CIPROFOL VS PROPOFOL

30 Dec 20225 Jan 2023THE ANESTHESIA CONSULTANT Leave a comment

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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.
emailrjnov@yahoo.com

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Ciprofol is a new intravenous (IV) anesthetic agent which is undergoing early clinical trials in China, and may become a significant tool in our anesthesia armamentarium if and when the drug is approved by the Food and Drug Administration (FDA) in the United States. Ciprofol has a chemical structure similar to propofol. Because of its rapid onset and rapid offset profile, propofol is currently the most used IV anesthetic drug in the world. Propofol is used for surgical anesthesia, procedural sedation, and intensive care unit (ICU) sedation. Propofol was FDA-approved in the United States in 1986 and is now off patent. Generic propofol is inexpensive, averaging about $2.27 for a 20 ml vial. Limitations of propofol include (a) respiratory depression, such that it can only be used by physicians who are expert in airway management (e.g. anesthesiologists, CRNAs, and emergency room doctors); (b) hemodynamic depression in some elderly or sick patients; (c) pain on injection; and (d) the propofol infusion syndrome (PIS) which can lead to hyperkalemia and cardiac arrest in ICU patients after prolonged exposure to propofol infusions.

The chemical formula of ciprofol is similar to propofol, but with single R-configured diastereoisomers.

Ciprofol is about 5 times more potent than propofol. Like propofol, ciprofol is formulated in a lipid emulsion with a drug concentration of 10 mg/mL. Let’s review the published literature on ciprofol to date. All of the following studies were done in China:

Phase 1 trials (small groups of subjects are given a single dose of the drug, and are observed and tested for a period of time to confirm safety):

Teng et al. (2021) conducted a phase I trial which demonstrated that a ciprofol dosing regimen of 0.4-0.9 mg/kg was well-tolerated and exhibited rapid onset and recovery properties. Peak plasma concentration occurred 2 minutes after injection, and all subjects recovered fully after ciprofol administration, with the shortest time being 9.2 minutes in the 0.4 mg/kg group.

Hu et al. (2021) also conducted a phase I trial in which subjects received continuous ciprofol or propofol infusions for up to 12 hours. The safety and tolerability of both drugs were comparable.

Phase II trials (performed on larger groups, e.g. 50–300 patients, to evaluate whether the drug has any biological activity or effect):

Teng et al. (2021) conducted a study on 1000 patients, which showed that ciprofol 0.4-0.5 mg/kg induced equivalent sedation/anesthesia to propofol 2.0 mg/kg during colonoscopy, and had a similar safety profile without producing serious adverse effects. No apnea was observed in any patients in the ciprofol group, but 5 patients in the propofol 2.0 mg/kg group experienced apnea. The incidence of injection pain was higher in the propofol group than in the ciprofol group (55% vs 6.8%). There were no significant dose-dependent changes in blood pressure in either the ciprofol or propofol groups.

Liu et al. (2021) conducted a phase II trial which involved 36 ICU patients who were on mechanical ventilation. A remifentanil infusion of 0.02–0.15 μg·kg⁻¹·min⁻¹ plus either ciprofol or propofol were used for analgesia and sedation. The ciprofol loading dose was 0.1–0.2 mg/kg with a maintenance infusion rate of 0.3 mg/kg/h. The propofol loading was at 0.5–1.0 mg/kg, with a maintenance infusion rate of 1.5 mg/kg/h. The tolerability, sedation characteristics, and adverse events such as hypotension were comparable between both groups. The authors concluded that “ciprofol is comparable to propofol with good tolerance and efficacy for sedation of Chinese intensive care unit patients undergoing mechanical ventilation in the present study setting.”

The propofol infusion syndrome (PIS) is a potentially lethal syndrome that occurs due to prolonged infusion described in adults and pediatric ICU patients who are on mechanical ventilation. To date, published studies have not administered multi-day infusions of ciprofol to mechanically ventilated ICU patients to determine whether there is anything similar to PIS with ciprofol.

