Upper Peripheral Nerve Blocks - Quiz 6 Flashcards
What considerations should be taken for Placing a Peripheral Nerve Block?
Tourniquet Placement
Bone Grafting
Duration of Surgery
Single Injection vs Continous Peripheral Nerve Block
What are the Risks and Contraindications of Placing a Peripheral Block?
- Patient Cooperation
- Bleeding Disorders
- Sites of Infection
- Nerve Injury
- Local Anesthetic Toxicity
- Catheter Retention
- Retroperitoneal Hematoma
- Falls from Femoral Nerve Catheter
What should you think about when choosing a Local Anesthetic for a Peripheral Block?
Desired Onset
Desired Duration
Desired Sensory/Motor Block
Procaine
Max Dose w/wo Epi?
Duration of Action w/wo Epi?
Without Epi
Max: 5mg/kg
Duration: 20-30 min
With Epi
Max: 7mg/kg
Duration: 30 min
Chloroprocaine
Max Dose w/wo Epi?
Duration of Action w/wo Epi?
Without Epi
Max: 11mg/kg
Duration: 15-30 min
With Epi
Max: 14mg/kg
Duration: 30 min
Lidocaine
Max Dose w/wo Epi?
Duration of Action w/wo Epi?
Without Epi
Max: 4mg/kg
Duration: 30-120 min
With Epi
Max: 7mg/kg
Duration: 3 hrs
Mepivacaine
Max Dose w/wo Epi?
Duration of Action w/wo Epi?
Without Epi
Max: 4mg/kg
Duration: 90-180 min
With Epi
Max: 7mg/kg
Duration: 20-30% Longer
Avoid in Pregnancy
Prilocaine
Max Dose w/wo Epi?
Duration of Action w/wo Epi?
Without Epi
Max: 7mg/kg
Duration: 30-90 min
With Epi
Max: 8mg/kg
Duration: 2 hrs
Bupivacaine
Max Dose w/wo Epi?
Duration of Action w/wo Epi?
Without Epi
Max: 2mg/kg
Duration: 2-4 hrs
With Epi
Max: 3mg/kg
Duration: 3-4 hrs
Avoid in Pregnancy til term
Ropivacaine
Max Dose w/wo Epi?
Duration of Action w/wo Epi?
Without Epi
Max: 5mg/kg
Duration: 2-6 hrs
What are the different Block Techniques?
Field Block
Paresthesia
Nerve Stimulation
Ultrasound
What is the Field Block Technique?
Local Anesthetic targets terminal cutaneous nerve to minimize incisional pain
Dont use if its going to be in the way or if there is tissue acidosis
What is the Paresthesia Technique?
Used to be the Main Technique
Needle is placed near target nerve until there is paresthesia, then inject the LA
Gotta know anatomy
What is the Nerve Stimulation Technique?
Wire attached to Insulated needle is placed near nerve and causes muscle contractions at less than 0.5 mA
Inject 30-40 mL of LA w/ gentle aspiration and divided doses
(< 0.2 mA = Intraneural)
What is the Ultrasound Technique for Peripheral Block Placement?
Used Alone or w/ other Techniques
Piezoelectric crystals emit high-frequency sound waves thru different tissues and return a signal to transducer at 1-20 MHz
How does the amplitude of the return signal of an Ultrasound create the picture?
The crystals deform to make and electronic 2D image
What is Echogenicity?
How efficient sound passes thru a substance
What is Hypoechoic?
Sound easily Passes
Appear Dark or Black
How do Hyperechoic structures appear on the Ultrasound?
Bright & White
What is Anechoic?
No Ultrasound Reflection
What is the Linear Ultrasound Probe used for?
High Frequency High-Res w/ less tissue penetration
Superficial Nerves
First Choice
What is the Curvilinear Ultrasound Probe used for?
Low Frequency w/ more tissue penetration
Low-Res & Poor Image
Good for Deeper Structures
What do Nerves look like on the Ultrasound?
