Monitored Anesthesia Care (MAC)

Number 7.02.500

Effective Date February 10, 2015

Revision Date(s) 02/10/15; 10/13/14; 05/12/14; 04/14/14; 05/13/13

Replaces 7.02.01


Use of monitored anesthesia care may be considered medically necessary for gastrointestinal endoscopy, bronchoscopy and interventional pain procedures, when there is documentation by the proceduralist or anesthesiologist that specific risk factors or significant medical conditions are present. Those risk factors or significant medical conditions that increase likelihood of complications or intolerance to moderate sedation anesthesia include any of the following:

  • Increased risk for complications due to severe comorbidity (ASA P3* or greater).
  • Morbid obesity (BMI >40).
  • Severe sleep apnea (oxygen or bi-pap required during sleep).
  • Inability to follow simple commands (cognitive dysfunction, intoxication, or psychological impairment).
  • Spasticity or movement disorder complicating procedure.
  • History of or anticipated intolerance to standard sedatives, such as:
  • Prior complications with anesthesia or conscious sedation.
  • Chronic opioid or benzodiazepine use. (See Policy Guidelines)
  • Patients with active medical problems related to drug or alcohol abuse.
  • Patients younger than 18 years or 70 years and older
  • Patients who are pregnant.
  • Patients with increased risk for airway obstruction due to anatomic variation, such as:
  • Dysmorphic facial features,
  • Oral abnormalities (e.g., macroglossia),
  • Neck abnormalities (e.g., neck mass), and
  • Jaw abnormalities (e.g., micrognathia).
  • Acutely agitated, uncooperative patients (e.g., delirium, organic brain disease, senile dementia)
  • Prolonged or therapeutic gastrointestinal endoscopy procedures requiring deep sedation. (See Policy Guidelines)

[*American Society of Anesthesiologists (ASA) physical status classification system for assessing a patient before surgery:

P1 – A normal, healthy patient

P2 – A patient with mild systemic disease

P3 – A patient with severe systemic disease

P4 – A patient with severe systemic disease that is a constant threat to life

P5 – A moribund patient who is not expected to survive without the operation

P6 – A declared brain-dead patient whose organs are being harvested ]

Use of monitored anesthesia care is considered not medically necessary for gastrointestinal endoscopic, bronchoscopic, or interventional pain procedures in patients at average risk related to use of anesthesia and moderate sedation.

Related Policies


Manipulation Under Anesthesia

Policy Guidelines

History of or anticipated intolerance to standard sedatives

The patient must be unable to tolerate standard sedatives (or it is anticipated that he/she will not be able to) due to:

  • Prior complications with anesthesia or conscious sedation or
  • Chronic daily use of narcotic pain medication (opioids) or chronic daily use of prescription sedatives (benzodiazepines such as Valium®, Xanax®, Halcion®, Ativan®, Klonopin®) whose dosages and/or frequency would be expected to affect sedation requirements.

Standard use of psychiatric medications such as antidepressants or sleep aids does not confer high risk.

Prolonged Endoscopic Procedures

Examples of prolonged endoscopy procedures that may require deep sedation include adhesions post-abdominal surgery, endoscopic retrograde cholangiopancreatography, stent placement in the upper GI tract, and complex therapeutic procedures such as plication of the cardioesophageal junction. Prolonged procedures are generally greater than 60 minutes.

Monitored anesthesia care may also be considered medically necessary during the procedure to dilate an esophageal stricture.

Mallampati Score

The Mallampati score is considered a predictor of difficult tracheal intubation and is routinely used in preoperative anesthesia evaluation. (5) The score is obtained by having the patient extend the neck, open the mouth, and extend the tongue while in a seated position.

Patients with Class 3 or 4 Mallampati scores are considered to be at higher risk of intubation difficulty. While the Mallampati score does not by itself determine a need for monitored anesthesia care, it may be considered in determining risk for airway obstruction. Other tests to predict difficult tracheal intubation include the upper lip bite test, the intubation difficulty scale, and the Cormack-Lehane grading system.

Patients are scored from Class 1-4 as follows:

Class 1 the tonsils, uvula and soft palate are fully visible

Class 2 the hard and soft palate, uvula and upper portion of the tonsils are visible

Class 3 the hard and soft palate and the uvula base are visible

Class 4 only the hard palate is visible.


Adequate sedation and analgesia are important parts of many diagnostic and therapeutic procedures. Various levels of sedation and analgesia (anesthesia) may be used, depending on the patient’s condition and the procedure being performed. This policy addresses the potential role of dedicated anesthesia providers during procedures performed in a properly-equipped and staffed outpatient setting.


