Novel Characteristics of Nora Cases

NORA cases are characterized by three distinctive features: location, operator, and relative novelty. First, the procedure does not take place in a standard operating suite and is typically remote to the main OR section. Second, the operator performing the procedure is generally a medical interventionalist rather than a surgeon. Finally, the procedures and technologies used are constantly evolving. Innovative applications of these procedures and technologies pose a challenge for a number of reasons as well. With advances in technology and expertise of the operators performing procedures outside of the OR, the procedures can be performed on patients with complex comorbidities and often on patients who are not candidates for a traditional surgical procedure or for whom surgery is no longer the only therapeutic option. For example, carotid artery stenosis can be treated in the OR, the catheterization laboratory, or the interventional radiology (IR) suite. The ultimate choice of venue may be a function of acuity of presentation but often depends on the referral—who the patient sees first, and who is available. As important, for many patients undergoing a NORA procedure, the scheduling is urgent, emergent, or unknown to the anesthesia provider until immediately before the procedure is to be performed, preventing an adequate periprocedural evaluation. These ever-expanding clinical services requiring anesthesia services outside of the OR provide an opportunity for anesthesiologists to reevaluate and reaffirm the importance of a preoperative assessment, as well as periprocedural and postprocedural needs, for this diverse group of patients. As a result, the perimeter of our landscape has expanded beyond the familiar domain of the OR and requires collaboration with a broad array of medical practitioners including interventional cardiologists, interventional radiologists, gastroenterologists, radiation oncologists, and electrophysiologists. Given the physical, medical, political, and economic challenges that may arise and that are often unanticipated, the goal must be to adapt to the new environments. We must also strive to evolve our anesthesia practice to meet the demands of a changing patient population.

Unique Obstacles: from Physical Environment to the Medicine–Anesthesiology Culture Gap

When anesthesiologists are faced with the need to provide services for non-surgeons in non-OR locations, issues such as scheduling inconsistencies, ad hoc requests, and resource limitations can be difficult to resolve, particularly if the usual scheduling process is not available. In addition, the increasing incidence of medically complex cases with patients needing urgent intervention, but lacking periprocedural evaluation, can create challenges. The two most common challenges are poor communication between providers exacerbated by the medicine–anesthesiology culture gap and, for many of the NORA procedures, inadequate physical space to accommodate the needs of a patient requiring anesthesia services.

Procedural suites are often remotely located. This increases the time lag between a request for assistance and the arrival of help, both with technological and medical problems. In addition, the lack of nearby supplies may exacerbate the timely resolution of common electrical and mechanical malfunctions or complicate the resolution of a medical emergency. This situation demands that care be taken before the start of the procedure to ensure that equipment is supplied and working and that backup options (emergency supplies, difficult airway equipment) are functioning and readily available.

In addition, non-OR procedure suites are frequently organized from the perspective of the proceduralist, and unfortunately, the needs of anesthesiologists are often overlooked. For example, procedure suites that use fluoroscopy for guidance are often configured so that the C -arm limits access to the patient’s head and obstructs direct communication between the anesthesiologist and the proceduralist. Inadequate access to the patient may be exacerbated if the area around the head of the patient is crowded due to constraints of the room and equipment. Lack of visibility of procedural screens may also make it difficult to follow the progress of the intervention without compromising the attention to the patient. Perhaps most important, hemodynamic monitors may be difficult to visualize by the anesthesiologist or, for some procedures, may not function properly because of interference with mapping systems or other electronic interfaces. Lead protective screens may not be available, and when they are available and positioned to protect the anesthesiologist from radiation, pumps and intravenous lines may become inaccessible. Gas scavenging may be unavailable, and oxygen and suction outlets may be suboptimally placed. For these and other reasons, anesthesiologists should be mindful of how best to orient both the patient and providers spatially within a procedure room, particularly if the setup of the room is unfamiliar. Distraction of focus away from patient care due to an unfamiliar environment can be potentially disastrous in the face of a novel or complex procedure.

The ASA has formulated a statement regarding NORA locations that articulates minimum standards for all procedures performed in these areas, but these standards are quite fundamental. Recognition of the constraints of the environment and anticipatory planning allow for the safe administration of anesthesia within this environment. The challenge is communicating the importance of these issues to the proceduralist and others involved in the care of the patient as well as hospital leadership to ensure that the needs of all parties are met. With newer procedures requiring anesthesia services in nontraditional environments, there may be a need to implement significant environmental changes to optimize the ability of anesthesiologists to deliver safe care.

Communication with the medical proceduralist is key to providing an optimal anesthetic; taking time to discuss the procedure and the patient allows for thoughtful consideration of anesthetic options in the context of both the principles of the procedure and the physiology of the patient. However, mismatches in culture can dominate interactions between medical practitioners and anesthesiologists and undermine communication. These conversations can be challenging since, unlike surgeons, medical providers may be unfamiliar with the skill sets of anesthesiologists and the needs for patient care or unaware of the intricacies associated with administering an anesthetic. For example, while surgeons are accustomed to sharing their procedures with other medical practitioners, proceduralists may be habituated to working alone and ordering sedation to be administered by a nurse. Medical interventionalists may also lack experience with relatively rare but serious complications that might arise during the procedure, such as loss of airway. In addition, proceduralists are frequently consultants who are enlisted by primary care providers to perform procedures, but who may not have received all relevant information that may be needed for a patient requiring anesthesia services. Even when all information is provided, specialization predisposes the proceduralists to concentrate on their point of expertise, so many of the concerns of the anesthesiologists are not taken into account.