Wu et al. (2022) published a single-center trial on 92 patients titled “Efficacy and safety of ciprofol-remifentanil versus propofol-remifentanil during fiberoptic bronchoscopy.” Fentanyl (50 μg) was given to all patient 2 minutes before the intravenous administration of either 0.3 mg/kg of ciprofol or 1.2 mg/kg of propofol, followed by a remifentanil infusion in both groups. Top-up doses of one-third to one-fourth of the initial dose of ciprofol or propofol were repeated at 2-minute intervals as needed. The two drugs were comparable. The authors concluded that “ciprofol-remifentanil was non-inferior to propofol-remifentanil with regard to successful sedation for flexible bronchoscopy.” Systolic, diastolic, and mean blood pressures declined significantly less in the ciprofol-remifentanil group (p < 0.05). There was no difference in respiratory depression between the two groups, and the only statistical difference in adverse effects was a decrease in pain on injection for ciprofol over propofol (p=.001).

Chen et al. (2022) compared ciprofol and propofol in 120 women for the induction of anesthesia in gynecologic surgery. Intravenous midazolam (0.03 mg/kg) and sufentanil (0.3 μg/kg) were administered initially, followed by ciprofol (0.4 mg/kg) or propofol (2 mg/kg). After the loss of consciousness, rocuronium (0.6 mg/kg) was administered and endotracheal intubation was performed. Within the initial 10 minutes following study drug administration, blood pressure declined significantly less in the ciprofol group than in the propofol group. The authors concluded that “ciprofol was associated with slightly less pronounced effects on the cardiovascular system.” The incidence of injection pain was higher in the propofol group than in the ciprofol group (58% vs 16%, p < 0.001).

Chen et al. (2022) studied adverse reactions of ciprofol and propofol in 96 patients for gastroenteroscopy. Neither ciprofol nor propofol caused statistically significant differences in vital signs. The authors concluded that “in painless gastroenteroscopy, compared with propofol, ciprofol is equally safe and effective for patients.”

Lan et al. (2022) randomized 150 patients to ciprofol or propofol for hysteroscopy. All patients received intravenous sufentanil 0.1 μg/kg IV initially. Ciprofol patients then received an induction dose of 0.4 mg/kg and a maintenance dosage of 1.0 mg/kg/h. Propofol patients received an induction dose of 2.0 mg/kg and a maintenance dosage of 5.0 mg/kg/h. After the sedative administration, the systolic, diastolic, and mean pressures all dropped significantly lower in the propofol group than in the ciprofol group. During the procedure, 2/75 ciprofol patients vs 17/75 propofol patients required an airway intervention such as a chin-lift or jaw-thrust maneuver (p< 0.05). The authors concluded that “the lower level of respiratory depression seen with ciprofol makes this drug more suitable and safer than propofol for hysteroscopic procedures.”

Phase III trials (randomized controlled multicenter trials on larger patient groups, aimed at determining how effective the drug is in comparison with the current “gold standard” treatment, i.e. propofol):

Li et al. (2022) conducted a phase III study at ten teaching hospitals, comparing ciprofol and propofol for deep sedation for colonoscopy or gastroscopy. A total of 289 patients were studied. Each patient received 50 μg fentanyl 1 minute before the intravenous infusion of either ciprofol (0.4 mg/kg) or propofol (1.5 mg/kg). Up to five top-up doses of 1/2 the initial dose were given upon signs of inadequate sedation, and repeated at 2-minute intervals as required. The mean time for a patient to become fully alert after the procedure was 3.3 minutes in the ciprofol group vs. 2.0 minutes for the propofol group (P < 0.001). The time to discharge was 7.4 minutes for the ciprofol group vs. 6.0 minutes for the propofol group (P < 0.001). Nine patients (6.3%) in the ciprofol group and 15 patients (10.3%) in the propofol group had respiratory events (respiratory depression, apnea, or hypoxemia), all of which were mild or moderate in severity. The authors concluded that “at a dose of 0.4 mg/kg for deep sedation, ciprofol was non-inferior to 1.5 mg/kg propofol in the success rate of gastroscopy and colonoscopy and exhibited a good safety profile.”