Monitored anesthesia care (MAC) refers to a service provided by anesthesia personnel who are present during a procedure, and does not implicitly indicate the level of anesthesia needed. The American Society of Anesthesiologists (ASA) has defined monitored anesthesia care (MAC). (1) The following is derived from ASA statements:

“Monitored anesthesia care is a specific anesthesia service for a diagnostic or therapeutic procedure. Indications for monitored anesthesia care include the nature of the procedure, the patient’s clinical condition and/or the potential need to convert to a general or regional anesthetic.”

MAC includes all aspects of anesthesia care – a preprocedure visit, intraprocedure care and postprocedure anesthesia management. During monitored anesthesia care, the anesthesiologist provides or medically directs a number of specific services, including but not limited to:

  • Diagnosis and treatment of clinical problems that occur during the procedure;
  • Support of vital functions;
  • Administration of sedatives, analgesics, hypnotics, anesthetic agents or other medications as necessary for patient safety;
  • Psychological support and physical comfort; and
  • Provision of other medical services as needed to complete the procedure safely.

MAC may include varying levels of sedation, analgesia, and anxiolysis as necessary. The provider of MAC care must be prepared and qualified to convert to general anesthesia when necessary. If the patient loses consciousness and the ability to respond purposefully, the anesthesia care is a general anesthetic, irrespective of whether airway instrumentation is required.

In 2004, the ASA defined four levels of sedation/ analgesia as follows: (2)

  • Minimal sedation (Anxiolysis): is a drug-induced state during which patients respond normally to verbal commands. Although cognitive function and coordination may be impaired, ventilator and cardiovascular function are unaffected.
  • Moderate sedation/analgesia (“conscious” sedation): is a drug-induced depression of consciousness during which patients respond purposefully to verbal commands, either alone or accompanied by light tactile stimulation. No interventions are required to maintain a patent airway, and spontaneous ventilation is adequate. Cardiovascular function is usually maintained.
  • Deep sedation/analgesia: is a drug-induced depression of consciousness during which patients cannot be easily aroused but respond purposefully following repeated or painful stimulation. The ability to independently maintain ventilatory function may be impaired. Patients may require assistance in maintaining a patent airway, and spontaneous ventilation may be inadequate. Cardiovascular function is usually maintained.
  • General anesthesia: is a drug-induced depression of consciousness during which patients are not arousable, even by painful stimulation. The ability to independently maintain ventilator function is often impaired. Patients often require assistance in maintaining a patent airway, and positive-pressure ventilation may be required because of depressed spontaneous ventilation or drug-induced depression of neuromuscular function. Cardiovascular function may be impaired.

Because sedation is a continuum, it is not always possible to predict how an individual patient will respond. Hence, practitioners intending to produce a given level of sedation should be able to rescue patients whose level of sedation becomes deeper than initially intended. Individuals administering moderate sedation/analgesia (conscious sedation) should be able to rescue patients who enter a state of deep sedation/analgesia, while those administering deep sedation/analgesia should be able to rescue patients who enter a state of general anesthesia.

According to the American Society of Anesthesiologists’ (ASA) standard for monitoring, MAC should be provided by qualified anesthesia personnel, including physicians and nurse specialists. (3) By this standard, the personnel must be in addition to the proceduralist, and present continuously to monitor the patient and provide anesthesia care. MAC may be used for varying levels of sedation, analgesia, and anxiolysis, including but not limited to moderate sedation. For patients at high risk of an unsuccessful procedure under moderate sedation, this allows for the safe continuation of the procedure under deep sedation or general anesthesia by trained personnel.

Moderate sedation can be achieved using pharmacologic agents for sedation, anxiolysis and analgesia. A frequently used combination is an opioid and benzodiazepine, for example fentanyl with midazolam, at doses individualized to obtain the desired sedative effect. Other combinations have also been utilized for this purpose. While both benzodiazepines and opioids can cause respiratory depression, effective reversal agents exist for both.

Propofol is an agent that has been used increasingly to provide sedation for procedures. Propofol is associated with a rapid onset of action and fast recovery from sedation. However, there have been concerns about potential side effects and safety when used by non-anesthesiologists. Propofol has the potential to induce general anesthesia, and there is no pharmacologic antagonist to reverse its action. ASA has offered practice guidelines for the provision of sedation by non-anesthesiologists, stating that personnel must be prepared to respond to deep sedation and loss of airway protection should these complications inadvertently occur during sedation. (4)

This policy only addresses anesthesia services for diagnostic or therapeutic procedures involving gastrointestinal (GI) endoscopy, bronchoscopy and interventional pain procedures performed in the outpatient setting.


Medical policies are systematically developed guidelines that serve as a resource for Company staff when determining coverage for specific medical procedures, drugs or devices. Coverage for medical services is subject to the limits and conditions of the member benefit plan. Members and their providers should consult the member benefit booklet or contact a customer service representative to determine whether there are any benefit limitations applicable to this service or supply. This medical policy does not apply to Medicare Advantage.

