Outpatient Anesthesia

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ANESTHESIA OUTSIDE THE
OPERATING ROOM
By
Hala S. El-Ozairy,MD.
Lecturer of anesthesia and ICU
Objectives
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Understanding that the standards of anesthesia care and
patient monitoring are the same regardless of location
(There are cases of minor surgery, but there are no cases
of minor anesthesia).
Remember that the key to efficient and safe remote
anesthetic relies on open communication between the
anesthesiologist and non-operating room personnel.
Realize that remote locations have different safety
concerns, such as radiation and powerful magnetic fields.
Remote anesthesia
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Anesthesiologists are increasingly being asked to provide
anesthetic care in locations outside of the OR.
These locations include: radiology suites, cardiac labs,
psychiatric units, GI lab, MRI, dental, ophthalmic, ENT and
urology clinics.
It is the responsibility of the anesthesiologist to ensure that
the location meets the ASA guidelines for safety.
The anesthesia needed can range from local
anesthetics, MAC, or general anesthesia.
Problems related to ‘isolated’
environment
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Equipment might be old, not regularly serviced and not in
standard use as in the rest of the hospital.
Monitoring standards may not be adequate.
Piped medical gases may not be supplied.
Other personnel may be unaware of the problems facing
the anesthetist.
Space may be limited by bulky equipment making access to
the patient difficult.
Poor environmental conditions (e.g. Lighting, temperature).
Recovery facilities may not be available.
Inadequate ventilation/scavenging causing pollution.
Problem related to transferring patients.
Problems related to patient
Patients who require general anesthesia are:
 Infants or uncooperative children.
 Older children or adults with psychological,
behavioral or movement disorders.
 Intubated patients such as acute trauma victims and
patients receiving intensive care.
 Interventional procedures under radio-guidance or
painful procedures like ECT, cardioversion which
require amnesia.
Problems related to the procedure
MRI related problems.
 Bleeding.
 Conversion from sedation to
anesthesia.
 Contrast related problems.
 Radiation.
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1994 Guidelines for non-operating room
anesthetizing locations.
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Reliable oxygen source with backup.
Suction source.
Waste gas scavenging.
Adequate monitoring equipment.
Self-inflating resuscitator bag.
Sufficient safe electrical outlets.
Adequate light and battery-powered backup.
Sufficient space.
Emergency cart with defibrillator, emergency drugs,
and emergency equipment.
Means of reliable two-way communication.
Compliance with safety and building codes.
Remote monitoring
Qualified anesthesia personnel must be present
for the entire case.
 Continuous monitoring of patient’s oxygenation,
ventilation, circulation, and temperature:
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Oxygen concentrations of inspired gas: low
concentration alarm.
 Blood oxygenation: pulse oximetry.
 Ventilation: end-tidal carbon dioxide detection and
disconnect alarm.
 Circulation: ECG, ABP, invasive BP, and oximetry.
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Remote facilities and equipment
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Know the physical layout of the location, unfamiliar
anesthetic equipment, and anesthetic implications of
the procedure being performed prior to the
induction of anesthesia.
Verify the availability of assistance.
Check piped-in gases and gas tanks.
Check suction.
Check power outlets (i.e. grounding and electrical
requirements).
Remote personnel
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Nurses and radiology techs are often less familiar
with the management of anesthesia, therefore they
are often unable to provide skilled assistance in an
emergency.
Remote recovery care
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Patient must be medically stable before transport.
Patient must be accompanied to the recovery area.
Provisions for O2 delivery and monitoring on the
transport cart are required.
Appropriate recovery facilities and staff must be
provided.
Procedural sedation
Procedural sedation is defined as "a technique
of administering sedatives or dissociative
agents with or without analgesics to induce a
state that allows the patient to tolerate
unpleasant procedures while maintaining
cardiorespiratory function."
Levels of Procedural Sedation
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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.
JCAHO Guidelines for sedation
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ASA class I & II.
Responsible adult to accompany the patient.
Responsible physician (anesthetist).
Support personnel.
Facilities: Immediate availability to manage emergency
situations as (apnea, vomiting, seizures, anaphylactoid
reactions and cardiac arrest).
Back up emergency service.
On-site equipments: monitors, emergency cart,..
IV access.
Health evaluation and consent.
Proper monitoring & documentation: ECG, BP, pulse oximetry,
capnography, consciousness.