Similar issues regarding the needs of the patient and the proceduralist may not be taken into account by the anesthesiologist who is unfamiliar with the procedure. In many cases, the anesthesiologist may have only a basic understanding about what is happening during the course of a noninvasive procedure and may not have asked enough questions about the plans, especially when they are new to a particular venue, the procedure is not observable, and fluoroscopy screens are out of the field of view or uninterpretable. Anesthesiologists may be unaware of pitfalls and likely complications of the procedure even though in the OR, they normally would not administer an anesthetic without understanding the idiosyncrasies of the surgery. These issues are important in planning for the anesthesia and procedure but are equally important during the procedure. Extra initiative is often required by the anesthesiologist since the proceduralist may not communicate the course of the procedure during the case. Other aspects of the procedure, such as how coughing on extubation might predispose patients who have had groin sheaths to serious hematomas, may not have been emphasized by the procedural team or likewise appreciated by anesthesiologists. Bridging the communication gap requires effort, but it is absolutely critical to optimizing outcomes.

When interventionalists undertake novel procedures using new technologies, the situation can become even more challenging. The course of the procedure may be unknown, the timing and sequence of events may be ill-defined, and the focus of the procedure may change midstream. At times, the proceduralist may be unsure of what is happening. In these situations, extensive preplanning, a commitment to communication, and the explication of goals for all involved in the care of the patient is crucial to the success of the procedure and, more importantly, the safety of the patient.

As medical procedures, particularly those performed outside of the OR environment, become even more technically demanding and patient clinical conditions more complex, the best possible patient management strategies will arise from collaboration and teamwork between medical proceduralists and anesthesiologists. This requires mutual respect, excellent communication, common vocabulary, shared experience, and overlapping competencies. In pursuit of this goal, we can build on the outstanding record of improved patient safety and outcomes that characterizes the history of anesthesiology.

Financial and Operational Constraints

The impact of performing procedures in new environments has significant financial and operational implications that must be addressed. In the desire and enthusiasm to advance clinical care and extend care to settings outside of the operating room, medical, financial, and operational implications often become blurred. As a result, it is important to understand the difference between what does and what should drive the direction of new program development related to NORA procedures and for all parties to address the specific operational needs while taking into account the financial implications of transitioning care to these alternative settings.

Effects of Payment Systems

A variety of payment methodologies are used to compensate providers and facilities for clinical services. While government payment methods remain important, private insurance has become the financial underpinning of the healthcare system in the United States—often allowing hospitals and providers to advance new technologies and innovative care that would otherwise be financially impossible. Private health insurance evolved as hospitals transitioned from repositories for the impoverished and dying into institutions where people actually recovered from illness. Hospitalization plans, initially developed by hospitals in the 1930s, were a way to supplement the economic resources needed for growth and expansion. At that time, hospitals often functioned as extensions of private offices and payment was, and continues to be, a fee-for-service system. As health care has become more expensive and the clinical options have expanded, both the public and private systems have had to adapt, becoming more complex and sophisticated—with the goal to minimize payment to those practices that have documented, evidence-based outcomes. These changes, and the goal to reduce costs of care, have both encouraged care outside of traditional and expensive environments, such as the OR, but also challenged providers to prove that the care remains safe and of high quality. These conflicting goals make expansion of care to non-OR locations challenging and, in some cases, undermine attempts to innovate.

Medical optimization and financial efficiency are predictably not the end products of fee-for-service payments. With increasing demand for clinical services, the need to reduce costs, hospital length of stay, and readmissions is critical. As the population ages, care is increasingly specialized and complex. The Medicare Payment Advisory Commission (MedPAC) reported that as of 2006, the average Medicare beneficiary saw five doctors per year and Medicare beneficiaries with three or more chronic conditions saw more than 10 physicians a year. With advances in care, transitions of some procedures from the OR to new settings, and care provided by a “new” group of providers that previously did not perform procedures (cardiologists, neurologists, and others), more providers participate in the care of patients. The implications of these changes are numerous. For example, for patients whose care involved four or more doctors, MedPAC reported that 48% experienced medical errors, medication errors, or laboratory errors. As technology advances and the population ages, risks and benefits change and new genres of service emerge and expand. Imaging services, which have exploded across disciplines in the last decade, are now provided by radiologists, vascular surgeons, cardiologists, internists, anesthesiologists, and surgical subspecialists. Traditional fee-for-service payment systems are not designed to ensure that the right treatment is performed on the right patient at the right time by the right physician in the right venue. The result is that groups of assorted medical proceduralists provide in-hospital care that is often fragmented, perpetuated by silos of specialized care despite the interdependent nature of specialty services. Coordination of care, particularly for the newer procedures requiring anesthesia services and performed outside of the OR, is needed but often not provided for a variety of reasons. Unfamiliarity with anesthesia services and requirements as well as lack of payment for coordination of care are primary reasons. This uncoordinated or fragmented care creates challenges for the patient and provider, often resulting in duplication of some service, variability of resource use, and inconsistent application of quality standards. Payment silos create misalignment of goals across specialties, creating competition rather than collaboration among disciplines and, in some cases, pitting the needs of one set of providers against another without intending to do so.