Benefit Application



Literature Review

This policy was created in 2009 and updated regularly with searches of the MEDLINE database. The most recent literature search was through January 2013. One updated systematic review on the use of propofol for sedation during colonoscopy has been published by the Cochrane Collaboration. One randomized controlled trial (RCT) has examined the use of moderate sedation with monitored anesthesia care (MAC) against moderate sedation without monitored care; it has been published in abstract form only. Many of the RCTs and comparative studies have focused on comparisons of agents for moderate sedation. Many recommendations for the indications for monitored anesthesia care come from narrative reviews and expert opinion. The following is a summary of the key literature to date:

Location of the Procedure

The American Society of Anesthesiologists (ASA) has recommended that any location providing MAC have the capability of cardiopulmonary resuscitation and monitoring equipment. (6, 7) In 2004, Fleisher and colleagues performed a retrospective claims data review on 564,267 outpatient surgical procedures: 360,780 at an outpatient department of a hospital, 175,288 at an ambulatory surgical center and 28,199 at a physician’s office. (8) The rates of all-cause death, emergency department visits and inpatient admissions within 7 days of the procedure were compared. The highest rates were seen among patients in the outpatient surgery department of the hospital, suggesting that patients evaluated to be at highest risk had their procedure in the location of lowest anesthesia risk. Multivariate analysis noted that increasing patient age, increasing procedural risk, and increasing past medical history of inpatient admissions were all independently predictive of adverse outcome.

In 2013. Whippey et al. published a case-control study of risk factors for unanticipated hospitalization following an outpatient procedure. The authors retrospectively identified 20,657 outpatient procedures and randomly selected 200 patients with an unanticipated hospitalization.These patients were compared with 200 randomly selected control patients without an unanticipated hospitalization. Predictors of unanticipated hospitalization included procedures lasting longer than 1 hour, high ASA physical status classification, older age, and higher BMI.

Use of Monitored Anesthesia Care in Endoscopy

An extensive review of the literature related to sedation for gastrointestinal (GI) endoscopy was published through the American Gastroenterological Association (AGA) Institute in 2007. (9) Portions of their review were relevant to this policy. The review recommended that use of an anesthesia professional should be strongly considered for American Society of Anesthesiologists (ASA) physical status III through V patients. They noted that other possible indications for participation by an anesthesia specialist include patients with pregnancy, morbid obesity, neurologic or neuromuscular disorders, a history of alcohol or substance abuse, and patients who are uncooperative or delirious. They also noted that endoscopic procedures that may require an anesthesia specialist include endoscopic retrograde cholangiopancreatography (ERCP), stent placement in the upper GI tract, and complex therapeutic procedures such as plication of the cardio-esophageal junction. This review was used in formulating the conclusions of this policy.

Enestvedt et al retrospectively reviewed 1,318,495 patients who underwent 1,590,648 endoscopic procedures and found the risk for serious adverse events with endoscopy increased with higher ASA physical status classification, especially class 3 to 5. These findings support the use of ASA physical status class as a predictor of periendoscopic adverse events and as a useful tool for risk stratification.

Comparison of Sedative Agents Used in Endoscopy

Given the interest in use of propofol, additional details are provided concerning its use in GI endoscopy. A recent Cochrane review by Singh et al. in 2008 summarized the results of 20 RCTs comparing the use of propofol and traditional agents for use during colonoscopy. (10) This review encompassed and enlarged on a prior review by McQuaid and Laine in 2008, which reviewed a broader set of studies of all randomized trials of any agents used for sedation for endoscopic procedures. (11) The reviews come to largely similar conclusions, but certain comparisons were only performed in one or the other review.

The primary objective of the Cochrane review was to compare the relative effectiveness, patient acceptance, and safety of propofol compared to traditional sedatives for patients undergoing colonoscopy. (10) The secondary objective was to synthesize the studies comparing propofol administration by anesthesiologists to that by non-anesthesiologists for sedation during colonoscopy. This review is an update of a previously published Cochrane systematic review in 2008.The literature search for the updated review was undertaken up to December 2010. The outcome measures of interest were technical performance of colonoscopy (recovery time, discharge time, procedure time), patient satisfaction, pain control, and complication rates (cardio-respiratory events, colonic perforations and hospital admission rate after procedure, and death). (10)

Twenty-two studies met the inclusion criteria for the primary objective in this updated review. (10) Eight (of 22) eligible RCTs evaluated propofol as a single agent, and 7 trials were published in only abstract format, including the largest trial from 2000 (n=7,286 patients), which reported on different rates of colonic perforation. Only one trial published in 2006 was a double-blinded RCT, where all patients as well as all those involved in administering the medications and assessing the outcomes were not aware of the intervention in different arms of the trial. The agents administered in the control arms across these trials included benzodiazepines alone (diazepam, midazolam) or a combination of a benzodiazepine and a narcotic (pethidine, fentanyl, remifentanil or alfentanil). One trial published in 2003 included only a narcotic (remifentanil), and all patients in the control arm of this study remained awake throughout the procedure. The dosage of the agents used varied across trials. The intended level of sedation when stated was defined in most studies as that needed for patients tolerance of the procedure. Many of the studies had a potential of moderate to high risk of bias and combining data for some of the outcomes for meta-analysis was problematic. Most studies included only healthy outpatients.

