Grand Rounds Recap 3.8.23

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Ultrasound guided nerve blocks in the ed WITH Dr. Arun Nagdev

  • Best practices for pain management in the ED

    • Active

    • Non-siloed

      • Should be available 24/7

    • Multimodal

      • Blocks, ketamine, NSAIDs, APAP

  • Goal is not 100% resolution with blocks, 50% is success with multi-modal treatment

  • Ketamine assisted blocks: 25mg ketamine in 100cc piggyback infused during block placement 

  • Equipment

    • Blunt tip needles are best, lower risk of trauma to neurovascular structures

    • 25g needle for local skin wheal

    • Inject saline first to dissect the tissue planes

  • Goal: All blocks are fascial plane blocks; do not need to surround the nerve

    • Bathe the nerve by filling the fascial plane

    • Do not inject within the epineurium

  • Complications

    • Peripheral nerve injuries

      • 1-3 per 100,000

      • Mechanical trauma

      • Anesthetic toxicity

      • Microvascular ischemia

      • Instruct patients to call if still numb 24 hours after block

    • Intravascular injection

      • CNS and cardiovascular toxicity

      • Treat with intralipid infusion

  • Anesthetic Selection and duration of action

    • 3% 2-Chloroprocaine (40-60 min)

    • 1.5% mepivacaine (1-3 h)

    • 1% lidocaine +/- epi (2-3h)

    • 0.25% bupivacaine (2-3 h)

    • 0.25-0.5% ropivacaine (4-10 h)

    • Always use calculator to determine maximum safe dose

  • Brachial Plexus Block

    • Interscalene and Supraclavicular

      • Indications:

        • Shoulder dislocation, humeral injury/abscess, elbow injury, forearm injury, distal radius, hand injuries

      • Above elbow = interscalene

      • Below elbow = supraclavicular

    • Anatomy

      • Lateral neck, at the level of the thyroid, between anterior and middle scalene muscles is the brachial plexus

        • C5-C8

        • Goal is to deposit anesthetic under prevertebral fascia

      • Slide distally, above first rib is the brachial plexus sheath where supraclavicular block is performed

      • Goal is to pop under pre-vertebral fascia

    • Setup:

      • Probe parallel to the clavicle to find supraclavicular brachial plexus, slide proximal up the neck to identify scalene muscles

      • Have patient look to contralateral side

      • Place a shoulder roll under shoulder to prevent needle from hitting the bed

    • Complications

      • With large volume of instillation, risk of phrenic nerve paralysis (max 10cc’s)

        • Do not perform with people at risk of respiratory depression (e.g. COPD patients)

      • Use color doppler to evaluate path of needle to make sure there are no vascular structures in the way

  • Superior Trunk Block

    • Regional anesthesia for analgesia of the shoulder

      • C5/C6 roots

      • Lower risk of hemidiaphragmatic paresis

      • Fascial plane is closer to the nerve sheath

      • More challenging block compared to interscalene/supraclavicular

  • Forearm Block

    • Supplies

      • Use short blunt tipped spinal needle

      • Control syringe (do not need a lot of volume, ~5-10ccs)

    • ED Indication

      • Hand wound debridement/laceration repair

      • Hand abscesses

      • Metacarpal fractures

    • Setup

      • Place machine across the bed/table from patient

    • Median Nerve

      • Mid-forearm, midline on volar forearm, surrounded by three fascial planes

    • Radial Nerve

      • Volar mid-forearm, radial to the radial artery, often difficult to visualize before hydrodissection

    • Ulnar nerve

      • Volar mid-forearm, ulnar to the ulnar artery, nerve will run with the artery but separates as you scan more proximally; Target the more proximal portion where the artery dives deeper into the arm and separates from the nerve.

  • Serratus Anterior Plane Block

    • ED Indications:

      • Anterior and lateral rib fractures

      • Stable chest tubes

      • Chest wall burns

      • Zoster

    • Anatomy:

      • Intercostal nerve branches between latissimus dorsi and pectoralis muscle and lies on top of the serratus anterior muscle

    • Setup:

      • Midaxillary line at level of the nipple, place probe in transverse orientation along ribs

      • Can inject anesthetic above the serratus anterior muscle, or deep to the serratus anterior muscle above the rib

      • Rib space does not matter, breathing will diffuse anesthetic along fascial plane

        • Takes ~30-45 minutes to take effect

      • Requires large volume of anesthetic (30ccs, inject slowly in 5cc aliquots every 30 seconds)

  • Distal Sciatic Nerve in the Popliteal Fossa

    • ED Indications

      • Ankle fractures

      • Achilles tear

      • Abscess drainage

      • Burns and amputations

      • Lower extremity wounds/lacerations

    • Anatomy:

      • Lower extremity except saphenous nerve

      • Posterior lower leg and foot except medial lower leg (saphenous)

