General and Local Anesthetics (Chapter 11)

Vocabulary flashcards covering key terms from the lecture notes on general and local anesthetics.

General anesthesia

State of complete loss of consciousness and loss of body reflexes, including paralysis of respiratory muscles.

Local anesthesia

Elimination of pain sensation in tissues innervated by the anesthetized nerves; no paralysis of respiratory function.

Monitored Anesthesia Care (MAC)

Local anesthesia with sedation and analgesia.

Inhalational anesthetics

Volatile liquids or gases vaporized in oxygen and inhaled.

Parenteral anesthetics

Administered intravenously.

Adjunct anesthetics

Drugs that enhance clinical therapy when used simultaneously with another drug.

Balanced anesthesia

Use of a combination of drugs to achieve anesthesia with lower doses of each drug and greater control.

Mechanism of action of general anesthetics

Varies by drug; overall effect is altered CNS function with pain relief, reduced consciousness, muscle relaxation, and diminished reflexes.

Vasodilation (in GA)

Widening of blood vessels that can occur as part of general anesthesia.

Indications for general anesthesia

Unconsciousness, skeletal muscle relaxation, visceral smooth muscle relaxation, rapid onset, and rapid metabolism; used in certain procedures and ECT.

Contraindications to general anesthesia

Known drug allergy; pregnancy; narrow-angle glaucoma; acute porphyria; history of malignant hyperthermia.

Malignant hyperthermia

Life-threatening hyperthermia during/after volatile inhaled anesthesia or depolarizing NMBD; symptoms include very high fever, tachypnea, tachycardia, muscle rigidity; treated with supportive care and dantrolene.

Dantrolene

Skeletal muscle relaxant used to treat malignant hyperthermia.

Adverse effects of general anesthesia

Effects vary by drug; may include myocardial depression; interactions can enhance hypotension with antihypertensives and β-blockers.

Antihypertensive interactions with GA

Antihypertensives can increase hypotensive effects during anesthesia.

Beta blocker interactions with GA

β-blockers can increase myocardial depression during anesthesia.

Dexmedetomidine (Precedex)

Alpha2-adrenergic receptor agonist providing dose-dependent sedation and analgesia without respiratory depression; short half-life; quick awakening after withdrawal.

Ketamine

Intravenous anesthetic with analgesia and dissociative effects; can cause psychomimetic hallucinations; may be used for GA and moderate sedation.

Nitrous oxide

“Laughing gas”; inhaled gas used as a general anesthetic adjunct; weakest GA; used in dental procedures.

Propofol

Intravenous anesthetic used for induction and maintenance of general anesthesia; used for conscious sedation; monitor triglycerides if given with total parenteral nutrition.

Conscious sedation (procedural sedation)

Also called procedural sedation; does not cause full loss of consciousness or typically respiratory arrest; usually combines an IV benzodiazepine or propofol with an opioid; patient remains able to maintain the airway.

Midazolam

IV benzodiazepine used for anxiolysis and amnesia in conscious sedation; commonly used in pediatric patients.

Rocuronium (Zemuron)

Nondepolarizing NMBD with rapid-to-intermediate onset; used to facilitate intubation and provide skeletal muscle relaxation.

Succinylcholine

Depolarizing NMBD that mimics acetylcholine; causes depolarization and rapid, short-lived paralysis before repolarization block.

Neuromuscular blocking drugs (NMBDs)

Drugs that prevent nerve transmission to skeletal muscles, causing paralysis; do not provide sedation or analgesia.

Depolarizing NMBDs

NMBDs that cause depolarization at the neuromuscular junction (e.g., succinylcholine) and produce fasciculations followed by paralysis.

Nondepolarizing NMBDs

NMBDs that block acetylcholine receptors at the neuromuscular junction (e.g., rocuronium); cause skeletal muscle relaxation.

Spinal anesthesia

Intrathecal injection into the subarachnoid space to produce regional anesthesia.

Epidural anesthesia

Injection into the epidural space to produce regional anesthesia.

Infiltration anesthesia

Local anesthetic injected directly into tissue to block nerve impulses.

Nerve block

Local anesthetic injected near a nerve to block impulses to a region.

Topical local anesthesia

Local anesthetic applied directly to skin or mucous membranes.

Peripheral nerve catheter (Pain Buster/On-Q)

Catheter delivering local anesthetic for continuous regional analgesia.

Amide local anesthetics

Class of local anesthetics including lidocaine; used for infiltration and nerve blocks; may be combined with epinephrine.

Ester local anesthetics

Class of local anesthetics; often associated with allergies; examples include procaine and chloroprocaine.

Local anesthetic adverse effects

Generally limited; major risks include inadvertent intravascular injection, excessive dosage, slow metabolism, injection into highly vascular tissue, and allergy.

Spinal headache

Headache after inadvertent dural puncture during epidural or intrathecal anesthesia; usually self-limiting; treated with hydration, analgesics, caffeine, or a blood patch.

Blood patch

Injection of autologous blood into the epidural space to seal a dural leak and relieve spinal headache.

Hydration to treat spinal headaches

Aggressive IV hydration increases CSF pressure to reduce spinal headache.

Indications for local anesthesia

Used for surgical, dental, and diagnostic procedures and some chronic pain; spinal anesthesia for childbirth.

Local anesthesia routes and types

Includes topical, infiltration, nerve block, spinal/epidural, intrathecal, and implanted catheter techniques.

ABCs in anesthesia monitoring

Airway, Breathing, Circulation; essential focus in perioperative care.

Perioperative nursing implications

Assessment before, during, and after surgery; monitor vital signs, baseline labs, ABCs, and monitor for malignant hyperthermia; provide preoperative teaching.