Computer-Assisted Personalized Sedation (CAPS): Will it Change the Way Moderate Sedation is Administered?

Steven Dale Boggs, MD, MBA
Director of the OR and Chief of the Anesthesia Service, James J. Peters VA Medical Center, Bronx, NY
Associate Professor of Anesthesiology, The Icahn School of Medicine at Mount Sinai, Manhattan, NY

I. Background

The medical specialty of anesthesiology is recognized for being in the forefront of adopting technology to enhance patient safety. The rapid dissemination of pulse oximetry and capnonography in anesthetic practice are two classic examples of early adoption of technology by the medical community to make our practice safer. The creation of the Anesthesia Patient Safety Foundation (APSF) further exemplifies our specialty’s commitment to both patient welfare and technological progress.

Over the past few decades, a new factor has prominently inserted itself into the equation, influencing the introduction of new technology. That is cost-effectiveness. In evaluating a new product, whether it provides ideal patient care or cost-effective care may give different answers.

The professional cost of anesthesia services is only a small percentage of total physician services (three percent of Medicare spending in 2010). Yet, the increase in spending on monitored anesthesia care (MAC) for esophagogastroduodenoscopy (EGD) and for colonoscopy has grown significantly over the past decade. A 2012 RAND study found that from 2003 to 2009, the number of colonoscopies and upper gastroenterology (GI) procedures increased 26 percent. In this same period, payments to anesthesia providers tripled among Medicare beneficiaries and quadrupled among commercially insured patients.

Striking regional variation exists. An anesthesia provider (2012) is most likely to be involved in a GI procedure in the Northeast (48 percent), followed by the South (38 percent), the Midwest (26 percent) and the West (14 percent). This RAND study concluded that $1.1 billion per year was spent on payments to anesthesia providers for care in what this study deemed to be low-risk patients.

Several questions come to mind. Why has there been such a significant increase in anesthesia involvement in EGD and colonoscopy? Studies suggests that both GI physician preference (clinical and financial) and patient preference for propofol versus traditional methods of GI sedation (midazolam and narcotic) are the primary drivers. For GI physicians, sedation of any type increases the rate at which cecal intubation is achieved and polyp detection rates are also increased. Moreover, with propofol, patient flow through the GI unit is quicker, patients are discharged sooner without lingering effects and more cases can be performed per day. For patients, they can truly “not remember anything,” and still emerge without nausea or lingering effects to be discharged promptly from the GI unit.

While there is regional variation in the payment model for MAC anesthesia for GI procedures, some vindication may be seen for anesthesia providers who have argued for our involvement in these procedures in the recent Centers for Medicare and Medicaid Services (CMS) Proposed Rule for the 2015 Medicare Fee Schedule. CMS has gone on record acknowledging that the prevailing standard of care for endoscopies in general and screening colonoscopies in particular is undergoing a transition and that anesthesia separately provided by an anesthesia professional is becoming “the prevalent practice” (Proposed Rule pp. 186-187). Therefore, CMS is revising the definition of “screening colonoscopy” to bring anesthesia furnished in conjunction with the service within the scope of the provision that Medicare Part B waives beneficiaries’ deductible and coinsurance and pays 100 percent of the Fee Schedule amount established for certain colorectal cancer screening tests.

By proposing to pay 100 percent of the fee for an anesthetic for a screening colonoscopy under the regulation to be revised (42 C.F.R. §410.160(b)(7)) and by waiving the patient’s share in every instance, CMS has admitted that anesthesia provided by an anesthesia professional is at least as “medically necessary” as the sedation that is currently bundled into the gastroenterologist’s fee. It would be anticipated that Medicare would pay the anesthesiologist. However, there are a number of Local Coverage Decisions (LCDs) in which various Medicare contractors have predetermined that anesthesia for routine screening colonoscopies is not medically necessary. LCDs may need to be modified accordingly.

II . Computer-Assisted Personalized Sedation

In the US, if an anesthesia provider is not available to provide sedation, the alternative has been for the patient to receive either traditional sedation administered under the supervision of the GI physician (midazolam/narcotic) or no sedation. Because of this, Ethicon, a subsidiary of Johnson & Johnson, became interested in the concept of a device that would permit the administration of propofol for moderate sedation. Per FDA labeling, propofol had previously only been permitted to be administered by an anesthesia provider or to a patient in an ICU setting.

The approval process was quite lengthy, with the Sedasys® system not receiving approval initially. However, in May, 2013 the Sedasys system received premarket approval (PMA) from the FDA1. Sedasys is presently the only FDA-approved computer-assisted personalized sedation (CAPS) device on the market. Function of the system is outside the scope of this article, but information can be found on the company website (http://www.sedasys.com).

Ethicon specifically states that Sedasys is not intended to replace an anesthesia provider, but rather to permit the administration of mild-to-moderate sedation to patients who would otherwise not be able to receive propofol. Sedasys is approved for use for the following:

  • Initiation and maintenance of minimal-to-moderate sedation
  • American Society of Anesthesiologists (ASA) physical status I and II patients ? 18 years old
  • Colonoscopy or (EGD)

Sedasys is not indicated in the following patient populations:

  • Patients <18 years old.
  • ASA physical status IV and V.
  • Patients using a fentanyl patch.
  • Patients with abnormal airway or diagnosed sleep apnea.
  • Patients with gastroparesis.
  • Patients with Body Mass Index ?35.
  • Patients undergoing both colonoscopy and esophagogastroduodenoscopy during the same procedure visit.
  • Patients undergoing emergent colonoscopy or esophagogastroduodenoscopy.

Sedasys is contraindicated in the following patients:

  • Patients with a known hypersensitivity to propofol injectable emulsion or its components.
  • Patients with allergies to eggs, egg products, soybeans or soy products.
  • Patients with a known hypersensitivity to fentanyl.
  • Pregnant or lactating women.
  • Delivery of any drug other than propofol emulsion.
  • Patients with a full stomach.

Notably, Sedasys is not approved for use in ASA III patients, but it is also not contraindicated in this patient population. One thing must be made clear. Repeatedly in the Sedasys literature, “the pivotal study”2 is cited by the manufacturer. It must be kept in mind that Sedasys administration of propofol was compared against “traditional” sedation with midazolam and narcotic, not against propofol administered by an anesthesia provider. Secondly, the numbers of patients over the age of 70 and in ASA class III were extremely limited. Out of 1000 study subjects, 28 were ASA III patients and “there were very few patients over 70 years of age.” With 1,000 subjects in the study, it can also be argued that this study was significantly underpowered to reach the conclusions that the authors made.

For anesthesia providers, perhaps the most concerning aspect of the Sedasys system is the inability of the system to prevent or manage loss of consciousness. The manufacturers have addressed this concern two ways. First, they have developed a clinical training program that is endorsed by the International Society for Anesthetic Pharmacology and is provided by an independent, qualified third party with expertise in airway management. Clinical training consists of online knowledge-based training (approximately 4 hours) and simulation-based training (approximately 6 hours). This training (from their website) provides clinicians with the:

  • Knowledge base underpinning moderate sedation practice
  • Skill set necessary to rescue patients from deeper-than-intended sedation states
  • Additional knowledge and skills required when propofol is used to provide sedation

A further safety measure for Sedasys is the requirement that, “an anesthesia provider must be immediately available.” What “immediately available” means is left to the discretion of each facility.

III. Critique:

I have been informed that the Sedasys system has been placed into practice in one location, so Ethicon is just starting to market the device. In discussion with industry representatives, the ideal pattern would be for its use in a high-turnover GI suite. In this circumstance, appropriately selected patients would be managed with Sedasys, with non-candidates being managed by anesthesia personnel. However, once the device is utilized clinically, there will be strong cost pressures to widen the indications for its use.

Airway training may appear to be a simple skill, but it could be reasonably argued that the skill set required to rescue a patient from a deep anesthesia or general anesthesia cannot be taught in 10 hours.

Gastroenterologists, indeed many specialists, may look on airway management quite differently than anesthesiologists. In the Sedasys FDA application, one gastroenterologist said, “I’ll say another word about airway management for gastroenterologists. I have performed over 10,000 endoscopies. I have seen more larynxes and backs of the throats than probably most anesthesiologists. So, a gastroenterologist’s familiarity with the anatomy of the throat and the vocal cords and the esophagus is probably more than most anesthesiologists and I think there is a disservice done to gastroenterologists to think that we don’t know how to manage an airway because we don’t intubate patients regularly. Remember, we do intubate patients regularly. We just intubate their esophagus regularly. We don’t intubate their bronchus.” The point here is precisely that anesthesiologists are focused on intubating the trachea to preserve the airway, not the esophagus for diagnosis. That constitutes a significant difference.

Five percent of the population is known to have a difficult airway. Identification of these patients poses problems for anesthesia providers who deal with this issue daily, let alone for the provider whose background is not in airway management.

The risk of MAC anesthesia has been demonstrated to be roughly equivalent to that of general anesthesia, in large part because of airway events. Airway events are also the most common cause of closed claims against anesthesiologists, especially in GI endoscopy. Furthermore, mild to moderate anesthesia can heighten the problems with the management of a reactive airway. Therefore, while the pharmacologic studies to date have revealed that patients will start breathing with the redistribution of propofol, a finite risk to the patient remains.

Simulation training is an excellent technique for training coordinated teamwork and a systems approach to managing critical issues. However, few would argue that current simulation models are effective in actually training airway management. The approximation of the best simulation models to human tissue and various morphologies is poor. Consequently, utilizing simulation training to teach GI and nursing providers airway rescue skills is an unproven proposition.

Scheduling in the GI suite has the potential to become problematic. What will occur when an ASA III patient is assigned to the Sedasys room? Who will make the ultimate determination of the ASA physical class? There will be pressure to downgrade the ASA physical class, changing the ASA class from ASA IV to III or from III to II. What will prevent this change? Or, if downgrading does not occur, will the patient be rescheduled for another suite, perhaps having to wait for the availability of an anesthesia provider?

Cost savings is also controversial. A 2009 RAND3 study sponsored by Ethicon Endo-Surgery made the following observations:

The potential demand for CAPS is huge, being 98 million procedures in 2005 and a projected 106 million in 2015. In 2005, the overall size of the sedation market delivered by anesthesia providers was approximately $5 billion. Approximately 40 percent of this market, or $2 billion, was considered by the study’s authors as suitable for moderate sedation and therefore redistribution to CAPS. Specialties for which CAPS could be used include Gastroenterology (fastest growth rate), Cardiology, Ophthalmology, General Surgery, ENT and OB/Gyn.

Proceduralists would be affected by CAPS in two ways, first by additional payments for use of the technology and second, by shifting procedure settings away from hospitals. For GI specialties, the study considers that nearly 45 percent of total expenditures on anesthesia would be available for reallocation. However, the study authors note that, “not all of these changes will fully materialize, because presumably payers will compensate (providers) for the use of the CAPS technology in lieu of anesthesia providers.”

CAPS is expected to save insurers significant money, with most saving coming from reduced facility revenue and anesthesia professional fees. For a total of 38 million procedures, the average cost reduction would be $11.35 per procedure ($431 million).

In June 2014, the Agency for Healthcare Research and Quality (AHRQ) released its Healthcare Horizon Scanning System – Potential High-Impact Interventions Report on Cross-Cutting Interventions and Programs4. The key expert comment was that “Sedasys® has significant potential to disrupt the current methods of delivering propofol-mediated sedation.” However, the authors were unsure “whether the potential benefits of wider access to propofol-mediated sedation were significant enough to offset safety concerns about potential over sedation of patients in a setting without an anesthesiologist present.”

In discussion with representatives from Ethicon, tentative costs figures for the Sedasys system are as shown in Figure 1.

It should also be noted that the Sedasys system requires that a nurse specifically monitor the patient and have no other duties during the procedure. This—in addition to the cost of the machine and disposables—significantly adds to the cost model for Sedasys.

To compare projected Sedasys costs with cost data from actual claims submitted for anesthesia providers, a representative national sample of claims submitted for Anesthesia Business Consultants’ clients from October 2013 through March 2014 and excluding self-pay, government payers and pending claims was analyzed. The results appear in Figure 2. These values include payments for anesthesiologists providing care, nurse anesthetists providing care alone and to anesthesiologists and nurse anesthetists (care team model) together. The numbers are consistent with the Rand study(3) which found that the average payment of Medicare patients was $150 and for commercially-insured patients was $500.

Measuring ASA Physical Status for 155,139 upper GI procedures, 51 percent of the patients were ASA I and II, 39 percent were ASA III and 8.5 percent were IV, V or VI. For upper GI procedures in patients over 18 years of age, out of 141,259 patients, 61 percent were between the ages of 18 and 65, while 38 percent were over the age of 65. Twenty-one percent of these patients were over the age of 75.

It can be seen that payments to anesthesia providers at these rates may be competitive with the cost of Sedasys, the disposables and the required nurse. Moreover, a large percentage of patients in this population who received care from an anesthesia provider did have a high ASA class and advanced age.

It is not entirely clear that CAPS will save the money that is alleged. It may be more effective at redistribution of revenue away from anesthesia providers and toward insurance companies and proceduralists. Also, GI nurses have voiced concerns about their responsibilities in administering a medication which is specifically labeled to be “administered by an anesthesia provider.” For the proceduralists, the savings may not be as dramatic as heralded, because with a nurse focused exclusively on monitoring the patient, the cost of the entire model is significantly increased.

IV. Conclusion

Anesthesiology has a proud history of continually providing better and safer care to patients. Now, as a specialty, we have to recognize an additional commitment, to provide cost-effective care for our patients. The seal of our society has a lighthouse on it with the word, Vigilance emblazoned above it. Anesthesia providers have always taken this to mean personal vigilance in the care of their patients. However, new models of providing care for our patients will continue to emerge and will challenge this interpretation of our motto.

CAPS is an interesting development and anesthesiologists have typically been “early adopters” of technology. Sedasys may find a place in large GI units, where an anesthesiologist is always available, where patients assigned the wrong ASA class can be moved to a room with an anesthesia provider and where the volume of patients permits amortization of Sedasys costs across a large pool of patients.

Conversely, the Sedasys model as presently is not likely to be useful in small GI offices, in smaller units where an anesthesia provider is not available and where the number of cases is not sufficient to recoup the substantial expenditure required for the system and its components.


1 Birnbach DJ (Chair) USA, DHHS, Center for Devices and Radiological Health, Medical Devices Advisory Committee, Anesthesiology and Respiratory Therapy Devices Panel. May 28, 2009. Transcripts from Free State Reporting, Inc. 1378 Cape Saint Claire Road, Annapolis, MD 21409
2 Pambianco DJ, Vargo JJ, Pruitt RE, et al. Computer-assisted personalized sedation for upper endoscopy and colonoscopy: a comparative, multicenter randomized study. Gastrointest Endosc. 2011;73(4):765-772.
3 Dick A, Mattke S, Yu, H. Assessing the Budget Impact of the Computer-Assisted Personalized Sedation Technology for Key Stakeholders. RAND Health, 2009.
4 http://effectivehealthcare.ahrq.gov/ehc/assets/File/Crosscutting-Horizon-Scan-High-Impact-1406.pdf


Steve Boggs, MD, MBA is the Director of the Operating Room and Chief of the Anesthesia Service at the James J. Peters VA Medical Center in the Bronx, NY. He is also Associate Professor of Anesthesiology at the Icahn School of Medicine in Manhattan, NY. Dr. Boggs has been involved in the administration of anesthesia departments for over a decade. For the past several years, he has been working closely with endoscopists at Mount Sinai and elsewhere, evaluating turnover time and safety metrics and is involved in developing a curriculum for GI sedation for low-and-middle income countries and in evaluating new methods of training providers in bag/valve/mask ventilation. He can be reached at stevendaleboggs@gmail.com.