The provision of hospital-based, non–operating room anesthesia (NORA) has become a burgeoning part of almost every anesthesiology practice in the United States. Cost savings, facilitated scheduling (as opposed to in the main operating rooms), and increased patient satisfaction are just a few of the reasons this branch of anesthesiology is expected to continue its exponential growth in the future. Medical device technology has advanced in tandem with NORA, allowing many surgical procedures once reserved for the operating room to be performed in a less invasive manner in an alternative site (e.g., intracranial coiling and stenting has obviated the need for many craniotomies). In other procedures still performed in the operating room, anesthesia is administered at an alternative anesthetizing site before the main surgical procedure (e.g., a patient with placenta percreta may have uterine artery balloon occlusion catheters placed under anesthesia in the interventional radiology suite before a caesarean section in the operating room). However, the provision of care in alternative sites has yet to garner the same level of academic scrutiny as the mainstream anesthesia subspecialties. Initial guidelines published almost 20 years ago seem quaint considering the current diversity of alternative-site procedures requiring anesthesia and analgesia.
Similar to the pediatric anesthesiologist who scoffs at the notion that an infant is merely a scaled-down adult, those who perform NORA testify that what they do is not simply a duplication of their operating room routines. Patients who require NORA are often elderly and quite ill and may undergo procedures that are unfamiliar to the anesthesiologist. The NORA environment itself may at times appear dark, crowded, and cold. Anesthesiologists may have to rely on machines and monitors they are unaccustomed to using. Ancillary staff may be unfamiliar with the needs of the anesthesiologist, and assistance, when necessary, may not be available in a timely manner.
Patient Selection
The benefits of anesthesia for alternative-site procedures are recognized by both clinicians and patients, resulting in a vigorous demand for these services. Patients expect amnesia and analgesia for even the most pedestrian procedures. Clinicians appreciate the patient relaxation and immobility afforded by a deep or general anesthetic and the freedom from having to personally control the patient’s sedation regimen. However, in the vast majority of cases, adequate patient comfort and cooperation can be ensured by a nurse familiar with sedation protocols who administers drugs under the direction of the physician performing the procedure. Although anesthesiologists may dictate and oversee the sedation policy in their institution, their direct involvement in these cases is often unwarranted. Which cases, then, typically require the services of an anesthesiologist during an alternative-site procedure?
Patients Who are Unable to Lie Still
This category encompasses a wide variety of patients, from those who are uncooperative because of mental or developmental disabilities, acute intoxication, or substance abuse, to those with movement disorders such as Parkinson’s disease and Huntington’s chorea. Both diagnostic imaging and interventional procedures often require the patient to remain motionless for prolonged periods. Other procedures require a cooperative patient to breath-hold at full inspiration or full expiration to target a lesion. As discussed earlier, many of these patients can be given a trial of nurse-administered sedation. If this fails, or if the situation is known to be challenging, an anesthesiology consult should be sought.
Patients Who Cannot Tolerate the Supine Position
Patients in this classification have cardiopulmonary issues such as pulmonary edema or right heart failure or neuromuscular issues such as severe lower back pain and sciatica. In the latter cases, the amount of analgesia that the patient may require to complete the study might result in apnea.
Practitioners Who are Uncomfortable Providing the Necessary Level of Sedation
The American Society of Anesthesiologists (ASA) has delineated four levels of sedation that exist along a continuous scale—minimal sedation (anxiolysis), moderate sedation (previously referred to as conscious sedation), deep sedation, and general anesthesia. Some have added a fifth level classified as dissociative sedation, produced by agents such as ketamine. The importance of the fact that these levels exist along a continuum and are not discrete destinations cannot be overstated. Even experienced clinicians may find a patient easily slipping into a deeper level of sedation than expected. If adequate and brisk resuscitation methods are not instituted, a direct correlation can be found between unintended deep sedation and the likelihood of adverse events. Given this facility to oversedate, The Joint Commission devised the sedation rescue philosophy, emphasizing that the clinician responsible for the sedation protocol must be able to rescue the patient from the next level of sedation beyond that intended. Therefore if deep sedation is the target, the practitioner must be prepared for the unexpected descent into general anesthesia.
