OFF-SITE ANESTHESIA Introduction I - virtanes

OFF-SITE ANESTHESIA
Michel Baurain, M.D., Ph.D.
Hôpital Erasme, U.L.B.
Introduction I
• 40% of all anesthetic procedures
• Small rooms, not intended for anesthesia
care
• Patients: within the extremes of ages and
health
• Unfamiliar or outdated anesthesia
equipment
1

Introduction II
• Unfamiliar to the anesthetic implications of
these procedures
• To work with personnel who are less (or
no) familiar with the anesthetic aspects of
patients care in these settings
• Remoteness from available help
• Rapid transfer to an operating room for
surgical procedure
Common Procedures I
Imaging Procedures:
Computed tomography
Interventional radiology (vascular & others)
Functional brain imaging
Interventional neuroradiology
Magnetic resonance imaging
Ultrasound-guided diagnostic and therapeutic
procedures
Radiotherapy procedures:
Teletherapy, brachytherapy
Intraoperative radiotherapy, radiosurgery
Psychiatric procedures:
Electroconvulsive therapy
2

Common Procedures II
Urology:
Extracorporeal shock, wave lithotripsy
Cystoscopy procedures (bladder, prostate)
Cardiology:
Cardiac catheterization, cardioversion
IAC & foramen ovale closing
Gastroenterology:
Upper endoscopy, colonoscopy
Liver biopsy, TIPS
Interventional procedures (cholangiography…..)
Gynecology:
In vitro fertilizations
Common Procedures III
Pneumology:
Rigid bronchoscopy, interventional procedures (bronchialtracheal
prosthesis), laser therapy
Ophtalmology:
Retinoscopy, tonometry, electro-retinography, selective
eyes surgery
Dental procedures
Neurophysiology
Brainstem auditory evoked response
Emergency room procedures:
Emergency endotracheal intubation, central venous line
insertion, orthopedic manipulations
3

Common procedures in Children
1. Diagnostic radiology:
CT, MRI, Bone Scan
2. Cardiovascular interventions:
angiography, cardiac catheterizations,
3. Therapeutic radiation
4. Diagnostic & interventional procedures:
bronchoscopy, eye examination, endoscopy,
ultrasound, transesophageal echo,…
5. Diagnostics exams:
lumbar puncture, bone marrow aspiration,
biopsy, evoked potentials
6. Painful procedures:
IV cannulation, dressing change, urodynamic study, minor
surgery in emergency department
Radiocontrast Media Use I
1. Caution:
Preexisting renal insufficiency
Diabetes mellitus
2. Contrast-induced nephrotoxicity:
Most reliable defenses:
1. Adequate hydration
2. Stable hemodynamics
3. Furosemide, mannitol, dopamine,
acetylcysteine, fenoldapam
3. Mechanisms:
1. Direct chemical toxicity
2. Effects of hypertonocity on red blood cells
hypoperfusion on end organs
4

Radiocontrast Media Use II:
Reactions
Mild
Nausea, retching
Perception of warmth
Headache
Itchy skin rash
Mild urticaria
Severe
Vomiting
Rigors
Feeling faint
Severe urticaria
Brochospasm,
Dyspnea
Chest pain
Abdominal pain,
Diarrhea
Arrhythmias
Renal Failure
Life-Threatening
Glottic edema /
Bronchospasm
Pulmonary edema
Life-Threatening
arrhythmias
Cardiac arrest
Seizures /
Unconsciousness
Radiocontrast Media Use III:
Prevention
1. Corticotherapy:
Methylprednisolone (Medrol):
4 X 32 mg / day PO &
2. Antihistaminic drugs:
Cetirizine (Zyrtec): 2 X 10 mg / day PO
3. 48 hours treatment before the procedure
5

Radiation Safety Principles
1. Maximize distance from the radiation
source
2. Minimize exposure times
3. Always use proper shielding with leaded
glasses, gowns, gloves, thyroid collars
Check List For Off-Site
Anesthesia I
• 1. Are O2 source and suction available
• 2. Are there freestanding or piped into the wall,
and if so are there in reach of the patient
• 3. Is the lighting sufficient
• 4. Are there enough elelectrical outlets
• 5. Is there an emergency cart
• 6. Are mo,itors available and adequate
• 7. Which drugs and equipment do I need to
bring Which are provided at the site
6

Check List For Off-Site
Anesthesia II
• 8. Are the staff familiar with utilizing the emergency
cart
• 9. Is there a place for general anesthesia to be
induced
• 10. If anesthesia is induced in an area different from the
procedure area, must equipment and drugs be
transported with the patient
• 11. Are the staff familiar with the response to anesthesia
emergencies
• 12. Are there any site-specific hazards to the anesthesia personnel
and to the patient
• 13. Where will the patient recover after the anesthesia procedure
Patients: Caracteristics
1. Patient’s age: extremes ,
From prematures to very old patients
2. Physical status:
High operative / anesthetic risk
Majority of patients: referred & complex
3. Off-Site Anesthesia standards of quality:
(ASA, SBAR standards):
The same as O.R. standards of quality
Safety: maximal
4. Global population aging
7

