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General and Local Anesthetics
moas and indications
60
Pharmacology
Undergraduate 3
10/17/2014

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Term
General Anesthesia
Definition
A drug induced state in which the CNS nerve impulses are altered to reduce pain and other sensations throughout the entire body. It normally involves complete loss of consciousness and depression of normal respiratory drive
Term
Local Anesthesia
Definition
A drug induced state in which peripheral or spinal nerve impulses are altered to reduce or eliminate pain and other sensations in tissues innervated by these nerves.
Term
Balanced anesthesia
Definition
The practice of using combinations of different drug classes rather than a single drug to produce anesthesia
Term
Malignant hyperthermia - definition
Definition
A genetically linked major adverse reaction to general anesthesia characterized by a rapid rise in body temperature, as well as tachycardia, tachypena, and sweating
Term
Moderate sedation
Definition
a milder form of general anesthesia that causes partial or complete loss of consciousness but does not generally reduce normal respiratory drive (also referred to as conscious sedation)
Term
Spinal anesthesia
Definition
Local anesthesia induced by injection of an anesthetic drug near the spinal cord to anesthesize nerves that are distal to the site of injection (also called intraspinal anesthesia)
Term
General Anesthetics
Definition
Drugs that induce a state in which the CNS is altered to produce varying degrees of
1. pain relief
2. depression of consciousness
3. skeletal muscle relaxation
4. reflex reduction
Term
Inhalational anesthetics
Definition
volatile liquids or gases that are vaporized in oxygen and inhaled
Term
Parenteral anesthetics
Definition
administered intravenously
Term
Parenteral Anesthetics - why are they used
Definition
to induce or maintain general anesthesia
to induce amnesia
as an adjunct to inhalation type anesthetics
Term
General Anesthetics - MOA
Definition
varies from drug to drug
Overton-Meyer theory proposes that for all anesthetics, potency varies directly with lipid solubility. Across continuum of drug potency, fat-soluble drugs are stronger anesthetics than water soluble drugs. Lipid-soluable drugs can bass the blood-brain barrier to concentrate in nerve cell membranes.
Term
general anesthetics - effects
Definition
orderly and systematic reduction of sensory and motor CNS functions. Progressive depression of cerebral and spinal cord functions

General anesthesia initially produces a loss of the senses of sight, touch, taste, smell and hearing along with a loss of conscieousness. Mechanical ventilatory support is absolutely necessary. In extensive surgery adrenergic drugs and inotropic drugs may be required.
Term
Malignant hyperthermia - adverse effect
Definition
1. occurs during or after general anesthesia or use of the NMBC succinylcholine
2. sudden elevation in body temperature(greater than 104 F)
3. Tachypnea, tachycardia, muscle rigidity
4. life-threatening emergency
5. treated with dantrolene (skeletal muscle relaxant)
Term
Postoperative priority assessment for general anesthesia
Definition
airway, breathing, and circulation
Term
Propofol
General Anesthetic
Definition
1. parenteral anesthetic
2. used for the induction and maintenance of general anesthesia and also for sedation for mechanical ventilation in intensive care unit settings
3. In lower doses it can be used as a sedative -hypnotic for moderate sedation
4. some states allow nurses to administer propofol as part of a moderate sedation protocol--some prohibit it.
5. Propofol is typically well tolerated, producing few undesirable effects.
6. propofol is lipid based emulsion and prolonged use, or given in conjuction with total parenteral nurtrition requires serum lipids to be monitored.
Term
Moderate sedation = uses
Definition
1. used for diagnostic procedures and minor surgical procedures that do not require deep anesthesia
2. topic anesthetic may be applied also
3. rapid recovery time and greater safety profile than general anesthesia
4. pt is usually awake during procedure, breaths on her own, able to follow directions, but probably won't remember it.
5. Oral endoscopy is an example.
Term
Moderate sedation - dosaging
Definition
midazolam- 0.02 to 0.1 mg over a 2 minute period not to exceed 2.5 mg; if needed, a repeat dose of 25% of initial dose may be used.