Patients Who are Unable to Control their Respiratory Rate
A small subset of patients undergoing invasive procedures within the radiology suite, most notably computed tomography (CT)-guided or ultrasound-guided ablations, will be required to perform voluntary breath-holds during certain phases of the procedure to allow precision targeting of a lesion. This is especially important for anatomic sites close to the diaphragm, including the kidneys, adrenal glands, liver, and basal lung segments. Patients who are unable to cooperate because of developmental delays, language barriers, or immaturity may require paralysis and controlled ventilation under general anesthesia.
Patients with Severe Claustrophobia
Although severe claustrophobia is typically more of a problem in magnetic resonance imaging (MRI) and CT, any procedure that requires the patient to be draped in a darkened room may be intolerable for a claustrophobic patient. Nurse-administered sedation may be adequate, but the most severe cases may require general anesthesia for even the most routine diagnostic tests.
Infants and Young Children
Pediatric patients typically account for the majority of patients requiring NORA. The presence of a parent in the room or techniques such as swaddling may be insufficient to keep the patient still and cooperative during the study or procedure. Small vessels may make intravenous access difficult in the pediatric patient, precluding the option of intravenous sedation. Oral sedative agents such as chloral hydrate and midazolam have unpredictable effects and may cause a paradoxical hyperexcitable state in some children. Finally, the lack of providers with Pediatric Advanced Life Support (PALS) certification may mandate (per institutional policy) the immediate availability of an anesthesiologist. However, in most institutions, the sheer volume of these cases would overwhelm almost any anesthesiology practice if each child required direct involvement. Therefore a selection protocol must be adopted that delineates which pediatric patients can be sedated in the absence of an anesthesiologist’s uninterrupted supervision. Most children are given an initial trial of sedation provided by either a nurse under the direction of the clinician performing the procedure or staff from the pediatric intensive care unit. Chloral hydrate or midazolam, either oral or intravenous, is typically the first-line drug and is often successful. Some clinicians have reported success with regimens as simple as midazolam, and others have expanded their practice to include the use of propofol or dexmedetomidine. If this regimen proves insufficient, the study or procedure is rescheduled for a time when it can be performed under the supervision of an anesthesiologist. Exclusions are made for children with a history of unsuccessful sedation, children with ASA class IV status or greater, and children with anatomic anomalies that may make airway management difficult; in these patients, anesthesia is administered immediately under the care of an anesthesiologist.
Pitfalls of Non–Operating Room Anesthesia
The sympathetic response before NORA can begin up to 1 hour before beginning the procedure. Tachycardia and tachypnea are often present, along with dry mouth and moist palms. Blood pressure may be mildly elevated, and gastrointestinal discomfort is almost universal. Surprisingly, these symptoms are present not in the patient but rather in the anesthesiologist assigned to the case. Most providers with stellar skills but limited NORA experience are loath to leave the security of the operating room. What is it about NORA that makes it seem so foreign?
Distance From the Main Operating Rooms
Many anesthesiologists feel out of their element when asked to work outside the operating room. Their colleagues and the anesthesia technicians might not be familiar with the off-site anesthetizing locations, making it difficult and time-consuming to acquire extra drugs, equipment, or personnel to provide a break during the case.
Distance From the Patient and Monitors
In some sites the patient is monitored from a different room through a window, by MRI or CT, or by closed-circuit television, such as in the radiation oncology suite ( Figure 8-1 ). Changes in intravenous line flow rates, vaporizer settings, frequency of monitoring, or any other interventions that require direct contact ideally should be timed to occur during pauses in the diagnostic or therapeutic sequence.
