Mod IV: Regional Anesthesia Part 3 Flashcards
Regional Anesthesia
Which blocks are a/w INCIDENTAL BLOCKADE?
IntraScalene
Supraclavicular
Superficial Cervical plexus
Paravertebral
Regional Anesthesia - INCIDENTAL BLOCKADE
Which nerves can be accidentaly blocked as a result of IntraScalene/Supraclavicular/Superficial Cervical block
Phrenic nerve
Recurrent laryngeal n.
Sympathetic cervical ganglion
Regional Anesthesia - INCIDENTAL BLOCKADE
Phrenic nerve block could cause:
Diaphragm paralysis
Which could cause ↓ ventilation
Very common!!!
Regional Anesthesia - INCIDENTAL BLOCKADE
Recurent laryngeal nerve block could cause:
Vocal cord paralysis
Regional Anesthesia - INCIDENTAL BLOCKADE
Sympathetic cervical ganglion block could cause:
Horner’s Syndrome
Rare condition characterized by miosis (constriction of the pupil), ptosis (drooping of the upper eyelid), and anhidrosis (absence of sweating of the face). It is caused by <strong>damage to the sympathetic nerves of the face</strong>
Regional Anesthesia - Complications and Risks
INTRAVASCULAR INJECTION could lead to:
LA TOXICITY
Regional Anesthesia - Complications and Risks
Most nerves run close to vascular structures. This is a blessing and a curse, why?
Facilitates identification of nerve structures, but
increase risk of INTRAVASCULAR INJECTION
=> LA TOXICITY
Regional Anesthesia - Complications and Risks
What is less worisome about intra-arterial injection of LA?
Most arteries flow to the periphery
Allows local some time to be absorbed by tissue
Regional Anesthesia - Complications and Risks
What’s the danger of Vertebral, Carotid injection of LA?
Direct flow to brain
Cause almost immediate seizure, neurological LA toxicity S/S
Even LA volumes of 1-3ml
Regional Anesthesia - Complications and Risks
Consequenque of intravenous injection of LA:
LA Systemic Toxicity (LAST)
Most veins flow directly to heart
Neurological S/S may be delayed or absent
CV instability may be first sign
Regional Anesthesia - Complications and Risks
What could be a reason why there would be No aspiration of blood during US/needling, even after IV puncture?
Compression of vessels may hide IV puncture
Regional Anesthesia
How to prevent Local Anesthetic Systemic Toxicity?
Monitors: ECG, BP, O2Sat
Communication with Pt
Frequent gentle aspiration every 3-5ml
Slow injection of LA
Avoid traumatic needling
Judicious dosing of LA
EPI marker in ↑ Vol blocks
<strong>Be prepared!!!</strong>
Prevention of Local Anesthetic Systemic Toxicity
Which Monitors must be used and for how long after high dose blocks?
ECG, BP, O2Sat
Continuous monitoring for at least 30 min
Prevention of Local Anesthetic Systemic Toxicity
What are some symptoms of Local Anesthetic Systemic Toxicity that may be communicated/reported by the pt?
Metal taste
Ears ringing
Circumoral numbness
Anxiety
Prevention of Local Anesthetic Systemic Toxicity
Aspiration:
Frequent gentle aspiration every 3-5ml
Prevention of Local Anesthetic Systemic Toxicity
To prevent Local Anesthetic Systemic Toxicity, decrease dose for which pts?
Advanced age
Poor cardiac function
Preexisting conduction abnormalities
↓ Plasma proteins
Prevention of Local Anesthetic Systemic Toxicity
What could you use to prevent LAST if you must inject large volume of LA?
Use “EPI marker”
Prevention of Local Anesthetic Systemic Toxicity
When using EPI marker in ↑ Vol blocks, >10% ↑ HR may indicate:
IV injection
Prevention of Local Anesthetic Systemic Toxicity
While readying a plan to use in case of Local Anesthetic Systemic Toxicity, which checklist and flowchart are useful?
ASRA checklist
NYSORA flowchart
Prevention of Local Anesthetic Systemic Toxicity
Why should you have 20% Lipid Emulsion in the area where blocks are performed?
