1. respiratory depression-this is the primary cause of death with over dose.
2. nausea and emesis (vomiting)
3. constipation
4.  Miosis (pinpoint pupils)
5.  urinary retention
6. CNS effects - anxiety, restlessness, nervousness
7. cardiovascular effects - postural hypotension, bradycardia, possibly syncope
8. billiary tract constriction-results in pain and indigestion. Do not use opiods in pts with gallstones.
9. histamine release-produces itching and urticaria (may be confused with allergic reactions)
10. pregnancy and nursing - offspring may be born addicted. Normal therapeutic doses OK with nursing a normal infant.
    

• overdose
  • pointpoint pupils, respiratory depression, coma
• withdrawl
  • "cold turkey" gooseflesh, lacrimation, perspiration, rhinorrhea (very runny nose), irritabilty, nausea, vomiting, tachycardia, and chills
• Identifying an addict:
  • specific drug requests (misprounces name)
  • claims allergy to everything else
  • cx tx appt, avoids tx to remove cause of pain and reason for needing opoids
  • complains of unusual pain after any tx
  • goes from dentist to dentist
  • claims low pain threshold

• substite oral opiod for injectable (methadone) with gradual withdrawl
• "cold turkey"
• methadone mtc-
• naltrexone (Trexan)- blocks action of opiod

• in the STRONGEST catagory

• parenteral or oral

• used with diazepam (Valium) for oral surgery

1. bactericidal- destroys the cell wall integrity leading to lysis, therefore more effective against rapidly growing organisms.
2. narrow spectrum- gram + cocci, certain gram - cocci, spirocheetes and some anaerobes

• spectrum matches microbes responsible for many periodontal condistions!

• bacteriostatic- interferes with protein synthesis
• broad spectrum
• calcium decreases oral absorption- avoid dairy products, iron supplements, antacids w/ aluminum, calcium, magnesium.
• Adverse reactions
  • GI- anorexia, nausea, vomiting, diarrhea, glossitis, xerostomia and super infection
  • Teeth and bones- permanent discoloration of teeth. Avoid use in last half of pregnancy through age 12. From 2 mos to 12 years permanent teeth may be affected. Tetracycline is depositied in enamel and darkens with age and exposure to light. Tx: porcelian laminate veneers.
  • hepatoxicity- esp in pregnant woman
  • nephrotoxicity- esp with old, degraded tetracycline
  • superinfection- broad spectrum allows over growth of C. albicans
  • photosensitivty (sunburn)- advise pt to wear sunscreen while outside
  • allergenicity is low
  • avoid other anti-infectives -antagonism

• bacteriostatic- in high doses could be bacteriocidal
• spectrum: gram +, some gram -, and anaerobic Bacteriodes species (works particullary well against these Bacteriods)
• administered orally, topically, IM, and IV
• food does not interfer with absorption
• cross resistance btw clindamycin and erythromycin (antagonistic)
• adverse reactions
  • PMC- pseudomembranous colitis which can be fatal - black, mucusy, bloody stool.
  • superinfection with C. albicans
• dose: 150-300 mg capsule qid

• drug of choice Bacteriodes fragilis infections
• used more for anaerobic periodontal infections in future (used more in the last 5 years)

• introduced in 1964
• bactericidal- inhibits cell wall synthesis
• broad spectrum- wide varitey of gram + and gram - oranisms
• resistant to penicillinase (but vulnerable to cephalosporinase)
• administration- oral, IM, IV
• most common adverse reaction is GI effect: diarrhea, nausea, vomiting, abdominal pain, anorexia, dyspepsia and stomatiis.
• dental use: only used when other agents are ineffective or can't be used. Pen V or erythromycin are preferable

• developed in 1963
• bacteriostatic
• eg. Bactrim, Septra

• Fungal infections in dentistry are rare and difficult to treat.
• occur often in immunocompromised pts
• they are classified by whether they are systemic or on the skin/mucosa
• usually caused by Candida albicans
• treated with nystatin (Mycostatin)

• fungicidal and fungistatic- alters fungal cell wall permeability allow loss of potassium and other constituents
• adverse reactions are minor and infrequent (least toxic of all anti-funals)
• available in aquas suspensions with 50% sucrose (can affect diabetics and cause tooth decay)
• used for 2 weeks or until 48 hrs after culture comes back neg.

