What must you make sure to turn off before leaving a room?
The O2 source. No pipeline available, only large cylinders. Limited O2 supply.
Equipment needed for satellite
- O2 source with backup
- Suction
- Scavenging
- Monitoring equipment
- Ambu bag with PEEP
- Enough electrical outlets
- Adequate lighting, with battery power back-up
- Emergency cart with defibrillator, drugs, and other emergency stuff
- Reliable communication for help
- Compliance with all safety and building codes
ASA requires monitoring of
Oxygenation (O2 sat)
Ventilation (EtCO2)
Circulation (EKG and BP)
Temperature
Considerations for radiology suites
- Patients often immobile for long periods of time
- Bulky equipment may get in the way of easily accessing the patient
- Lack of scavenging can limit GA options if you end up needing them
- You need lead aprons with thyroid shields
- Dosimeters should be worn
Adverse reactions to contrast media require these interventions
- O2
- Bronchodilators (B2 agonists)
- Antihistamines
- Corticosteroids (blocking the immune response, and supporting the SNS)
If patient is at risk, you may want to consider giving prophylactic corticosteroids and H1 & H2 antagonists
Contrast reactions are more likely in patients with
- Bronchospasm history
- History of other allergies
- Renal or cardiac disease
- Extremes of age
What should you be aware of if your patient says they were itchy the last time they received contrast medium?
They may have a similar reaction, or it could be worse the next time they receive it
Why is contrast medium nephrotoxic?
Free oxygen radicals are release that damage renal tubules and the microvascular circulation. It can also cause microvascular obstruction.
Contrast media is hypertonic, so if your patient is dehydrated, it could be extremely concentrated within the nephron and cause damage. NPO deficits should be replaced prior to receiving contrast. Hydration is also key to its clearance.
If a patient has a bad response to contrast media, azotemia starts at __-__ hours, and peaks at ___-___ days. It’s important to avoid surgical procedures during this period.
24-48 hours
3-5 days
How can the effects of contrast be minimized?
- Hydration is the first line of protection
- -> Give 1mL/kg of NS 4 hours before the procedure, and continue for 12 hours after the procedure.
- Careful administration and limitation of total dose
- Monitor serum Cr levels for 72 hours
This PO drug can be given to blunt the renal effects of contrast for the with CRI (name and dose)
N-Acetylcysteine
600mg BID
Minimimal Sedation
Moderate Sedation/Analgesia
Deep Sedation/Analgesia
General Anesthesia
Minimal Sedation
- Anxiolysis
- Pt responds normally to verbal commands
- Normal cardiac and pulmonary function
Moderate Sedation
- Responds to commands alone or with light tactile stimulation
- Normal cardiac and pulmonary function
Deep Sedation
- Not easily aroused, but responds purposefully to repeated or painful stimuli
- Normal cardiac function, but ventilation may be impaired, and may need help maintaining an airway (oral/nasal airway)
General Anesthesia
- Loss of consciousness
- Not aroused by painful stimuli
- Often needs help ventilating and maintaining an airway
- Cardiovascular function may be impaired
During MAC, is coughing good or bad?
Good, because it means the patient is able to manage and protect their own airway. It’s only bad when they start having stridor.
In MRI, the strong magnetic field exerts a strength of ___ Tesla, or ___ Gauss
1.5 Tesla
15,000 Gauss
(The earth’s magnetic field is only about 0.5 Gauss)
MRI and EKG leads
Either use ones that are MRI compatible, or frequently switch the positions of normal ones during the scan. Failure to do so could cause burns.
Where does anesthesia induction occur when providing anesthesia for MRI
In an adjacent area. Can’t be within the room, because airway equipment such as laryngoscopes can’t be used within the MRI’s magnetic field. Patient is then transported on MRI safe stretcher, and connected to the anesthesia machine. Patient is emerged in the same area where the induction took place (where emergency equipment is available)
Contraindications to MRI scans
- Pacemakers
- Aneurysm clips
- Intravascular wires
- First trimester of pregnancy (although little data exists to support this)
- Metal implants (need to be monitored for increase in temperature)
Procedures that occur in interventional neuro-radiology
Endovascular approach to CNS lesions or related circulatory structures
- Embolization of AVMs
- Aneurysm coilings
- Angioplasty of atherosclerotic lesions
- Thrombolysis of acute embolic strokes
- Carotid stent placement
Anesthetic considerations for neuro-radiologiy
- May need deliberate hypotension or tight BP control (obtain an a-line)
- Also have all ASA monitors
- Foley catheter
- 2 IVs
Meds used for deliberate hypotension
Esmolol, labetolol, SNP
Meds for deliberate HTN
Phenylephrine to increase BP by 30-40%
What is important on emergence for neuro-radiology?
Antiemetics***
We don’t want coughing, bucking, or retching following the procedure that could lead to device migration or intracranial hemorrhage
Risks involved in interventional cardiology
Hemorrhage of coronaries, infection, ischemia of coronaries or distal limb to access point, thromboembolic events, contrast reactions.
Bottom line is, there area lot of risks, so make sure you are prepared to handle an emergency situation.
These are provocative agents used to induce coronary spasm
Ergonovine maleate
or
Methylergonovine maleate
