Monitored Anesthesia Care

Section: Anesthesia
Effective Date: June 30, 2018
Revised Date: February 25, 2020
Last Reviewed: March 16, 2020


Monitored Anesthesia Care

Monitored anesthesia care (MAC) is a set of anesthesia services defined by the type of anesthesia personnel present during a procedure, not specifically by the level of anesthesia needed. The American Society of Anesthesiologists (ASA) defined MAC, and the following is derived from the ASA's 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 individual's clinical condition and/or the potential need to convert to a general or regional anesthetic.

Monitored anesthesia care includes all aspects of anesthesia care-a pre-procedure visit, intra-procedure care, and post-procedure 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
  • Provision of other medical services as needed to complete the procedure safely.

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

Sedation Depth

In 2004 (amended in 2014), ASA defined 4 levels of sedation and analgesia, as shown in Table 1.

Table 1. ASA's Definitions of General Anesthesia and Levels of Sedation and Analgesia

Terms Minimal Sedation (Anxiolysis) Moderate Sedation or Analgesia (Conscious Sedation) Deep Sedation or Analgesia General Anesthesia
Responsiveness Normal response to verbal stimulation Purposeful response to verbal or tactile stimulation Purposeful response following repeated or painful stimulation Unarousable even with painful stimulation
Airway Unaffected No intervention required Intervention may be required Intervention often required
Spontaneous ventilation Unaffected Adequate May be inadequate Frequently inadequate
Cardiovascular function Unaffected Usually maintained Usually maintained May be impaired

Adapted from American Society of Anesthesiologists (2013).

ASA: American Society of Anesthesiologists.

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

Sedation for Diagnostic and Therapeutic Procedures

Multiple diagnostic and therapeutic procedures performed in the outpatient setting (e.g., endoscopy, colonoscopy, bronchoscopy, interventional pain management procedures) rely on some degree of sedation for anxiolysis and pain control. Regardless of sedation depth, sedation and anesthesia services provided in outpatient settings should be administered by qualified and appropriately trained personnel. Moderate sedation is generally sufficient for many diagnostic and uncomplicated therapeutic procedures. Moderate sedation using benzodiazepines, with or without narcotics, is frequently administered under the supervision of the proceduralist.

According to the ASA's standard for monitoring, MAC should be provided by qualified anesthesia personnel, including physicians and nurse specialists. By this standard, the personnel must be, in addition to the proceduralist, present continuously to monitor the individual and provide anesthesia care. For individuals 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 (e.g., fentanyl with midazolam) at doses individualized to obtain the desired sedative effect. Other combinations have also been used. While benzodiazepines and opioids can cause respiratory depression, effective reversal agents exist for both.

Propofol has increasingly been used to provide sedation for procedures. It is associated with a rapid onset of action and fast recovery from sedation. However, there are concerns about potential adverse 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. When used as moderate sedation, propofol may be administered by anesthesia personnel or under the direction of the proceduralist. 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.

Regulatory Status

In 1989, propofol Diprivan® (AstraZeneca) was approved by the U.S. Food and Drug Administration (FDA) through the premarket approval process for the induction and maintenance of anesthesia. The current FDA-approved label for Diprivan® states that it is indicated for initiation and maintenance of MAC sedation, combined sedation, and regional anesthesia; the label also states that Diprivan® is indicated for the sedation of adults in the intensive care unit who have been intubated or mechanically ventilated. Moreover, Diprivan® is also approved for induction of general anesthesia in individuals 3 years of age and older and maintenance of general anesthesia in individuals 2 months of age and older.

Many other FDA-approved medications for pain relief, anxiolysis, and sedation may be used in outpatient sedation.


The 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 and anesthesiologist that specific risk factors or significant medical conditions are present.Those risk factors or significant medical conditions include any of the following:

  • Increased risk for complications due to severe comorbidity (American Society of Anesthesiologists class III, IV, or V [see Table PG1])
  • Morbid obesity (body mass index >40 kg/m2)
  • Documented sleep apnea
  • Inability to follow simple commands (cognitive dysfunction, intoxication, or psychological impairment)
  • Spasticity or movement disorder complicating the procedure
  • History or anticipated intolerance to standard sedatives, such as:
  • Chronic opioid use
  • Chronic benzodiazepine use
  • Individuals with active medical problems related to drug or alcohol abuse
  • Individuals younger than 18 years or 70 years or older
  • Individuals who are pregnant
  • Individuals with increased risk for airway obstruction due to anatomic variation, such as:
    • History of stridor
    • Dysmorphic facial features
    • Oral abnormalities (e.g., macroglossia)
    • Neck abnormalities (e.g., neck mass)
    • Jaw abnormalities (e.g., micrognathia)
  • Acutely agitated, uncooperative individuals
  • Prolonged or therapeutic gastrointestinal endoscopy procedures requiring deep sedation.