• indicated for orophyaryngeal candidiasis
• adult dose: 1 lozenge (10 mg) 5 x day for 2 weeks
  
  • disolve in the mouth to make direct contact w the thrush 
  • lozenge contains glucose
• adverse effects involve the GI tract

• antifungal
• wide ranging and potentially serious side effects in 50-80% of pts including nephrotoxicity, fever, chills, headache, joint pain
• serious drug interactions
• only used in life threatening fungal infections when it is the only effective option
• used topicaly my produce contact dermatitis

• tx of Herpes simplex virus (cold sore)
• less toxic, taken up preferentially by infected cells, interferes with replication
• topical, oral, and parenteral forms
• effective oral form in prophylaxis of recurrent gential herpes and in injectable form for severe initial herpes genitialis and herpes zoster (shingles).
• Not effective topically for management of herpes labialis in dentistry, although widely used (not FDA approved)
• not as high blood levels of acyclovir as valtrex

• pts are often treated w/ "cocktails"
• zidovudine (AZT), lamivudine (3TC), nevirapine (Viracept), saquinavir (Invirase)

• Nuleoside analogs (AZT and 3tC)
  • inhibits HIV synthesis and reduces morbidity and mortality from aids and aids-related complex.Opportunistic infections are reduced in # and frequency.
  • toxicty: bone marrow suppression leading to anemia, granulocytopenia, and thrombocytopenia. Transfustions are often required. Nausea in 50 % of pts. Altered taste, bleeding gums, edema of tongue, oral ulcers.
  • Avoid acetaminophen- increases toxity of both drugs.
  • has no effect on cells already containing HIV
• Nonnucleioside analogs (Viracept)
  • resistance to the drug develops quickly
  • adverse reactions: CNS, rash, GI, liver
  • has no effect on cells already containing HIV
• Protease inhibitors (Invirase)
  • can interfere with cells infected with HIV
  • adverse effects: GI, rash, hyperglycemia, paresthesias
    

• pKa determines how much will be in base and salt forms.
• At 7.4 25% is RN and permeates into the nerve.  
• Some of the RNH+ will be left behind
  • continues to convert to RN and permeate the  nerve
  • diffuses and is absorbed by blood vessels and soft tissue at the injection site.
• Once inside the nerve the RN reequilibrates. RNH+ competes with Ca for binding sites. The Ca is what lets the Na in, so no Ca=no Na. No Na no action potential.

1. decreased rate of depolarization of nerve cell membrane.
2. increased threshold for excitability of nerve cell membrane
3. prevention of propagation of action potential

1. In carpule- Polar (ionized) salt form in acidic (low pH) environment. Creates a more soluable liquid, easier to put through a needle.
2. Injected into normal tissues- Nonpolar, nonionized, free base form in basic (higher pH) environment. LA is now more permeable through membranes.
3. Injected into infected tissues- acidic invironment = anesthetic is more polar, ionized, salt, and less able to permeate the nerve.
4. Within the nerve fiber- 75% is in the ionized RNH+ form and able to block the sodium channels.

1. Absorption (systemic)

• greater with increased vascularity of tissue
• greater if anesthetic has greater vasodilating properties (all do except cocaine)
• greater if increased heat or massage
• less if vasoconstrictor is added to local anesthetic

• distributed throughout the body
• more vascular organs have higher concentration
• crosses the placenta and blood-brain barrier

• Esters
  
  • metabolized/hydrolized in PLASMA by pseudocholinesterase and liver esterases.
  • allery to esters may actually be allergy to PABA (para-aminobenzoic acid) a metabolite of hydrolysis of esters.
  • Toxicity may be due to some pts have an atypical form of pseudocholinesterase that prevents them from metaboloizing the anesthetic.
• Amides
  • metabolized in the LIVER
  • in pts with liver disease it may accumulate and produce systemic toxicity.

• Via the kidneys. May accumulate with renal diesase and reach toxic levels.

• Reversible blockage of peripheral nerve conduction from small unmylinated fibers to large heavily myelnated fibers
  • at nerve fibers
  • at sensory endings
  • at myoneuronal junctions
  • at synapes

1. autonomic (all post ganglionic fibers are small unmyelinated type C)
2. cold
3. warmth
4. pain   LA usuall stops at pain
   

   ---

5. touch
6. pressure
7. vibration
8. proprioception (position recognition)
9. motor

1. block cardiac sodium channels
2. depress abnormal cardiac pacemaker activity, excitability, and conduction
3. depresses strength of contractions and produce arteriolar dilation which leads to hypotention

• Factors that influence toxicity are
  • drug's inherent toxicity and vasodilating effect
  • concentration
  • route of administration: IV has highest systemic affect, even topical can have systemic effect
  • rate of injection: rapid injection increasee systemic blood level
  • vascularity: inflamed or infected tissue = higher blood levels
  • pt weight: larger pts tolerate larger doses. Muscle is more vascular than fat, accounting for why pts of similar weight may have diff effects
  • metabolic rate and excretion: amides accumulate with liver disease. Both amides and esters may accumulate with renal disease.

