and Hildebrandt both developed a headache after their experiment that, at least with Bier himself, was posture related. The wine and cigars consumed during the celebration of a successful experiment may have augmented the development of headache. [ABSTRACT FROM AUTHOR]

Paravertebral, intercostal nerve blocks and interpleural analgesia are used to provide intermittent, temporary, or continuous anesthesia or analgesia in the thoracic and abdominal regions. These regional techniques may be appropriate alternatives to the standard methods of providing analgesia (i.e., epidural analgesia, intravenous opioids) for selected groups of patients. These analgesic techniques have been used to treat pain related to thoracotomy,1,2 rib fractures,3-5 trauma,6 and chronic pain.7 In recent years, utilization of these techniques has been extended to include breast surgery,8,9 shoulder surgery,10,11 laparoscopic cholecystectomy,12 and inguinal hernia repair.13 Paravertebral blocks have recently been described as an effective means of providing analgesia after hepatectomy.14 [ABSTRACT FROM AUTHOR]

Although there are relatively few published reports of anesthesia-related nerve injury associated with the use of peripheral nerve blocks (PNBs), it is likely that the commonly cited incidence (0.4%) of severe injury is underestimated because of underreporting.1-3 The less frequent clinical application of lower-extremity nerve blocks may be the main reason that there are even fewer reports of anesthesia-related nerve injury associated with lower-extremity PNBs as compared with upper-extremity PNBs. Although neurologic complications after PNBs can be related to a variety of factors related to the block (e.g., needle trauma, intraneuronal injection, neuronal ischemia, and toxicity of local anesthetics), a search for other common causes should also include surgical factors (e.g., positioning, stretching, retractor injury, ischemia, and hematoma formation). In some instances, the neurologic injury may be a result of a combination of these factors. [ABSTRACT FROM AUTHOR]

Effective regional block is not possible without the use of local anesthetics. Even though local anesthetics have been used for more than 115 years, details about balancing risks of their toxic effects with the benefits of their therapeutic effects remain poorly focused for many clinicians. In this chapter, the most frequent toxic effect of local anesthetics — local anesthetic systemic toxicity — will be covered, as will the less-frequent clinical situations of allergy to local anesthetics and myelotoxicity. [ABSTRACT FROM AUTHOR]

There is widespread conviction among anesthesiologists that regional anesthesia offers significant advantages over general anesthesia in certain settings. At the same time, there is a fear of complications related to the performance of regional anesthetic techniques that is held with almost equal intensity. Complications related to regional anesthesia have been described by many authors, although our understanding of the numerous factors leading to these complications is limited. Auroy et al.1 described the risk of complications related to regional blocks as lower than 5 in 10,000 patients in their series, which included spinal, epidural, and peripheral nerve blocks. In the case of spinal or epidural hematoma, the relative risk has been described as 1 : 220,000 and 1 : 150,000, respectively, a rate that approaches the risk of routine general anesthesia.2 However, the risk of neurologic complications after central neuraxial block can be markedly elevated (1 : 1,800) in patients with risk factors such as female sex, osteoporosis, or concurrent use of anticoagulants.3 Despite the relatively infrequent occurrence of complications related to regional anesthesia, the fear of complications exceeds their actual occurrence. This may be attributable in part to widespread misperceptions regarding the role of regional anesthesia in producing neurologic injury on the part of patients, surgeons, anesthesiologists, and other healthcare providers. The absence of a clear understanding often leads to blame being assigned to the regional anesthetic without careful assessment and diagnosis of the neurologic deficit to determine its etiology. These misconceptions have also led to "chart wars," in which written statements assigning blame before establishment of a clear diagnosis are placed in the medical record. [ABSTRACT FROM AUTHOR]

The author of this chapter, Professor John McIntyre (Figure 1-1), is unfortunately no longer with us. He died tragically in a pedestrian accident, very close to the University of Alberta Hospital and to his home, in the spring of 1998. [ABSTRACT FROM AUTHOR]