Another factor that contributes to the challenges associated with performing procedures requiring anesthesia care in NORA environments is the lag in payment for new technologies by Medicare and other payors. While delaying implementation of new procedures into the clinical environment until peer-reviewed evidence documents the value may be appropriate, particularly when new and/or proprietary, high-cost equipment is required, the lack of payment may actually contribute to higher costs of care or reduced quality.

Anesthesiologists are particularly vulnerable to inadequate or no compensation for some of the procedures performed outside of the OR. In some cases, the lack of payment is related to “historical controls”—healthier patients undergoing procedures outside of the OR with sedation provided by a nurse or proceduralist. The anesthesia service is only compensated when the patient meets criteria for “medical necessity”—and there may be inadequate documentation of the need for anesthesia care by the proceduralist. As important, for some patients there are associated services for which there may be no compensation. Routine preprocedure evaluation and postprocedure care are included in the anesthesia fee; other services often needed to optimize clinical management so the patient is able to undergo the procedure may not be compensated. Discussion of some of these issues related to payment for anesthesia services for the NORA procedures is ongoing at a national level.

Some newer payment methods may help address the challenges of providing anesthesia services for procedures performed outside of the OR. Bundled payment methodologies, accountable care organizations, and the perioperative surgical home are three payment reforms intended to improve coordination and interdisciplinary collaboration. While these models of payment may effectively improve delivery of care in the most appropriate environment with improved outcomes, it remains to be seen how effective these undertakings will be in improving care. In any case, payment models remain a key determinant of behavior. It is incumbent on anesthesiologists to remain at the forefront of new developments as demand for anesthesia services in less traditional arenas broadens in an environment that diminishes control over the revenues we generate.

Operational Constraints

It is quite clear that despite a multitude of publications documenting significant OR inefficiency, institutional tradition, provider idiosyncrasy, and surgical convenience continue to compromise efficient OR scheduling practices and policies. Outside of the OR, these issues have even greater significance. Medical proceduralists and surgeons performing procedures in unfamiliar environments often do not understand the physical limitations that affect anesthesia care and the need for appropriate preprocedure evaluation and management, and in many cases are not aware of some of the underlying clinical conditions of the referred patient. To make matters worse, the specific procedure(s) to be performed on the patient may not be well-defined until the procedure begins while in other cases the procedure is “novel,” often involving equipment and supplies unfamiliar to the proceduralist or assisting staff. All of these variables make scheduling non-OR cases extremely difficult.

With respect to scheduling and staffing non-OR cases, a number of issues must be considered, including:

• 1.
  

  Non-OR anesthetizing locations are often adapted to the specific procedure being undertaken and the needs of the medical proceduralist. Unlike ORs, they are non-interchangeable. They are often neither designed for nor take the needs of the anesthesia provider into account.

  
  
• 2.
  

  Most of the venues for these procedures are smaller and less flexible than traditional OR environments.

  
  
• 3.
  

  Block time may not be utilized to facilitate scheduling of NORA cases, making it difficult to utilize anesthesiology staff productively and increasing the likelihood of underutilized personnel and space.

  
  
• 4.
  

  Non-OR procedures may take place a long distance from the OR suite. Lack of storage space for anesthesia equipment may also impose longer turnover time and the need for additional anesthesia technical services.

  
  
• 5.
  

  Many non-OR procedure suites perform procedures on patients referred from outside providers or services that are booked through a central scheduling office. For most of these patients, the usual preprocedure evaluation process is not used to facilitate assessment and preparation of the patient. Periprocedural evaluations are often very cursory—if performed at all. This imposes an additional bottleneck for the anesthesiologist who may need to perform a preoperative evaluation immediately before the procedure and cancel or delay cases at the last minute.

  
  
• 6.
  

  Because many non-OR procedures are novel, it is difficult to estimate the length of time the procedure will take. Booking times may be unrealistic, and scheduling anesthesiology time may be difficult. Additionally, with new technology and noninvasive methods, it is very easy for the proceduralist to modify or extend the procedure after it is started.

As noted, non-OR cases tend to be more variable, less predictable, and, therefore, more difficult to staff cost-effectively. Some of these difficulties are technical, but some are the result of cultural discontinuity and poor communication between anesthesiologists and proceduralists. To ensure effective management for these cases, a number of requirements should be met:

• 1.
  

  Prospectively establish a contract between the anesthesiology and procedural departments that encourages appropriate utilization of available time and minimization of differences between “staffed (contracted) time” and “productive time.” In addition, in those environments where NORA cases cannot or are not scheduled efficiently, the department may need to define a “backstop” to compensate the anesthesia providers for “availability” time that is not associated with a specific case.

  
  
• 2.
  

  All non-OR cases should be scheduled and managed within the electronic database for OR cases, so that resource deployment can be planned and modified as needed.

  
  
• 3.
  

