What is Office based-Anesthesia? Office based-Anesthesia in detail A practical guide

1. Office-based Anesthesia
M.HADAVI
ANESTHESIOLOGIST

2. Definitions
 More than 25% of all surgical procedures today are being performed in offices rather than
hospitals and other surgery centers
 Subset of both Non-Operating Room Anesthesia (NORA) and Ambulatory anesthesia
 An anesthetic that is performed in an outpatient venue such as an ofice or procedure
room that is not accredited as either an Ambulatory Surgery Center (ASC) or as a
hospital
 Understanding that the standards of anesthesia care and patient monitoring are the
same regardless of location
 Terms
 • Non-Operating Room Anesthesia (NORA)
 • Ambulatory anesthesia
 • Anesthesia at remote location
 • Outpatient anesthesia
 • Office-based anesthesia (OBA)

3. Pros and Cons
Pros Cons
patient and surgeon convenience safety concerns
cost containment little to no oversight regarding the
certification/qualification
greater personal attention and privacy to
Patients
Lack of documentation, general policies and
procedures, and the reporting of adverse outcomes
greater ease of scheduling for Surgeons Inadequate preoperative or postoperative
nursing personnel consistency Lack of experience
Lower rates nosocomial infection
 Today an estimated 1 in every 4 elective surgical procedures is
performed in the officebased setting, accounting for over 10 million
cases annually

4. Characteristic
1. Location: procedure never takes place in a typical operating suite
2. Operator: for the most part (although not always) the operator performing the
procedure is not a surgeon but rather a medical interventionalist or proceduralist
3. Relative novelty: procedures and technologies used may be novel in one way or
another
 All of above => • Scheduling inconsistencies
• Ad hoc requests
• Inadequate physical plant
• Poor communication
• Resource limitations can obstruct
• Expeditious resolution
 Anesthesia is a discipline that requires the constant vigilance of well trained and experienced
providers; safety derives from high-level dedicated care, teamwork,and rapid availability of
physicians, especially during medical crises

5. Conceptual Model Development of OBA

6. Procedures
 Levels I-III refer to the complexity of surgeries
 Level III:
Surgical procedures that require deep sedation/analgesia, general anesthesia or major
conduction blocks and support of vital bodily functions
 Level II:
Minor or major surgical procedures performed in conjunction with oral, parenteral or
intravenous sedation or under analgesic or dissociative drugs
 Level I:
Minor surgical procedures performed under topical, local or infiltration block anesthesia not
involving drug-induced alteration of consciousness, other than minimal sedation utilizing
preoperative oral anxiolytic medications

7. Procedures
Services Personnel Required Equipment Required
Level I
2 personnel including: a physician certified in AHA-
approved BCLS.
Bag mask valve
Oxygen
AED
Pre-measured doses of certain
drugs
Level II
2 personnel including: a physician certified in AHA-
approved ACLS or PALS and another person
certified in AHA-approved BCLS.
One of the above persons must attend the patient
until discharge.
Crash cart equipped to carry out
ACLS protocols
Level 1 equipment
IV equipment
Pulse oximeter
EKG monitor
Level III
2 personnel including: a physician certified in AHA-
approved ACLS or PALS and another person
certified in AHA-approved BCLS.
One of the above persons must monitor the
during the procedure.
One of the above persons must attend the patient
until discharge.
Crash cart equipped to carry out
ACLS protocols
Level 1 equipment
IV equipment
Pulse oximeter
EKG monitor

8. Procedures
 PROCEDURE SELECTION
-Can patient safely undergo surgery in a given office-based setting?
-Will the patient be able to recover from the procedure and be discharged within a reasonable
timeframe?
 Inappropriate surgical procedures:
-Blood loss that may require transfusion
-Major fluid shifts
-Moderate to severe postoperative pain requiring opioids
 Examples:
• gastrointestinal endoscopy
• Liposuction
• aesthetic facial and breast
surgery
• oral and maxillofacial surgery
• orthopedic surgery (including
podiatry procedures)
• gynecologic and genitourinary
surgery
• Ophthalmologic surgery
• otolaryngology procedures

9. Procedures

10. Patient Selection
 Preoperative History and Physical Examination
 within 30 days prior to the procedure
 laboratory as indicated
 any medically indicated specialist consultation(s)
 Ideal patient for an office-based procedure has an ASA physical status of 1 or 2
 ASA physical status 3 patients undergo an office-based procedure only after an
anesthesia consultation and only have an office-based procedure performed under
local anesthesia without sedation
 Features for evaluation: • Abnormalities of major organ
systems, and stability and
optimization of any medical
illness.
• Difficult airway, morbid obesity
and/or obstructive sleep apnea.
• Previous adverse experience with
anesthesia and surgery, including
malignant hyperthermia.
• Current medications and drug
allergies, including latex allergy.
• Time and nature of the last oral
intake.
• History of alcohol or substance
use or abuse.
• Presence of a vested adult who
assumes responsibility specifically
for accompanying the patient
from the office.