Medication
Side Effects
Route
Total Dose
Onset
Duration
Methohexital
Respiratory
depression,
hypotension
IV
PR
0.75 –1 mg/kg
20 –30 mg/kg
45 sec
8 –10 min
5 –10 min
45 – 60 min
Pentobarbital
Respiratory
depression,
hypotension
IV
IM
PO/PR
2.5 mg/kg
2.5 mg/kg
2– 6 mg/kg
45 sec
10 –15 min
15 – 60 min
15 min
NA
1– 4 hr
IV
IM
PO
PR
Nasal
0.02– 0.1 mg/kg
0.7–1 mg/kg
0.2– 0.4 mg/kg
2–3 min
2–5 min
15 –20 min
10 –15 min
10 –15 min
30 min
30 – 40 min
45 – 60 min
45 min
45 min
Barbiturates
Benzodiazepines
Midazolam
Respiratory
depression
0.05 – 0.15 mg/kg
0.5 – 0.75 mg/kg
Opioids
Fentanyl
Respiratory
depression
IV
2 μg/kg
1–2 min
20 –30 min
Morphine
Respiratory
depression,
hypotension,
nausea &
IV
IM/SQ
0.1– 0.2 mg/kg
0.1– 0.2 mg/kg
1–5 min
30 min
3 – 4 hr
4 –5 hr
Other sedative agents
Chloral
hydrate
Prolonged
sedation
PO/PR
50 –75 mg/kg
30 – 60 min
1–8 hr
Ketamine
Postemergence
delirium
IV
IM
PO
PR
Nasal
0.5 –1 mg/kg
4 mg/kg
5 –10 mg/kg
5 –10 mg/kg
3 – 6 mg/kg
1 min
5 min
30 – 40 min
5 –10 min
5 –10 min
15 min
15 –30 min
2– 4 hr
15 –30 min
15 –30 min
Propofol
Respiratory
depression,
hypotension
IVI
IV bolus
0.05 – 0.1 mg/kg/min
30 sec
30 sec
8 –10 min
Flumazenil
Withdrawal
symptoms
(agitation)
IV
0.2 mg
0.01 mg/kg
(pediatrics)
1–3 min
30 – 45 min
Naloxone
Withdrawal
symptoms
(agitation)
IV/IM/SQ
0.1–2 mg
1–2 min (IV)
15 – 45 min
1 mg/kg
Reversal agents
Radiology suite
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Includes: US, CT, RFA, and neuro-coiling.
The rooms are often crowded with bulky equipment.
Patients are often required to hold still for long periods of
time.
Unique hazard: radiation exposure.
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Leukemia and fetal abnormalities.
Dosimeters are required (maximum exposure 50 mSv annually).
Lead aprons, thyroid shields, leaded glass screens, and video
monitoring.
Radiology suite, contd.
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Iodinated contrast media.
 Older
ionized contrast media were hyperosmolar and
toxic.
 Newer non-ionized contrast media have lower
osmolality and improved side-effects.
 Predisposing factors to adverse reactions from contrast
media include a history of: bronchospasm, allergy,
cardiac disease, hypovolemia, hematologic disease,
renal dysfunction, extremes of age, anxiety, and
medications (beta-blockers, aspirin, and NSAIDs).
Radiology suite, contd.
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Reactions to iodinated contrast media.
 Mild:
nausea, perception of warmth, headache, itchy
rash, and mild urticaria.
 Severe: vomiting, rigors, feeling faint, chest pain,
severe urticaria, bronchospasm, dyspnea, arrythmias,
and renal failure.
 Life-threatening: glottic edema/bronchospasm,
pulmonary edema, arrythmias, cardiac arrest, and
seizures/unconsciousness.
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Treatment: O2, bronchodilators, epinephrine,
corticosteroids, and antihistamines.
CT
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Two-dimensional, cross-sectional image.
Each cross-section requires a few seconds of
radiation exposure.
Pt immobility is required.
It is often noisy, warm, and claustrophobic.
CT can be used for diagnostic and therapeutic
purposes.
Number one problem: inaccessibility to the patient.
Anesthesia for CT
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Anesthetist can remain in the room wearing X-ray
protection or view the patient and monitors from the
control room.
The CT scanner does not interfere with monitoring
equipment.
The scans are short and can be interrupted.
The patient couch moves during examination.
Temporarily interruption of ventilation to improve
image quality – immediately re-ventilate.
Patient positioning.
Radiology RFA
Often done in CT but occasionally MRI.
 Kidney, lung, and liver.
 Currently requesting general anesthesia with
ETT secondary to prone positioning and the
need to lay still for extended periods of time.
 It is our job to check pressure points and
padding. Radiology techs are not trained to
be concerned.
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Interventional Radiology
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Embolization of cerebral and dural AVM’s, coiling
of cerebral aneurysms, angioplasty of sclerotic
lesions, and thrombolysis of acute thromboembolic
stroke.
These procedures often require deliberate
hypotension and deliberate hypocapnia.
Radiologist may request rapid transition between
deep sedation and an awake responsive state.
Cerebral Coiling
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The anesthetist should prepare:
 Arterial line set up.
 Fluid warmer.
 Infusion pump.
 Medications: NTG, nipride, esmolol, labetalol, heparin, and
protamine.
 ACT machine.
Radiologist may request anything from deep IV sedation to GA with
ETT.