Table PG1: ASA's Physical Status Classification System

Class Definition
ASA I A normal, healthy patient
ASA II A patient with mild systemic disease
ASA III A patient with severe systemic disease
ASA IV A patient with severe systemic disease that is a constant threat to life
ASA V A moribund patient who is not expected to survive without the operation
ASA VI A declared brain-dead patient whose organs are being harvested

ASA: American Society of Anesthesiologists

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

Procedure Codes

00635 01936 01991 00520 00740 00810 96373

Diagnosis Codes

C15.3 C15.4 C15.5 C15.8 C15.9 C16.0 C16.1
C16.2 C16.3 C16.4 C16.5 C16.6 C16.8 C16.9
C17.0 C17.1 C17.2 C17.3 C17.8 C17.9 C18.0
C18.1 C18.2 C18.3 C18.4 C18.5 C18.6 C18.7
C18.8 C18.9 C19 C20 C21.0 C21.1 C21.2
C21.8 C22.0 C22.1 C22.2 C22.3 C22.4 C22.7
C22.8 C22.9 C23 C24.0 C24.1 C24.8 C24.9
C25.0 C25.1 C25.2 C25.3 C25.4 C25.7 C25.8
C25.9 C26.0 C26.1 C26.9 C34.00 C34.01 C34.02
C34.10 C34.11 C34.12 C34.2 C34.30 C34.31 C34.32
C34.80 C34.81 C34.82 C34.90 C34.91 C34.92 D01.0
D01.1 D01.2 D01.3 D01.40 D01.49 D01.5 D01.7
D01.9 D02.20 D02.21 D02.22 D12.0 D12.1 D12.2
D12.3 D12.4 D12.5 D12.6 D12.7 D12.8 D12.9
D13.0 D13.1 D13.2 D13.3 D13.30 D13.39 D13.4
D13.5 D13.6 D13.7 D13.9 D14.30 D14.31 D14.32
G56.40 G56.41 G56.42 G56.43 G57.70 G57.71 G57.72
G57.73 G89.0 G89.11 G89.12 G89.18 G89.21 G89.22
G89.28 G89.29 G89.3 G89.4 G90.50 G90.511 G90.512
G90.513 G90.519 G90.521 G90.522 G90.523 G90.529 G90.59
J40 J41 J41.0 J41.1 J41.2 J41.8 J42
J43.0 J43.1 J43.2 J43.8 J43.9 J44.0 J44.1
J44.9 J45.20 J45.21 J45.22 J45.30 J45.31 J45.32
J45.40 J45.41 J45.42 J45.50 J45.51 J45.52 J45.901
J45.902 J45.909 J47.0 J47.1 J47.9 J96.00 J96.01
J96.02 J96.10 J96.11 J96.12 J96.20 J96.21 J96.22
J96.90 J96.91 J96.92 J98.01 J98.09 J98.11 J98.19
J98.2 J98.3 J98.4 J98.51 J98.59 J98.6 J98.8
J98.9 J99 K80.00 K80.01 K80.10 K80.11 K80.12
K80.13 K80.18 K80.19 K80.20 K80.21 K80.30 K80.31
K80.32 K80.33 K80.34 K80.35 K80.36 K80.37 K80.40
K80.41 K80.42 K80.43 K80.44 K80.45 K80.46 K80.47
K80.50 K80.51 K80.60 K80.61 K80.62 K80.63 K80.64
K80.65 K80.66 K80.67 K80.70 K80.71 K80.80 K80.81
K81.0 K81.1 K81.2 K81.9 K82.0 K82.1 K82.2
K82.3 K82.4 K82.8 K82.9 K82.A1 K82.A2 K83.01
K83.09 K83.1 K83.2 K83.3 K83.4 K83.8 K83.9
K85.00 K85.01 K85.02 K85.10 K85.11 K85.12 K85.20
K85.21 K85.22 K85.30 K85.31 K85.32 K85.80 K85.81
K85.82 K85.90 K85.91 K85.92 K86.0 K86.1 K86.2
K86.3 K86.81 K86.89 K86.9 K87 M25.50 M25.511
M25.512 M25.519 M25.521 M25.522 M25.529 M25.531 M25.532
M25.539 M25.541 M25.542 M25.549 M25.541 M25.542 M25.549
M25.551 M25.552 M25.559 M25.561 M25.562 M25.569 M25.571
M25.572 M25.579 M54.00 M54.01 M54.02 M54.03 M54.04
M54.05 M54.06 M54.07 M54.08 M54.09 M54.10 M54.11
M54.12 M54.13 M54.14 M54.15 M54.16 M54.17 M54.18
M54.2 M54.30 M54.31 M54.32 M54.40 M54.41 M54.42
M54.5 M54.6 M54.81 M54.89 M54.9 M79.60 M79.601
M79.602 M79.603 M79.604 M79.605 M79.606 M79.609 M79.621
M79.622 M79.629 M79.631 M79.632 M79.639 M79.641 M79.642
M79.643 M79.644 M79.645 M79.646 M79.651 M79.652 M79.659
M79.661 M79.662 M79.669 M79.671 M79.672 M79.673 M79.674
M79.675 M79.676 R52 Z12.0 Z12.10 Z12.11 Z12.12
Z12.13 Z12.2 Z13.811 Z13.83 Z80.0 Z80.2 Z82.5
Z83.6 Z83.71 Z83.79 Z85.00 Z85.01 Z85.020 Z85.028
Z85.030 Z85.038 Z85.040 Z85.048 Z85.110 Z85.118 Z86.010