Recovery time (reported in 11 studies; 776 patients) was shorter with propofol compared to the control arm (weighted mean difference [WMD]: -14.2 minutes; 95% confidence interval [CI]: -17.6, -10.8), with no significant heterogeneity (p=0.41). Discharge time (7 studies; 542 patients) was also reported to be shorter with use of propofol (WMD: -20.9 minutes; 95% CI: -30.9, 10.8); however, there was significant heterogeneity between studies (p<0.0001). There was higher patient satisfaction (10 studies, 819 patients) with use of propofol (odds ratio [OR]: for dissatisfaction 0.35; 95% CI: 0.23, 0.53). There was no difference in procedure time (9 studies; 736 patients) or complication rates. There was also no difference in pain control with non-patient controlled sedation (5 studies; 396 patients) between propofol and the control arm (OR: 0.90; 95% CI: 0.58, 1.39). (10)

The Cochrane review found only one RCT, reported in abstract format, for the secondary objective, comparison of propofol administration by anesthesiologists (Group A) to that by endoscopists (Group B). (12) This RCT has subsequently been published by Poincloux and colleagues. (12) Ninety adult patients (from a university center in France) undergoing colonoscopy were randomized into the above 2 groups. The goal of propofol administration by anesthesiologists was anesthesia and that by endoscopists was sedation. There was no difference in procedure time (16.7 minutes for Group A and 17.7 minutes for Group B) or patient satisfaction (average score on Visual Analog Scale, 90.8 vs. 89). A higher proportion of patients administered propofol by an anesthesiologist experienced hypoxia, but no patient required an intervention. (12)

There are numerous observational studies, and some of the representative publications are summarized here. Horiuchi et al. reported an observational study from Japan. (13) Low-dose propofol was administered by nurses supervised by the endoscopist during diagnostic endoscopy. In this study, 10,662 patients were observed following the receipt of an age-dependent standard dose protocol of propofol, which was administered by bolus injection, with additional doses given when required for adequate sedation prior to esophagogastroduodenoscopy (EGD). The incidence of respiratory depression was the primary outcome for this study, and further measures of successful completion of the procedure and patient satisfaction were analyzed. Twenty-eight patients required transient supplemental oxygen supply, while none required mask or endotrachael intubation. All procedures were successful and 79.1% diagnostic EGDs were completed with a single bolus of propofol. The authors conclude that low-dose nurse-administered propofol sedation is safe when supervised by the endoscopist, and practical for diagnostic EGD. The study is limited by the lack of a comparison group. Patients with ASA classification III and IV were excluded from the study, so these conclusions may not be generalized to that group.

Coté et al. reported another prospective observational study on 766 patients undergoing advanced endoscopic procedures such as endoscopic retrograde cholangiopancreatography (ERCP), endoscopic ultrasound and small-bowel enteroscopy who received propofol. (14) These procedures are notable for the duration and complexity of these procedures compared to diagnostic EGD. The primary outcome measure was airway modifications (AMs) with a comparison of defining characteristics of the group requiring at least one airway modification, such as chin lift or nasal airway, to those requiring no modification. No patients in the study required endotrachael intubation. Body mass index (BMI), male sex, and ASA class III or above were associated with a need for AM. Patients in this study received anesthesia from a certified registered nurse anesthetist (CRNA) and generally had a level of deep sedation, and thus continue to meet the definition of MAC.

Rex et al. reviewed case series of endoscopist-directed propofol sedation published in MEDLINE, CINAHL and EMBASE over the period of 1966 to 2008, resulting in 646,080 procedures in 28 studies published between 2002 and 2008. (15) Incidence of mask ventilations, endotrachael intubation, neurologic injuries and death were collected from the published studies and calculated to reveal a death rate 0.62 per 100,000 cases. A direct comparison group was not included in this review. The authors state this death rate compares favorably to published surveys of death rates of endoscopic procedures utilizing opioids and benzodiazepines of 11 per 100,000. They also compare this to published data on the general anesthesia overall death rate of 1-2 per 100,000. As mentioned, a direct comparison group is not available nor is death rates available for endoscopic procedures under MAC. However, the incidence of published adverse events appears to be low.

