Neuropharmacology Pt.2: 2/2

Rocuronium

(Nondepolarizing neuromuscular blocker class medication)

(Administered IV; generic names have -curonium or -curium.)

MOA: Competitively binds to nicotinic M receptors on the motor end plate to block activation by acetylcholine causing muscle relaxation. Persists as long as the amount of medication is sufficient to prevent receptor occupation by acetylcholine.

Indications:

• To provide muscle relaxation during surgery, Mechanical Ventilation, and ET intubation.

Rocuronium Adverse Effects

• Respiratory arrest

• Hypotension

*Rocuronium Nursing Considerations

• Duration 30-60 minutes (dose dependent)

• Due to drug unable to cross BBB, dose does not affect LOC or perception of pain and should be used w/ anesthesia.

• Monitor patients on Mechanical Ventilation and promote comfort.

• Sedation is often nurse driven—don’t leave your patient paralyzed and un or under sedated!*

Succinylcholine (Anectine)

(Depolarizing Neuromuscular Blocker class medication)

(Administered via IV & IM)

MOA: Binds to nicotinic M receptors on the motor end plate thereby causing a constant state of depolarization.

Indications:

• To provide muscle relaxation during ET intubation and adjunct to ECT.

Succinylcholine (Anectine) Adverse Effects

• Prolonged apnea in patient with low pseudocholinesterase activity.

• Malignant hyperthermia

• Hyperkalemia (contraindicated w/ known ^K)

• Postoperative muscle pain

Succinylcholine (Anectine) Nursing Considerations

• Caution in patients w/ MG, muscular dystrophy

• Duration 4-10 min

• Does not affect LOC or perception of pain—all NMB

• Malignant hyperthermia is rare, but an emergency: Ice packs, cold IV saline, and IV dantrolene.

Anesthetic Classifications

General: Produce unconscious, analgesia, and amnesia during surgery/procedure.

Regional: Sensation from the body is blocked to CNS (e.g., epidural) in minor surgeries and ambulatory settings.

Local: Similar to regional but affects smaller areas of the body via injection by nerve blocking nerve conduction.

Esters

Tetracaine, Porcaine, Benzocaine, Cocaine

Amides (Two I’s)

Bupivacaine, Ropivacaine, Lidocaine

Lidocaine (Xylocaine)

(Amide-type local anesthetic class medication)

(Administer via topically or injections.)

MOA: Stops axonal conduction by blocking sodium channels in the axonal membrane.

*Lidocaine (Xylocaine) Adverse Effects

• CNS depression and excitation w/ sufficient systemic absorption.*

• CV suppression, including bradycardia, heart block, decreased contractility, and cardiac arrest.

• Allergic reactions (ester anesthetics more likely)

Lidocaine (Xylocaine) Nursing Considerations

• Proper documentation via transdermal route.

• Injected form has higher risk for systemic effects.

• Watch for vasoconstriction s/s if used w/ epinephrine.

• Closely monitor neurological and cardiovascular status w/ administration.

• Aspirate prior to injection to avoid IV administration.

• Concentrations can range from 0.5% to 5%.

*Nitrous Oxide

(Inhalation anesthetic class medication)

MOA: Low anesthetic potency, high analgesic potency*

Indications:

• An adjunct agent w/ inhaled and intravenous anesthesia.

*Nitrous Oxide Adverse Effects

• Minimal adverse effects like other anesthetics; such as respiratory and cardiac depression, malignant hyperthermia, aspiration of gastric contents, and hepatotoxicity.

• Postoperative N/V is most common.

Nitrous Oxide Nursing Considerations

• More analgesia than anesthesia, used with other anesthetics for surgery.

• Adding nitrous oxide can reduce the dose of other anesthetics.

• Monitor for adverse effects of other anesthetics and adjunct medications.

• Assess and treat postoperative pain and N/V once anesthesia wears off.

Midazolam (Versed)

(Intravenous benzodiazepine anesthetic class medication)

MOA: Enhance transmission at inhibitory synapse and depress transmission at excitatory synapse through activation of receptors for GABA.

Indications:

• Induction of anesthesia, conscious sedation, and seizures. (anxiety)

Midazolam (Versed) Adverse Effects

• Respiratory Depression

• Hypotension

• Cardiac Arrest

Midazolam (Versed) Nursing Considerations

• Rapid onset and ultrashort duration can result in rapid onset and awakening; monitor sedation and mental status closely.

• Slow injection administration can help to minimize adverse effects.

• Monitor respiratory and cardiovascular status closely, and support both as needed for in the event of overdose.

• Used w/ opioid (fentanyl/morphine) for conscious sedation.

Midazolam (Versed) Antidote

Flumazenil

Propofol (Diprivan)

(Intravenous anesthetic class medication)

MOA: Promotes the release of GABA (inhibitory)

Indications:

• Used for anesthesia induction, procedural sedation (not by RNs), and sedation during mechanical ventilation.

Propofol (Diprivan) Adverse Effects

• Respiratory depression and hypotension

• Higher risk for bacterial infection due to lipid-based medium that can facilitate bacterial growth (frequent tubing & bottle change)

• Propofol infusion syndrome (rare, long-term use) w/ metabolic acidosis, cardiac failure, renal failure, and rhabdomyolysis.

Propofol (Diprivan) Nursing Considerations

• Rapid onset and ultrashort duration can result in onset and awakening; monitor mental status closely.

• Monitor respiratory and cardiovascular status closely.

• Monitor creatinine phosphokinase (CPK)—infusion syndrome.

• Lipids from infusion should be included when considering nutrition.

Ketamine (Ketalar)

(Intravenous anesthetic class medication)

MOA: Dissociative anesthetic. Also provides sedation, analgesia, and amnesia.

Indications:

• Anesthesia, pain management, intubation, depression.

Ketamine (Ketalar) Adverse Effects

• Respiratory depression and hypotension or hypertension (Catecholamine release)

• Psychological reactions, including hallucinations, disturbing dreams, and delirium.

• Potential for abuse.

Ketamine (Ketalar) Nursing Considerations

• Reduce risk for psychological reactions by giving verbal reassurance and/or medicating w/ a benzodiazepine.

• Assess for prior psychiatric illness; generally, should be avoided in patients w/ prior history.

• Frequently used in hanging of burn dressing in patients w/ large body surface area burns.

Neostigmine is a cholinesterase inhibitor which will…

reverse muscle paralysis