  Create a block schedule that takes into account all of the procedural areas and the most effective utilization of the space. The block time should account for the needs of all providers. For example, if cases in some areas tend to run late, anesthesia providers should be scheduled appropriately to reflect the actual times for the cases to be completed.

  
  
• 4.
  

  Implement real-time scheduling, including patient arrival times and other issues affecting utilization. Calculate earliest start times, optimal arrival times, and adjusted preoperative fasting (nothing by mouth [NPO]) guidelines for all patients. Avoid having patients sitting in preoperative holding areas for extended periods and account for postprocedure evaluation and monitoring needs wherever recovery of the patient is provided.

  
  
• 5.
  

  Improve specialized triage for scheduled outpatients in each procedural area to ensure that patients are appropriately evaluated and prepared for the anticipated procedure. The use of triage forms and staffing intake procedures, either locally within each environment or centrally, will minimize delays and cancellations. Ensure that the proceduralist is invested in the preprocedure process and supports the needs of the patient and anesthesia providers.

  
  
• 6.
  

  Oversight of periprocedural triage and postprocedure recovery areas should be provided by the anesthesia department to ensure that the appropriate preprocedure assessment has been completed and, when necessary, that additional preprocedure optimization is required. As part of the oversight process, tracking of unexpected admissions, prolonged recovery times, throughput, efficiency, length of stay, and medical outcomes should be performed and reviewed with all providers.

The scheduling of space, staff, and resources for NORA procedures should be standardized within the institution but can be performed in a number of ways. In general, the principles that apply in the OR should also be used for cases performed outside of the OR. These principles include reducing variability, scheduling to minimize variability as much as possible, and using actual institutional data to guide decision making whenever possible (i.e., real-time scheduling for blocks). In addition, the scheduling should take into account available time and actual productive time. Full schedules and adequate revenue collection should be incentivized; otherwise a subsidy of the anesthesia department is needed because the opportunity cost incurred is often significant. In situations where specific contracts for NORA cases are negotiated, the contracts should take into account full costs and not differentiate costs associated with specific procedures individually. Whenever possible, proceduralists should be involved in scheduling schemes so they are invested in the process. When the institution has specific, predefined areas in which these procedures will be performed, identifying a dedicated anesthesia team, as is done for selected OR service lines, should be considered. Identifying a dedicated team that understands the specific issues in each NORA environment and collaborates with the proceduralists, nurses, and others can greatly improve operational issues, patient and provider satisfaction, and clinical outcomes.

Defining Interdisciplinary Safety in Non-Operating Room Locations: Standardization, Reliability, and Communication

The unparalleled record of OR safety established by surgeons and anesthesiologists has been dependent on implementation of standardized, routinized practice. Anesthesiologists depend on the predictable characteristics of ORs and surgical procedures to gauge the process of procedures and optimize anesthetic outcomes. While unplanned challenges arise even in the most standardized environment, a dedicated team with an understanding of the expected (and unexpected) events is best able to tailor care to meet the needs of the patient and providers. For non-OR cases, many of the standards are not predefined and the procedures often are not yet considered routine. In some cases, the technology is novel and, for some patients, preprocedure optimization is not ensured. For many procedures, anesthesia is required because of the inherent challenges and inability to predict clinical responses and needs. In each of these situations, communication at every step in the process is critical to optimizing patient care and outcomes. If communication is poor between proceduralist and anesthesiologist, the potential for error and a less-than-optimal outcome increases.

Frankel and others have emphasized that environments that facilitate safety and reliability are characterized by the following:

• 1.
  

  Encouragement of continuous learning among all participants

  
  
• 2.
  

  A just and fair culture of accountability and responsibility

  
  
• 3.
  

  Support for teamwork

  
  
• 4.
  

  Data-based drive for safety and reliability

  
  
• 5.
  

  Effective communication and flow of information

Depending on the specific venue, routines can be defined for many NORA procedures—though for many NORA procedures, the routines may differ from those developed for specific OR procedures. Specialty-specific procedure units can accommodate each of the above with varying degrees of difficulty, depending on the medical, financial, and operational constraints and priorities in place. All of these elements are critical characteristics of a safe environment.

Other General Considerations for Nora Care

A number of other processes are relevant to the practice of anesthesiology in general with some specific examples of their importance for anesthesia provided in settings outside of the OR environment. They include continuous learning, accountability, teamwork, and communication, all of which are critical to improving systems to optimize care.

