Nerve Injury Prevention and Anesthesia Techniques

Nerve Injury Prevention During Procedures

• Chlorhexidine gluconate (CHG) reduces nerve injury by creating a strong bacterial barrier.

Postdural Puncture Headache Treatment

• Epidural blood patch is the gold standard treatment.

Local Anesthetics and Procedures

• Lidocaine is frequently used with transcutaneous electrical nerve stimulation (TENS) and continuous electrical stimulation (CES) when injected intrathecally.

Qualities of Needles and PDPH

• Cutting needles and larger sizes can cause postdural puncture headache (PDPH).

Nerve Innervation of the Diaphragm

• The phrenic nerve, formed by C3-C5 nerves, innervates the diaphragm.

Respiratory Muscles and Epidural Anesthesia

• High thoracic epidurals can impair the external intercostal, internal intercostal, and abdominal muscles.

Proper Positioning of Neuraxial Anesthesia

• Proper positioning signs are not detailed in this document.

Meningeal Layers

• The meninges are the dura mater, arachnoid mater, and pia mater. The pia mater adheres directly to the spinal cord. The arachnoid mater is important for limiting diffusion of drugs.

Autonomic Blockade and Neuraxial Anesthesia

• Neuraxial anesthesia blocks transmission of B fibers which are part of the autonomic nervous system.

Causes of Nausea and Vomiting Post-Anesthesia

• Nausea and vomiting after neuraxial anesthesia can be caused by anxiety, opioid stimulation of the chemoreceptor trigger zone(CTZ), and/or hypotension.

Factors Increasing Epidural Spread

• Pregnancy and older age increase the spread of epidural anesthesia.

Medications and Delayed Respiratory Depression

• Morphine can cause delayed respiratory depression when administered neuraxially.

Local Anesthetic Spread Factors

• A primary factor determining the spread of local anesthetics in spinal anesthesia is the baricity of the anesthetic and patient position.

Absolute Contraindications to Neuraxial Anesthesia

• Patient refusal and infection at the injection site are absolute contraindications to neuraxial anesthetic procedures. Increased intracranial pressure is also an absolute contraindication.

Relative Contraindications to Neuraxial Anesthesia

• Spine surgery is a relative contraindication to neuraxial procedures.

First-Line Medication for Patient Code

• Epinephrine is the first-line medication for treating a code after a local anesthetic.

Local Anesthetic Ionization

• Basic local anesthetics are more ionized in acidic environments.

Types of Channels Affected by Local Anesthetics

• Local anesthetics affect sodium, potassium, calcium, and GPCR channels.

Appearance of Nerve Bundles on Ultrasound

• Nerve bundles appear hyperechoic in ultrasound scans.

Risk Factors for Regional Anesthesia Injuries

• Diabetes, hypertension, and obesity are risk factors for nerve injuries associated with regional anesthesia.

Lateral Rectus Muscle Innervation

• The abducens nerve (CN VI) innervates the lateral rectus muscle.

Superior Oblique Muscle Innervation

• The trochlear nerve (CN IV) innervates the superior oblique muscle.

Oculocardiac Reflex

• The oculocardiac reflex involves the vagus nerve (CN X) and the ophthalmic branch of the trigeminal nerve (CN V1).

Eye Protection for Lasers

• Argon lasers require orange eye protection, Nd:YAG lasers need green, and CO2 lasers require clear eye protection.

OR Fire Precautions

• Never let preps dry for less than 3min. Use non-flammable materials in the OR.

High-Risk OR Fire Precautions

• Stop supplemental oxygen at least 1 minute before and during electrocautery.

Postponing Tonsillectomy/Bilateral Myringotomy

• Active chest symptoms (fever, rhonchi) are criteria for postponing the surgery.