ANESTHESIA OUTSIDE THE OPERATING ROOM

ByHala S. El-Ozairy,MD.

Lecturer of anesthesia and ICU

Objectives

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

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 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.

1994 Guidelines for non-operating room anesthetizing locations. 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: 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.

Remote facilities and equipment 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

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

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 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  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

Barbiturates

Methohexital

Respiratory depression, hypotension

IVPR

0.75 –1 mg/kg20 –30 mg/kg

45 sec8 –10 min

5 –10 min45 – 60 min

Pentobarbital

Respiratory depression, hypotension

IVIMPO/PR

2.5 mg/kg2.5 mg/kg2– 6 mg/kg

45 sec10 –15 min15 – 60 min

15 minNA1– 4 hr

Benzodiazepines

Midazolam Respiratory depression

IVIMPOPRNasal

0.02– 0.1 mg/kg0.05 – 0.15 mg/kg0.5 – 0.75 mg/kg0.7–1 mg/kg0.2– 0.4 mg/kg

2–3 min2–5 min15 –20 min10 –15 min10 –15 min

30 min30 – 40 min45 – 60 min45 min45 min

Opioids

Fentanyl Respiratory depression

IV 2 μg/kg 1–2 min 20 –30 min

Morphine Respiratory depression, hypotension, nausea & vomiting

IVIM/SQ

0.1– 0.2 mg/kg0.1– 0.2 mg/kg

1–5 min30 min

3 – 4 hr4 –5 hr

Other sedative agents

Chloral hydrate

Prolonged sedation

PO/PR 50 –75 mg/kg 30 – 60 min

1–8 hr

Ketamine Post-emergence delirium

IVIMPOPRNasal

0.5 –1 mg/kg4 mg/kg5 –10 mg/kg5 –10 mg/kg3 – 6 mg/kg

1 min5 min30 – 40 min5 –10 min5 –10 min

15 min15 –30 min2– 4 hr15 –30 min15 –30 min

Propofol Respiratory depression, hypotension

IVIIV bolus

0.05 – 0.1 mg/kg/min

1 mg/kg

30 sec30 sec

8 –10 min

Reversal agents

Flumazenil Withdrawal symptoms(agitation)

IV 0.2 mg0.01 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

Radiology suite

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.

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.

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.

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.

Treatment: O2, bronchodilators, epinephrine, corticosteroids, and antihistamines.

CT

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

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.

Interventional Radiology

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

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

Elective cardioversion: 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.

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.

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. 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

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 

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.

Anesthetic considerations: Strong vagal nerve stimulation as result of

stimulation to colon. Most patients tolerate these procedures well.

ECT

Major depression.

Mania. Certain forms of

schizophrenia. Parkinson’s

syndrome.

Pheochromocytoma. Increased ICP. Recent CVA. Cardiovascular

conduction defects. High risk pregnancy. Aortic and cerebral

aneurysms.

Indications Contraindications

Physiologic effects of ECT

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.

ECT contd.

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 

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

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 

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