11. Patient Selection
Function Examples
1. Identify absolute contraindications to ambulatory
surgery
Inability to identify a responsible caregiver other than for
minor surgery with full and rapid recovery anticipated;
severe uncorrectable cardiovascular
disease
2. Identify need for optimization Patient requires further investigation, therapeutic
modification, or intervention to improve functional status;
identify a friend, relative or neighbor to act as caregiver
3. Highlight issues for anesthesiologist or other staff
(which may alter management but do not preclude
ambulatory surgery)
Potentially difficult intubation necessitating advanced
airway management skills; malignant hyperpyrexia–
susceptible patient requiring trigger-free anesthetic; latex
allergy; obese patient requiring operating table/trolley
with high weight limit and extra width
4. Provide patient information Written information on preoperative preparation,
medication management, preoperative fasting, etc.
THE FOUR KEY FUNCTIONS OF A PREOPERATIVE ASSESSMENT AND PREPARATION SERVICE
FOR AMBULATORY SURGERY

12. Patient Selection
ASA Physical status Functional status Examples Risk status
1 Healthy, no disease outside
surgical process
Can walk up one flight of stairs or two
level city blocks without distress
Little or no anxiety
Little or no risk
Green flag for treatment
2 Mild to moderate systemic
disease, medically well controlled,
with no functional limitation
Can walk up one flight of stairs or two
level city blocks but will have to stop
after completion of the exercise
because of distress
ASA I with extreme anxiety and fear, a
respiratory condition, pregnancy or
active allergies
Well controlled disease states including
diabetes, hypertension, obesity, epilepsy,
asthma or thyroid conditions
Minimal risk
Yellow flag for treatment
3 Severe systemic disease that
results in functional limitation
Can walk up one flight of stairs or two
level city blocks but will have to stop
enroute because of distress
History of angina pectoris, MI, CVA; HF >6
months ago, COPD, diabetes with vascular
complications, poorly controlled HTN,
morbid obesity
Yellow flag for treatment
4 Severe incapacitating disease
process that is a constant threat to
life
Unable to walk up one flight of stairs
or two level city blocks
Distress is present even at rest
History of unstable angina, MI or CVA
within last six months; severe HF, severe
COPD; uncontrolled diabetes, HTN,
epilepsy or thyroid condition
Advanced pulmonary, renal or hepatic
dysfunction
The risk may be too great for elective
surgical procedure
Medical consultation needed for
emergency treatment
Red flag for treatment
5 Moribund patient not expected to
survive 24 hours without an
operation
Ruptured abdominal aneurysm,
pulmonary embolus, head injury with
increased intracranial pressure
Elective treatment is contraindicated;
however, emergency surgery may be
necessary
Red flag for treatment
6 A declared brain-dead patient
being maintained for harvesting of
organs
E Suffix to indicate emergency
surgery for any class
Any patient in whom an emergency
operation is required
Otherwise healthy young woman
requiring D&C for persistent vaginal
bleeding

13. Patient Selection
 Poor Candidates
• Severe obesity
• Severe obstructive sleep apnea (OSA)
syndrome
• Potentially difficult airway
• Aspiration risk
• Possible anaphylaxis risk (eg,
significant drug or latex allergies,
mast cell activation syndrome)
• Possible malignant hyperthermia risk
• Previous adverse outcomes after
anesthesia
• Severe chronic obstructive pulmonary
disease
• Seizure disorder
• Myocardial infarction within the last
six months
• Stroke within the last three months
• Abnormal bleeding or clotting
tendency, including risk for deep vein
thrombosis
• Sickle cell disease
• Poorly controlled diabetes
• Poorly controlled hypertension
• Poorly controlled psychiatric
problems
• History of substance abuse