Professional Statements and Societal Positions Guidelines

Practice Guidelines and Position Statements

American Society of Anesthesiologists

In 2014, the American Society of Anesthesiologists (ASA) updated its statement on the safe use of propofol:

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

"Rescue" was defined as correcting "adverse physiologic consequences of the deeper-than-intended level of sedation (such as hypoventilation, hypoxia, and hypotension) and returns the individual to the originally intended level."

In 2016, ASA updated its statement on anesthetic care during interventional pain procedures. ASA indicated that:

"Many individuals can undergo interventional pain procedures without the need for supplemental sedation in addition to local anesthesia. For most individuals who require supplemental sedation, the physician performing the interventional pain procedure(s) can provide moderate (conscious) sedation as part of the procedure. For a limited number of individuals, a second provider may be required to manage moderate or deep sedation or, in selected cases other anesthesia services….

Significant anxiety may be an indication for moderate (conscious) sedation or anesthesia services. In addition, procedures that require the individual to remain motionless for a prolonged period of time and/or remain in a painful position may require sedation or anesthesia services. Examples of such procedures include but are not limited to sympathetic blocks (celiac plexus, paravertebral and hypogastric), chemical or radiofrequency ablation, percutaneous discectomy, trial spinal cord stimulator lead placement, permanent spinal cord stimulator generator and lead implantation, and intrathecal pump implantation. Major nerve/plexus blocks are performed less often in the chronic pain clinic, but the Committee believes that these blocks may more commonly require moderate (conscious) sedation or anesthesia services (e.g., brachial plexus block, sciatic nerve block, and continuous catheter techniques)."

In 2014, ASA updated its statement on respiratory monitoring during endoscopic procedures. The statement advised that "Monitoring for exhaled carbon dioxide should be conducted during endoscopic procedures in which sedation is provided with propofol alone or in combination with opioids and/or benzodiazepines, and especially during these procedures on the upper gastrointestinal tract."

American Society for Gastrointestinal Endoscopy

Guidelines on sedation during gastrointestinal endoscopy were released in 2018 by the American Society for Gastrointestinal Endoscopy (ASGE). The guidelines stated that anesthesia provider assistance during gastrointestinal endoscopy should be considered in the following situations: prolonged or therapeutic endoscopic procedures requiring deep sedation, anticipated intolerance to standard sedatives, increased risk for adverse event because of severe comorbidity (ASA class IV or V), and increased risk for airway obstruction because of anatomic variant. The guidelines made the following recommendations for the use of propofol during endoscopies:

  • "A sedation team with appropriate education and training [including] at least 1 person … qualified in advanced life support skills….
  • Trained personnel [for] uninterrupted monitoring of individual's clinical and physiologic parameters….
  • Physiologic monitoring must include pulse oximetry, electrocardiography, and intermittent blood pressure measurement. Monitoring oxygenation by pulse oximetry is not a substitute for monitoring ventilatory function. Capnography should be considered because it may decrease the risks during deep sedation…
  • Personnel should have the ability to rescue a individual who becomes unresponsive or unable to protect his or her airway or who loses spontaneous respiratory or cardiovascular function.
  • Age-appropriate equipment for airway management and resuscitation must be immediately available.
  • A physician should be present throughout propofol sedation and remain immediately available until the individual meets discharge criteria."

In 2015, ASGE published quality indicators for all gastrointestinal endoscopic procedures. Specific to this evidence review, ASGE stated: "Individuals administering moderate sedation should be able to rescue individuals who enter a state of deep sedation, whereas those administering deep sedation should be able to rescue inidividuals who enter a state of general anesthesia."

In 2013, ASGE published guidelines for endoscopic modification for geriatric individuals. Specific to this evidence review, ASGE recommended "standard monitoring procedures in the elderly during moderate sedation with heightened awareness of this population's increased response to sedatives."