Room Configuration
Anesthesiologists may find themselves positioned very close to the patient in a room that clearly was not designed to handle anesthetic equipment. Standard operating rooms are built with space for the anesthesia machine and cart, ample lighting, gases and suction available from a wall or tower source, and electrical outlets that will continue to provide power in the event of a generalized power loss. NORA sites may have none of these amenities, forcing the anesthesiologist to rely on items such as gas cylinders and portable suction devices. These extra pieces of equipment must compete for limited space with the bulky surgical equipment that is often used off-site, such as C-arm fluoroscopy units and endoscopy carts ( Figure 8-2 ). Adequate lighting may be an issue, especially if the room is kept dark during fluoroscopic procedures. Loud, continuous noise may make alarms difficult to hear. Positioning of the patient with an anticipated difficult airway may be problematic, because the tables in off-site locations typically are not as accommodating as tables in the operating room.
Lack of Emergency Equipment
Most NORA sites are equipped with crash carts containing Advanced Cardiac Life Support (ACLS) drugs, intubation supplies, and a defibrillator. More specialized equipment, such as tools to access a difficult airway or supplies for treating malignant hyperthermia, however, will almost certainly be located near the main operating rooms at a remote location, thereby stripping another layer of comfort from the anesthesia provider.
Scarcity of Support Staff
The personnel employed in the gastrointestinal suite, cardiac catheter laboratories, interventional radiology suites, and similar settings are well trained in their fields of expertise. Unfortunately, these fields have little to do with anesthesiology. Assistance with lines, difficult airways, or anesthetic emergencies may be delayed or completely unavailable. A request for cricoid pressure that will be immediately fulfilled in the main operating room may be met with blank stares in a NORA site. Surgical airway assistance may likewise be delayed or unattainable. Furthermore, the staff present in these locations are typically not as well trained in ACLS as the personnel in the operating and recovery rooms.
Radiation Hazard
In addition to interventional radiology or neuroradiology areas that rely on a fixed source of radiation-based imaging, the anesthesiologist may be asked to work in the cardiac catheter laboratory or gastrointestinal suite, where the radiation source is portable or derived from the patient by nuclear medicine. Anesthesiologists must be familiar with the methods to reduce radiation exposure to both themselves and their patients and be willing to wear leaded aprons, wear glasses and shields, maintain a safe distance from the radiation source, or follow other institutional protocols to minimize this risk.
Renal Status
Many cases performed with radiographic assistance require the use of contrast to identify fluid-filled structures. The contrast agent is often nephrotoxic above a certain dose; thus it is the shared responsibility of all the providers to ensure that this threshold is not exceeded. The use of contrast necessitates frequent flushing of the lines, so the anesthesiologist also must be mindful of the patient’s volume status. Maintenance fluids should be reduced, and diuresis may be necessary.
Room Temperature
Pediatric and elderly patients may be especially sensitive to the temperature in many NORA sites, especially those in the radiology area. Patients with cold-sensitive conditions such as sickle cell anemia or cryoglobulinemia also may be at risk. Imaging machinery functions over a narrow (and often low) ambient temperature ; therefore the rooms are typically kept uncomfortably cold. To prevent temperature adjustment that might cause malfunction of the imaging equipment, no thermostats are located in the room. Instead, room temperature is controlled from a central, inaccessible location. Items such as forced-air warmers or fluid warmers may be difficult to obtain; challenging to fit in a limited space; and, in the case of MRI, impossible to use because of their ferrous components.
Unfamiliar Equipment
In some practices, NORA is still considered an inferior assignment within the department and thus older anesthesia machines and monitors may be relegated to NORA areas. Many junior anesthesiologists may never have worked with or even seen some of the older equipment present at these sites.
Nowhere is the issue of unfamiliar equipment more salient than in the MRI suite, where objects containing iron, cobalt, or nickel will be forcibly attracted to the magnet with a logarithmically increasing intensity. Depending on the volume of general anesthetics administered in the MRI scanner, the hospital may choose one of the following arrangements:
- 1.
