general and local anesthetics

what is anesthesia

a state of reduced neurologic function; can range from drowsiness (mild) to total loss of consciousness and reflexes

types of anesthesia

• General 

• Moderate sedation 

• Local

• Neuromuscular blocks 

general nursing interventions for anesthetics

• Review the patient’s medical and surgical history

• Assess medications, alcohol, and drug use

• Baseline lab work and EKGs

• Surgical and anesthesia plan

• Preop teach about Turn, cough, deep breath in post op period

general anesthetics key fx

• Drugs to eliminate feeling pain/sensation during medical procedures through central and peripheral nervous system

• Patient loses consciousness - completely unaware of surroundings with loss of stimuli

• Reserved for major or invasive surgeries

• Rapid onset and quickly metabolized

are protective reflexes lost with general anesthetics?

yes

Patient loses protective reflexes (gag, blink, respiratory muscles -> paralysis) -> mechanical ventilation required

who are general anesthetics administered by

• ADMINISTERED BY: ANESTHESIOLOGIST, CRNA, ANESTHESIA ASSISTANT

types of general anesthetics

• Inhalation - Liquids or gases that are vaporized in oxygen and inhaled

• Parenteral - Administered IV

• Adjunct - Medications given along with anesthetics to enhance effects

what is overton-meyer theory

• Explains why some anesthetics are stronger than others

• Varies according to drug

what are classic stages of anesthesia

• Progress from analgesia and amnesia -> excitement or delirium -> surgical anesthesia -> medullary depression (danger → too deep → respiratory and cardiac support necessary)

nursing interventions for general anesthetics

• Verify that anesthesia machine, suction, and emergency drugs (dantrolene) are available before induction

• Monitor patent IV access

• Monitor v/s, ECG, oxygen, and temp continuously

• Monitor for malignant hyperthermia

• During recovery, position patient on side to maintain airway and reduce aspiration risk

• Provide frequent orientation as patient emerges

• Evaluate for pain, nausea, and shivering

• Administer antibiotics as prescribed

patient teaching general anesthetics

• May experience drowsiness, sore throat, or mild nausea after anesthesia

• Deep breathing, coughing, and early ambulation to prevent complications (DVT or pneumonia)

• Do not drive or make major decisions 24 hours after

contraindications for general anesthetics 

• Allergy

• Depending on drug type

  • pregnancy

  • narrow-angle glaucoma

  • Acute porphyria

  • Know history of malignant hyperthermia

adverse effects of general anesthetics

• malignant hyperthermia

• toxicity or OD

malignant hyperthermia key fx

• Can occur during or after use of inhaled anesthetics or succinylcholine

• genetic life threatening reaction that causes a sudden spike in body temperature, along with muscle rigidity, tachypnea, and tachycardia

• the skeletal muscles go into a hypermetabolic state, producing excessive heat and lactic acid -> can quickly lead to acidosis and organ failure if not treated promptly

nursing interventions for malignant hyperthermia

• Recognize early signs (unexpected rise in ETCO2, tachycardia, muscle rigidity)

• stop anesthetic immediately, notify provider, administer dantrolene IV, initiate rapid cooling using cooling fluids, blankets

• monitor for complications (arrhythmias and electrolyte imbalances)

• document and notify family

toxicity/OD of general anesthetics key fx

• The ultimate cause of death with OD is usually cardiac or respiratory arrest

• if arrest occurs, initiate basic life support and oxygenation

general anesthetics drug interactions

• Antihypertensives - Cause HOTN

• Beta blockers - Can increase risk of bradycardia and myocardial depression

• Alcohol and CNS depressants - Additive sedative effects

general anesthetic drug examples

• Dexmedetomidine (Precedex)

• ketamine

• nitrous oxide

• propofol

• sevoflurane

dexmedetomidine key fx

• Procedural sedation - Provides dose dependent sedation, anxiety reduction, and pain relief without significantly depressing respiratory system; often used for short, surgical procedures 

• Also used in ICU for sedation of mechanically ventilated patients

dexmedetomidine s/e

• bradycardia

• HOTN

dexmedetomidine nursing interventions

• Monitor for bradycardia and HOTN

• Assess level of sedation frequently and titrate per protocol

ketamine key fx

• IV, IM, SUBQ

• Produces a dissociative effect -> patient appears awake but is unaware of surroundings

• Rapid onset and causes minimal depression to CV and RR function -> useful in emergency or trauma settings

ketamine s/e

• Can cause hallucinations, nightmares, or vivid dreams

ketamine nursing interventions

• Provide calm and quiet environment

• Frequently orient patient as they wake up

• Continuously monitor airway and oxygen

nitrous oxide key fx

• AKA laughing gas

• Weakest general anesthetic 

• Inhaled

• Often used as dental agent or adjunct to more potent agents

nitrous oxide nursing interventions

• Monitor for n/v or dizziness post procedure

• Use in well ventilated area since the gas can linger and cause exposure

propofol key fx

• Parenteral anesthetic - Used for both induction and maintenance

• Used in ICU 

• Monitor triglycerides if used with TPN and long-term infusions

propofol nursing interventions

• Use strict aseptic technique, since it supports bacterial growth

• Monitor RR, airway, and oxygenation

• Discontinue if patient shows signs of propofol infusion syndrome (bradycardia, metabolic acidosis, cardiac failure)

sevoflurane key fx

• Widely used (esp. outpatient settings) because it is non-irritating to the airway

