Physician anesthesiologist at Stanford at Associated Anesthesiologists Medical Group
Richard Novak, MD is a Stanford physician board certified in anesthesiology and internal medicine.Dr. Novak is an Adjunct Clinical Professor in the Department of Anesthesiology, Perioperative and Pain Medicine at Stanford University, the Medical Director at Waverley Surgery Center in Palo Alto, California, and a member of the Associated Anesthesiologists Medical Group in Palo Alto, California.

Will robots replace anesthesiologists? I am the Medical Director of a surgery center in California that does 5,000 gastroenterology endoscopies per year.  In 2013 a national marketing firm contacted me to seek my opinion regarding an automated device to infuse propofol. The device was envisioned as a tool for gastroenterologist/nursing teams to use to administer propofol safely for endoscopy procedures on ASA class I – II patients.

The marketing firm could not reveal the name of the device, but I believe it was probably the SEDASYS®-Computer-Assisted Personalized Sedation System, developed by the Ethicon Endo-Surgery, Inc., a division of Johnson and Johnson.  The SEDASYS System is a computer-assisted personalized sedation system integrating propofol delivery with patient monitoring. The system incorporates standard ASA monitors, including end-tidal CO2, into an automated propofol infusion device.

The SEDASYS system is marketed as a device to provide conscious sedation.  It will not provide deep sedation or general anesthesia.

Based on pharmacokinetic algorithms, the SEDASYS infuses an initial dose of propofol (typically 30- 50 mg in young patients, or a smaller dose in older patients) over 3 minutes, and then begins a maintenance infusion of propofol at a pre-programmed rate (usually 50 mcg/kg/min).  If the monitors detect signs of over- sedation, e.g. falling oxygen saturation, depressed respiratory rate, or a failure of the end-tidal CO2 curve, the propofol infusion is stopped automatically.  In addition, the machine talks to the patient, and at intervals asks the patient to squeeze a hand-held gripper device.  If the patient is non-responsive and does not squeeze, the propofol infusion is automatically stopped.

As of February, 2013, the SEDASYS system was not FDA approved. On May 3, 2013, Ethicon Endo-Surgery, Inc. announced that the Food and Drug Administration (FDA) granted Premarket Approval for the SEDASYS® system, a computer-assisted personalized sedation system.  SEDASYS® is indicated “for the intravenous administration of 1 percent (10 milligrams/milliliters) propofol injectable emulsion for the initiation and maintenance of minimal to moderate sedation, as identified by the American Society of Anesthesiologists Continuum of Depth of Sedation, in adult patients (American Society of Anesthesiologists physical status I or II) undergoing colonoscopy and esophagoduodenoscopy procedures.”  News reports indicate that SEDASYS® is expected to be introduced on a limited basis beginning in 2014.

Steve Shaffer, M.D., Ph.D., Stanford Adjunct Professor, editor-in-chief of Anesthesia & Analgesia, and Professor of Anesthesiology at Columbia University, worked with Ethicon since 2003 on the design, development and testing of the SEDASYS System both as an investigator and as chair of the company’s anesthesia advisory panel.

Dr. Shafer has been quoted as saying, “The SEDASYS provides an opportunity for anesthesiologists to set up ultra-high throughput gastrointestinal endoscopy services, improve patient safety, patient satisfaction, endoscopist satisfaction and reduce the cost per procedure.” (Gastroenterology and Endoscopy News, November 2010, 61:11)

In Ethicon’s pivotal study supporting SEDASYS, 1,000 ASA class I to III adults had routine colonoscopy or esophagogastroduodenoscopy, and were randomized to either sedation with the SEDASYS System (SED) or sedation with each site’s current standard of care (CSC) i.e. benzodiazepine/opioid combination.  The reference for this study is Gastrointest Endosc. 2011 Apr;73(4):765-72. Computer-assisted personalized sedation for upper endoscopy and colonoscopy: a comparative, multicenter randomized study. Pambianco DJ, Vargo JJ, Pruitt RE, Hardi R, Martin JF.

In this study, 496 patients were randomized to SED and 504 were randomized to CSC. The area under the curve of oxygen desaturation was significantly lower for SED (23.6 s·%) than for CSC (88.0 s·%; P = .028), providing evidence that SEDASYS provided less over-sedation than current standard of care with benzodiazepine/opioid.  SEDASYS patients were significantly more satisfied than CSC patients (P = .007). Clinician satisfaction was greater with SED than with CSC (P < .001). SED patients recovered faster than CSC patients (P < .001). The incidence of adverse events was 5.8% in the SED group and 8.7% in the CSC group.