Agostoni and colleagues evaluated a prospective database of 17,999 GI endoscopies performed under MAC during the period of October 2001 to December 2009. (16) The authors identified 6 variables predicting any sedation-related complication using multivariate logistic regression models: age (1-year OR: 1.02 [95% confidence interval [CI]: 0.01-1.02]), BMI (1-point OR: 1.03 [95% CI: 0.02-1.05]), ASA score (“3-4” vs. “1-2” OR: 1.69 [95% CI: 1.44-1.99]), Mallampati score (“3-4” vs. “1-2” OR: 1.33 [95% CI: 1.04-1.70]), emergency nature of the procedure (OR: 1.48 [95% CI: 1.13-1.94]), length of the procedure (OR: 2.00 [95% CI: 1.78-2.24]). The authors noted the Mallampati score is used to assess potential difficulty in tracheal intubation, and it is unclear why this score was predictive of any complication.

In a prospective cohort study of 470 ERCP patients receiving MAC, Berzin and colleagues reported adverse respiratory events were strongly associated with higher body mass index using multivariate regression models. (OR: 1.08; p=0.0006). (17) Patients with obesity experienced respiratory events almost twice as often as non-obese patients (p=0.03). Higher ASA class was not associated with adverse respiratory events under MAC (OR: 1.2; p=0.25) but was associated with cardiovascular events (OR: 2.88; p<0.0001).


The evidence base comparing different anesthetic methods is not robust, consisting primarily of non-randomized comparisons and observational studies. A single RCT comparing propofol administration by anesthesiologists to that by non-anesthesiologists for sedation during colonoscopy did not show any differences in procedure time or patient satisfaction, and reported a higher rate of hypoxia in patients treated with propofol. However, a Cochrane review of randomized studies concluded that recovery time, discharge time, and patient satisfaction were all improved with propofol compared to alternative agents. This review did not find any evidence of increased complications. However, this evidence base does not rule out an increased complication rate with propofol, since there is a low complication rate in general, thus making it difficult to discern differences in the absence of large RCTs.


In 2009, Silvestri and colleagues published an RCT comparing two doses of the sedative agent fospropofol in patients undergoing diagnostic bronchoscopy. (18) The study was performed by pulmonologists without anesthesia supervision. Patients (n=252) were randomized to receive either 2 mg/kg or 6.5 mg/kg induction doses of fospropofol, followed by additional doses per protocol. All patients received a pre-procedural dose of fentanyl. The primary endpoint was sedation success using the Modified Observer’s Assessment of Alertness/Sedation (MOAA/S). A secondary endpoint was treatment success, as measured by percentage of patients who did not require alternate sedation or ventilation. The higher dose group had greater sedation success (88.7% vs. 27.5%, respectively; p < 0.001). Treatment success also favored the higher dose group (91.3% vs. 41.25, respectively; p < 0.001). Adverse events were higher for the higher dose group; for example, the number of patients requiring any type of airway assistance (33 vs. 14, or 21.5% vs. 13.6%, respectively). The trial does not compare alternate sedation approaches; that comparison is necessary to evaluate the clinical value of the fospropofol sedation strategy for bronchoscopic procedures.

The British Thoracic Society published guidelines for flexible bronchoscopy in 2001 and updated these guidelines in 2013. With respect to sedation, the guidelines state that sedation should be offered, patients should be monitored during and immediately after the procedure, and that at least two assistants, at least one a qualified nurse, should be in attendance. Resuscitation equipment should be readily available. The sedation should be limited to a depth which permits verbal contact at all times. The preferred sedation agent is a benzodiazepine, intravenous midazolam.

Interventional Pain Management Procedures

In 2008, Bernards and colleagues published a review of the literature around neurologic complications of regional anesthesia in anesthetized or heavily sedated patients. (21) Some experts postulate that the inability of a sedated patient to express atypical symptoms during a regional block may lead to increased risk of injury. No comparative studies have been done, and limited information is available from registries. The American Society of Regional Anesthesia and Pain Medicine has acknowledged the scarce and conflicting literature on the topic, and recommends carefully weighing the risks and benefits in considering performing those procedures while the patient is heavily sedated or anesthetized. (22)

In 2005, the American Society of Anesthesiologist released a statement on anesthetic care during interventional pain procedures. (23) While recognizing that conditions exist which may make skilled anesthesia care necessary, most minor pain procedures, under most routine circumstances, do not require anesthesia care other than local anesthesia.

Other Procedures

Any procedure which may be complicated by patient characteristics noted in the policy statement may be appropriate for MAC.


Concerns regarding procedures and sedation during pregnancy are two-fold: sensitivity of the fetus to the agents and/or procedural hypotension, and maternal factors that increase sensitivity to sedation and that make intubation more difficult in an emergency situation. In a large (n=720,000) Swedish registry of pregnant patients from the 1970’s and 1980’s, 5405 operations took place. (24) Congenital malformations and stillbirths were not increased in the offspring of women having an operation. Incidence of low birth weight infants was increased as a result of both prematurity and intrauterine growth retardation. Neonatal death was also increased in the patients who had an operation. No specific types of anesthesia or operation were associated with these outcomes. The contribution of the underlying condition which led to the need for surgery could not be separated from the effects of the surgery or sedation/anesthesia.