• LAs can cross the blood brain barrier: initial OD is thought to selectively block inhibitory pathways in the cerebral cortex resulting in CNS stimulation (preconvulsive and convulsive phases). Greater OD blocks both inhibitory and facilitory (excitatory) pathways producing generalised CNS depression.
  • preconvulsive signs and symptoms:
    • signs: slurred speech, shivering, muscluar twitching, tremor in muscles of face and distal extremeties.
    • sypmtoms: numbness of tongue, warm flushed feeling, dreamlike state, light-headedness, dizziness, visual disturbances(inability to focus), tinnitus, drowsiness (more common w lidocaine) and disoreintation
  • convulsive phase
    • tonic clonic seizure r/t Pco2 level.
      
• respiritory depression, respiratory arrest, and coma may occur with increasing blood levels of LA
  

1. vasoconstrictor: slows absorption, increases duration, and reduces systemic toxicity
2. antioxidant (sodium bicarbonate, sodium metabisulfite, acetone sodium bisulfite): prolongs the shelf life of the vasoconstrictor. May affect asthmatics.
3. Sodium hydroxide: alkalinezes pH to btw 6and 7
4. Sodium chloride: makes solution isotonic (to make Na concentration the same as in the tissues)

• brand names Xylocaine and Octocaine
• amide
• xylidine derivative
• anesthetic standard by which all others are measured
• rapid onset (2-3 min)
• medium duration (pulpal 60 min, soft tissue 3-5 hrs)
• no cross allergenicity with esters or other amides
• toxic reaction: CNS depression rather than stimulation as with other LAs
• topical, infiltration, block, spinal, epidural, and caudal use
• IV to treat cardiac arrhythmias
• available as 2% with 1:50,000 (used for excessive bleeding) ; 1:100,000; 1:200,000 and plain.
• available as 5% ointment, 10% spray, 2% viscous solution

• brand names Carbocaine, Polocaine, Isocaine
• amide
• xylidine derivative
• onset, duration, potency, allergenicity, and toxicity similar to lidocaine, though it is less dialating, has less CV effects and lasts longer
  
• infiltration, block, spinal, epidural, caudal, but not effective as topical
• does NOT used epinepherine as it's vasoconstrictor, uses levonordefrin
• available as 2% with 1:20,000 levonordefrin (Neo-Cobefrin) vasoconstrictor or 3% plain bc it produces less vasodilation than lidocaine (used only for very short procedures.
  

• brand names: Citanest, Citanest Forte
• amide
• a toluidine derivative
• less potent  and less toxic than lidocaine, slightly longer duration
• methemoglobinemia (hemoglobin incapable of transporting oxygen) has been reported with excessive doses. Avoid in pts where oxygenation is critical.
  
• Available as 4% plain and 4% 1:200,000 (forte)

• an adverse reaction to Clindamycin
• can be fatal
• black, mucusy, bloody stool
  

• brand name:Marcaine
• amide
• xylidine derivative
• the only long acting LA, 90-180 min pulpal, 4-9 hours soft tissue- great for post op pain and/or long procedures
• able to be long duration bc it has a stronger bind in the Na+ channel
• more potent and less toxic than other amides
• slightly longer onset time than lidocaine
• infiltration, block, peridural
• available as 0.5% with 1:200,00 epi

• brand name: Novocaine
• use in dentistry is historical
• PABA ester- not available for injection in the US as too many ppl are allergic
• slow onset, short duration
• half the toxicity and potency of lidocaine
• infiltration, block, spinal, epidural, and caudal, (no topical)
• in dentistry 2% procaine onlyused in combo with the stronger 0.4% propoxycaine.
• Available as either 1:20,000 levonordefrin, or 1:30,000 levarteronol vasoconstrictor.

• brand name : Pontocaine

• PABA ester
• use in dentristry is historical
• slow onset, long duration
• 10 times as potent and  toxic as procaine
• max dose of 20 mg topically (sold as Viractin for cold sores)
• available as sprays, solutions, and ointments usually at 2%

• brand name: Hurricaine
• most commonly used topical anesthetic (lido is the 2nd most common topical)
• dental product 20% benzocaine
• ester
• poorly soluable, therefore poorly absorbed w low systemic toxicity
• can produce contact dermatitis in operator if gloves not used
• available OTC for many topical applications

• expressed as a %
• 100% means 1Gm/ml or 1,000mg/ml
• therefore 2% means 0.02 of 1,000 mg/ml which equals 20 mg/ml.

• Each carpule contains 1.8 ml so the amount of LA is calculated by 1.8 X 20 mg/ml = 36 mg

• 100% means 1,000 mg/ml
• 4% means .04 X 1,000 mg/ml = 40 mg/ml
• multiply this by the number of mls per carpule which is 1.8: 1.8 X 40 mg/carpule = 72 mg

• expressed as Gm:ml
• 1:100,000 means 1 gram/100,000 ml or                1,000 mg/ 100,000 ml
• which can be reduced to 0.01 mg/ml

• We know each carpule contains 1.8 ml
• so multiply 1.8 X 0.01 = .018mg of vasoconstrictor

• expressed as Gm/ml
• 1:200,000 means 1 gm/ 200:000 ml, or           1,000 mg / 200,000 ml
• which can be reduced to .01mg/2ml

• Now set up the equation to determine how many mg for 1.8 mls:
  •    0.01 mg/ 2ml = xmg / 1.8ml
  • = 0.009 mg / 1.8 ml              

• decrease blood flow to the injection site
• decrease absorption into the CVS
• prolong and increase depth of anesthesia
• reduce toxic effect by delaying absorption
• reduce hemorrhage at injection site

• primarily by reuptake by adrenergic nerves
• the rest is rapidly inactivated in the blood by catechol-0-methylthransferase (COMT) and monamine oxidase (both are present in the liver)
• only about 1% is excreted in urine

1. behavioral: anxiety reduced at low doses (dental use). Causes drowisness or sleep at high doses
   
2. anticonvulsant- increases seizure threshold
3. muscle relaxant- of skeletal muscles
4. tx of insomina

• stimilates receptors for melatonin in the brain
• melatonin and its receptors control the ciccadean rhythem of the body, that in turn controls the sleep/wake cycle
• not addictive
• not a controlled substance (where as benzodiazepines are Class IV)

• similar to benzodiazapines but newer
• examples
  • Sontata (zalephlon) Class IV
  • Lunesta (eszopidone) Class IV
  • Ambien (zolpidem) Class IV
• effects last 1-3 hours
• T 1/2 = 1 hr
• remember these are NOT benzos

• oral is most common in dental settings
• IV requires advanced training and being prepared to handle potentially serious medical emergencies
• equipment for respiratory and cardiovascular assistance must be available
• it is recommended that practitioners stick with the same 1 or 2 drugs so they will become very familar with them

• exert their effects on the CNS
• increases effect of inhibitory transmitter GABA
  • acts as minor tranquilizer

• well absorbed orally
• IM dose gives slow, erratic and unpredictable results
• highly protein bound, present in un-ionized form (lipid soluble)
• crosses blood brain barrier easily
• crosses placenta easily and can accumulate infetus

• class IV so addiction is possible
• CNS depression (with tolerance built over time)
• amnesia (sometimes the desired rather than adverse effect)
• respiratory- none at normal doses
• CVS- decrease in BP and HR as a result of resolving anxiety
• visual- diplopia (double vision), nystagmus (oscillation of eyes), blurred vision
• dental effects- xerostomia,  swollen tongue, bitter/metalic taste (very uncommon)
• phlebitis: when propylene glycol is used to stabilize diazepam (Valium)
• pregnacy- avoid in the 1st trimester (could cause cleft lip/palate, microencephaly, GI and cardio abnormalities) Near term admin has resulted in floppy infant syndrom

• produces superior amnesia (often used for oral surgery)
• does not contain propalyine glycol (which can cause phlebitis)
• has a shorter 1/2 life

1. anxiety control: genreral, panic disorder, post traumatic stress disorder
2. insomnia management: reduces time it takes to fall asleep, and time spent in REM (dreaming). May also reduce bruxism from the reduced REM sleep.
3. Epilepsy: diazepam (Valium) IV can arrest a status elipeptious seizure. No oral value.
4. tx of alcoholism: reduces signs and symptoms of accute withdrawl
5. control of muscle spasms: used with multiple sclerosis and cerebral palsy.  Also back pain spams.
6. premedication: used prior to general anesthesisa in hospital settings.