If midazolam is combined with an opioid such as fentanyl or morphine, the dose should be reduced by 30-50%. Most common dose of fentanyl is 1-2 mcg/kg, which may be repeated every 30 minutes

morphine for moderate sedation is 2mg IV

when combined with benzodiazepine, smaller doses should be used

propofol is 0.5 -1 mg/kg followed by 0.5 mg/kg every 3 to 5 minutes

Mild amnesia is often an effect
Term
Local Anesthetics - types
Definition
1. Topical - applied directly to skin or mucous membranes or creams, solutions, ointments, gels , ophthalmic drops, lozenges, suppositories
2. Parenteral - injected intravenously or into the CNS by var
3. Spinal or intraspinal (intrathecal, epidural)
4. infiltration
5. nerve block
6. topical
Term
Nerve block anesthesia- local anesthesia - peripheral
Definition
anesthetic solution is injected at the site where a nerve innervates a specific area such as a tissue. Allows large amounts of anesthetic drug to be delivered to a very specific area without affecting the whole body. Method is often reserved for more difficult to treat pain syndromes such as cancer pain and chronic orthopedic pain
Term
infiltration anesthesia - local anesthesia - peripheral
Definition
Small amounts of anesthetic solution are injected into the tissue that surrounds the operative site. This approach to anesthesia is commonly used for such procedures as wound suturing and dental surgery. Often drugs that cause constriction of local blood
Term
Topical Anesthesia - local anesthesia - peripheral
Definition
the anesthetic drug is applied directly onto the surface of the skin, eye, or any mucous membrane to relieve pain or prevent it from being sensed. It is commonly used for diagnostic eye examinations and skin suturing
Term
Spinal or intraspinal anestesia - local anesthesia - central
Definition
anesthetic drugs are injected into the area near the spinal cord within the vertebral column. Intraspinal anesthesia is commonly accomplished by one or two injection techniques: intrathecal and epidural
Term
Intrathecal anesthesia - local - central
Definition
involves injection of anesthetic intoo the subarachnoid space. Intrathecal anesthesia is commonly used for patients undergoing major abdominal or limb surger for whom the risks of general anesthesia are too high or for patients who prefer this technique instead of complete loss of consciousness during their surgical procedure. More recently, intrathecal injection of anesthetics through implantable drug pumps is even being used on an outpatient basis in patients with severe chronic pain syndromes, such as those resulting from occupational injuries
Term
epidural anesthesia - local- central
Definition
involves injection of anesthetic via a small catheter into the epidural spac without puncturing the dura. Epidural anesthesia is commonly used to reduce maternal discomfort during labor and delivery and to manage postoperative acute pain after major abdominal or pelvic surgery. This route is becomoing mor popular for the administration of opiods for pain management.
Term
Parenteral anesthetics
Definition
lidocaine (xylocaine)
mepivacaine (Carbocaine)
procaine (Novocain)
tetracaine(Pontocaine)
others
Term
Spinal Anesthesia - common side effect
Definition
Spinal headache is one side effect of spinal anesthesia. It is worse when the patient is sitting upright and btter when positioned flat. Effective remedy for a spinal headache is bed rest and analgesia.
If spinal headache is severe may be teated by injection of small volume (15mL) of pts' own blood into the epidural space (blood patch) Effective in 90%
Term
Local Anesthetics - MOA
Definition
work by rendering a specific portion of the body insensitive to pain by interfering with the nerve transmission. Nerve conduction is blocked only in the area in which anesthetic is applied.
Term
Local Anesthetics - drug effects - Paralysis
Definition
First, autonomic activity is lost.
Then, pain and other sensory fuctions are lost
Last, motor activity is lost
As local drugs wear off recovery occurs in reverse order (motor, sensory, then autonomic activity are restored)
Term
Local Anesthetics - other drug effects
Definition
1. possible systemic effects include effects on circulatory and respiratory function
2. Produce sympathetic blockade (block the action of the two neurotransmitters of the sympathetic nervous syster norepinephrine and epinephrine)
3. cardiac effects include a decrease in stroke volume, cardiac output, peripheral resistance.
4. respiratory effects include reduced respiratory function and altered breathing patterns - complete paralysis of respiratory function is unlikely
Term
Local Anesthetics - Indications
Definition