• Good for pediatric patients

nursing interventions for sevoflurane

• Monitor for post-op shivering or nausea

• Monitor for malignant hyperthermia

• Ensure adequate ventilation during emergence to remove residual gas

moderate sedation key fx

• AKA conscious or procedural sedation

• No complete loss of consciousness - Provides pain relief, anxiety reduction, and sometimes mild amnesia → memory loss

• Patient can maintain own airway and respond to commands

• Given in combination with other drugs (IV benzodiazepine with opioid analgesic)

what is moderate sedation used for

Minor procedures and diagnostic tests - Endoscopy/colonoscopy, cardioversion, minor orthopedic or dental procedures

moderate sedation nursing interventions

• Monitor respiratory effort, oxygen saturation, cardiac rhythm, LOC, and ECO2

• Keep reversal agents (flumazenil and naloxone) immediately available

• Provide calm environment 

• Continue to monitor until patient is alert and v/s are stable

• Assess for delayed sedation, dizziness, or HOTN

• Educate patient to not drive or make major decisions for 24 hours after

local anesthetics key fx

• Block pain in specific area of the body

• Does not affect consciousness or breathing

types of local anesthetics

Can be central (spinal and epidural) or peripheral (nerve blocks, infiltration, topical, continuous nerve catheters for post-op pain)

drug examples of local anesthetics

• “Caines” - Lidocaine, bupivacaine, prilocaine, tetracaine

what can local anesthetics be combined with

• May be combined with epinephrine to reduce bleeding and prolonged duration

• never use epinephrine on areas with end arteries (fingers, toes, ears, nose) because it can cause tissue necrosis

drug effects of local anesthetics

• Autonomic activity lost first

• Pain and sensory lost second

• Motor activity lost last

• Recovery returns in opposite order: Motor function, pain/sensory, then autonomic

adverse effects of local anesthetics

usually limited - usually only occur if it enters blood stream

• HOTN

• bradycardia

• restlessness

• tremors

• seizure

• spinal headache (only with epidural or spinal -> can be treated with blood patch)

nursing interventions of local anesthetics

• Assess for allergies and previous reactions

• Monitor for signs of local toxicity (tinnitus, metallic taste, confusion, perioral numbness)

• If epinephrine is used in combination, monitor for tachycardia or HTN

• If spinal is used, keep patient flat for 6-8 hours after to reduce spinal headache risk

• Encourage fluids and caffeine post-op to help seal dural leak

• Reassure patient about temporary numbness or tingling after administration

neuromuscular blocking drugs key fx

• Results in paralysis of skeletal and smooth muscles by blocking nerve transmission

• Used in combination with general anesthetics to facilitate intubation, control ventilation, reduce muscle contractions, and in diagnostic doses for myasthenia gravis

• Patient remains conscious, no sedation or pain relief 

what has to be used when neuromuscular blocking drugs are used in surgery

• artificial ventilation required and patient must me adequately anesthetized

effects of neuromuscular blocking drugs

• Muscle weakness

• Total flaccid paralysis

adverse effects of neuromuscular blocking drugs

• HOTN

• vasodilation

• bradycardia/tachycardia

• hyperkalemia (succinylcholine only)

contraindications of neuromuscular blocking drugs

malignant hyperthermia

drug interactions of neuromuscular blocking agents

• Aminoglycosides, clindamycin, calcium channel blockers, mag sulfate and diuretics  - Additive effects

nursing interventions of neuromuscular blocking agents

• After surgery, monitor for full return of muscle strength and airway control before extubation

• Ensure airway and ventilatory support prior to administration

• Label IV lines clearly and verify correct drug

• Continuously monitor oxygenation, ECG, and muscle twitch response using nerve stimulator

what are the two classes of neuromuscular blocking drugs

• depolarizing - succinylcholine

• nondepoloarizing - rocuronium

depolarizing NMBDs key fx

• Causes initial muscle contraction, followed by a prolonged depolarization because it isn’t broken down quickly

• Causes flaccid paralysis

• Monitor for twitching, potassium levels, and malignant hyperthermia

non depolarizing key fx

• Prevents muscle contraction all together

• Used to facilitate intubation and maintain skeletal muscle relaxation during surgery

• Monitor depth of blockage using nerve stimulator and be prepared to administer reversal agents once procedure ends

• Reversal agent/antidote: Neostigmine and pyridostigmine