14. Patient Selection

15. Patient Selection
Country, year Fasting requirements at time of induction Comments
American Society of
Anesthesiologists, 2017[1]
2 hours clear liquids, not including alcohol
4 hours breast milk
6 hours nonhuman milk, infant formula, light meal
8 hours or more fried or fatty food or meat
Healthy patients, elective surgery, pregnant
patients not in labor
Light meal defined as toast or cereal with clear
liquid
European Society of
Anesthesiology, 2011[2]
2 hours clear liquids
4 hours breast milk
6 hours milk, infant formula, solid food
Chewing gum and sucking hard candy allowed up until time of induction
Applies to patients with obesity, diabetes, GERD,
nonlaboring pregnant patients
Encourages oral fluid up to 2 hours prior to
induction
Canadian Anesthesiologists'
Society, 2014[3]
2 hours clear liquids
4 hours breast milk
6 hours light meal, infant formula, and nonhuman milk
8 hours meat, fried, or fatty food
Association of Anaesthetists in
Great Britain and Ireland, 2010[4]
2 hours clear liquids
4 hours breast milk
6 hours solid food, infant formula, and cow's milk
Gum chewing should be treated as clear
Scandinavian Society of
Anaesthesiology and Intensive
Care Medicine, 2005[5]
2 hours clear liquids
4 hours breast milk and infant formula
6 hours solid food and cow's milk
2 hours chewing gum and any form of tobacco
Up to 1 hour prior to induction, 150 mL water
2 hours for preoperative carbohydrate drinks
intended for preoperative nutrition
German Society of
Anesthesiology and Intensive
Care, 2004[6]
2 hours clear liquids
4 hours breast milk and infant formula
6 hours meal
Australian and New Zealand
College of Anaesthetists, 2016[7]
2 hours clear liquids, all ages
3 hours breast milk for infants <6 months of age
4 hours formula for infants <6 months of age
6 hours breast milk, formula, limited solid food for children >6 months of
age and adults
Encourages oral fluid up to 2 hours prior to
induction
Up to 200 mL clear liquids per hour up until two
hours prior to induction for adults
Fasting guidelines of international anesthesia societies

16. ASA Guidelines for Non-O.R. Anesthetizing Locations
 Sufficient space for equipment/personnel to allow expeditious access to pt, machine, monitoring equipment
 Reliable O2 source and back-up supply
 Adequate/reliable suction
 Adequate/reliable scavenging system for inhalation Anesthesia
 Self-inflating resuscitator bag for PPV
 Monitoring equipment to adhere to ASA standards
 Adequate anesthesia drugs, supplies, equipment for intended anesthesia care
 Sufficient electrical outlets, including clearly labeled outlets to backup emergency power, isolated with ground
fault circuit interrupters if in a “wet location”
 Adequate lighting and backup illumination available
 Adequate trained staff to support the anesthesiologist
 Immediately available and reliable means of 2-way communication to request assistance.
 Emergency drugs, cart with defibrillator and other equipment for CPR
 Appropriate post-anesthesia management
Statement on Nonoperating Room Anesthetizing Locations (2013)

17. RCoA recommendations(2011)
 • Familiarity with all remote areas
 • Standardized anesthetic equipments
 • Mandatory monitoring should be as for any location.
 • Availabilty of fully trained assistant
 • Ensuring patients safety
 • Expert recovery care
 • Accurate documentation of anesthetic procedure
 • Wherever poosible anesthesia provided by expert consultants

18. Requirements
Monitors
Noninvasive blood pressure with an assortment of cuff sizes
Heart rate/ECG
Pulse oximeter
Temperature
Capnography
Airway supplies
Nasal cannulae
Oral airways
Facemasks
Self-inflating bag-mask ventilation device
Laryngoscopes with blades in multiple sizes and styles (eg, Macintosh and Miller)
Endotracheal tubes in multiple sizes
Stylettes
Supraglottic airway devices (eg, LMA) in multiple sizes
Emergency airway equipment (supraglottic airway devices [eg, LMAs] in multiple sizes, videolaryngoscope [eg, Glidescope or CMAC], cricothyrotomy kit)
Suction catheters and suction equipment
Cardiac defibrillator
Emergency drugs
ACLS drugs (refer to UpToDate topics on ACLS)
Dantrolene and malignant hyperthermia supplies (refer to UpToDate topics on malignant hyperthermia)
20% lipid emulsion for local anesthetic systemic toxicity
Anesthetic drugs
Vascular cannulation equipment

19. Requirements (ASA recommendation)
 At a minimum, all facilities should have a reliable source of oxygen, suction, resuscitation
equipment and emergency drugs. Specific reference is made to the ASA “Statement on
Nonoperating Room Anesthetizing Locations.”
 There should be sufficient space to accommodate all necessary equipment and personnel and
to allow for expeditious access to the patient, anesthesia machine (when present) and all
monitoring equipment.
 All equipment should be maintained, tested and inspected according to the manufacturer’s
specifications.
 Back-up power sufficient to ensure patient protection in the event of an emergency should be
available.
 In any location in which anesthesia is administered, there should be appropriate anesthesia
apparatus and equipment which allow monitoring consistent with ASA “Standards for Basic
Anesthetic Monitoring” and documentation of regular preventive maintenance as
recommended by the manufacturer.
 In an office where anesthesia services are to be provided to infants and children, the required
equipment, medication and resuscitative capabilities should be appropriately sized for a
pediatric population.