1. surgical, dental, and diagnostic procedures
2. treatment of certain types of chronic pain
3. spinal anesthesia to control pain during surgical procedures and childbirth
4. local anesthetics are given by infiltration anesthesia and nerve block anesthesia
Term
Local Anesthesia - Adverse Effects
Definition
1. usually limited
Adverse effects if:
1. inadvertent intravascular injection occurs
2. excessive dose or rate of injection is given
3. slow metabolic breakdown occurs
4. injection into highly vascular tisue occurs
5. "spinal headache" treated with an epidural blood patch
Term
Local Anesthesia - Toxicity and management of overdose
Definition
vasoconstrictors keep drug from going into the systemic circulation (eg lidocaine/epinephrine; bupivacaine/epinephrine)
Term
Lidocaine - local anesthesetic
Definition
1. belongs to amide class
2. If pt reports allergic reaction to the "caines" may be amide drug - try ester drug
3. one of most commonly used
4. available in several strengths, both alone and with epinephrine
5. used in both infiltration and nerve block anesthesia
6. available in topical forms, including EMLA a cream mixture of lidocaine and prilocaine that is applied to skin to ease pain of needle punctures (starting IV line)
7. also a transdermal lidocaine patch for relief of postherpetic neuralgia
8. parenteral lidocaine is used to treat certain cardiac dysrhythmias
9. Lidocaine is a pregnancy category B drug
Term
Neuromuscular Blocking Drugs (aka NMBDs)
Definition
1. prevent nerve transmission in certain muscles, resulting in muscle paralysis
2. used with anesthetics during surgery
3. when used during surgery, artificial mechanical ventilation is required
4. these drugs paralyse the respiratory and the skeletal muscles
5. pt cannot breath on his/her own
6. pt may be paralyzed, yet conscious
7. do not cause sedation or pain relief
8. if given in error, pt would experience horrendous death because mind remains alert, pt cannot speak or move
Term
NMBDs - MOA
Definition
1. Depolarizing NMBDs work similarly to neurotransmitter acetycholine (
ACh) They bind in place of ACh to cholinergic receptors at the motor endplates of muscle nerve or neuromuscular junctions
2. Nondepolarizing NMBDs also bind to ACh receptors at the neuromuscular junction, but instead of mimicking ACh, they block its action
Term
Succinylcholine (Depolarizing NMBD)
Definition
1. works similarly to neurotransmitter acetylcholine ACh causing depolarization
2. Metabolism is slower than ACh, as long as succinylcholine is present, repolarization cannot occur
Result: flaccid muscle paralyis
Term
NMBDs - Effects
Definition
1. prevent ACh from acting at the neuromuscular junctions
2. nerve cell membrane is not depolarized; muscle fibers are not stimulated
3. skeletal muscle contraction does not occur
Term
NMBD induced paralysis
Definition
1. 1st sensation is muscle weakness
2. this is followed by total flaccid paralysis
3. small, rapidly moving muscles affected first (fingers, eyes) then limbs, neck and trunk
4. Finally, intercostal muscles and diaphragm affected, resulting in cessation of respiration
5. recovery of muscular activity usually occurs in reverse order
6. transient muscle fasciculations may result in later muscle soreness
7. Recovery is in reverse order
Term
NMBDs Indications
Definition
1. main use: maintaining controlled ventillation during surgical procedures
2. endotracheal intubation (short acting)
3. to reduce muscle contraction in an area that needs surgery
4. diagnostic drugs for myasthenia gravis
5. laryngoscopy, bronchoscopy, esophagoscopy
6. reduction of laryngeal or general muscle spasms
7. reduction of spasticity from tetnus and neurologic diseases such as multiple schlerosis
8. prevention of bone fractures during electroconvulsive therapy
Term
NMBDs - toxicity and overdose
Definition
prolonged paralysis with overdose and prolonged mechanical ventilation
cardiovasuclar collapse may be seen and is thought the release of histamine is the cause
Anticholinesterase drugs such as neostigmine, pyridostigmine, and endrophonium are antidotes aand are used to reverse muscle paralysis
Term
Succinylcholine NMBDs
Definition
1. popular due to rapid onset of action, its depth of neuromuscular blockade, and its short duration of action
2. preferred to nondepolarizing NMBDs for rapid sequence induction of anesthesia (emergency intubation)
3. has been associated with hyperkalemia, dysrhythmias; fasciculations; muscle pain; myoglobinuria; increase intraocular,intragastric and intracranial pressure and malignant hyperthermia
4. currently the only drug in the depolarizing subclass
5. structure similar to that of parasympathetic neurotransmitter ACh and produces same physiologic responses initially
