Anesthesia/Analgesia


Auricular Nerve Block

Rapid Review

  • Background
    • Injection of local anesthetic around the sensory nerves of the ear (greater auricular nerve, lesser occipital nervous, auricular branch of vagus nerve, and auriculotemporal nerve) for anesthesia of the entire ear
  • Indications
    • Ear laceration repair, I&D of abscess or auricular hematoma
  • Contraindications
    • Overlying infection, allergy to local anesthetic, coagulopathy
  • Complications
    • Inadequate anesthesia, infection, vascular injury

Pearls

  • Be sure to avoid puncturing the superficial temporal artery (located medial to the ear). This may cause a facial hematoma. 
  • Ultrasound can be a helpful adjunct to identify the location of the key nerves.
Video Credit: EMRAP


Digital Nerve Block

Rapid Review

  • Background
    • Injection of local anesthetic into the base of the finger or toe to accomplish regional anesthesia. 
  • Indications
    • Laceration repair, nail trephination, dislocation/fracture reduction, paronychia/felon.
  • Contraindications
    • Distortion of landmarks, overlying skin infection
  • Complications
    • Unintentional intravascular injection, bleeding, infection

Pearls

  • A simple, less painful alternative to the traditional ring block is the transthecal technique involving a single subcutaneous injection at the volar base of the digit. 
  • Although dogma suggests that we should never use epinephrine on “fingers, nose, ears, and toes”, the use of lidocaine w/ epinephrine has been shown in several studies to be safe in digital nerve blocks.
Video Credit: Core EM


Femoral Nerve Block

Rapid Review

  • Background
    • Injection of local anesthetic around the femoral nerve for anesthesia of the anterior thigh, knee, medial lower extremity below the knee
  • Indications
    • Femur fracture, femoral neck fracture, patella fracture 
  • Contraindications
    • Overlying infection, allergy to anesthetic
  • Complications
    • Nerve injury, infection, hematoma, allergic reaction

Pearls

  • A “3-in-1-block” is an alternative to traditional femoral block that targets the femoral nerve, lateral femoral cutaneous nerve, and obturator nerve. This allows for better anesthesia of the knee and hip. 
  • As you advance the needle, you may feel a “pop” sensation it punctures through the fascia iliaca.
Video Credit: NYSORA


Hematoma Block

Rapid Review

  • Background
    • Injection of local anesthetic into the hematoma surrounding a fracture site when reduction or manipulation is required. 
    • Used as an alternative to procedural sedation.
  • Indications
    • Reduction or manipulation of fracture site. 
    • Commonly used in wrist and ankle fractures
  • Contraindications
    • Complex or open fractures
  • Complications
    •  Inadequate analgesia, vascular injury, infection

Pearls

  • Confirm correct placement of the needle by pulling back on the plunger as you advance until blood is aspirated from the hematoma
  • Allow 10-15 minutes for the analgesia to take effect prior to attempting reduction.
Video Credit: Larry Mellick


Local Anesthesia (General)

Rapid Review

  • Background
    • Direct injection of local anesthetics (lidocaine, bupivacaine, etc.) into the tissues to block transmission of impulses in nerve fibers and provide a temporary loss of sensation, generally for the purposes of reducing pain for further surgical intervention.
  • Indications
    • For anesthesia prior to wound closure, incision/drainage, or other painful procedures. 
  • Contraindications
    • Allergies to anesthetic agent
  • Complications
    • Unintentional intravenous injection, pain/discomfort, infection

Pearls

  • Although subdermal injections look more painful, it is actually less painful than intradermal injections.
  • You can decrease the pain of the injection by using a smaller gauge neede (insulin needle), warming the anesthetic to body temperature, and/or buffering the agent with sodium bicarbonate in a 1:10 ratio.
Video Credit: MiniMedLessons


Median Nerve Block

Rapid Review

  • Background
    • Injection of local anesthetic around the median nerve to anesthetize the volar surface of the thenar half of the hand and the dorsal surfaces of corresponding fingertips, excluding the thumb
  • Indications
    • Ring removal
    • Laceration repair within region of the median nerve
  • Contraindications
    • Overlying infection, allergy to anesthetic agent, coagulopathy.
  • Complications
    • Anesthetic toxicity, infection, nerve injury, hematoma