Wang et al. (2022) published a multi-center, double-blind phase III trial in which 186 surgery patients were randomly assigned to either ciprofol 0.4 mg/kg or propofol 2.0 mg/kg for the induction of general anesthesia. Ciprofol was “non-inferior” to propofol. Once again, the incidence of injection pain was significantly lower in the ciprofol patients compared to the propofol patients (6.8% vs. 20.5%, p < 0.05).

MY TAKE: WILL CIPROFOL BE A SUCCESSFUL ADDITION TO OUR IV ANESTHESIA DRUG ARSENAL?

It depends.

If ciprofol and propofol were cost-equivalent, ciprofol would gain some market share, and might prove to be a superior drug to propofol. However, when and if it is FDA-approved in the United States, ciprofol will cost significantly more than propofol because ciprofol will be on patent. Hospitals and surgery centers will be reluctant to pay more for the drug unless there are proven advantages. Ciprofol appears to have significantly less pain on injection when compared to propofol, but pain on injection with propofol is not a major issue. Pain on injection does not lead to any long term adverse outcomes, and the pain can be blocked by injecting IV lidocaine immediately prior the initial dose of IV propofol.
The data that ciprofol leads to less blood pressure decreases than propofol shows only a mild difference—too small an advantage to mandate replacing propofol with ciprofol for that reason alone.
So far there are no data to confirm or deny that there is any equivalent to propofol infusion syndrome with ciprofol. If there is no prolonged infusion syndrome, then ciprofol may find a market for ICU sedation of mechanically ventilated patients.
Overall, I believe ciprofol must promise a lack of respiratory depression if the new drug is to capture any of propofol’s market share for procedural sedation/surgical anesthesia. The most bothersome issue with propofol is the risk of respiratory depression, which requires an anesthesia professional or airway expert administer the drug. If a patient is oversedated with propofol, that patient may stop breathing or have upper airway obstructed breathing, which can lead to hypoxia, cardiac arrest, and anoxic brain damage. The FDA warnings for propofol include:

For general anesthesia or monitored anesthesia care (MAC) sedation, DIPRIVAN Injectable Emulsion should be administered only by persons trained in the administration of general anesthesia and not involved in the conduct of the surgical/diagnostic procedure. Sedated patients should be continuously monitored, and facilities for maintenance of a patent airway, providing artificial ventilation, administering supplemental oxygen, and instituting cardiovascular resuscitation must be immediately available. Patients should be continuously monitored for early signs of hypotension, apnea, airway obstruction, and/or oxygen desaturation. These cardiorespiratory effects are more likely to occur following rapid bolus administration, especially in the elderly, debilitated, or ASA-PS III or IV patients.

In the Li study above, 6.3% of the ciprofol patients had mild to moderate respiratory adverse events when sedated for GI endoscopy. While the 6.3% rate is lower than the 10.3% rate for the propofol patients, the non-zero incidence of respiratory events with ciprofol in this one study points to an anesthesia professional still needing to be present if ciprofol is administered for endoscopy.

In the Lan study above, during IV sedation only 2/75 ciprofol patients, compared with 17/75 propofol patients, required airway intervention such as with a chin-lift or a jaw-thrust maneuver during hysteroscopy (p< 0.05). This lower incidence of required airway intervention is encouraging, but the incidence is still not zero, and we’ll need more data to document the respiratory risks of ciprofol.

If ciprofol sedation is found to NOT produce any significant respiratory depression, apnea, or upper airway obstruction (therefore less risk of hypoxia and anoxic brain damage), this would be a profound advance over propofol. Then ciprofol could be administered for procedural sedation, e.g. for gastroenteroscopy, without an anesthesia airway expert attending to the patient. There is insufficient studies to date to know whether this will be true or not.