20. Requirements (Basic Monitoring)
Primary physiologic
process/parameter targeted
Monitoring
equipment
Principle Derived information Additional function
Oxygenation Inspired gas
O2content
O2 analyzer (with a
low-limit alarm in
use)
Paramagnetic sensor, fuel (galvanic) cell, polarographic (Clark)
electrode, mass spectroscopy, or Raman scattering
Inspired/expired
O2 concentration when
placed downstream from
fresh flow control valves
A low-level alarm is automatically activated by
turning on the anesthesia machine
Blood oxygenation Pulse oximeter The Beer-Lambert law applied to tissues and pulsatile blood flow.
The relative absorbency at wavelengths of 660 and 940 nm is used
to estimate saturation, which is derived from the ratio of
oxyhemoglobin to the sum of oxyhemoglobin plus
deoxyhemoglobin.
Hemoglobin saturation,
pulse rate, relative pulse
amplitude displayed on
plethysmography waveform
Continuous evaluation of circulation, variable
pitch pulse tone, and audible low-threshold
alarm
Ventilation Exhaled CO2 Capnograph CO2 molecules absorb infrared radiation at 4.26 micrometers,
proportionate to the CO2 concentration present in the breath
sample
ETCO2, inspired CO2,
diagnostic waveforms,
respiratory rate, apnea
detection
Instantaneous information about:
-Perfusion (how effectively CO2 is being
transported through the vascular system)
-Metabolism (how effectively CO2is being
produced by cellular metabolism)
-Confirmation of tracheal tube placement after
intubation
Integrity of
ventilation system
during mechanical
ventilation
Disconnection
alarm
Detects the cyclical changes in airway pressure in the normal range Alarms if a
significant decrease in rate
or pressure occurs
Alarms if high pressures are sensed
Pulmonary
mechanics (volume,
flow, pressure)
Pulmonary flow and
pressure sensors
Volume of gas proportional to a drum movement, changes in
differential pressure (near the Y-connector) or in electrical
resistance (hot wire housed in a monitor or ventilator)
Inspired and expired
volume, flow, and airway
pressure
Pressure volume and flow volume loops
Circulation Cardiac activity ECG The ECG monitor detects, amplifies, displays, and records the ECG
signal.
Heart rate and rhythm ST segment depression/elevation and trend over
time, with an audible alarm warning of
significant arrhythmias or asystole
Arterial BP Noninvasive BP
monitor
Oscillometric devices automatically inflate and deflate the cuff, and
have electronic pressure sensors that record the pressure
oscillations of the arteries. The pressure at which maximal
oscillations occur as the cuff is deflated corresponds with MAP.
Proprietary algorithms are used to calculate systolic and diastolic
BP.
Arterial BP Indicator of organ perfusion
Temperature Temperature Devices with a semiconductor, electrical resistance decreases as Core or peripheral A greater than 2°C core-to-periphery

21. Requirements Drugs
1. Epinephrine
2. Atropine, glycopyrrolate
3. Antihistamines
4. Hydrocortisone
5. Ephedrine
6. Vasopressors (norepinephrine,
phenylephrine, vasopressin, dopamine)
7. Calcium chloride or gluconate
8. Glucose
9. Naloxone
10. Flumazenil (Romazicon)
11. Antiemetics
12. Sodium bicarbonate
13. Lidocaine
14. Adenosine
15. Magnesium sulfate
16. Digoxin
17. Furosemide
18. Potassium chloride
19. Heparin sodium
20. Aspirin
21. Amiodarone
22. Verapamil
23. Procainamide
24. Nitroglycerin
25. Esmolol
26. Labetolol
27. A minimum of 20 ampules of dantrolene
sodium readily available

22. Safety
 Two literature reviews : Adverse incidents occurred in 0.05 percent and deaths in 0.0017 percent of
office-based surgeries
 Office facility resources:
>> Facilities should comply with all applicable federal, state and local laws, codes and regulations
pertaining to fire prevention, building construction and occupancy, accommodations for the disabled,
occupational safety and health, and disposal of medical waste and hazardous waste
>> Should have a Medical Director or Governing Body for stablishing policy and being responsible
>> Ideally, these procedures should be performed in an accredited facility
>> Anesthesiologist should participate in ongoing continuous quality improvement and risk
management activities
 Anesthetic techniques:
>> Conscious sedation, deep sedation, general anesthesia, or local anesthesia were all safe options for
oral and maxillofacial surgery in an office setting
 Regulation:
>> Paucity of guidance and regulation implies additional responsibility for anesthesiologists practicing
in office-based settings

23. Safety
 Major factors that contribute to OBA safety include
those related to:
1. Procedure and/or surgery selection
2. Patient Selection
3. Facility Preparedness
4. Use of Checklists
5. Provider Education
6. Accreditation

