Pharm: Conscious Sedation

What is anesthesia used for?
to produce a controlled loss of sensation during a diagnostic or surgical procedure

What are the three types of anesthesia?
1. General Anesthesia
2. Local Anesthesia
3. Regional Anesthesia

General Anesthesia
loss of sensation throughout whole body

Local Anesthesia
-loss of sensation to limited body area, no LOC changes (body awake)

Regional Anesthesia
-similar to local
-encompasses larger body area, such as entire limb

Monitored anesthesia care (MAC)
-responsive, respirations without assistance
-MAC is the newer way that has gained popularity

Minimal sedation (anxiolysis)
patient responds to verbal commands

Moderate (conscious) sedation
-patient responds to verbal or light tactile prompting
-say name, might not respond but gently tap on shoulder and prompt them they will respond

Deep sedation/ analgesia
patient aroused by repeated or painful stimulation (aggressive stimulus)
-airway, ventilation interventions
-cardiovascular functions usually adequate

What are the purposes of general anesthesia?
-hypnosis (mental state where open to suggestion but at the end they will not remember the event)
-loss of reflexes (inhaled anesthetics after patient loses consciousness)

Principles of General Anesthesia:
inducing someone into anesthetic stage is the first step and then maintaining with multiple drugs that stage is the second stage

Neuromuscular blockers
prevents movement

Short-acting benzodiazepines
amnesia effect and reduce anxiety

for pain

General Anesthetics
helps patient stay under during procedure

Order of Anesthesia
1. IV medications
2. General Anesthetic( benzodiazepines and opioids then anesthetics)
3. inhaled anesthetics (help to maintain)

Fentanyl (Sublimaze) CLASSIFICATIONS:
IV anesthetics: opioid drug
-Therapeutic: analgesic, anesthetic,
-Pharmacologic: opioid agonist

-short duration anesthesia
-neurolept anesthesia
-severe chronic pain (transdermal)

Fentanyl (Sublimaze) MECHANISM OF ACTION:
-opioid agonist against mu and kappa receptors
-more rapid onset of action than morphine

Fentanyl (Sublimaze) ADVERSE EFFECTS:
-respiratory depression
-skeletal muscle rigidity

-head trauma
-respiratory impairment
-hepatic/renal impairment

Fentanyl (Sublimaze) DRUG INTERACTIONS:
-additive CNS depression
-interacts with drugs that induce/inhibit CYP450 enzyme
-cardiovascular depression (nitrous oxide)

-Monitor for respiratory depression
-Monitor ECG for cardiac dysrhythmias
-Monitor for adverse effects
-Monitor for dystonia
-Assess for therapeutic effect

-used in anesthesia to produce relaxation, sedation, and amnesia
-Commonly used in MAC
-primarily to treat symptoms of anxiety

-most commonly used for surgical procedures;
-prototype drug

midazolam (Versed) CLASSIFICATIONS:
-Therapeutic: Antianxiety agent, anesthetic
-Pharmacologic: Benzodiazepine, GABA receptor agonist (GABA in brain has calming effect on human brain)

-Reduces anxiety and stress during surgery
-Status epilepticus
-Mechanically ventilated patients-to sedate patients so they can tolerate discomfort of ventilator

midazolam (Versed) MECHANISM OF ACTION:
-Produces CNS depression and skeletal muscle relaxation
-Acts at limbic, thalamic, hypothalamic regions of brain

midazolam (Versed) ADVERSE EFFECTS:
-Slurred speech

midazolam (Versed) SERIOUS EFFECTS:
-Respiratory depression
-CV collapse

-Depressed vital signs

midazolam (Versed) DRUG INTERATCIONS:
-Additive CNS depression
-Increased serum phenytoin levels/additive CNS depression
-Interactions with drugs that inhibit or induce CYP3A4 enzyme
-Increased action with melatonins
-pregnancy category D

midazolam (Versed) Treatment of Overdose:
-General supportive measures
-Flumenazil (romazicon)
(May induce seizures with rapid reversal)

-assess vital signs q. 3 to 5 minutes before, during, after administration
-Monitor for respiratory depression
-Ensure patent airway
-Side-lying position to prevent aspiration
-Monitor for adverse effects
-Assess for history of smoking (may require higher dose)

Diazepam (Valium)
-similar to midazolam (Versed)
-Induction of amnesia or reduction of anxiety prior to short surgery, procedure
Impairs memory
-slower onset, longer duration

propofol (Diprivan)
-prototype drug
-widely used intravenous drugs for inducing and maintaining anesthesia during MAC

propofol (Diprivan) CLASSIFICATIONS:
Therapeutic: General anesthetic
Pharmacologic: N-methyl-D-aspartate (NMDA) receptor agonist

-IV sedative‚Äíhypnotic agent
-Induction and maintenance of general anesthesia
-Antiemetic effect (Anti nausea)

propofol (Diprivan) MECHANISM OF ACTION:
-Exact mechanism is not clear.
-Believed to activate GABA receptors, causing general inhibition of CNS activity

propofol (Diprivan) ADVERSE EFFECTS:
-Injection site pain
SERIOUS adverse effects:
–Respiratory depression
–Metabolic abnormalities
–Organ system failure (PIF)

-Hypersensitivity to soybean and egg products
-Obstetric patients
-Intracranial pressure
-Cardiac or respiratory impairment

propofol (Diprivan) DRUG INTERACTIONS:
-Dose reduced in patients receiving preanesthetic medications such as opioids
-Use with CNS depressants can cause additive CNS and respiratory depression.
-pregnancy category B

Ketamine (Ketalar)
-similar to propofol (Diprivan
-produces dissociative anesthesia-give weird out of body experiences
-extreme effects in adults (Don’t tolerate well)
-children don’t have extreme behaviors
-good agent for children

Example Procedures Using Conscious Sedation
-Foreign-body removal – ie child’s ear
-Orthopedic procedures-“Reducing” fracture with dislocation

Procedural Considerations
The following minimum equipment/personnel must be present, in working order and ready for use:
In the room:
– Oxygen supplementation rate for at least 60 minutes
– Suction to remove sections from oral cavity
-Emergency airway equipment (bag and mask)
– Noninvasive blood pressure monitor or manual blood pressure cuff
– Pulse oximeter- measure oxygen saturation
– Cardiac monitor
– Emergency ventilation and drug boxes- to put breathing tube in if patient becomes unstable
– A cardiac arrest cart with defibrillator
-RN certified in BLS and ACLS to assist MD. Both must have had specialized training to perform and monitor conscious sedation

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