Always have 2 large-gauge IV’s in place. One for drug infusion and
one for rapid fluid administration.
Stay in constant communication with OR in case of an emergency.
Pt often transported to the ICU post-op.
Remote Cardiac Lab
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Elective cardioversion:
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Cart with emergency drugs.
Induction drug (Etomidate).
Standard monitoring.
Preoxygenate.
Give small incremental doses of etomidate until the eyelash reflex
is abolished.
Remove the mask immediately before the shock and confirm no
one is touching the pt.
Ventilate with 100% O2 post-shock until consciousness is regained.
Consider RSI with ETT if high risk for aspiration.
Remote Cardiac Lab contd.
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Cardiac RFA
 IV sedation to GA with ETT depending on the
pt’s co-morbidities.
 Possible need for an arterial line setup.
 Propofol is oftenly used.
 Midazolam and fentanyl are used to titrate
in during the more painful parts of the
procedure (esp. the ablation).
Remote Cardiac Lab contd.
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Pacemaker/ ICD placement:
We are often called just for the ICD check, in which case
proceed like an elective cardioversion.
 If the pt. is very sick, they may require GA. Therefore,
proceed like RFA.
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These pt’s will often need an arterial line for BP monitoring.
These ICD checks are not without risk. Check pulses and
watch the ECG, pulse oximetry and arterial wave-forms
closely. People have been known to code and require CPR.
GI Lab
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Endoscopy, Colonoscopy and ERCP.
Pt’s are often uncooperative or very sick.
Current rooms in the GI lab are very small.
Anesthesia for GI Procedures
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Pre anesthetic assessment: Age, cooperative, anxiety,
allergies, fluid status, electrolytes, cardiac history,
GERD.
Type of anesthesia:
Moderate sedation- midazolam and Fentanyl.
 Deep sedation- Addition of propofol.
 Some cases may require general anesthesia.
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Anesthetic considerations:
Strong vagal nerve stimulation as result of stimulation to
colon.
 Most patients tolerate these procedures well.
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ECT
Indications
 Major
depression.
 Mania.
 Certain forms of
schizophrenia.
 Parkinson’s syndrome.
Contraindications
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Pheochromocytoma.
Increased ICP.
Recent CVA.
Cardiovascular conduction
defects.
High risk pregnancy.
Aortic and cerebral
aneurysms.
Physiologic effects of ECT
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Electrical stimulus: brief period of muscular contraction
followed by the tonic and then clonic phases of the
seizures.
Cardiovascular effects of ECT: immediate
parasympathetic response followed within seconds by
a sympathetic response.
The muscular activity of the seizure and the increased
sympathetic activity causes a rise in myocardial
oxygen consumption, increases CMRO2, cerebral
blood flow, intracranial, intra-ocular intra-gastric
pressure briefly.
Anesthesia for ECT
General anesthesia is used to provide a brief
period of amnesia and modify the motor
effects of the seizure to protect the patient.
 Don’t forget the suction and the Bite block.
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ECT contd.
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Pre-op: These pt’s have often had this procedure multiple times,
therefore you can use old records as templates.
Place IV and give glyco (0.2 mg IV). Give caffeine if the psychiatrist
requests.
 Treats the bradycardia/ asystole from the initial parasympathetic
discharge from the seizure activity.
Hyperventilate the pt. with 100% O2.
Thiopentone and suxamethonium are commonly used.
Place the bite block.
Goal is a seizure 30-60 seconds long.
Ventilate until spontaneous respirations return.
The parasympathetic discharge is often followed by a sympathetic
discharge associated with HTN and tachycardia. This is treated with
esmolol.
Dental Procedures
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Pediatric Dentistry: fillings, crowns, pulpotomies, tooth
extractions and space maintainers.
Oral and Maxillofacial Surgery: extractions of
impacted teeth, insertion of dental implants, treatment
of infections of the head and neck and facial cosmetics.
Peridontics: surgery of teeth, gingiva, connective tissue,
periodontal ligament and alveolar bone.
Anesthesia : general anesthesia, minimal sedation,
moderate sedation with local anesthetic for particular
areas of surgery.
Ophthalmology
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Cataract extraction is the most common procedure
done for the elderly.
Strabismus operations are the most common
pediatric procedures.
Requirements for anesthesia:
 Unmoving
globe.
 Minimal bleeding.
 Smooth emergence.
 Usually done under MAC.
Urologic Procedures
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ESWL: sound waves are focused on kidney and ureteral stones.
The stone located by flouroscopy.
Cystoscopy/ ureteroscopy: are performed to diagnosis and
treat lesions of the lower (urethra, prostate, bladder) and
upper (ureter, kidney) urinary tracts.
Type of Anesthesia
 Depending on the pt and procedure anesthesia can range
from topical lubrication ,MAC, or regional.
 If regional is used T-6 level of blockade is required for
upper tract instrumentation and T-10 for lower-tract surgery.
Thank you
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