    • Setup:

      • Place patient prone

      • Posterior midline leg proximal to popliteal fossa

        • Aim for the split of the distal sciatic into the common peroneal nerve and tibial nerve

      • 10-20 cc's of anesthetic

      • If unable to lie prone, can elevate leg and place probe underneath leg

    • Do not block mid shaft tibial fractures due to risk of compartment syndrome

    • Novel approach: Crosswise approach to Popliteal Sciatic (CAPS)

      • Patient can lay supine, use curvilinear probe on the lateral leg, and needle inserts in the lateral leg

  • Transgluteal Sciatic Nerve Block (TGSNB)

    • ED indication

      • Sciatica

    • Anatomy

      • Nerve lies in the fascial plane below gluteus maximus

      • Find sciatic nerve in between ischial tuberosity (medial) and greater trochanter (lateral)

      • Place anesthetic in the fascial plane underneath the gluteus maximus

    • Setup:

      • Curvilinear probe

      • Needle comes from lateral to medial approach (inserts over greater trochanter)

      • 10cc anesthetic

      • Steeper needle angle

        • Steeper angle may portend more difficult needle visualization

    • 10% will get foot drop and foot numbness- expect this if performing this block

      • If it persists for >24 hours, return to ED

CPC: CO Toxicity WITH Drs. Harward and Roche

Carbon Monoxide Toxicity

  • Incidence

    • 50,000 cases per year

  • Pathophysiology

    • Decreased O2 delivery by Hgb

      • 250x greater affinity than O2

      • Stabilizes the high affinity conformation

    • Binds cytochrome C oxidase, inhibiting ATP production within the electron transport chain

    • Platelets and inflammation

      • Displaces NO from platelets

      • Triggers neutrophil degranulation

      • Neurologic and cardiac injury

    • Neurotoxicity

      • Reactive oxygen species

      • Hypoxia

      • Acidosis

  • Presentation

    • Neurologic: Dizziness, headache, confusion → somnolence, seizures

    • Cardiopulmonary: Dyspnea, cough, chest pain → syncope, MI, arrhythmias

  • Diagnosis:

    • CO Measurement

      • CO Hgb > 2% in nonsmokers, > 10% in smokers

      • Clinical severity does not correlate with level

      • Standard pulse oximetry is not helpful

      • CO-oximetry is specific but not sensitive

      • Hydroxycobalamin interferes with COHgb measurement

    • EKG to evaluate for ischemia

    • Lactate

    • Cardiac biomarkers

  • Treatment

    • Increased FiO2

      • Increased PEEP = CPAP, BiPAP

        • ETT if cannot participate

      • Hyperbaric oxygen therapy (HBOT)

        • Indications for HBOT = 13-15% for pregnant patients, 20-25% for nonpregnant patients

Pediatric simulation: Seizure WITH CCHMC PEM Faculty and fellows

 Pediatric seizure

  • Benzodiazepine dosing:

    • Ativan: 0.1 mg/kg IV

    • Versed: 0.2 mg/kg IM, 0.2 mg/kg IN (may repeat to max of 0.4 mg/kg IN), 0.2 to 0.5 mg/kg buccal 

  • Febrile Seizure

    • 6 mo to 6 years

    • Simple:

      • Generalized tonic clonic seizure

      • < 15 minutes

      • 1 per 24 hours

    • Complex:

      • > 15 minutes

      • More than 1 in 24 hours

      • Partial/focal seizure

    • Status

      • Seizure greater than 30 minutes

      • No return to baseline between seizures

    • If age < 2, likelihood of repeat febrile seizure is 30%, if greater than 2, likelihood is 50%

    • If child is < 6 mo, workup alternative causes:

      • NAT (consider CTH)

      • CNS infection (consider LP)

  • Infantile Spasms

    • Patients under 6 months will not have generalized tonic clonic seizures due to the absence of myelin

      • Usually 3-7 months, 90% present under 1 year

    • Portends very poor future neurologic outcome

    • Make sure to ask about prenatal history, birth history

      • Make sure to ask about regression of milestones

    • Ddx:

      • Benign myoclonus = 3-8 months of life

        • Benign sleep myoclonus = occurs during onset of sleep

    • Clinical Presentation

      • Usually involve neck, trunk and extremities

      • Last seconds at a time (initial contraction ~2 seconds followed by a tonic phase of 8-10s)

      • May look like crunches

    • Disposition

      • If infantile spasms is suspected, should be admitted to pediatric hospital for spell capture

        • Hypsarrhythmia on EEG

        • MRI

    • Treatment

      • ACTH

      • Vigabatrin

        • Blindness is a known side effect

  • Hyponatremic Seizures

    • Acute symptomatic hyponatremia (altered mental status, seizures) should be treated with 3% hypertonic saline 1 cc/kg

      • May repeat if seizures continue