An anesthesia machine and monitoring equipment are stationed outside the room containing the magnet, and the door is left ajar to allow for the passage of cables and the breathing circuit. This is the least desirable configuration, because the open door can result in degradation of the MRI images.
- 2.
An anesthesia machine and monitoring equipment are stationed outside the room containing the magnet, but the door remains closed throughout the study. The cables and circuit are threaded through reinforced holes in the wall or floorboards ( Figure 8-3 ).
Figure 8-3
A reinforced floorboard in the magnetic resonance suite provides openings for intravenous tubing and circuit hoses.
- 3.
An MRI-compatible anesthesia machine and monitoring panel are purchased that can safely remain in the MRI room at a certain distance—typically 6 feet—from the magnet bore. Most MRI-compatible machines are similar enough to their non-MRI counterparts to be familiar to most providers ( Figure 8-4 ). Laryngoscopes are typically nonferromagnetic, although the batteries inside will be weakly attracted to the magnet unless they are MRI-compatible lithium batteries. Equipment for vital sign monitoring is specific for the MRI suite, relying on distortion-free fiberoptic cables for the signal. The electrocardiogram may seem particularly foreign to the provider, because it will contain four graphite leads arranged in a cloverleaf pattern over the left sternal border ( Figure 8-5 ). The short cable distance lessens the chance of a radiofrequency heating–induced burn.
Figure 8-4
This magnetic resonance imaging–compatible anesthesia machine is similar to its standard operating room counterparts.
Figure 8-5
The cloverleaf pattern of electrocardiogram leads in the magnetic resonance imaging suite.
- 4.
An MRI-compatible infusion pump is used, which allows the practitioner to administer total intravenous anesthesia. If necessary, assisted ventilation is provided with an MRI-compatible ventilator. It is important that all infusion pumps used in the MRI area are MRI-compatible, because use of a standard pump may result in an infusion rate that differs from what is entered into and displayed on the device.
Pitfalls of Non–Operating Room Anesthesia
The sympathetic response before NORA can begin up to 1 hour before beginning the procedure. Tachycardia and tachypnea are often present, along with dry mouth and moist palms. Blood pressure may be mildly elevated, and gastrointestinal discomfort is almost universal. Surprisingly, these symptoms are present not in the patient but rather in the anesthesiologist assigned to the case. Most providers with stellar skills but limited NORA experience are loath to leave the security of the operating room. What is it about NORA that makes it seem so foreign?
Distance From the Main Operating Rooms
Many anesthesiologists feel out of their element when asked to work outside the operating room. Their colleagues and the anesthesia technicians might not be familiar with the off-site anesthetizing locations, making it difficult and time-consuming to acquire extra drugs, equipment, or personnel to provide a break during the case.
Distance From the Patient and Monitors
In some sites the patient is monitored from a different room through a window, by MRI or CT, or by closed-circuit television, such as in the radiation oncology suite ( Figure 8-1 ). Changes in intravenous line flow rates, vaporizer settings, frequency of monitoring, or any other interventions that require direct contact ideally should be timed to occur during pauses in the diagnostic or therapeutic sequence.
Room Configuration
Anesthesiologists may find themselves positioned very close to the patient in a room that clearly was not designed to handle anesthetic equipment. Standard operating rooms are built with space for the anesthesia machine and cart, ample lighting, gases and suction available from a wall or tower source, and electrical outlets that will continue to provide power in the event of a generalized power loss. NORA sites may have none of these amenities, forcing the anesthesiologist to rely on items such as gas cylinders and portable suction devices. These extra pieces of equipment must compete for limited space with the bulky surgical equipment that is often used off-site, such as C-arm fluoroscopy units and endoscopy carts ( Figure 8-2 ). Adequate lighting may be an issue, especially if the room is kept dark during fluoroscopic procedures. Loud, continuous noise may make alarms difficult to hear. Positioning of the patient with an anticipated difficult airway may be problematic, because the tables in off-site locations typically are not as accommodating as tables in the operating room.