24. Safety (Accreditation)
1. Physical layout of the office
2. Environmental safety/infection control
3. Patient and personnel records
4. Surgeon qualification
a. Training
b. Local hospital privileges (surgical and admission)
5. Office administration
6. Anesthesiologist requirements
7. Staffing intraoperatively and postoperatively
8. Monitoring capabilities both intraoperatively and postoperatively
9. Ancillary care
10. Equipment
11. Drugs (emergency, controlled substances, routine medications)
12. BLS, ACLS/PALS certification
13. Temperature
14. Neuromuscular functioning
15. Patient positioning
16. Pre- and postanesthesia care/documentation
17. Quality assurance/peer review
18. Liability insurance
19. PACU evaluation
20. Discharge evaluation
21. Emergency preparedness (fire/admission/transfer, etc.)
Factors considered in
accrediting an office
for surgical
procedures

25. Safety (WHO surgical safety checklist)
Sign in
Before induction of anesthesia
Patient has confirmed:
--Identity
--Site
--Procedure
--Consent
--Site marked/not applicable
--Anesthesia safety check completed
--Pulse oximeter on patient and functioning
Does patient have a:
Known allergy?
--No
--Yes
Difficult airway/aspiration risk?
--No
--Yes, and equipment/assistance available
Risk of >500 mL blood loss (7 mL/kg in children)?
--No
--Yes, and adequate intravenous access and fluids planned
Time out
Before skin incision
--Confirm all team members have introduced themselves by name and role
--Surgeon, anesthesia professional, and nurse verbally confirm
-Patient
-Site
-Procedure
Anticipated critical events
--Surgeon reviews: What are the critical or unexpected steps, operative
duration, anticipated blood loss?
--Anesthesia team reviews: Are there any patient-specific concerns?
--Nursing team reviews: Has sterility (including indicator results) been
confirmed? Are there equipment issues or any concerns?
Has antibiotic prophylaxis been given within the last 60 minutes?
--Yes
--Not applicable
Is essential imaging displayed?
--Yes
--Not applicable
Sign out
Before patient leaves operating room
Nurse verbally confirms with the team:
--The name of the procedure recorded
--That instrument, sponge, and needle counts are correct (or not
applicable)
--How the specimen is labeled (including patient name)
--Whether there are any equipment problems to be addressed
--Surgeon, anesthesia professional, and nurse review the key
concerns for recovery and management of this patient

26. Safety (WHO surgical safety checklist)

27. Safety

28. Anesthesia type
 The choice of technique depends on the procedure and the preferences
of the surgeon, patient and anesthesiologist
 Analgesia: Decreased perception of painful Stimuli.
 Anxiolysis: Decreased anxiety.
 Sedation: Decreased awareness of environment.
 Conscious sedation: Decreased level of awareness that allows toleration of an
unpleasant procedure while maintaining the ability to spontaneously breathe
and protect the airway.
 Deep sedation: Unconscious state during which patients do not respond to voice
or light touch; minimal spontaneous movement; may be accompanied by partial
or complete loss of protective reflexes.
 General anesthesia: Loss of response to painful stimuli and loss of protective
reflexes.
 Regional Anesthesia

29. • Class A-C refer to the level of
anesthesia provided as described
by the American College of
Surgeons
Class C:
Provides for major surgical procedures that require
general or regional block anesthesia and support of
vital bodily function. AAASF standards use a similar
A, B, C, C-M classification, and specifically restrict
the use of propofol to Class C facilities.
Class B:
Provides for minor or major surgical procedures
performed in conjunction with oral, parenteral or
intravenous sedation or under analgesic or
dissociative drugs.
Class A:
Provides for minor surgical procedures performed
under topical and local infiltration blocks with or
without oral or intramuscular preoperative sedation.
Excluded are spinal, epidural, axillary, stellate
ganglion block, regional blocks (such as interscalene),
supraclavicular, infraclavicular, and intravenous
regional anesthesia.
Anesthesia type

30. Anesthesia type
1. Minimal sedation (anxiolysis)
a. Drug-induced sedation
b. Patient responds normally to verbal commands
c. Cognitive and motor function may be impaired
d. Ventilatory and cardiovascular functions maintained normally
2. Moderate sedation/analgesia (conscious sedation)
a. Drug-induced sedation
b. Patient responds purposefully to verbal commands either alone or with light tactile
stimulation
c. Patient maintains a patent airway and spontaneous ventilation
d. Cardiovascular function maintained
3. Deep sedation/analgesia
a. Drug-induced sedation
b. Patient cannot be easily aroused but can respond purposefully to repeated or
painful stimulation
c. Ventilatory function may be impaired, requiring assistance in maintaining a patent
airway, and spontaneous ventilation may be inadequate
d. Cardiovascular function is usually maintained
4. General anesthesia
a. Drug-induced loss of consciousness
b. Patients are not aroused by painful stimulation
c. Ventilatory function is often impaired; patient may require assistance in maintaining
a patent airway
d. Spontaneous ventilation may be impaired, as well as neuromuscular functioning
e. Positive pressure ventilation is often required
f. Cardiovascular function may be impaired
American Society
of
Anesthesiologists
(ASA) definitions
of levels of
sedation/anesthesi
a