Non – Operating Room Anesthesia Locations: Some Logistical Issues

Monitoring in Non-Operating Room Anesthesia Locations

Physiologic monitoring is a critical feature of safe anesthesiology practice wherever the anesthetic is delivered (see also Chapter 36, Chapter 41 ). Just as monitoring standards of care exist throughout the OR, they must be consistently in place in NORA locations as well. Some studies suggest that adverse events occurring outside of the OR may in fact be associated with more deleterious outcomes and serious injury than those in the OR because minimal monitoring standards are lacking. Monitoring in NORA locations is often suboptimal because the need is not identified by anesthesiologists and, in some cases, the proceduralist is not well-educated about what may be required. Until recently, pulse oximetry was the primary monitoring used to assess adequacy of oxygenation and ventilation, despite the fact that pulse oximetry has significant limitations. Several publications indicate significant misunderstanding among non-anesthesiologists using pulse oximetry to monitor patients outside of the OR. Anesthesiologists providing services outside of the OR should clarify the need for both pulse oximetry and monitors of ventilation. Several excellent articles and websites are available as resources. Over the last 20 years, capnography has become the standard of care for monitoring not only for ventilation, but also for circulation and metabolism by directly measuring expired carbon dioxide levels and indirectly measuring production of CO ₂ at the tissue level and delivery of CO ₂ to the lungs. Despite broad utility and clear clinical superiority, capnography is not always available in non-OR locations. The mandate for capnography may not be understood by either proceduralists or hospital administrative staff without significant education about its utility. Capnography equipment is bundled with other monitoring equipment on the anesthesia machine. Similar monitoring should be routinely available in NORA locations independent of the anesthesia machine which may not be required for every case.

Preprocedural Evaluation for Non-Operating Room Anesthesia Cases

Preprocedural evaluation is an essential component of anesthesia practice, regardless of where the procedure is performed or who is performing it (see also Chapter 31 ). Increasingly, patients with serious comorbidities and/or significant compromise are scheduled to undergo procedures outside the OR. For many of these patients, preprocedure assessment identifies clinical issues that may be difficult to optimize prior to proceeding with the procedure. In some cases the procedure is an emergency or of such urgency that a delay to address underlying clinical issues is not possible. For all NORA cases, the ASA Guidelines for Preanesthesia Evaluation of 2012, should guide management. They specifically define a preanesthesia evaluation which should, at a minimum, include the following:

• 1.
  

  A patient interview that includes a physical examination and a review of medical, surgical, anesthetic, and medication history

  
  
• 2.
  

  Diagnostic laboratory tests and other relevant diagnostic information

  
  
• 3.
  

  Assessment of ASA status

  
  
• 4.
  

  Formulation of potential anesthetic plans and presentation of these to the patient

Because several studies have dispelled the notion that there is a body of routine testing that reduces anesthetic risk, anesthesiologists should obtain testing based on the patient’s history, the procedure they are to undergo, and anesthesia requirements. Since many NORA cases are performed as urgent referrals to a proceduralist, patients may not have been evaluated by any provider prior to the procedure. As a result, accumulating the appropriate clinical information in a timely manner may be challenging, if possible at all. For patients known to have significant underlying medical conditions, the proceduralist should require that, if possible, the patient be evaluated in a preoperative evaluation clinic (if one is available). If not, the patient may require an extensive preprocedure assessment that could delay the procedure or necessitate rescheduling at a later time. Occasionally, periprocedural admission or consultation with a specialty service is required. Guidelines regarding preanesthetic evaluation can be found in Chapter 31 and many other texts ; in general, the same guidelines apply to procedures performed in the OR or non-OR locations.

Other Considerations

Additional issues must be considered for patients undergoing NORA procedures, particularly related to the management of underlying clinical conditions or periprocedure needs that might not be anticipated by other providers. These include the following limitations that should be considered before proceeding:

• 1.
  

  Many procedure suites have beds with lower weight limits and less mobility than OR beds.

  
  
• 2.
  

  Procedure suites for fluoroscopy have beds that cannot be placed in Trendelenburg or reverse Trendelenburg position.

  
  
• 3.
  

  Anticoagulation status is often an issue and guidelines may be extended for some procedures.

  
  
• 4.
  

  Renal status may impact the use of contrast.

  
  
• 5.
  

  During percutaneous procedures, bleeding may be occult, and the potential need for transfusion should be addressed preprocedurally.

  
  
• 6.
  

  Percutaneous procedures often require that the patient remain still. Patients with extreme anxiety, chronic pain, claustrophobia, mental disability, movement disorders, obesity, or obstructive sleep apnea (OSA) or those who are at the extremes of age may not tolerate lying on a table for long, even if the proposed procedure is not very stimulating. For these patients, deeper sedation or general anesthesia may be needed.

Current NPO guidelines for procedures are 6 hours for a light meal, 8 hours for a full meal, and 2 hours for clear liquids applied to patients without increased risk for aspiration (gastroesophageal reflux disease, gastric dysmotility, hiatal hernia, diabetes mellitus, bowel obstruction, or intraabdominal pathologic conditions). This is often a source of disagreement between anesthesiologists and proceduralists, who may not realize the ramifications of a full stomach or may insist that contrast or barium be administered before the procedure. Timely preprocedure evaluation and enforcement of clear standards for NPO status can help prevent scheduling mishaps and unnecessary delays and cancelations. This may require education of the proceduralists and their staff.

Gastrointestinal Procedures in The Endoscopy Suite

Over the past 10 years, enormous growth in the number of gastrointestinal (GI) endoscopic procedures related to an aging patient population, increased awareness of cancer screening benefits, broad-based reimbursement for screening colonoscopies, and better technology is quite evident. Increasingly complex procedures, higher-acuity patients, and increased case volume broaden the scope of challenges anesthesiologists face in caring for these patients. The choice of anesthetic approach requires a thorough understanding of both the procedure and the comorbidities of the patient. Similarly, preprocedure evaluation and postprocedure care, which carry financial and operational constraints, assume greater importance. Historically, most endoscopists managed healthy patients undergoing minor procedures with moderate sedation administered by nurses. However, moderate sedation is often inadequate in the context of sicker patients for simple procedures or healthy patients for complex procedures. Therefore, this chapter discusses the focus and methods of common GI procedures, reimbursement issues that may affect practice, the frequent comorbidities associated with patients undergoing those procedures, and anesthetic approaches suggested by anesthesiologists with expertise in the area.