Fetal heart rate monitoring is considered to be a more sensitive indicator of placental perfusion and fetal oxygenation than observations of maternal hemodynamic stability alone. The American College of Obstetricians and Gynecologists (ACOG) has recommended that the use of intermittent or continuous fetal monitoring during surgery be individualized. (25)

Physiologic changes in pregnancy may require changes in standard doses of anesthetic or sedative agents. However, propofol does not generally require a change in loading dose for induction. (26) Physiologic changes in pregnancy may warrant MAC when airway protection may become necessary, due to additional difficulties noted with emergent intubation in pregnant patients and the urgency to restore full oxygenation to the maternal and fetal patients. (27) Thus MAC can be considered medically necessary for procedures performed during pregnancy.

Ongoing Clinical Trials

A search of online site did not identify any open studies evaluating predictive factors for risks of sedation-related adverse events.

Practice Guidelines and Position Statements

In 2004, and amended in 2009, the American Society of Anesthesiologists released a statement on the safe use of propofol:

“The Society believes that the involvement of an anesthesiologist in the care of every patient undergoing anesthesia is optimal. However, when this is not possible, non-anesthesia personnel who administer propofol should be qualified to rescue patients whose level of sedation becomes deeper than initially intended and who enter, if briefly, a state of general anesthesia.” (28)

Recent guidelines regarding sedation during endoscopy were released by the American Society for Gastrointestinal Endoscopy (ASGE). (29) These guidelines indicate “Adequate and safe sedation can be achieved in most patients undergoing routine esophagogastroduodenoscopy [EGD] and colonoscopy by using an intravenous benzodiazepine and opioid combination.” These guidelines also include a discussion of use of propofol for routine endoscopy, and their overall conclusion is that “clinically important benefits in average-risk patients undergoing upper endoscopy and colonoscopy have not been consistently demonstrated with regard to patient satisfaction and safety. Therefore, the routine use of propofol in average-risk patients cannot be endorsed.” In addition to addressing the efficacy and safety of propofol, the guidelines discuss the issue of who is qualified to give propofol. The ASGE endorses gastroenterologist-directed propofol use when adequate training for its use has been achieved. Numerous case series studies were cited showing very low rates of clinical adverse events when propofol was administered by registered nurses under gastroenterologist supervision.

The American Society for Gastrointestinal Endoscopy guideline titled Modifications in Endoscopic Practice for Pediatric Patients recommends the use of general anesthesia or MAC for pediatric endoscopy, usually based upon age or anticipated patient intolerance for the procedure. In pediatric patients, there is an increased risk of adverse events and the pediatric patient is often psychologically traumatized by this invasive procedure. Therefore, the policy statement is amended to include all patients age 18 and younger.

Wang and colleagues performed a retrospective cohort analysis of the number of polyps found on colonoscopy when using moderate conscious sedation or deep sedation. (30) The study has several flaws that limit its reliability. First, according to Table 1 in the study, there were differences in the rates of administration of deep sedation versus moderate conscious sedation according to race, gender, age, practice setting, and ASA classification. It is noted that a higher percentage of patients receiving deep sedation were ASA classification level 3 (9.4% vs 3.5% in the moderate sedation group). Interpretation of results when baseline characteristics of the populations being compared differ on so many important factors is generally regarded as unreliable in the scientific community. As such, the comparison of these two populations is unreliable and no meaningful conclusions can be drawn. Secondly, the study design is a retrospective cohort study. There was no control for the criteria that were used to determine whether or not patients received moderate conscious sedation or deep sedation. As such, it is impossible to extrapolate any conclusions or recommendations about when moderate conscious sedation or deep sedation is appropriate. Lastly, the authors actually report higher rates of polyp detection with moderate conscious sedation and more advanced lesions were found with deep sedation. However, because the study design does not have a way to establish the true rate of polyps, it is impossible to determine if the results demonstrate a difference in the actual rate of detection of polyps that existed at the time of the procedure. The study uses the number of patients receiving colonoscopy as a determinant of the rate of polyp detection rather than the number of actual polyps. There could be selection bias involved in the choice of patients undergoing deep sedation rather than moderate conscious sedation that skews the actual prevalence rate of advanced lesions in that population. This would be expected if endoscopists applied the AGA guidelines noted above. Therefore, the true rate of detection of polyps or advanced lesions is unknown. The authors acknowledge the limitations of this study, concluding: “… this retrospective design has limitations that necessitate follow-up with prospective studies. These follow-up studies would be essential to support any change in the standard practices of sedation.”