In 2014, ASGE issued guidelines on the safety of the endoscopy unit, which made several recommendations on procedural sedation: "Staff Recommendations for intra-procedure care based on level of sedation

  • No sedation-One assistant …other than the physician performing the procedure should be present to assist with the technical aspects of the procedure.
  • Moderate sedation (also known as conscious sedation)-Sedation should be directed by a physician who is credentialed and privileged to do so and can be administered by an RN. During the period in which the individual is sedated, the RN must monitor the individual for vital sign changes, hypoxemia and comfort. The RN may assist with minor, interruptible tasks. In the event that more intense technical assistance is required, a second assistant (RN, LPN, or UAP [unlicensed assistive personnel]) should be available to join the care team for the technical aspects of the procedure.
  • Deep sedation-Most institutions require that deep sedation be administered by ananesthesiaprofessional such as an anesthesiologist, Certified Registered Nurse Anesthetist (CRNA), or Anesthesiologist Assistant who is credentialed and privileged to do so. In this situation, theanesthesiaprovider should be responsible for administering sedation and monitoring the individual. A second staff person (RN, LPN, or UAP) is required to assist with technical aspects of the procedure."

"Recommendations for Individual Monitoring”

  • All individuals undergoingendoscopyshould be monitored, the frequency of which depends on procedural and individual factors (e.g., type of sedation, duration and complexity of procedure, individual’s condition). At a minimum, monitoring should be performed before the procedure, after administration of sedatives, at regular intervals during the procedure, during initial recovery, and just before discharge.
  • Units should have procedures in place to rescue individuals who are sedated deeper than intended.
  • When the target level is moderate sedation (also known as conscious sedation):
    • The individual assigned responsibility for inidividual monitoring may perform brief, interruptible tasks.
    • Minimal monitoring requirements include electronic assessment of blood pressure, respiratory rate, heart rate, and pulse oximetry combined with visual monitoring of the individual's level of consciousness and discomfort.
  • Currently, there are inadequate data to support the routine or required use of capnography during endoscopic procedures in adults when moderate sedation is the target.


  • When deep sedation is targeted:
    • The individual responsible for inidividual monitoring must be dedicated solely to that task and may not perform any other function during the procedure.
    • The use of capnography in EUS [endoscopic ultrasound], ERCP [endoscopic retrograde cholangiopancreatography], and colonoscopy to assess the adequacy of ventilation may reduce the incidence of hypoxemia and apnea, but its impact on the frequency of other sedation-related adverse events such as bradycardia and hypotension is unknown. As such, capnography may be considered for the performance ofendoscopyunder deep sedation. However, there is no safety data to date to support the universal use of capnography in such cases.


  • Documentation of the clinical assessments and monitoring data during sedation and recovery is required."

In 2009, ASGE-along with the American Association for the Study of Liver Diseases, American College of Gastroenterology, and American Gastroenterological Association-issued a joint position statement on non-anesthesiologist administration of propofol (NAAP) for gastrointestinal endoscopy. The societies found that NAAP was as safe and effective as anesthesiologist-administered propofol. They asserted that proper training and proper individual selection were necessary for the safe practice of NAAP sedation.

European Society of Gastrointestinal Endoscopy et al

The European Society of Gastrointestinal Endoscopy, as well as the European Society of Gastroenterology and Endoscopy Nurses and Associates, updated their guidelines on NAAP in 2015. Table 2 summarizes the main recommendations.

Table 2. Recommendations on NAAP for GI Endoscopy




1. Before NAAP, individual assessment of physical status, age, body mass index, Mallampati's classification, and obstructive sleep apnea risk factors



2. Primary involvement of an anesthesiologist for high risk individualsa



3. Capnographic monitoring in high risk individuals, intended deep sedation, and long procedures



4. Propofol monotherapy except in particular situations



5. Administration of propofol through intermittent bolus infusion or perfusor systems, including target-controlled infusion and individual-controlled sedation



6. Individual listen to self-selected music during upper and lower GI endoscopy procedures



7. Do not use pharyngeal anesthesia during propofol sedation for upper GI endoscopy



8. Use post-anesthetic discharge scoring system to determine individualdischarge



9. For individuals of ASA class >2, upon discharge, individualshould be accompanied by a responsible person and refrain from driving, drinking alcohol, operating heavy machinery, or engaging in legally binding decisions for 24 hours. Advice should be provided verbally and in written form



10. For individuals of ASA classes 1-2 who have received low-dose propofol monotherapy, a 6-hour limit is suggested



ASA: American Society of Anesthesiologists; GI: gastrointestinal; NAAP: non-anesthesiologist-administered propofol; QOE: quality of evidence; SOR: strength of recommendation.

aASA class ≥3, with a Mallampati's class ≥3 or other conditions that put them at risk of airway obstruction, in individuals receiving significant amounts of narcotic analgesics, or in long-lasting procedures.

ND Committee Review

Internal Medical Policy Committee 11-14-2019 Annual Review



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