A broad spectrum of GI procedures takes place in the endoscopy suite, ranging from routine screening colonoscopies to complex endoscopic pancreatic necrosectomies. Each of these requires specific levels of anesthesia depending on the invasiveness and stimulation imposed by the procedure as well as patient factors relating to their comorbidities. The most common procedures are esophagogastroduodenoscopy (EGD), sigmoidoscopy and colonoscopy, and endoscopic retrograde cholangiopancreatography (ERCP).

Natural orifice transluminal endoscopic surgery: the next frontier?

Natural orifice transluminal endoscopic surgery (NOTES) represents an approach to abdominal and peritoneal procedures that integrates the perspectives of endoscopic medicine and minimally invasive surgery. The use of NOTES in humans is in the early phases, and several cases have been reported of transvaginal and transgastric cholecystectomy. Thus far these cases have required a pneumoperitoneum and general anesthesia; however, as technology improves, these parameters may change and NOTES procedures may take their place among the numerous other interventions performed outside the OR.

An example of a NOTES used by GI endoscopists to treat esophageal achalasia is peroral endoscopic myotomy (POEM). Esophageal achalasia is characterized by poor peristalsis of the esophagus in combination with increased muscle tone and incomplete relaxation of the lower esophageal sphincter (LES). Symptoms arising from impaired entry to the stomach include nausea and vomiting, dysphagia, and/or pain. The POEM procedure has been developed as a minimally invasive procedure to correct achalasia by endoscopically insufflating the esophagus with CO ₂ and then making an incision into the mucosa from the mid-esophagus (through the gastroesophageal [GE] junction) to 2 to 3 cm into the proximal stomach. During insufflation, patients may have an increase in ETCO ₂ that can be controlled using mechanical ventilation. Potential risks of insufflation range from subcutaneous emphysema to pneumothorax, pneumomediastinum, and pneumoperitoneum. This procedure commonly requires several hours and is best accomplished using general anesthesia with an endotracheal tube, which protects the patient from aspiration of gastric contents and allows the anesthesiologist to minimize the perils of CO ₂ insufflation. As with all NORA procedures, vigilance, teamwork, and communication are vital to ensure not only the success of the procedure but the safety of the patient as well.

Common Bronchoscopic Procedures

Common bronchoscopic procedures include the following (see also Chapter 53 ):

• 1.
  

  Endobronchial stenting: placement of self-expanding metallic stents to treat stenosis

  
  
• 2.
  

  Endobronchial biopsy, laser treatment, and cauterization

  
  
• 3.
  

  Balloon dilation and cryotherapy

Technological advances in this field have given rise to new innovative procedures used in treating a broader patient population. Several interventions that represent amalgamations of preexisting technologies in the bronchoscopy suite are as follows:

• 1.
  

  Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA). This procedure is used to image the bronchial wall and adjacent structures. It allows ultrasonic visualization of mediastinal lymph nodes and other peribronchial lesions and therefore is a useful staging tool.

  
  
• 2.
  

  Electromagnetic navigation bronchoscopy (ENB). This technique permits biopsy of endobronchial tissue that is not visible using computer software that creates a virtual multiplanar lung reconstruction from computed tomography (CT) data. A sensor probe and electromagnetic location board guides the operator to the appropriate location during the bronchoscopy.

  
  
• 3.
  

  Fiducial marker implant. Markers are placed before stereotactic radiosurgery via bronchoscopy or ENB.

Equipment Layout

The layout in any radiology suite can be problematic for anesthesiologists because x-ray tubes and moving C -arms create a zone of inaccessibility around the patient’s head and limit placement of the anesthesia machine. This necessitates the use of extensions on ventilator circuits and intravenous lines, increasing the potential for mishap. Infusion pumps, blood warmers, and other monitors must be placed far away from moving imaging equipment to prevent them from being knocked down or tangled during C -arm rotation and movement. In addition, imaging screens are often at right angles to the anesthesiologist, making it impossible to see what the interventionalist is doing or assess the progress of the case. Anticipating events is therefore difficult unless good communication occurs between the anesthesiology and radiology teams.

Vascular Interventional Procedures

Angiography, the general term for imaging of blood vessels, includes arteriography and venography (see also Chapter 56 ). This involves the acquisition of images during injection of contrast material. In many institutions, this technique has been replaced by CT angiography (CTA). DSA, a technique that imposes a contrast-injected image on top of a previously acquired non-contrast image, improves accuracy. Arteriography can be used to evaluate atherosclerotic and ischemic disease, define the arterial supply of tumors and vascular anomalies, and define traumatic injury. After diagnostic imaging, interventions using balloons, stents, balloon-mounted stents, or delivery catheters take place. Follow-up arteriography is used to evaluate the result. In some cases, arteriography serves as a precursor to later surgery.