31. Anesthesia type (Regional and Neuroaxial)
1. rapid onset and offset
2. easy administration
3. minimal expense
4. minimal side effects or complications
 Ultrasound-guided interscalene and supraclavicular blocks
 spinal anaesthetic techniques for common ambulatory procedures highlight the
success of combining subclinical doses of local anaesthetics and intrathecal opioid
adjuncts
 The neuraxial block with shorter acting local anaesthetic agents, specific to the
expected duration of surgery, may provide superior recovery profiles
 small-gauge, pencil-point needles are responsible for the success of outpatient spinal
anaesthesia with acceptable rates (0–2%) of (PDPH)

32. Anesthesia type (SPINAL ANAESTHESIA)
 Use of small 25- or 27-gauze pencil point needle
 Fine-gauge, pencil-point spinal needles has reduced the incidence of
significant postdural puncture headache to 0.5% to 1%
 Prevent prolonged motor block or impairment of joint position sense
 Lidocaine has an appropriate duration but ceased as a result of a high
incidence of TNS
 Bupivacaine may cause unacceptable delays in home discharge if used in
standard doses
 Reduce the dose of bupivacaine by using of patient positioning or the
addition of adjuvants, such as fentanyl
 Clonidine can be used to supplement low-dose spinal anesthesia, but it
may prolong motor block, exacerbate hypotension, and delay voiding

33. Anesthesia type (Selection of anesthetic agents)
 Goals —short duration of action, absence of postoperative nausea and vomiting (PONV), and cost-
effectiveness.
 Short duration — To facilitate rapid discharge after the procedure (ideally, one hour or less), only short-
acting agents are used to produce either sedation (eg, midazolam, propofol, ketamine,
or dexmedetomidine) or general anesthesia (eg, propofol, ketamine, or
dexmedetomidine and/or inhalational agents [eg, sevoflurane or desflurane]). Similarly, short-acting
opioids are used to provide analgesia (eg, fentanyl or remifentanil).
Nitrous oxide increases the risk of PONV, which has limited its use in patients susceptible to this
complication. However, in patients without risk factors for PONV, many anesthesiologists use nitrous
oxide in combination with intravenous agents or with a volatile anesthetic agent. Nitrous oxide reduces
the doses of other agents and may reduce costs and expedite emergence from anesthesia because of
its rapid offset.
 Avoidance of postoperative nausea and vomiting (PONV) — Major consideration in any ambulatory
surgery setting. Incidence of PONV after outpatient surgery may be as high as 50 %, use a multimodal
approach to both prophylaxis and treatment. In patients at risk for PONV, employ a variety of antiemetic
drugs targeting different receptors, as well as anesthetic and analgesic techniques that do not cause
PONV. (see next page)
 Cost-effectiveness — Cost is a valid but lesser concern in selection of anesthetics. Side effects such as
PONV and delayed recovery might negate cost advantages for certain agents and techniques
(eg, nitrous oxide)

34. Anesthesia type
(Selection of anesthetic
agents)
General Anesthesia MAC Anesthesia
Premedication Midazolam 2 mg IV (in holding
area) andMidazolam 2 mg IV (in holding area)
Induction 0.25-1 mg IV during procedure
titrated to effectPropofol 2.0-2.5 mg/kg IV or
Thiopental 3-5 mg/kg IV or O2 3-4 L/min by nasal cannula or 6-8
L/min by face mask with
capnograph
± Fentanyl 1 μg/kg IV
Muscle Relaxation
Succinylcholine 1 mg/kg IV (for intubation)
Propofol 1-1.5 mg/kg IV then 50-
100 μg/kg/min or
Vecuronium 0.1 mg/kg IV or Dexmedetomidine 1 μg/kg for 15-
20 min then 0.2-0.7 μg/kg/h orCisatracurium 0.2 mg/kg IV or
Rocuronium 0.6-1.2 mg/kg IV or Remifentanil 0.25-0.75 μg/kg/min
Maintenance of Anesthesia Fentanyl 12.5-25 μg IV can be
titrated to effect and monitor for
respiratory depression
O230%-100%
± N2O 0%-70% plus
Desflurane or sevoflurane
Reversal of muscle relaxation
Neostigmine 0.07 mg/kg IV plus
Glycopyrrolate 0.01 mg/kg IV
Analgesia
Fentanyl 25 μg IV titrated to effect up to 100 μg total
Morphine 1-4 mg IV titrated to effect up to 8 mg total
(Monitor for respiratory depression)
Nausea prophylaxis
Dolasetron 12.5 mg IV
± Metoclopramide 10 mg IV
Consider OG tube placement and suction for patients at risk for postoperative nausea and vomiting
(PONV).
O2100%
Suction oropharynx
Extubate (based on standard extubation criteria)
• The use of muscle relaxants in office-based
surgery is the same as in any ambulatory
surgical setting. A rapid-onset short-duration
non-depolarizing neuromuscular junction
blocking drug, Rapacuronium, is being
developed and might prove ideal for office-
based anesthesia which was withdrawn from
clinical use because of a frequent incidence of
severe bronchospasm, although other factors
such as inconvenient administration, declining
use of endotracheal intubation, and large costs
also contributed to its lack of commercial
success
• An alternative to short-acting NMBDs is
terminating the neuromuscular blockade with
sugammadex, which can rapidly and
completely reverse rocuronium (or
vecuronium) independent of the degree of
residual neuromuscular block