My guess? After all the data is in, ciprofol will cause a non-zero incidence of respiratory depression, and therefore a non-zero risk of hypoxia and anoxic brain damage, so an anesthesia airway expert will be necessary to administer the drug. The advantage of ciprofol’s lower but non-zero incidence of required airway intervention will not be a major advance in the hands of anesthesia professionals. The higher cost of ciprofol will preclude the decision of hospitals and surgery centers to switch to ciprofol until the new drug is off patent.

We’ll have to wait for more data on ciprofol, but don’t be surprised if propofol remains on top of the intravenous sedative/hypnotic anesthesia drug pedestal after the studies are concluded.

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PRESIDENT BIDEN’S COLONOSCOPY ANESTHESIA

22 Nov 202122 Nov 2021THE ANESTHESIA CONSULTANT Leave a comment

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Physician anesthesiologist at Stanford at Associated Anesthesiologists Medical Group

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Three days ago, I was giving anesthesia for six consecutive colonoscopy patients. Following my first case, I checked my phone and discovered that the President of the United States Joe Biden was having a colonoscopy at Walter Reed Medical Center that very morning. The headlines stated that for the first time, temporary acting presidential power was being turned over to a woman, Vice President Kamala Harris, during the time of President Biden’s colonoscopy anesthesia.

I mentioned this to the gastroenterologist I was working with that day, and he asked, “How long do you think he will be unable to make decisions as the President? We tell our patients not to drive the rest of the day, and not to make any important life decisions after their general anesthetic. Biden has the most difficult and most important job on Earth. When can he return to duty?”

I answered, “My guess is that he’ll have the same propofol anesthetic we’re administering today. The procedure will last thirty minutes, he’ll begin to awaken five minutes after the propofol is discontinued, and within an hour he’ll feel clear-headed.” The gastroenterologist was dubious that the leader of the free world would be alert enough to resume power only one hour after receiving propofol. Joseph Biden was one day short of his 79^th birthday when the colonoscopy took place. Later that morning the news services reported that the President had transferred presidential powers to Kamala Harris at 10:10 a.m. EST and resumed his presidential powers at 11:35 a.m., a mere 1 hour and 25 minutes later.

The evening after the colonoscopy, comedian Colin Jost of Saturday Night Live joked about Biden’s colonoscopy. During Weekend Update, Jost reported on Biden’s resumption of all his presidential responsibilities immediately following the colonoscopy, and noted that Biden had just turned 79. “Half the country already thinks he’s senile,” Jost said. “You can’t drop all that on him the second he comes out of the gas.”

A note from an anesthesiologist to the comedy writers: No one uses “gas” for anesthesia for a colonoscopy. The anesthetic is solely from intravenous (IV) drug(s).

I have no specific knowledge of what anesthetic drug regimen the President received for his colonoscopy, but more likely than not he received propofol. Anesthesia for colonoscopy is typically administered so that patients have no awareness during this procedure, a procedure which does not involve surgical pain, but rather involves the uncomfortable entrance of a 66-inch-long flexible hose, one-half-inch in diameter, into their anus, rectum, and colon.

For the quickest recovery after colonoscopy, one option is no anesthesia at all. Very few patients sign up for a colonoscopy without any intravenous anesthesia. The press reports about Biden’s colonoscopy stated that he had anesthesia, so let’s discount the option that he had the procedure while awake.

Colonoscopy sedation is typically done with one of two recipes: 1) conscious sedation with a combination of intravenous Versed (generic name midazolam, a benzodiazepine in the Valium family) plus intravenous fentanyl, such that the patient has no memory of the procedure; or 2) intravenous general anesthesia with propofol by continuous infusion or by intermittent boluses so that the patient is unresponsive. The combination of Versed and fentanyl leads to a slower wakeup and recovery than with propofol. The duration of effect of Versed is approximately 30 to 45 minutes after a single dose, with a recovery time of 2 to 6 hours. The duration of effect of IV fentanyl begins within minutes and lasts for 30 to 60 minutes after a single dose.

