Anesthetics Flashcards
What was The first local anesthesia- abolition of sensation: leading to need for 1. Unconscious 2. Analgesia 3. muscle relaxation?
Cocaine.
What is the abolition of pain?
Analgesia
This value is the concentration that results in immobility in 50% of patients when exposed to noxious stimuli?
Min. alveolar anesthetic concentration. Higher the MAC= lower potency
What is only anesthetic agent that is inorganic, odorless, tasteless, no burn, never metabolized?
Nitrous oxide. MAC 105% LOW POTENT. Weak ANESTHETIC POWERFUL ANALGESIC
What are the systemic effects of NO?
Low blood solubility- Recovery faster
Min HR, BP, RR, and safe
What is concern of NO with sick pts?
- Myocardial depression.
- Manufacture impurities.
- BEg of case- INC in partial pressures.
- End of case O2 and CO2 blood diluted by this gas. DEC in Partial pressure=HYPOXIA
- Inhibits B12 metabolism
- Inhibits methione synthase-DNA precursor
What has the most significant reduction in systemic vascular resistance?
ISOflurane- MAC 1.30% HIGH POTENT. effect inc coronary steal syndrome, INC ICP, muscle relaxant
What receptors do Isoflurane work on?
*baroecptors. Depress RR and ventilatory response.
Avoid this drug if HF, arrhythmia, and asthma?
Isoflurane
What is a potent inhalant with MAC 7.2%
Desflurane- low solubility in blood, faster recovery. MILD respiratory and cardiac suppression
Which inhalant is ideal for kids and Why?
Sevoflurane- Faster recovery, less RR and CV effects. Masks, pleasant smelling
What are ADE of Sevoflurane?
- More respiratory depression
- Eliminated by lungs
- Excitement during recovery
- **NO p/o analgesia
- Reacts with KOH to create a chemical that cause RENAL damage
Which inhalant needs close monitor of HR and BP, O2 SAT?
Desflurane-
ADE: 1. Cough w/ strong vapors 2. AVoid lyme soda
What IV anesthetic is similar to AZOLES, CNS depressant and GABA agonist?
ETOMIDATE: Works how: dose dependent, DEC cerebral metabolism
ADE; **N/V, myoclonic activity, Cortisol suppression, inj pain,
What IV anesthetic causes dissociative anesthesia via stimulation of SNS?
KETAMINE: Works; maintains laryngeal and tone, similar to PCP, SNS ADE; hallucinatin dreams
What IV anesheic is painful bc not water soluble, lipid soluble-rapid onset, short duration?
PROPOFOL- Works: Myocaridal depression and peripheal vasodialstion. Normal Baroreflex
Which RX produce sedation and amnesia via GABA receptors?
Benzo- azepam Works; pre anesthic, relax b4 surgery, NOT water soluble most
What BENZO is used premeditation and seizure activity?
Diazepam (Valium) Works- mim systemic effects.
ADE- liver metabolized, AVOID narcotics
Which BENZO is an adjunct for anxiolytic and sedative properties?
LORAZEPAM- Works; slower, not for induction
Which BENZO used for drowsiness preop with slow induction, MOST potent?
MIDAZOLAM;
ADE- prolonged recovery via metabolite, Min cardiac effects.
What are some ADE of Opioids of anil/yl that are potent analgesic?
- Bradycardia
- NO Myocardial depression
- peripheral vasodilator and histamine -HYPOTENSION
- Chest wall rigidity
Does inhaled and IV muscle relaxants work?
NO, not good for muscle tone. WORK- block ACH receptor. PK- plasma ACHe, Hepatic or Renal. USE- muscle relax in surgery, 2. intubatin 3. control ventilation
What short acting muscle relaxant is used for intubation and last only 5-10min?
1.Succinylcholine; WORKS- DEPOLARIZING nicotinic receptor
ADE: myalgia day later** Malignant hyperthermia-fever, rhabdo
What are the duration and Elimination of neuromuscular blockers?
SA- succinylcholine, Mivacurium- Plasma ACHe eliminated 5-20min.
IA- ATRA, VE, RO- curonium- 20-35min - HEPATIC and RENAL.
LA- Pancuriium, tubocuraine, metocurine- 60min Renal
What are the concerns with muscle relaxants?
- Dont work
- INC by inhaled isoflurane
- INC by ahminoglycosides CCB
- HIGH doses, ANS ganglia blocked
- Respiratory paralysis
How do non-depolarizing muscle relaxants work?
Competitively inhibit end plate nicotinic cholinergic receptor;
ROcuronium, Cisatracurium, vecuronium, mivacruim, Pancurium, tubcruien, metocurine
How are muscle relaxants reversed?
Anticholinesterase: neostigmine, pryidostigmine, edrophonium- muscarinic stimulation
What RX block NA channels to prevent depolarization thus excitation?
Local anesthetics; -caines
Esters- plasma AchE –caine
Amides- CYP450 isoenymes i-caine
How does ionization affect crossing membrane?
Ionizable- lipohillic and hydrophilic end.
Ionized= low ph CANNOT cross membrane
What can be used to help cross membrane for less pain?
Sodium Bicarb- Higher PH not ionized cross membrane
What are the progression steps to local anesthetic toxicity?
Initial- Numbness of tongue, dizzy, tinnitus, vision
Later- drowsy, slurred speech, convulsions.
Final - Respiratory depression
How do you prevent local anesthesia toxicity?
Causes IV inj or excessive dose.
- Aspirate often slow IV
- Ask about CNS toxicity ADE
- Monitor
- Be prepared to Ventilate w/ O2
- Seizure- TX Diazepam
- Hypotension- trendelenburg-head down legs up, IV bolus, vasopressor
- ACLS for arrhythmia- But NO MORE Lidocaine
How was cocaine used in the day and today?
Euphoria, reduce hunger strikes, INC work tolerance. 2. Vasoconstrictor
What is MOA of Cocaine?
Blocks Na channel, prevents uptake of Epi and NorEPi
What are used for epidural analgesia?
Bupivacaine
Ropivacaine- CV risk, less motor impairment
What are used for conditions such as Cerebral Palsy, MS, spinal cord damage, muscle inflamed?
Spasmolytics: Diazepam, Baclofen, Tizanidine, Cyclobensaprine, Dantrolene. Goal- reduce spasticy and pain, but retain function
What spasmolytic activated K+, inhibitory, less sedation?
Baclofen-
ADE- WD, confusion, rhabdo
What a2 adrenergic receptor agonist cause presynaptic inhibition of motor neurons?
Tizanidine- less lowering effect ADE- drowsy, hypotension, dry mouth
What spasmolytic is a strong antimuscarinic sedative acting at the brain steM?
Cyclobenzaprin Flexeril- rarely works muscle relaxant. NOT for CNS d/o. Maybe relief of acute muscle injury OTHERS: Chlorzoxaone (paraflex), orphneadrine (norflex)
What is a better muscle/spasmolytic but risk of physical dependence?
Coarisoprodoal (SOMA) metabolite potent
Which spasmolytic IV administered can reverse malignant hyperthermia?
Dantrolene Sodium-
MOA- PO-interferes with excitation coupling and CA release of SR. Blocks contraction.
ADE- **HEPATITIS, MKS weakness, sedation. USE- CP, MS.