Patient Care I
1. ASA « Standards for basic anesthetic
monitoring »
ASA guidelines for Off-Site Anesthesia
ASA guidelines for Office-Based Anesthesia
2. Preprocedure evaluation
Identification of specific clinical indicators
or risk factors
Preoperative testing (laboratory, cardiology,
pneumology…)
Patient Care II
3. Monitoring
Standard I:
Presence of qualified anesthesia personnel in the
Procedure room throughout the conduct of anesthesia
Standard II:
Continual evaluation of the patient’s oxygenation,
Ventilation, circulation, temperature….
Basic monitoring:
Pulse oxymeter, multiple inhaled & exhaled gases
analyzer, capnography, ventilatory parameters (AP,
TV), blood pressure (NIBP, IA device), ECG, T°
monitoring, urine output, NMT monitoring
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Patient Care III
4. Postanesthesia Care
The patient should be observed in a
postanesthesia care unit or its equivalent
unless he or she has met recovery criteria in
the procedure room.
Discharge of the patient is a physician
responsability, and this decision should be
documented in the medical record.
Continuum of Depth of Sedation
Minimal
Sedation
(Anxiolysis)
Moderate
Sedation /
Analgesia
(Conscious
sedation)
Deep Sedation /
Analgesia
General
Anesthesia
Responsiveness
Normal
response to
verbal
stimulation
Purposeful
response to
verbal or tactile
stimulation
Purposeful
response
following
repeated or
painful
styimulation
Unarousable
even with
painful stimulus
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
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Fasting Protocol for Elective
Procedures
Solids & nonclear
liquids
Clear liquids
Adults
Children
> 36 months old
Children
6 - 36 months old
6 – 8 hours or
nothing after
midnight
6 – 8 hours
6 hours
2 – 3 hours
2 – 3 hours
2 – 3 hours
Children
< 6 months old
4 – 6 hours
2 hours
High-Risk pediatric patients for
sedation
Patients with a higher susceptibility to
respiratory depression:
general anesthesia
- preterm neonates, neonates,
- obstructive sleep apnea or
adenotensillar hypertrophy,
- CNS diseases
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General Anesthesia vs Sedation
in pediatric patients
General
Anesthesia
Sedation
Ease of
administration
Cost
Time to initiation of
scan
Failed Scans
Adverse events
Anesthesiologists
Costly
Shorter
Minimal
Minimal
Nurse or other
physicians
Cost-effective
Longer
3,7 %
20 %
Interventional neuroradiology I
• Common procedures performed:
1. Embolization of cerebral AV malformations &
fistula
2. Coiling of cerebral aneurysms
3. Cerebral angioplasty for vasospasm
4. Carotid stenting or balloon occlusion testing
5. Embolization of tumors, epistaxis
6. Superficial vascular malformations treatment
7. Intraarterial chemotherapy
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Interventional neuroradiology II
• Indications for general anesthesia:
1. Motionless patients provide improved images
& facilitate treatment
2. Airway control in the supine position
3. Induced hypotension facilitated
4. Improved control of elevated ICP
5. Increase of blood pressure in patients with occlusive
disease
6. Prevention and/or vasospasm treatment
7. Better & easier management of potential
complications
Interventional neuroradiology III
• Indications for treatment modality:
Indications interventional
neuroangiology
Indications for surgery
Medically unstable patient
Wide-neck aneurysms
Poor neurological grade
Early vasospasm
Multiple aneurysms in different
territories
Vessels emanating from aneurysm
dome
Hemetoma or mass effect with
aneurysm
Recurrent aneurysms after GDC
coiling
Unruptured aneurysms
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Interventional neuroradiology IV
• Complications:
1. Radiocontrast reactions
2. Embolizations of particles
3. Aneurysm perforation
4. Obliteration of physiologic arteries
5. Intracranial bleeding
6. Cerebral vasospasm
MRI: QUALITIES &
ADVANTAGES
1. MRI can produce images in any plane
2. Excellent soft tissue contrast
3. Intravascular contrast without the need for IV
contrast
4. Very little preparation of the patient
5. Does not produce ionizing preparation
6. Non invasive
7. No biologically deleterious effects
8. Imaging quality (anatomy, physiology,
pathology): not possible with other imaging
techniques
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MRI: LIMITATIONS & HAZARDS
1 Attraction of ferromagnetic objects to the magnet
2 Dislodgement & malfunction of implemented biologic
devices:
- vascular clips & shunts
- wire spiral endotracheal tube
- pacemakers
- automatic implantable cardiac defibrillator
- implanted biologic pumps
3 Duration of the procedure: 30 to 60 minutes
4 Perfect collaboration of the patient: strict immobility
5 Noise, Burns, anxiety, claustrophobia
PREOPERATIVE TESTING ALGORITHM II
Does patient have significant systemic disease
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PREOPERATIVE TESTING ALGORITHM II
PREOPERATIVE TESTING ALGORITHM I
Does patient have significant systemic disease
YES
Testing as indicated
by specific condition
Examples
HYPERTENSION
BUN/ Creatinine
Electrolytes if on diuretic
or ACE-inhibitor
Electrocardiogram
DIABETES
Blood glucose
BUN/ Creatinine
Electrocardiogram
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MRI: ANESTHESIA &
MONITORING PROBLEMS
1 Limited patient access & visibility
2 The need to exclude ferromagnetic components
3 The interference / malfunction of monitoring
equipment produced by the changing magnetic
field & RF currents
4 The potential degradation of the imaging caused
by the stray RF currents produced by the
monitoring equipments & leads
5 The necessity to not move the anesthetic &
monitoring equipment during the procedure
6 Tunnel structure
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MRI: CONTRAST AGENT
1 Gadolinium
2 Reported adverse effects:
- Thrombophlebitis
- Hypotension
- Headache
- Nausea, vomiting
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