Honeycomb
Best seen in Cross Section
What is In-Plane Needle Alignment when using Ultrasound?
Needle is placed along the long side of the transducer so you can see the entire shaft & tip
Need great hand-eye
Easy to lose image
What is the Out-of-Plane Needle Alignment when using Ultrasound?
Needle is placed perpindicular to the transducer
Need to move transducer as needle advances
Easier Approach
What are Single Injection Nerve Blocks?
Local Anestehtic is given one time
What is involved in placing a Continous Peripheral Nerve Block?
Percutaneous catheter next to peripheral nerve, then give Local Anesthetic to prolong effects
What are the types of Brachial Plexus Blocks?
Interscalene
Supraclavicular
Infraclavicular
Axillary
What are the types of Terminal Nerve Blocks?
Median Nerve
Ulnar Nerve
Radial Nerve
Musculocutaneous Nerve
Digital Nerve
Intercostobrachial Nerve
What is a type of Intravenous Regional Anesthesia?
Bier Block
What are characteristics of an Interscalene Block?
Used for Shoulder/Upper Arm Procedures
Mostly blocks C5-C7 roots (possibly C3-C4 branches)
C8-T1 Ulnar Nerves Spared
Dont use for Elbow or lower surgeries
What are Contraindications for a Interscalene & Supraclavicular Blocks?
Local Infection
Severe Coagulopathy
Local Anesthetic Allergy
Patient Refuse
Why should extra caution be taken when placing an Interscalene Block for pts w/ Pulmonary Disease?
Interscalene blocks will block the ipsilateral Phrenic Nerve
What are the possible complications of Interscalene Blocks?
Horner’s Syndrome
Recurrent Laryngeal Nerve Palsy - Hoarseness & Resp Distress
Seizure d/t Vertebral Artery Injection
Spinal/Epidural Injection
Pneumothorax
What is Horner’s Syndrome?
Complication of Interscalene Block
Local Anesthetic travels to Cervicothoracic Ganglion causing myosis, ptosis, and anhydrosis
What are the characteristics of a Supraclavicular Block?
Used for Elbow or lower surgeries
Unreliable for Axillary & Suprascapular Nerves
High risk for PTX using Paresthesia & Nerve Stimulator Techniques
What are the possible complications of Supraclavicular Blocks?
Ipsilateral Phrenic Nerve Palsy
Horner’s Syndrome
Recurrent Laryngeal Nerve Palsy
Pneumothorax
Subclavian Artery Puncture
What are characteristics of an Infraclavicular Block?
Blocks @ Level of Cords
Used for Elbow or Lower Procedures
Spares Intercostobrachial Nerve (T2)
What is effected by an Axillary Block?
Multiple injections of LA at the lateral border of Pectoralis Minor blocks entire arm below the elbow
What are the Contraindications to an Axillary Block?
Local Infection
Neuropathy
Bleeding Risk
When are Terminal Nerve Blocks used?
Minor procedures w/ Limited Field
Supplement Incomplete Brachial Plexus Block
Can be anywhere along nerve, but Elbow & Wrist Preferred
When is a Bier Block used?
Short Procedures - 45-60 min, Carpal Tunnel Release
How long must the turniquet be inflated when placing a Bier’s Block?
15-20min to avoid Rapid IV Sytemic Bolus of LA
then slowly, incrementally deflate
What are the Lower Extremity Peripheral Nerve Blocks?
Femoral Nerve
Lateral Femoral Cutaneous Nerve
Obturator Nerve
Posterior Lumbar Plexus
Saphenous Nerve
Sciatic Nerve
Ankle
What are the types of Peripheral Nerve Blocks of the Trunk?
Superficial Cervical Plexus
Intercostal
Paravertebral
Transverse Abdominis Plane
After which type of Blocks does a rapid absorption of LA occur leading to toxicity?
Intercostal Block
Caudal-Lumbar Epidural
Brachial Plexus Block
Sciatic-Femoral Block
Subcutaneous Block