Lack of Emergency Equipment
Most NORA sites are equipped with crash carts containing Advanced Cardiac Life Support (ACLS) drugs, intubation supplies, and a defibrillator. More specialized equipment, such as tools to access a difficult airway or supplies for treating malignant hyperthermia, however, will almost certainly be located near the main operating rooms at a remote location, thereby stripping another layer of comfort from the anesthesia provider.
Scarcity of Support Staff
The personnel employed in the gastrointestinal suite, cardiac catheter laboratories, interventional radiology suites, and similar settings are well trained in their fields of expertise. Unfortunately, these fields have little to do with anesthesiology. Assistance with lines, difficult airways, or anesthetic emergencies may be delayed or completely unavailable. A request for cricoid pressure that will be immediately fulfilled in the main operating room may be met with blank stares in a NORA site. Surgical airway assistance may likewise be delayed or unattainable. Furthermore, the staff present in these locations are typically not as well trained in ACLS as the personnel in the operating and recovery rooms.
Radiation Hazard
In addition to interventional radiology or neuroradiology areas that rely on a fixed source of radiation-based imaging, the anesthesiologist may be asked to work in the cardiac catheter laboratory or gastrointestinal suite, where the radiation source is portable or derived from the patient by nuclear medicine. Anesthesiologists must be familiar with the methods to reduce radiation exposure to both themselves and their patients and be willing to wear leaded aprons, wear glasses and shields, maintain a safe distance from the radiation source, or follow other institutional protocols to minimize this risk.
Renal Status
Many cases performed with radiographic assistance require the use of contrast to identify fluid-filled structures. The contrast agent is often nephrotoxic above a certain dose; thus it is the shared responsibility of all the providers to ensure that this threshold is not exceeded. The use of contrast necessitates frequent flushing of the lines, so the anesthesiologist also must be mindful of the patient’s volume status. Maintenance fluids should be reduced, and diuresis may be necessary.
Room Temperature
Pediatric and elderly patients may be especially sensitive to the temperature in many NORA sites, especially those in the radiology area. Patients with cold-sensitive conditions such as sickle cell anemia or cryoglobulinemia also may be at risk. Imaging machinery functions over a narrow (and often low) ambient temperature ; therefore the rooms are typically kept uncomfortably cold. To prevent temperature adjustment that might cause malfunction of the imaging equipment, no thermostats are located in the room. Instead, room temperature is controlled from a central, inaccessible location. Items such as forced-air warmers or fluid warmers may be difficult to obtain; challenging to fit in a limited space; and, in the case of MRI, impossible to use because of their ferrous components.
Unfamiliar Equipment
In some practices, NORA is still considered an inferior assignment within the department and thus older anesthesia machines and monitors may be relegated to NORA areas. Many junior anesthesiologists may never have worked with or even seen some of the older equipment present at these sites.
Nowhere is the issue of unfamiliar equipment more salient than in the MRI suite, where objects containing iron, cobalt, or nickel will be forcibly attracted to the magnet with a logarithmically increasing intensity. Depending on the volume of general anesthetics administered in the MRI scanner, the hospital may choose one of the following arrangements:
- 1.
An anesthesia machine and monitoring equipment are stationed outside the room containing the magnet, and the door is left ajar to allow for the passage of cables and the breathing circuit. This is the least desirable configuration, because the open door can result in degradation of the MRI images.
- 2.
An anesthesia machine and monitoring equipment are stationed outside the room containing the magnet, but the door remains closed throughout the study. The cables and circuit are threaded through reinforced holes in the wall or floorboards ( Figure 8-3 ).
Related posts:
Critical Monitoring Issues for Non–Operating Room Anesthesia
Intravenous Anesthesia and Sedation Outside the Operating Room
Anesthesia for Colonoscopy
Anesthesia for Upper Gastrointestinal Endoscopy
Anesthesia Concerns in the Magnetic Resonance Imaging Environment
Anesthesia and Competitive Strategies
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