Donald E. Martin, MD, associate dean for administration at Pennsylvania State Hershey College of Medicine and chair of the Section on Clinical Care at the American Society of Anesthesiologists (ASA), expressed concerns about the safety of the device.  Dr. Martin (Gastroenterology and Endoscopy News, November 2010, 61:11) was quoted as saying, “SEDASYS is requested to provide minimal to moderate sedation and yet the device is designed to administer propofol in doses known to produce general anesthesia.”

Dr. Martin added that studies to date have shown that some patients who had  propofol administered by SEDASYS experienced unconsciousness or respiratory depression (Digestion 2010;82:127-129, Maurer WG, Philip BK.). In the largest prospective, randomized trial evaluating the safety of the device compared with the current standard of care, five patients (1%) experienced general anesthesia with SEDASYS. The ASA also voiced concern that SEDASYS could be used in conditions that do not comply with the black box warning in the propofol label, namely that propofol “should be administered only by persons trained in the administration of general anesthesia and not involved in the conduct of the surgical/diagnostic procedure.”

Anesthetists, emergency room doctors, and trauma helicopter nurses are trained in the administration of general anesthesia. Gastroenterologists and endoscopy nurses are almost never experts in airway management.  For this reason, propofol anesthetics for endoscopy are currently the domain of anesthesiologists and nurse anesthetists.

In my phone conversation regarding the automated propofol-infusion system, I told the marketing company’s representative that in my opinion a machine that infused propofol without an airway expert present could be unsafe.  The marketing consultant responded that in parts of the Northeastern United States, including New York City, many GI endoscopies are done with the assistance of an anesthesia provider administering propofol.  If SEDASYS were to be approved, the devices could replace anesthesiologists.

In the current fee-for-service model of anesthesia billing, anesthesiologists and CRNA’s bill insurance companies or Medicare for their professional time.  If machines replace anesthesiologists and CRNA’s, the anesthesia team cannot send a fee-for-service bill for professional time.  The marketing consultant foresaw that with the advent of ObamaCare and Accountable Care Organizations, if a health care organization is paid a global fee to take care of a population rather than being paid a fee-for-service sum, then perhaps the cheapest way to administer propofol sedation for GI endoscopy would be to replace anesthesia providers with SEDASYS machines.

A planned strategy is to have gastroenterologists complete an educational course that would educate them on several issues.  Key elements of the course would be: 1) anesthesiologists are required if deep sedation is required, 2) SEDASYS is not appropriate if the patient is ASA 3 or 4 or has severe medical problems, 3) SEDASYS is not appropriate if the patient has risk factors such as morbid obesity, difficult airway, or sleep apnea, and 4) airway skills are to be taught in the simulation portion of the training.  Specific skills are chin life, jaw thrust, oral airway use, nasal airway use, and bag-mask ventilation.  Endotracheal intubation and LMA insertion are not to be part of the class.  If the endoscopist cannot complete the procedure with moderate sedation, the procedure is to be cancelled and rescheduled with an anesthesia provider giving deep IV sedation.

Some anesthesiologists are concerned about being pushed out of their jobs by nurse anesthetists.  It may be that some anesthesiologists will be pushed out of their jobs by machines.

I’ve been told that the marketing plan for SEDASYS is for the manufacturer to give the machine to a busy medical facility, and to only charge for the disposable items needed for each case. The disposable items would cost $50 per case. In our surgery center, where we do 5,000 cases per year, this would be an added cost of $25,000 per year. There would be no significant savings, because we do not use anesthesiologists for most gastroenterology sedation.

There have been other forays into robotic anesthesia, including:

1) The Kepler Intubation System (KIS) intubating robot, designed to utilized video laryngoscopy and a robotic arm to place an endotracheal tube (Curr Opin Anaesthesiol. 2012 Oct 25. Robotic anesthesia: not the realm of science fiction any more. Hemmerling TM, Terrasini N. Departments of Anesthesia, McGill University),

2) The McSleepy intravenous sedation machine, designed to administer propofol, narcotic, and muscle relaxant to patients to control hypnosis, analgesia, and muscle relaxation. (Curr Opin Anaesthesiol. 2012 Dec;25(6):736-42. Robotic anesthesia: not the realm of science fiction any more. Hemmerling TM, Terrasini N.)