A lipid infusion improves success of resuscitation from cardiac arrest because of local anesthetic toxicity if given immediately after a local anesthetic overdose
Regional Anesthesia - Detection of LAST
Most important step:
Recognition/Diagnosis
Regional Anesthesia - Detection of LAST
Why is frequent communication with the pt important?
Make sure they know what symptoms to report
Regional Anesthesia - Detection of LAST
CNS symptoms:
May be subtle/absent
Metal taste, tinnitus, double vision, dizziness, circumoral numbness
Excitation: agitation, confusion, twitching, seizure
Depression: Drowsy, obtunded, coma, apnea
Regional Anesthesia - Detection of LAST
Benefit and drawback of Benzodiazepine sedation when suspecting LAST
May prevent seizure
Also may prevent Pt from reporting CNS symptoms
Regional Anesthesia - Detection of LAST
Cardiovascular signs:
May be first/only
Excitation followed by depression may be present
↑ BP, ↑HR,
Ventricular ectopy, multiform VT, VF
Progressive ↓BP, bradycardia => asystole
Regional Anesthesia - Detection of LAST
Hallmarks of cardiac toxicity of LA
Ventricular ectopy, multiform VT, VF
Regional Anesthesia - Detection of LAST
Hallmark of severe LA toxicity:
Progressive ↓BP, bradycardia => asystole
Regional Anesthesia - Detection of LAST
How do S/s of LAST progress?
May be slow or very fast
Some S/S may be subtle or absent
Regional Anesthesia - Detection of LAST
ALWAYS BE VIGILENT IN MONITORING DURING AND AFTER RA!!
True
Regional Anesthesia - Treatment of LAST
Why should you Get Help! Fast!
You cannot manage this alone!
Call for Lipid Emulsion
ASRA checklist, NYSORA flowchart
Alert Cardiopulmonary bypass team
Or nearest facility with one
Regional Anesthesia - Treatment of LAST
Airway management interventions:
100% via mask
Secure airway!!!!
ETT/vent
Regional Anesthesia - Treatment of LAST
How could you abolish seizure?
Versed
Propofol
Avoid propofol if CV unstable
Regional Anesthesia - Treatment of LAST
How would you manage cardiac arrhythmias?
CPR/ACLS
EPInephrine/vasopressin (controversial)
Amiodarone (300/150)
Magnesium 1-2 grams
Regional Anesthesia - Treatment of LAST
In the management of cardiac arrhythmias, which drugs should be avoided?
Calcium channel blockers
Beta blockers
Lidocaine
Phenytoin
Vasopressin (controversial)
Regional Anesthesia - Treatment of LAST
20% Lipid Emulsion Therapy - When to start?
Based on clinical severity and rate of progression
Use your professional judgment
Regional Anesthesia - Treatment of LAST
20% Lipid Emulsion Therapy - BOLUS dose:
1.5 ml/kg
(~100ml)
Based on lean body weight
Regional Anesthesia - Treatment of LAST
20% Lipid Emulsion Therapy - INFUSION rate:
0.25 ml/kg/min
(~18ml/min)
Regional Anesthesia - Treatment of LAST
20% Lipid Emulsion Therapy - If persistent CV collapse:
Repeat BOLUS Q 5minutes
Regional Anesthesia - Treatment of LAST
20% Lipid Emulsion Therapy - If hypotension continues:
DOUBLE INFUSION rate 0.5 ml/kg/min
Regional Anesthesia - Treatment of LAST
20% Lipid Emulsion Therapy - after CV stable:
CONTINUE INFUSION
For at least 10 minutes after CV stable
Regional Anesthesia - Treatment of LAST
20% Lipid Emulsion Therapy - Upper limit over first 30 minutes:
10 mg/kg
Diagnosis and Treatment of LA Toxicity
NYSORA LA toxicity flow chart
NYSORA LA toxicity flow chart
Diagnosis and Treatment of LA Toxicity
Checklist for Treatment of Local Anesthetic Systemic Toxicity
Checklist for Treatment of Local Anesthetic Systemic Toxicity
(American Society of Regional Anesthesia and Pain Medicine)