• primarily to reduce preop anxiety
• downside- pts cannot drive themselves so they need to find a ride

• all produce various degrees of tranquilization, from anti-anxiety to conscious sedation
• triazolam (Halcyon): fast onset, short half-life
• diazepam (Valium): very fast onset, long half-life (24-36 hrs, so not a good sleep aid)
• lorazepam (Ativan): intermediate onset, short half-life, currently more popular than Valium

• occurance is very rare due to high therapeutic index
• Emesis, activated charcoal, saline cathartic.
• Monitor respirations and BP
• Flumazenil (Mazicon) used IV- agonist which revers CNS depression

• an anti-anxiety agent of its own class (not a benzo)
• unique, only agent in its group
• mechanism unknown
• anxioselective: as anxiolytic effect w/o hypnotic, convulsant or mucsle relaxing properties
• may not be addictive

• class of anti-anxiety agents that have been almost completely replaced with benzodiazepines due to abuse
• still used as anticonvulsants, and to induce general anesthesia
• Some are Class II drugs
• have lower therapeutic index so it is much easier to over dose

• absorption: well absorbed orally and rectally
• metabolism: short and intermeiate acting are almost completely metabolized by the liver. Long acting excreted mostly as free drug via the kidneys.
• avoid in pts with liver or kidney damage

1. CNS depression: small doses=sedation, large doses=disinhibiation and euphoria. Large doses can lead to cardiac arrest. Effects speed up when mixed w alcohol
2. analgeisa: but pts still require a normal analgisic agent as well
3. anticonvulsant: phenobarbital (long lasting) used to tx epilepsy (Class IV)

• sedative/hypnotic doses: relatively safe, though may cause harm to fetus
• anesthetic doses: can be lethal
• acute poisoning: 10-15 x hypnotic dose, death due to respirtory failure
• chronic long term use: progressive depression, tolerance (not to lethal dose), cross tolerance with other anti-anxiety agents
• contraindicated with family hx of porphyria
  • pt has enzyme disfunction that will be exaserbated by barbitureates and lead to build of products that the pt cannot break down.

• barbiturates are potent stimulators of liver microsomal enzymes.
• They increase the rate of destruction of other drugs and thereby reduces their duration of action
• Example: phenytoin (Dilantin), Doxycycline, Warfarin, Estrogens, etc

• Ultra short acting-thiopental
  • induction of general anesthesia
• short and intermediate acting-
  
  • have little medical value and have been replaced by benzodiazepiens
• long acting- phenobarbital
  • epilepsy

• Chloral hydrate ( "mickey finn" - date rape drug)
  • traditionally used for children in pedo dental offices
  • inexpensive, orally effective
  • rapid onset (20-30 min)
  • sort duration (4 hours)
  • no respiratory or CVS dperesssion at therapeutic doses
  • GI irritation- dilute with food or milk
  • childrens hypnotic dose: 50mg/kg up to a max of 1 gm.
• meprobamate (miltown, equanil)
  • hx of abuse
  • sedative, anticonvulsant, anti anxiety, muscle relaxant
  • few side effects
  • OD= CNS depression, CVS and respiratory depression, unconcsiousness, death
  • additive effect when mixedwith other CNS depressants
  • congential malformations in 1st trimester of pregnancy

• reduced sensation to pain
• pt is conscious
• can respond to commands
• reflexes intact
• respiration is regular
• some degree of amnesia may occur
  

• begins with unconsciousness
• involuntary movement and excitement
• respiration irregular
• muscle tone decreases
• emesis (vomiting) and incontinence
• tachycardia, mydriasis (dilated pupils), hypertension
• ultrashort acting barbiturates used to get pt through stage I and II as fast as possible
  • examples: Brevital, Pentothal and Surital

•  most major surgery preformed at this stage
• return of regular respiratory movements
• muscle relaxation
• normal HR and pulse
• conjuncitvel and eyelid reflexes disappear
  

• complete cessation of all respiration and circulatory failure
• pupils maximally dilated
• blood pressure falls
• leads to death if not rapidly reversed

1. IV
2. inhalation gas (when using N20 can't get to stage 3 without use of an additional drug)
3. inhalation of volatile liquids eg ether, halogenated hydrocarbons (halothane, ethrane)

• phlebitis
  • caused by solvent in verset, which is not found in valium
• respiratory depression
• cardiac depression