In a randomized controlled trial, Paspatis and colleagues reported on 520 individuals undergoing colonoscopy for the detection of polyps. (31)They were randomized to either deep sedation (n=258) or moderate sedation (n=262) with the hypothesis that deep sedation may increase the rate of polyp detection compared to moderate sedation which would enhance the quality of the colonoscopy. Secondary objectives included the patient’s and the endoscopist’s satisfaction, recovery time and the adverse events related to sedation between the two groups. There were no differences between the two groups in the following three areas: (1) The overall detection of polyps, (2) polyp size ≥ 10 mm, and (3) polyp size < 10 mm. There was no significant difference in the rate of adenoma detection. There were no differences in levels of participant satisfaction between the two groups. However, the endoscopist's satisfaction rating was greater in the deep sedation group compared to the moderate sedation group. The authors concluded that the study demonstrated no difference in the detection of polyps by colonoscopy using deep or moderate sedation.

Following the Paspatis study, Metwally and colleagues performed a retrospective study to determine if anesthesiologist-monitored use of propofol results in improved detection of adenomas when compared with routine conscious sedation. (32) This study was conducted at two separate hospital-based endoscopy units where approximately 12,000 endoscopic procedures are performed annually, with one endoscopy unit exclusively using anesthesiologist-monitored propofol. Three thousand two hundred and fifty-two patients underwent initial screening or surveillance colonoscopies. The primary end point was the adenoma detection rate, defined as the number of patients in whom at least one adenoma was found, associated with the type of sedation. Three thousand two hundred and fifty-two outpatient colonoscopies were performed by five selected endoscopists. At least one adenoma was detected in 27.6% of patients with no difference in the detection rate between the anesthesiologist-propofol group and the gastroenterologist-midazolam/fentanyl group. As with the Paspatis study, they concluded that the type of sedation used during colonoscopy does not affect the number of patients in whom adenomatous polyps are detected.

Liu and colleagues noted that the use of an anesthesiologist or nurse anesthetist for low-risk colonoscopies and upper gastroenterology procedures is rapidly increasing, with recent data suggesting a 24% rate in 2007 and a projected increase to 53% by 2015. (33) They stated: “It is unknown at this point what drives the increase in anesthesia use during endoscopies and to what degree the increase reflects potentially discretionary spending, which may present an opportunity to reduce cost”. The authors performed a retrospective analysis of claims data to determine the frequency with which anesthesiologists or nurse anesthetists provide sedation for gastrointestinal endoscopies, especially for low-risk patients, and the regional variation. They sampled 1.1 million adults in the Medicare population 5.5 million commercially insured patients between 2003 and 2009. Their main outcome measure was the total number of upper gastrointestinal endoscopies and colonoscopies, proportion of gastroenterology procedures with associated anesthesia claims, payments for gastroenterology anesthesia services, and proportion of services and spending for gastroenterology anesthesia delivered to low-risk patients (American Society of Anesthesiologists physical status class 1 or 2). They found that the number of gastroenterology procedures per million enrollees remained largely unchanged in Medicare patients, but increased more than 50% in commercially insured patients from 2003 to 2009. In both populations, the proportion of procedures using anesthesia services increased from approximately 14% in 2003 to more than 30% in 2009, and more than two-thirds of anesthesia services were delivered to low-risk patients. In addition, there was substantial regional variation in the proportion of low-risk procedures using anesthesia services in both populations, ranging from 13% in the West to 59% in the Northeast. Payments for gastroenterology anesthesia services doubled in Medicare patients and quadrupled in commercially insured patients. The authors state that the substantial regional variation in gastroenterology anesthesia use for low-risk patients suggests that a significant share of the spending for gastroenterology anesthesia may be considered potentially discretionary. Supporting the hypothesis of potentially discretionary use is the 4-fold difference in use between the lowest-use and the highest-use regions. They felt that this variation is unlikely to be fully explained by regional difference in patient risk.

In an editorial, Fleisher commented on a complex set of factors has been proposed that contribute to the increased use of anesthesia services, including patient and physician preferences, clinical need, regulatory requirements, and financial considerations.

In another editorial, Rex states that there is limited and mixed evidence regarding whether the use of sedation affects detection during colonoscopy.


Monitored anesthesia care (MAC) is the use of anesthesia personnel during a procedure to provide various levels of sedation and analgesia (anesthesia) depending on the patient’s condition and the procedure being performed. This policy addresses the potential role of dedicated anesthesia providers during diagnostic or therapeutic procedures involving gastrointestinal endoscopy, bronchoscopy, and interventional pain procedures performed in the outpatient setting.

Comparative evidence supporting the use of monitored anesthesia care in specific procedures is limited. Patient characteristics, such as comorbidities, airway features or the ability to cooperate with the proceduralist, are more indicative of the need for this service. Physician-directed moderate sedation is a safe and effective alternative to MAC for the majority of patients undergoing procedures for which deep sedation or anesthesia is unnecessary, such as gastrointestinal endoscopy, bronchoscopy, and interventional pain procedures. Propofol may be used both for general anesthesia and moderate sedation. The principal differences between propofol and the traditional agents used in these clinical trials of moderate sedation are a shorter recovery period (a mean of 14.2 minutes), shorter discharge time, and higher overall satisfaction scores. Pain control and incidence of complication rates appear to be similar overall, but the available evidence does not rule out small differences in these outcomes. The use of MAC may be considered medically necessary in specific cases of high risk of potential complications related to moderate sedation as outlined in the policy statement.