Thrombolytic therapy can be delivered to veins, arteries, or conduits that are thrombosed. The earlier the intervention the more successful it is likely to be. Various agents are used, including recombinant tissue plasminogen activator (r-TPA), urokinase, and others. Thrombolytic therapy is generally contraindicated in patients with ongoing bleeding, recent bleeding, pregnancy, known allergy to thrombolytic agents, suspected aortic dissection, or the presence of a nonviable extremity.

Embolization therapy is used in a wide range of conditions, including trauma, hemorrhage, vascular anomalies, fibroids, aneurysms, and tumors. The goal is to occlude arteries or veins either temporarily or permanently. This can be done mechanically with coils, balloons, or glue or with chemical agents that are temporary (Gelfoam) or permanent (alcohol). In these cases, arteriography first defines and localizes the lesion and the embolic agent is then delivered to the appropriate place with imaging guidance.

For all of these vascular interventions, the nature of the case, the comorbidities of the patient, and the intricacies of the procedure will determine the need for and extent of an anesthesiologist’s involvement. Complications to anticipate include bleeding during thrombolysis, undesired embolization of nearby structures during embolization, and vessel disruption. Depending on where the target vessels are, potential complications should be appropriately anticipated in terms of planning for physiologic sequelae and the need for blood products.

Venography or imaging of the venous system is used in the context of stent placements, inferior vena cava (IVC) filter placement or removal, pulmonary arteriography, embolization of pulmonary arteriovenous malformations (AVMs), thrombolysis, and selective venous sampling. Central venous angioplasty is most frequently undertaken in patients who have indwelling devices. IVC filters are placed to minimize the risk for pulmonary embolus arising from the migration of deep vein thromboses from the lower extremities or pelvic veins. Indications for IVC placement include high risk for pulmonary embolism, failure of anticoagulation or contraindications for anticoagulation, and allergy to anticoagulants. Both removable and permanent filters are available and can be placed via transfemoral or transjugular approach. For the most part, these procedures require little or no sedation; however, patients who cannot lie flat or with extreme anxiety will need anesthesia support. Pulmonary arteriography is used less frequently than in the past because of the speed and reliability of pulmonary CTA; however, the procedure is useful to evaluate pulmonary hypertension. This modality is also useful for diagnosis and treatment of pulmonary and bronchial AVMS and pseudoaneurysms.

Fistulograms, graftograms, and tunneled hemodialysis (HD) lines, grouped collectively as hemodialysis vascular access procedures, represent a unique type of vascular interventional case and a large percentage of IR caseload. Their uniqueness derives from the fact that the patient population is entirely comprised of those with end-stage renal disease (ESRD). These patients often require multiple interventions in the maintenance of their dialysis access lines. Vascular access dysfunction may be due to failure of maturation of an arteriovenous (AV) fistula, excessive bleeding or increased pressures during dialysis, or clotted vascular access. As a result, these patients require both diagnostic procedures such as fistulograms and therapeutic interventions such as balloon angioplasty and thrombectomy. Anesthesia care is needed as ESRD is rarely an isolated medical condition and this patient population tends to have multiple complex medical comorbidities that are often not optimized. Patient evaluation is like any procedure requiring anesthesia care with special consideration placed on volume status, serum potassium level, and electrocardiograph (ECG) changes. Patients with dysfunctional access require special attention to these parameters, as dialysis runs are often suboptimal. Care must be taken to weigh the risks and benefits of proceeding with borderline high potassium levels versus postponing the case and asking for a temporary dialysis line to get potassium to reasonable levels. Sedation is adequate in most cases. However, angioplasty can cause extreme discomfort for some patients, especially in cases where access is distally located (radiocephalic fistulas). Regional anesthesia techniques can be tailored for these cases but care must be taken as these patients are often on chronic anticoagulation. For patients unable to lie flat, ramping can be useful. Most patients have a history of prior anesthetics and this can guide future anesthetic plans. Procedure duration can range from very short (<30 minutes) to very long (several hours or more) depending on whether there are multiple stenotic areas or whether thrombectomy needs to be performed. Thrombectomies present a special consideration as declotting procedures use r-tPA. Thrombus can be dislodged from the fistula/graft and travel into the circulation. Patients with severe pulmonary hypertension or right ventricle failure should be considered for open surgical thrombectomy.

Biliary and Hepatic Interventions

Procedures to treat biliary or hepatic pathology are particularly challenging in that they are painful, intricate, and technically demanding. Patients are often extremely compromised. Hepatic and biliary procedures include transhepatic cholangiography, percutaneous transhepatic biliary drainage, hepatic venography with hemodynamic measurement, liver biopsy and the creation of TIPS, and portal vein embolization (PVE). Patients scheduled for biliary procedures may present with jaundice, cholangitis, shock, bile duct leak, or other related abnormalities. Clearly, significant comorbidities accompany these disorders. Contraindications for these procedures include bleeding diathesis, inability to tolerate contrast, and the presence of large hepatic AVMs, significant ascites, and hydatid disease.

Biliary drainage is accomplished by placing the patient supine on the table and inserting a long needle obliquely into the hepatic parenchyma (the ninth intercostal space). Contrast is delivered with the goal of imaging the necessary structures. Cholecystostomy tube placement is performed to improve symptoms in patients with acute cholecystitis but who are not candidates for surgery. Here, the gallbladder is imaged with ultrasound, CT, or fluoroscopy; the gallbladder is accessed through a needle that traverses the liver; and a drainage catheter is placed. For these procedures, the choice of anesthetic depends entirely on the patient’s body habitus, comorbidities, and pain tolerance. Obese patients are difficult to image, and optimization of needle position also can be difficult. Patients may present with a history of tolerance to opioids and with compromised metabolism, which requires careful choice of drugs. Regional anesthesia may be useful for procedural or postprocedural pain management. Lying flat may be difficult for patients with pulmonary compromise or ascites.

Hepatic venography and hemodynamic assessment are performed to assess suspected venous anomalies (Budd-Chiari) and quantitation of portal hypertension. Liver biopsies can be performed during these procedures. Access for these procedures is usually transjugular and involves needle insertion followed by wire access and insertion of a long vascular sheath. Many patients find this extremely difficult to tolerate. Hepatic venography and pressure monitoring is done through an angled catheter before it is advanced to wedge in the hepatic vein. A calculation of corrected sinus pressure, the difference between free pressure and wedge pressure, defines the degree of portal hypertension. The creation of a portosystemic shunt requires positioning of a needle advanced through the hepatic parenchyma and into the portal vein. The parenchymal tract is dilated with an angioplasty balloon and a stent is inserted. This is a painful and difficult procedure, vastly oversimplified for clarity. It may be quite lengthy and general anesthesia is advisable. Indications for the creation of TIPS include repeated esophageal variceal bleeding refractory to medical treatment and intractable ascites. It is often used as a bridge to liver transplant. Relative contraindications to this procedure include preexisting hepatic encephalopathy and ongoing alcohol abuse, which preclude liver transplantation. In elective situations, significant pulmonary hypertension, valvular heart disease, and congestive heart failure are contraindications to this procedure. TIPS can be performed emergently in patients with end-stage liver disease as a way to treat ongoing bleeding. The risk for bleeding from TIPS is high and a blood bank sample should always be obtained. Adequate access and blood products, including fresh frozen plasma (FFP) should be secured. PVE is a relatively new technique designed to reduce blood flow in hepatic segments containing tumor while encouraging hypertrophy of remaining hepatic tissue. The goal is to improve survival among patients undergoing resection of hepatic neoplasms by increasing postsurgical hepatic tissue mass. Embolization is accomplished with portal vein angiography and coils. Postprocedure pain can be significant. Acute complications include bleeding, bile leak, pleural insults, and contrast reactions.

Gastrointestinal and Genitourinary Interventions

Interventional radiologists perform direct-access GI procedures, the most common of which is the percutaneous gastrostomy tube (G-tube). Other variants include cecostomy and jejunostomy tubes. For G-tube placement, the stomach is distended with air via a nasogastric (NG) tube or a small French catheter and glucagon administered to decrease gastric emptying. Subsequent gastropexy is performed by some practitioners as a means of stabilizing the stomach; the stomach is entered with a needle and a wire and an appropriate tube is inserted and placed in the proper location. Acute complications include bleeding, violation of adjacent structures, and peritonitis. In many cases, these procedures can be tolerated with sedation except in situations where patients are at high risk for gastric aspiration (e.g., esophagectomy).

Genitourinary (GU) procedures in the radiology suite focus on obtaining direct access to the renal collecting system. Dilation and stenting can be performed, and suprapubic cystostomy is also a procedure commonly performed in radiology suites. Nephrostomy tube placement is performed to divert urine in the face of obstruction from stones, tumor, or other obstructive pathology. In general, the technique involves injecting contrast medium, identifying the renal pelvis, accessing it, and inserting a tube. Prone positioning of the patient is preferred, which generates an attendant list of potential anesthesia concerns including airway issues, pain management, access, and more. In formulating the anesthesia plan, one must carefully weigh the risks and benefits of prone sedation versus general anesthesia. Factors to take into consideration include patient body habitus and hemodynamic condition, proceduralist skill, and duration of procedure (e.g., accessing a dilated renal pelvis in a thin patient may be quicker than in a morbidly obese patient).

Percutaneous Interventions for Oncology

Interventional oncology is a rapidly expanding area and is revolutionizing oncologic care. These treatment modalities are gaining momentum over surgical interventions. Imaging guidance is achieved via CT, ultrasound, or fluoroscopy. Transarterial chemoembolization and percutaneous ablations (with microwave or to a lesser extent radiofrequency, laser, cryoablation, or alcohol) can be directed at tumors and image-guided insertion of radioactive materials can be performed. Commonly, hepatic, kidney, lung, and adrenal lesions are targeted. Complications are similar to those of other percutaneous interventions. Positioning depends on the site to be accessed. Anesthesia services are frequently used as these patients are truly high risk for surgical intervention. General anesthesia works best as the interventions may be intermittently painful, control of breathing may be optimal, and patient cooperation may not be compatible with the level of sedation required. Postprocedure patients can experience pain, malaise, and nausea and vomiting, as part of a postembolization syndrome or postablation syndrome. High-dose steroids can be beneficial in prophylaxis and non-opioid analgesics can be beneficial in treating symptoms.