Peripheral Nerve Block Techniques Flashcards
What type of hormones are increased during a stress response?
Catabolic (cortisol and catechols)
What types of hormones are decreased during a stress response?
Anabolic (human growth hormone and testosterone)
How is glucose increased during a surgical stress response?
Increase in conversion of amino acids to glucose through liver gluconeogenesis
What form of anesthesia can blunt the surgical stress responses and increased metabolic demand?
Regional anesthesia
Define regional anesthesia.
Loss of sensation in a region of the body produced by application of an anesthetic agent to all the nerves supplying that region
What is a significant difference between regional anesthesia and general anesthesia?
There is no loss of consciousness with regional anesthesia
What is conduction anesthesia?
Anesthesia of an area supplied by a specific nerve, produced by an anesthetic agent applied to the nerve
What are absolute contraindications for regional anesthesia?
Patient refusal
Infection at injection site
Coagulopathy
What are relative contraindication for regional anesthesia?
Hypovolemia
Systemic sepsis
Preexisting neurological conditions
If the patient has received regional anesthesia what does that indicate regarding the characteristics of the block?
Implies loss of all sensations –> autonomic, motor, and sensory
If the patient has received regional analgesia what does that indicate regarding the characteristics of the block
Loss of pain sensations –> only sensory and autonomic
What are the goals of local anesthetic?
Rapid Onset
Appropriate duration
Lowest toxicity
Adequate analgesia/anesthesia
What type of tool can aid the provider in using less LA?
Ultrasound
What type of regional anesthesia is the exception to volume equalling success?
Spinal, use a very small amount compared to other blocks
What are the three components that must be balanced when administering regional anesthesia?
Volume
Concentration
Toxicity
If a local anesthetic has a faster onset, what can be assumed about the duration?
Shorter duration
What order do nerve fibers become blocked?
B C & A-delta A-gamma A-beta A-Alpha
What is the function of A-Alpha nerve fibers?
Motor and proprioception
What is the function of A-beta nerve fibers?
Motor, proprioception, touch and pressure
What is the function of A-gamma nerve fibers?
Muscle tone
What is the function of A-delta nerve fibers?
Pain, touch and cold
What is the function of B nerve fibers?
Preganglionic sympathetic
What is the function of C nerve fibers?
Pain, touch, warm and cold
What drugs should be readily available prior to performing regional anesthesia?
Supplemental O2
Narcotics/sedatives
Resuscitation drugs –> LAST