  1. American Society of Anesthesiologists (ASA). ASA position on monitored anesthesia care. Amended September 2, 2008. Last accessed April 2, 2014.
  2. American Society of Anesthesiologists (ASA). Levels of sedation/analgesia. Amended October 29, 2009. Last accessed April 2, 2014.
  3. American Society of Anesthesiologists (ASA). Distinguishing monitored Anesthesia care ("MAC") from moderate sedation/analgesia. Amended October 21, 2009. Last accessed April 2, 2014.
  4. American Society of Anesthesiologists (ASA). Statement on qualifications of anesthesia provides in the office-based setting. Amended October 21, 2009. Last accessed April 2, 2014.
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  8. Fleisher LA, Pasternak LR, Herbert R et al. Inpatient hospital admission and death after outpatient surgery in elderly patients: importance of patient and system characteristics and location of care. Arch Surg 2004; 139(1):67-72.
  9. Cohen LB, Delegge MH, Aisenberg J et al. AGA Institute review of endoscopic sedation. Gastroenterology 2007; 133(2):675-701.
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  14. Coté GA, Hovis RM, Ansstas MA et al. Incidence of sedation-related complications with propofol use during advanced endoscopic procedures. Clin Gastroenterol Hepatol 2010; 8(2):137-42.
  15. Rex DK, Deenadayalu VP, Eid E et al. Endoscopist-directed administration of propofol: a worldwide safety experience. Gastroenterology 2009; 137(4):1229-37; quiz 518-9.
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  17. Berzin TM, Sanaka S, Barnett SR et al. A prospective assessment of sedation-related adverse events and patient and endoscopist satisfaction in ERCP with anesthesiologist-administered sedation. Gastrointestinal Endoscopy 2011; 73(4):710-7.
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  32. Metwally M, Agresti N, Hale WB et al. Conscious or unconscious: The impact of sedation choice on colon adenoma detection. World Journal of Gastroenterology 2011; 17(34): 3912 -3915.
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  38. Du Rand IA, Blaikley J, Booton R et al. Summary of the British Thoracic Society guideline for diagnostic flexible bronchoscopy in adults. Thorax 2013; 68(8):786-7.
  39. Triantafillidis JK1, Merikas E, Nikolakis D, et al. Sedation in gastrointestinal endoscopy: current issues. World J Gastroenterol. 2013;19(4):463-81. doi: 10.3748/wjg.v19.i4.463.







Anesthesia for upper gastrointestinal endoscopic procedures, endoscope introduced proximal to duodenum



Anesthesia for lower intestinal endoscopic







New policy. Replaces 7.02.01. This policy differs in that the policy statement is revised: Severe sleep apnea criterion previously requiring both oxygen and bi-pap now allows either oxygen or bi-pap as medically necessary. Further, for clarification, history of sleep apnea or stridor removed as an indication of anatomic variation. Policy Guidelines clarified with no significant change. Rationale and Reference sections updated.


Replace policy. Policy updated with literature review to January 16, 2013. The following policy statement was changed: The bullet point on patients of extreme age was changed to “patients younger than 18 years or 70 years or older”. Policy Guideline on “History of or intolerance to standard sedatives” clarified to state that chronic use of narcotic pain medication or prescription sedatives must be in dosages and/or frequency which would be expected to affect sedation requirements. References 12 and 20 added.


Update Related Policies. Add 11.01.504.


Replace policy. Policy statement updated to indicated documentation from either the proceduralist “or” the anesthesiologist is sufficient, rather than from both. One record is acceptable now.


Annual Review. Policy updated with literature review. Rationale and References added. No change to the policy statement. Remove CPT codes 00520, 00635, 01936, 01991, 96373-4, 99143-45, 99148-50) and ICD-9/ICD-10 diagnosis codes; these are not utilize in policy adjudication.


Update Related Policies. Change title to 11.01.504.


Interim Update. Reference added. No change to the policy statement.


Interim Update. Policy statement clarified with the addition of medically necessary indication for prior complications with anesthesia or conscious sedation.

Disclaimer: This medical policy is a guide in evaluating the medical necessity of a particular service or treatment. The Company adopts policies after careful review of published peer-reviewed scientific literature, national guidelines and local standards of practice. Since medical technology is constantly changing, the Company reserves the right to review and update policies as appropriate. Member contracts differ in their benefits. Always consult the member benefit booklet or contact a member service representative to determine coverage for a specific medical service or supply. CPT codes, descriptions and materials are copyrighted by the American Medical Association (AMA).
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