metabolizes more slowly than ACh
6. subjects the motor endplate to ongoing depolarizing stimulation and repolarization cannot occur
7. commonly used to faclitate endotracheal intubation
8 seldom used over long periods because of its tendentcy to cause muscular fasciculations
9. contraindicated in pts with personal or familial history of malignant hyperthermia, skeletal muscle myopathies and known hypersinsitivity to the drug
10. only available in injectable form
Term
Vecuronium - NMBDs (nonpolarizing)
Definition
1. intermediate acting nondepolarizing NMBD
2. used as an adjunct to general anesthesia to facilitate tracheal intubation and to provide skeletal muscle relaxation during surgery or mechanical ventilation
3. one of the most commonly used NMBDs
4. long term use in the ICU setting has resulted in prolonged paralysis and subsequent weaning from mechanical ventiltion
5. this is believed to be due to an active metabolite, 3-desacetyl vecuronium which tend to accumulate with prolonged use
6. available only in injectable form
Term
NMBDs Safety Concerns
Definition
1. respiratory muscle paralysis occurs with these drugs
2. emegency ventilation equipment must be immediately available
Term
Infilatration Anesthesia
Definition
commonly used for minor surgical procedures
lidocaine is commonly used by injecting intradermally, subcutaneously, or submucosally across the path of nerves supplying the area to be anesthetized. VAsoconstrictors such as epinephrine are co-administered with local anesthetics to keep the anesthetic at its local site of action to prevent systemic absorption
Term
Immediate postoperative assessment of a pt reveals a body temp of 102 F. Which action should nurse perform?
Definition
notify physician
Term
Which postoperative nursing action will help the pt recover from the effects of anesthesia?
Definition
turning, coughing, and deep breathing every 2 hours
Term
a mechanically ventilated pt receiving a neuromuscular-blocking drug was tearing in the eyes and had increased heart rate and blood pressure. The nurse interprets
Definition
level of sedation is inadequate
Term
an intubated, mechanically ventilated pt in the ICU is becoming increasingly restless and anxious. Nurse expects to administer which IV anesthetic drug?
Definition
propofol (Diprivan)
Term
while taking pt's history prior to surgery for a cardiac problem, the pt informs nurse he is addicted to cocaine. Nurse alerts anesthesiologist because cocaine use can cause
Definition
anesthetic induced complications
Term
A pt questions the use of epinephrine for repair of a laceration stating he thought that drug was used in the ER for coding. Nurse says
Definition
Vasoconstriction caused by epinephirine enhances the duration of action for lidocaine and decreases bleeding at site of laceration.
Term
While completing preoperative pt teaching nurse explains that general anesthesia produces
Definition
deep muscle relaxation and loss of consciousness
Term
A pt expresses fear of nausea and vomiting postoperatively from anesthesia. Nurse says
Definition
nausea and vomiting occur less frequently than in past due to use of balanced approach to anesthesia
Term
A 75 yr old man undergoing knee replacement. Physically active, cardiac bypass, smoked until 2 yrs ago. What should be considered regarding administration of anesthesia to this pt?
Definition
Malignant hyperthermia
1. occurs during or after general anesthesia
2. sudden elevation in body temp
3. tachypnea, tachycardia, muscle rigidity
4. life threatening emergency
5. treated with dantrolene (skeletal muscle relaxant
Term
Components of balance anesthesia in general anesthesia
Definition
sedatives and anxiolytics

neuromuscular blocking drugs used to cause respiratory and skeletal muscle paralysis. Artificial ventilatin is required during anesthesia.
Term
During immediate postoperative recover the nurse's priority assessment is
Definition
airway, breathing, circulation
Term
a technique in which pt is awake during the procedure, able to breath on own, able to follow directions but probably won't remember
Definition
moderate sedation
Term
example of moderate sedation
Definition
oral endoscopy
Term
commonly used for minor surgical procedures.
Definition
infiltratin anesthesia
Term
commonly used in infiltration anesthesia by injecting intradermally, subcutaneously or submucosally across the bath of nerves supplying the area to be anesthized.
Definition
Lidocaine
Term
This vasoconstricor is co-administered with local anesthetics to keep the anesthetic at its local site of action and to prevent systemic absorption
Definition
epinephrine
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