Propofol for colonoscopy leads to a quicker wakeup, a quicker discharge home, and less hangover. Virtually every surgical general anesthetic in the United States includes propofol, and anesthesiologists are experts at the administration and pharmaceutical properties of the drug. Propofol is an intravenous nonbarbiturate anesthetic which induces anesthesia quickly and provides a rapid emergence from anesthesia. The onset of action is within 20 – 40 seconds. The anesthesia provider for a colonoscopy will continue administering IV propofol until the procedure is over. A typical colonoscopy will last 20 – 40 minutes, depending on whether the gastroenterologist needs to take extra time to remove any colonic polyps. In Biden’s case, a single 3 mm benign-appearing polyp was identified and removed.

Propofol’s pharmacokinetics are described by two phases:

In the first phase (red curve), the plasma concentration decreases rapidly because the drug redistributes, or spreads, out of the bloodstream into other tissues of the body. The half–life of this fast redistribution is only 2 – 8 minutes, meaning the concentration of propofol in the bloodstream is halved every 2 to 8 minutes. This first phase explains the quick transition to wakefulness up after the drug is stopped. The second phase (black curve) is the elimination of propofol from the body. The half-life time of this elimination from the body is 4 – 7 hours (reference: MILLER’S ANESTHESIA, 9^thedition, chapter 23 on Intravenous Anesthetics).

The graph below depicts the timeline after propofol is discontinued. After a one-hour infusion, the concentration of propofol in the blood drops to near zero within 30-40 minutes.

THE PROPOFOL CONCENTRATION APPROACHES ZERO 40 MINUTES AFTER THE END OF INFUSION

The website PDR.net affirms this, stating that “Recovery from anesthesia is rapid (8 to 19 minutes for 2 hours of anesthesia) and is associated with minimal psychomotor impairment.” The PDR also states that “The elimination half-life of 3 to 12 hours is the result of slow release of propofol from fat stores. About 70% of a single dose is excreted renally (by the kidneys) in 24 hours.”

While the President would be awake one hour after receiving 30 minutes of propofol, and the blood concentration would be minimal, it still takes 24 hours for 70% of a single dose of propofol to be excreted by the kidneys. Therefore, one hour after the propofol was discontinued, even though the blood concentration was minimal, a significant amount of the drug would still be in the President’s body.

I’ve had propofol anesthesia for a colonoscopy, and I can attest that I woke up promptly and was in an automobile heading home within 45 minutes after the end of the procedure. I felt alert, albeit a bit woozy, after 60 minutes of recovery time. Did I feel it would have been safe for me to resume my duties administering general anesthetics to patients at that time? No. Would a major American airline allow one of its pilots to fly passengers at that time? No. Would the U.S. Army allow a general to command thousands of soldiers at that time? I doubt it.

One hour after a propofol colonoscopy anesthetic, the President would be awake enough to converse and give a “thumbs up.” Would he be alert enough at that point to make decisions regarding the nuclear football, a potential attack on Taiwan by mainland China, or a terrorist attack on a major United States city? Was this nearly 79-year-old man safe to make all the acute decisions the United States President could have to make, only one hour after discontinuing propofol?

The Mayo Clinic website states that, “After the exam (colonoscopy), it takes about an hour to begin to recover from the sedative. You’ll need someone to take you home because it can take up to a day for the full effects of the sedative to wear off. Don’t drive or make important decisions or go back to work for the rest of the day.”

Was Biden fit to run the country 55 minutes after his colonoscopy anesthetic?

Hmmm. The decision as to whether he was recovered enough to resume running the country . . . was a decision made by President Biden’s doctors on that day.

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ROBOT ANESTHESIA

27 Nov 20127 Feb 2022THE ANESTHESIA CONSULTANT 4 Comments

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THE ANESTHESIA CONSULTANT

Physician anesthesiologist at Stanford at Associated Anesthesiologists Medical Group

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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.

KIRKUS REVIEW

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: