Robo-Anesthesia?

With remarkable timing, news of a lawsuit brought by the parents of a teenager left in a permanent vegetative state after a routine endoscopy coincides with the announcement that the Food and Drug Administration (FDA) has granted Premarket Approval for the SEDASYS^® system, a computer-assisted personalized sedation system.

The patient was not anesthetized using a SEDASYS machine or any other form of robo-anesthesia, of course.  According to the May 1^st New York Daily News article, “The suit to be filed in Westchester Supreme Court alleges that doctors improperly administered anesthesia in failing to consider the patient’s height and weight; improperly monitored her vital signs; excessively inflated her abdomen, causing cardiac arrest, and removed a breathing tube prematurely.”  The point of the juxtaposition of the two news items is to highlight the inherent risks of routine anesthesia even when administered and monitored by experienced anesthesiologists.

The SEDASYS manufacturer, Ethicon Endo-Surgery, Inc., a subsidiary of Johnson & Johnson (J&J), stated in its May 3 press release that: “The SEDASYS System is indicated for the intravenous administration of 1% (10 mg/mL) propofol injectable emulsion for the initiation and maintenance of minimal-to-moderate sedation, as defined by the American Society of Anesthesiologists (ASA) Continuum of Depth of Sedation, in ASA physical status I and II patients 18 years old undergoing colonoscopy and esophagogastroduodenoscopy (EGD) procedures.”  It has described the SEDASYS system as:

[T]he first computer-assisted personalized sedation (CAPS) system designed to provide minimal-to-moderate sedation with propofol. By integrating drug delivery and patient monitoring, the SEDASYS System enables physician/nurse teams to deliver personalized sedation. It automatically detects and responds to signs of over-sedation (oxygen desaturation and low respiratory rate/apnea) by stopping or reducing delivery of propofol, increasing oxygen delivery and automatically instructing patients to take a deep breath. The System monitors and records patient vital signs and additional parameters, including oxygen saturation, respiratory rate, heart rate, blood pressure, end-tidal carbon dioxide and patient responsiveness.

Approved several years ago for use in colonoscopy (Canada, European Union) and in EGD procedures (European Union), the SEDASYS system was first rejected by the FDA’s Medical Devices Advisory Committee in early 2010.  The American Society of Anesthesiologists had written to the FDA in May, 2009 to express its “serious concerns regarding the proposed use of SEDASYS^™ [sic], including:

1. The lack of data to demonstrate the level of safety required of a complex device such as this, which monitors critical life support functions and determines the delivery rate of a potent intravenous anesthetic;
2. The limitations of oxygen saturation (SpO2) and end tidal CO2 (ETCO2) measurements when used for the purpose of detecting respiratory depression in sedated patients;
3. The inability of SEDASYS^™ to prevent or manage loss of consciousness;
4. The properties, inherent risks and current labeling of the anesthetic drug propofol itself; and
5. Safety requirements for closed loop control devices such as SEDASYS^™.

Although the FDA panel agreed with ASA in its 2010 decision, Ethicon’s appeal was successful and the SEDASYS system received final Premarket Approval on May 3, 2013.

Ethicon’s press release reveals that the manufacturer intends the SEDASYS system to be operated by a non-anesthesiologist physician, quoting the principal investigator thus: “The technology will empower health care facilities to more effectively use their limited resources to deliver greater value in the increasingly resource-constrained U.S. health care environment."  The FDA’s letter informing Ethicon of the Premarket Approval requires that an anesthesiologist or nurse anesthetist be “immediately available for assistance or consultation”—which only means present in the facility.  The approval is contingent upon Ethicon’s conducting and providing “the results of two (2) post-approval studies intended to demonstrate that the SEDASYS System is safe for use in clinical practice without the need for immediate availability of a trained anesthesia professional.”

What is not clear is how the administration of propofol by the SEDASYS system will comply with FDA-mandated black box warning in propofol packaging inserts that limits the administration of propofol to professionals who are trained in the administration of general anesthesia and not involved in the procedure.  The FDA’s letter requires different training for the SEDASYS operator, and a different warning label:

Specifically, the device labeling must include the requirement that the member of the physician-led team who is administering sedation must have training in the management of the cardiorespiratory effects of propofol when administered using computer-assisted personalized sedation systems. The device labeling must also state that the training must include: (I) pharmacology of propofol, (2) identification of high risk patients, (3) recognition of progression of levels of sedation, and actions necessary to return a patient to intended levels of sedation, (4) use of capnometry and the determination of adequate ventilation and (5) management of airway obstruction and hypoventilation.

The inconsistency between the propofol black box warning requiring training in the administration of general anesthesia and the SEDASYS system warning mandating training in propofol pharmacology and certain aspects of the knowledge of an anesthesia professional may be due to the involvement of two different offices within the FDA.  The FDA will need to resolve that inconsistency, as will the Centers for Medicare and Medicaid Services (CMS), whose policy currently bars payment for the administration of propofol by non-anesthesia professionals.  These are certain to be among the issues raised as ASA pursues the three-prong strategy that it announced on May 15^th:

• ASA established an Ad Hoc Committee on SEDASYS … charged with reviewing the FDA’s restrictions for use and conditions of approval for the device and determining whether the FDA addressed ASA’s concerns and recommendations raised in our previous formal communications to the FDA.
• ASA will convene a meeting with J&J representatives during the week of May 20 to seek information on FDA conditions, particularly around supervision, training and post-market studies. …
• ASA will initiate a strategy to engage the FDA’s Center for Devices and Radiological Health to discuss ASA’s questions and explore an enhanced role for ASA with the FDA relative to this device and other future devices.

ASA states that it will update members on progress and new developments as they occur.  The Society has also established a process and an email address, SEDASYS@asahq.org, for members to communicate their concerns.  ABC encourages our readers to keep up with the news posted by ASA and, if they are members, to send any questions to the dedicated address or to the ASA leadership.