• used in many dental office, esp oral surgery
• almost always given by IV
• commonly uses a combo of either
  • Demoral + Valium   or
  • Demeroal+ Versed
• if not a combo of drugs, then a single benzodiazepine is used
• The reason concious sedation is used is bc the pt retains their reflexs (kinda important to retain gag/cough reflex when you have lots of stuff in your mouth)

• relief of both anxiety and pain is frequently required in the pt
• sedatives potentiate analgesic agents (enhance)
• sedatives may induce excitiation when given with out an analgesic to pts with uncontrolled pain

• young, old, or debilitated pts may experiance exaggerated effects due to impared elimination
• avoid alcohol and other CNS depressants
• warm pt against driving or signing important papers (impared alertness and muscle control)
• limit use of these drugs due to abuse potenial
• limit Rx to a minimum to reduce possiblity of use for suicide
• never administer to a pregnant pt without very carefully weighing alternatives
• sedatives do not provide analgesia

• general anesthetics are potent CNS depressants that produce
  • reversible loss of consciousness
  • insensibility to pain
• the pt must be monitiured bc of
  
  • respiratory depression
  • loss of protective reflexes

• IV
  • opiods
    • morphine, fentanyl
    • prolonged resiratory depression is a disadvantage of these
  • ultra short acting barbiturates
    • rapid onset
    • may have prolonged recovery due to build up in tissues
    • no analgesia produced- must use additional anesthetic
  • benzodiazapines
    • midazolam (Versed) used for induction of anesthesai
    • water soluable
    • short duration
  • ketamine (also used IM)

• volatile liquids
  • halogenated hydrocarbons(contain fluorine, chlorine, or bromine)
  • chloroform, trichlorethyline (no longer used)
  • halothane (Fluothane) rarely used
    • fruity pleasant flavor
    • non flammable, non explosive
    • rapid induction and recovery
    • safe for usewith asthmatics
    • incomplete muscle relaxation
    • depresses renal function
    • bradycardia, peripheral vasodiation, hypotention
    • sensitizes myocardium to epinephrine which leads to arrhythmias and ventricular fibrillation
    • causal relationship w postanesthetic hepatisis (has reduced popularity

• enflurane (Ethrane) currently used
  • pleasant smell
  • rapid induction and recovery
  • depresses respiration (requires ventilator)
  • requires supplemental muscle relaxants
  • BP reduced
  • sensitization of mycardium to epinephrine is less than w halothane
  • excessive motor activity possible
  • no hepatoxicity
  • transient depression of renal function
    

• reduces fertility in females
  • only a concern for the clinicians who have long term exposure compared to pts
• still need to use anesthetic
• nausea- most common side effect
• causes hysteria if you administer too much
  

• a general anesthetic
• colorless, little odor
• low potency, can't be used for general anesthesia alone bc it would take 100% nitrous (noO2) to acheive stage 3
• it is the least soluable in the blood and tissues compared to other anesthetic gasses
• used synergistically with IV agent and in combo w a volatile anestheic to produce excellant balanced anestheisa

• rapid onset
• colorless
• odorless
• very safe
• analgesic- in kids may not need additional anesthetic
• anxiolytic- most common use for dentistry
• amnesic
• rapid recovery
• easy to administer through nasal hood
• close control- easy to adjust level
• acceptable for children
• dental team is more relaxed if pt is more relazed

• must be properlly made and installed
• fail safe-does not allow clinician to deliver N20 w/o O2
• cannot be installed w crossed lines (color codes, pin indices, etc)
• automatic min flow of 2.5-3.0 of 02
• nitrous alarm with light and sound to alert clinician to low pressure in the line
• use of scavenging system to exhaust exhaled gass out of the room

• start pt with 100% 02
• adjust slowly adding N20 by 20% per min
• usual flow of N20 in dentistry is 30-50%
• have pt breath 100%02 for 3-5 min at the end
• evaluate pt before dismissing

• happens if nasal hood is removed before giving pt adequate amount of 100% 02
• causes sudden out flow of N20, 02, and C02 from lungs
• loss of C02, which is a stimulant for breathing, can result in hypoxia
• similar to "the bends"

• CNS: analgeisa, amnesai
• circulatory: slight if any
• respiratory: slight if any
• GI: neasuea and vomiting are uncommon but possible w larger doses

• respiratory disorder
  • COPD, emphysema
• emotional instability
• pregnacy
• infectious disease- bc you can't sterilize the tubing

• numbness and paresthesia in hands and legs
• may progress to more severe neuological symtoms
• liver and kidney problems also possible