35. Monitored Anesthesia Care
According to the ASA position statement, MAC is a specific anesthesia service for a diagnostic or therapeutic procedure
and does not describe the continuum of depth of sedation
Indications for MAC include the type of procedure, the patient’s clinical condition, and the potential need to convert to a
general or regional anesthetic. Furthermore, it includes all aspects of anesthetic care, including a preprocedure visit,
intraprocedure care, and postprocedure recovery management
The anesthesia provider must be prepared and qualified to convert to general anesthesia if 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
ASA standard monitoring, which includes electrocardiography (ECG), pulse oximetry, noninvasive blood pressure, and
more recently end-tidal carbon dioxide (ETCO2) monitoring, must be used for every anesthetic including MAC.
Patients scheduled for MAC should receive a preoperative assessment similar to any other preoperative patient
MAC is unique in that it also requires an element of cooperation on the part of the patient. It is important for the patient
to accept the possibility to some degree of awareness during the procedure, to tolerate positioning required for surgery,
and in some instances, to be able to communicate with the surgeon or proceduralist
Successful MAC involves the use of combinations of anesthetic agents. Typically, a combination of a sedative hypnotic
and an analgesic agent is used in dosages that vary depending on the goals of the anesthetic and the requirements of
the procedure. Medications with minimal side effects and short duration of action are preferable in ambulatory
anesthesia, where efficiency and rapid recovery are highly desirable.

36. Monitored
Anesthesia
Care
Profile of Drugs Frequently
Used in Monitored
Anesthesia Care

37. Anesthesia type (Avoidance of PONV)
 Prophylactic drugs: may include: scopolamine, and/or intravenous administration of one or more of the following
intravenous agents: dexamethasone, ondansetron, famotidine, and/or metoclopramide.
 Anesthetic techniques: to minimize PONV include use of TIVA, usually with propofol alone or in combination with an
opioid. Also, dexmedetomidine may be used as an adjunct anesthetic agent.
 Other techniques include use of Neuraxial Anesthesia (spinal or epidural) or Peripheral Nerve Blocks, with or without
catheters.
 Opioid-sparing analgesics: are used when feasible (eg, acetaminophen and/or NSAIDs).
 Nitrous oxide: is avoided in patients at high risk for PONV.
 Adequate Hydration: may be useful in prevention of PONV (avoiding orthostatic hypotension and consequent decreased
blood flow to the midbrain emetic centers). For most healthy adult patients undergoing minimally-invasive relatively
short outpatient surgical procedures that are not associated with significant fluid shifts or blood loss, 1 to 2 L of a
balanced electrolyte solution (eg, Ringer’s lactate solution) is administered during surgery. Such empiric fluid
administration addresses the mild dehydration caused by preoperative fasting, and is associated with less postoperative
nausea and vomiting as well as less postoperative pain.
 Postoperative period: patients who develop PONV receive additional multimodal therapy including the same agents
used for prophylaxis. Promethazine, Haloperidol, and/or Diphenhydramine are given, if needed. Aprepitant (neurokinin-
1 receptor antagonist)is another option.
 Persistent severe PONV may be necessary to admit a to an inpatient facility.

38. RECOVERY
 Suitable clinical area for recovery of the patient which must include oxygen,
suction, resuscitation drugs and equipment
 Almost all the potentially preventable office-based injuries result from adverse
respiratory events in the recovery or postoperative periods; therefore, strict
surveillance should be exercised until full recovery
 The ideal recovery area should be ‘near’
the location where the patient was
treated
• Standard Equipment
 Oxygen
 Suction
 Pulse oximeter
 Electrocardiogram
 Blood pressure monitor
 Temperature monitor
• Emergency Equipment
 Airway = oral/nasal airways, oxygen cannulae
 Breathing = face masks, endotracheal tubes,
laryngoscopes, and laryngeal mask airways (LMAs)
 Circulation = intravenous catheters and fluids
 Drugs = emergency cart containing all life support
equipment
• Design
Close proximity to the operating room (OR)
Open designated area
Well lighted
Easily accessible
Allow room for equipment
Electrical outlets