Pearls

  • Injecting the anesthetic too deep is a common cause of failure with this nerve block. Avoiding inserting the needle more than 1 cm deep to the palmaris longus tendon. 
  • Ultrasound guidance with a linear probe on the volar aspect of the mid-forearm can help identify the median nerve and improve success rates.
Video Credit: RAUKvideos


Occipital Nerve Block

Rapid Review

  • Background
    • Injection of local anesthetic along the greater and lesser occipital nerves. 
  • Indications
    • Migraine (refractory to conservative treatment), cluster headache, occipital neuralgia, cervicogenic headache
  • Contraindications
    • Overlying skin infection at injection site
  • Complications
    • Rare, but include bleeding, infection, and damage to surrounding structures

Pearls

  • A “fanning technique” should be used to inject the anesthetic medial, lateral, and immediately adjacent to the greater occipital nerve.
  • If a migraine is felt bilaterally, you may perform this procedure on the other side as well.
Video Credit: CHA Communications


Radial Nerve Block

Rapid Review

  • Background
    • Injection of local anesthetic around the radial nerve to anesthetize the dorsum of the thenar half of the hand.
    • Can block at the humerus, elbow, or wrist level
  • Indications
    • Ring removal
    • Laceration of the dorsum of the radial (lateral half of the hand). Excluding fingertips
  • Contraindications
    • Overlying soft tissue infection, allergy to anesthetic agent
  • Complications
    • Infection, nerve injury, anesthetic toxicity

Pearls

  • Compared to other nerves in the hand and wrist, the radial nerve has a less predictable distribution. Use generous amounts of local anesthesia. 
  • To anesthetize the entire dorsum of the hand, you may need to perform a ulnar and median nerve block.
Video Credit: NYSORA


Serratus Anterior Nerve Block

Rapid Review

  • Background
    • Injection of local anesthetic around the thoracic intercostal nerves to provide regional anesthesia to the anterolateral chest wall
  • Indications
    • Rib fractures, rib contusions, thoracotomy
  • Contraindications
    • Overlying soft tissue infection, allergy to local anesthetic
  • Complications
    • Pneumothorax, infection, vascular injury

Pearls

  • The lateral decubitus position is the ideal position for this technique, unless injuries require the patient to stay supine.
  • Identify the thoracodorsal artery with color doppler (between te LD and SA muscles) prior toperforming the block.
Video Credit: Temple EM


Sphenopalatine Ganglion Block

Rapid Review

  • Background
    • Application of local anesthetic to the sphenopalatine ganglion located behind the nose. 
  • Indications
    • Acute cluster headaches, migraine, trigeminal neuralgia, herpes zoster neuralgia
  • Contraindications
    • Allergy to anesthetic, infection within intranasal canal, altered patient.
  • Complications
    • Bleeding, infection, epistaxis

Pearls

  • Although technically 3 different ways to perform (transnasal, transoral, and lateral infratemporal), the transnasal approach is safe and the most practical choice. 
  • To improve comfort, you can anesthetize the nares by injecting 1% lidocaine (via atomizer) into each nare.
Video Credit: ALiEM


Trigger Point Injection

Rapid Review

  • Background
    • Injection of local anesthetic into area of focal, hyper-irritated muscle spasm for pain relief.
  • Indications
    • Focal, reproducible pain with movement/palpation in a defined, accessible location.
  • Contraindications
    • Allergy to anesthetic, overlying skin infection, coagulopathy/bleeding disorder
  • Complications
    • Bleeding, infection, pain

Pearls

  • Avoid causing a pneumothorax when treating trigger points on the thoracic region. Pinch the affected tissue and pull it away from the intercostal spaces prior to injection. 
  • Injecting sterile saline or simple dry needling may be just as effective as injecting local anesthetic
Video Credit: Larry Mellick

Brandon Simpson, PA-C
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  • Blog - 25 Feb 2021