3) The use of the DaVinci surgical robot to perform regional anesthetic blockade. (Anesth Analg. 2010 Sep;111(3):813-6. Epub 2010 Jun 25. Technical communication: robot-assisted regional anesthesia: a simulated demonstration. Tighe PJ, Badiyan SJ, Luria I, Boezaart AP, Parekattil S.).

4) The use of the Magellan robot to place peripheral nerve blocks (Anesthesiology News, 2012, 38:8)

Each of these applications may someday lead to the performance of anesthesia by an anesthesiologist at geographical distance from the patient.  In an era where 17% of the Gross National Product of the United States is already being spent on health care, one can question the logic of building expensive technology to perform routine tasks like I.V. sedation, endotracheal intubation, or regional block placement.  The new inventions are futuristic and interesting, but a DaVinci surgical robot costs $1.8 million, and who knows what any of these anesthesia robots would sell for?  The devices seem more inflationary than helpful at this point.

Will robots replace anesthesiologists?  Inventors are edging in that direction.  I would watch the peer-reviewed anesthesia journals for data that validates the utility and safety of any of these futuristic advances.

It will be a long time before anyone invents a machine or a robot that can perform mask ventilation.  SEDASYS is designed for conscious sedation, not deep sedation or general anesthesia.  Anyone or anything that administers general anesthesia without expertise in mask ventilation and all facets of airway management is courting disaster.

NOTE: In March of 2016, Johnson & Johnson announced that they were going to stop selling the SEDASYS system due to slow sales and company-wide cost cutting. The concept of Robot Anesthesia will have to wait for some future development, if ever, if it is to ever become an important part of the marketplace.

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Published in September 2017:  The second edition of THE DOCTOR AND MR. DYLAN, Dr. Novak’s debut novel, a medical-legal mystery which blends the science and practice of anesthesiology with unforgettable characters, a page-turning plot, and the legacy of Nobel Prize winner Bob Dylan.


In this debut thriller, tragedies strike an anesthesiologist as he tries to start a new life with his son.

Dr. Nico Antone, an anesthesiologist at Stanford University, is married to Alexandra, a high-powered real estate agent obsessed with money. Their son, Johnny, an 11th-grader with immense potential, struggles to get the grades he’ll need to attend an Ivy League college. After a screaming match with Alexandra, Nico moves himself and Johnny from Palo Alto, California, to his frozen childhood home of Hibbing, Minnesota. The move should help Johnny improve his grades and thus seem more attractive to universities, but Nico loves the freedom from his wife, too. Hibbing also happens to be the hometown of music icon Bob Dylan. Joining the hospital staff, Nico runs afoul of a grouchy nurse anesthetist calling himself Bobby Dylan, who plays Dylan songs twice a week in a bar called Heaven’s Door. As Nico and Johnny settle in, their lives turn around; they even start dating the gorgeous mother/daughter pair of Lena and Echo Johnson. However, when Johnny accidentally impregnates Echo, the lives of the Hibbing transplants start to implode. In true page-turner fashion, first-time novelist Novak gets started by killing soulless Alexandra, which accelerates the downfall of his underdog protagonist now accused of murder. Dialogue is pitch-perfect, and the insults hurled between Nico and his wife are as hilarious as they are hurtful: “Are you my husband, Nico? Or my dependent?” The author’s medical expertise proves central to the plot, and there are a few grisly moments, as when “dark blood percolated” from a patient’s nostrils “like coffee grounds.” Bob Dylan details add quirkiness to what might otherwise be a chilly revenge tale; we’re told, for instance, that Dylan taught “every singer with a less-than-perfect voice…how to sneer and twist off syllables.” Courtroom scenes toward the end crackle with energy, though one scene involving a snowmobile ties up a certain plot thread too neatly. By the end, Nico has rolled with a great many punches.

Nuanced characterization and crafty details help this debut soar.

Click on the image below to reach the Amazon link to The Doctor and Mr. Dylan:


Learn more about Rick Novak’s fiction writing at by clicking on the picture below:  




Physician anesthesiologist at Stanford at Associated Anesthesiologists Medical Group
Richard Novak, MD is a Stanford physician board certified in anesthesiology and internal medicine.Dr. Novak is an Adjunct Clinical Professor in the Department of Anesthesiology, Perioperative and Pain Medicine at Stanford University, the Medical Director at Waverley Surgery Center in Palo Alto, California, and a member of the Associated Anesthesiologists Medical Group in Palo Alto, California.