39. RECOVERY (non Opioid Pain medication)
Drug Usual analgesic
dose (intravenous) Maximum dose per day (mg)
Para-aminophenol derivative
Acetaminophen
(paracetamol, APAP)
Weight ≥50 kg: 650 mg
IV every 4 hours or 1000
mg IV every 6 hours
Weight <50 kg: 12.5
mg/kg IV every 4 hours
or 15 mg/kg IV every 6
hours
Weight ≥50 kg: 4000 mg IV
Weight <50 kg: 75 mg/kg per day up to 3750 mg IV
Nonselective NSAIDs*
Ketorolac Age <65 years and
weight ≥50 kg: 15 to 30
mg IV every 6 hours
Age ≥65 years or weight
<50 kg: 15 mg IV every 6
hours
Age <65 years and weight ≥50 kg: 120 mg IV per day for up to five
days
Age ≥65 years or weight <50 kg: 60 mg per day IV for up to five
days
Ibuprofen 400 to 800 mg IV every 6
hours
3200 mg IV
Diclofenac 37.5 mg IV every 6 hours 150 mg IV
Selective COX-2 inhibitor
Parecoxib
(not available in
United States)
20 to 40 mg IV every 6 to
12 hours
Age <65 years: 80 mg IV
Age ≥65 years and body weight <50 kg: 40 mg IV

40. DISCHARGE Postanesthesia Recovery Score
(Modified Aldrete Score) (0-2 point
scale)
Activity
2=Moves all extremities voluntarily or on command
1=Moves two extremities
0=Unable to move extremities
Respiration
2=Breathes deeply and coughs freely
1=Dyspneic, shallow or limited breathing
0=Apnea
Circulation
2=BP ± 20mm of preanesthetic level
1=BP ± 20-50mm of preanesthetic level
0=BP ± 50mm of preanesthetic level
Consciousness
2=Fully awake
1=Arousable on calling
0=Not responding
Oxygen saturation
2=SpO2 >92% on room air
1=Supplemental O2 required to maintain SpO2 >90%
0=SpO2 <92% with O2 supplementation
10=Total score
Score >9 required for PACU discharge

41. DISCHARGE
Criteria for discharge from the Post Anesthesia Care Unit
Extended Criteria Minimum Criteria
Central nervous system
Awake, alert, oriented, moves all
extremities
Hemodynamically stable
Airway and breathing
Can take deep breaths, color pink, and
oxygen saturation >92% on room air
Adequate pain control
Circulatory Stable vital signs No nausea or vomiting
Renal Ability to void urine
Gastrointestinal
Absence of severe nausea/vomiting,
able to tolerate fluids
Pain Control of significant pain
Regional anesthesia Resolution of a spinal/epidural block
Temperature Normothermia
Major surgical complications Absent
Home discharge Ride available

42. DISCHARGE
 following simple recovery criteria are beneficial in routine clinical practice:
I. simple psychomotor tests like memory and sensory motor coordination
II. recovery of motor and sensory functions: With spinal anaesthesia, it is generally
accepted that motor and sensory functions return before recovery of sympathetic
nerve system
III. two successive orthostatic MAP decrease of 10% or less
IV. prior to ambulation, patients should have normal perianal sensation (S4–5), ability to
plantarflex the foot, and proprioception of the big toe

43. COMPLICATIONs
 The severity of injury for office-based claims was greater than for other
ambulatory anesthesia claims
 Some of the early literature
broaches concerns about the safety
of office-based procedures and
anesthesia. However, more recent
data have shown that care in
ambulatory settings is comparable
to hospitals and ambulatory
surgery centers, especially when
offices are accredited and their
proceduralists are board-certified
Examples of adverse events to be reviewed in
office-based anesthesia
 Death, cardiac or respiratory arrest
 Re-intubation (unplanned)
 Central or peripheral nervous system deficit
 Myocardial infarction
 Pulmonary edema or aspiration pneumonia
 Anaphylaxis or adverse drug reaction, including drug
errors
 Postdural puncture headache
 Dental injury
 Eye injury
 Surgical infection or excessive blood loss
 Unplanned admission
 Wrong procedure, patient, surgical or regional block
site

44. COMPLICATIONs
 More than 46 percent of office-based injuries are preventable by better monitoring
 All the potentially preventable office-based injuries resulted from adverse respiratory
events in the recovery or postoperative periods
• The most common damaging events in the Closed Claims database overall (including
inpatient and pain claims):
--Respiratory system (22 percent)
--Cardiovascular system (11 percent)
--Equipment-related (10 percent) events
• The damaging events in office-based claims involved:
--Respiratory system events (50 percent) (included airway obstruction, bronchospasm,
inadequate oxygenation-ventilation and esophageal Intubation)
--drug-related events (25 percent) (included wrong dose or drug, malignant hyperthermia
and allergic drug reaction)