Do you need an anesthesiologist for a colonoscopy?  The answer is:  it depends. It depends on 1) your health, 2) the conscious sedation skills of your gastroenterologist, and 3) the facility you have your colonoscopy at.


1)  YOUR HEALTH. The majority of colonoscopies in the United States are performed under conscious sedation.  Conscious sedation is administered by a registered nurse, under specific orders from the gastroenterologist.  The typical drugs are Versed (midazolam) and fentanyl.  Versed is a benzodiazepine, or Valium-like medication, that is superb in reducing anxiety, sleepiness, and producing amnesia.  Fentanyl is a narcotic pain reliever, similar to a short-acting morphine.  The combination of these two types of medications renders a patient sleepy but awake.  Most patients can minimal or no recollection of the colonoscopy procedure when under the influence of these two drugs.  I can speak from personal experience, as I had a colonoscopy myself, with conscious sedation with Versed and fentanyl, and I remembered nothing of the procedure.

If you are a reasonably healthy adult, you should be fine having the procedure under conscious sedation.  Patients with high blood pressure, diabetes, asthma, obesity, mild to moderate sleep apnea, advanced age, or stable cardiac disease are have conscious sedation for colonoscopies in America every day, without significant complications.

Certain patients are not good candidates for conscious sedation, and require an anesthesiologist for sedation or general anesthesia.  Included in this category are a) patients on large doses of chronic narcotics for chronic pain, who are tolerant to the fentanyl and are therefore difficult to sedate, b) certain patients with morbid obesity, c) certain patients with severe sleep apnea, and d) certain patients with severe heart or breathing problems.

2)  THE CONSCIOUS SEDATION SKILLS OF YOUR GASTROENTEROLOGIST.  Most gastroenterologists are comfortable directing registered nurses in the administration of conscious sedation drugs.  Some, however, are not.  These gastroenterologists will disclose this to their patients, and recommend that an anesthesiologist administer general anesthesia for the procedure.

3) THE FACILITY YOU HAVE YOUR COLONOSCOPY AT.  Most endoscopy facilities have nurses and gastroenterologists comfortable with conscious sedation.  Some do not.  The facility you are referred to may have a consistent policy of having an anesthesiologist administer general anesthesia with propofol for all colonoscopies.  If this is true, they should disclose this to you, the patient, before you start your bowel prep for the procedure.  A facility which always utilizes general anesthesia means that you, the patient, will incur one extra physician bill for your procedure, from an anesthesiologist.

I refer you to an article from the New York Times, which summarizes this phenomenon in the New York region:

One last point: If the drugs Versed and fentanyl are used, there exist specific and effective antidotes for each drug if the patient becomes oversedated. The antagonist for Versed is Romazicon (flumazenil), and the antagonist for fentanyl is Narcan (naloxone). If these drugs are injected promptly into the IV of an oversedated patient, the patient will wake up in seconds, before any oxygen deprivation affects the brain or heart.

Propofol, however, has no specific antagonist. Propofol only wears off as it is redistributed out of the blood stream into other tissues, and its blood level declines. A propofol overdose can cause obstruction of breathing, and/or depression of breathing, such that the blood oxygen level is insufficient for the brain and heart. The Food and Drug Administration (FDA) mandates that a Black Box warning be included in the packaging of every box of propofol. That warning states that propofol “should be administered only by persons trained in the administration of general anesthesia and not involved in the conduct of the surgical/diagnostic procedure.”

Anesthesiologists are experts at using propofol. I administer propofol to 99% of my patients who are undergoing general anesthesia for a surgical procedure. Anesthesiologists are experts at managing airways and breathing. Individuals who are not trained to administer general anesthesia should never administer propofol to a patient, in a hospital or in an outpatient surgery center.

I serve as the Medical Director of an outpatient surgery center in Palo Alto, California. We perform a variety of orthopedic, head and neck, plastic, ophthalmic, and general surgery procedures safely each year. In addition, our gastroenterologists perform thousands of endoscopies each year. I review the charts of the endoscopy patients as well as the surgical patients prior to the procedures, and in our center, approximately 99% of endoscopies can be safely performed under Versed and fentanyl conscious sedation, without the need for an anesthesiologist attending to the patient.

If you have an endoscopy, ask questions. Will you receive conscious sedation with drugs like Versed and fentanyl, or will an anesthesiology professional administer propofol? You deserve to know.



Learn more about Rick Novak’s fiction writing at by clicking on the picture below: