sedation and general anesthesia in dentistry
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Sedation and general anesthesia in dentistryTRANSCRIPT
Sedation and General Anesthesia in Dentistry
Assistant professor : Akram Thabet NasherB.D.S, M.Sc. , Ph.D.
Head department of oral and maxillofacial surgeryFaculty of Dentistry- Sana`a university
Anesthesia
The practice of various psychological,
physical, and chemical approaches to the
prevention and treatment of preoperative,
operative, and postoperative anxiety and
pain.
Sedation and General Anesthesia Dr.Akram Thabet
Levels of Anesthesia
Local anesthesia
Conscious Sedation
Deep Sedation
General Anesthesia
Sedation and General Anesthesia Dr.Akram Thabet
Local Anesthesia
Local, or regional, anesthesia involves the
injection or application of an anesthetic
drug to a specific area of the body. It
eliminates sensation and pain in a local
area of the body without loss of
consciousness. Sedation and General Anesthesia Dr.Akram Thabet
According to the degree of CNS depression:
◦Conscious Sedation
◦Deep Sedation
◦General Anesthesia
Sedation and General Anesthesia Dr.Akram Thabet
Sedation
It is a technique where one or more drugs
are used to depress the Central Nervous
System of a patient thus reducing the
awareness of the patient to his surrounding.
Sedation and General Anesthesia Dr.Akram Thabet
Conscious Sedation It is a controlled, pharmacologically
Induced, minimally depressed level of
consciousness that retains the patient’s
ability to maintain a patent airway
independently and continuously and
respond appropriately to physical and/or
verbal command. ventilatory and cardiovascular functions are
unaffected Sedation and General Anesthesia Dr.Akram Thabet
Deep Sedation
It is a controlled, pharmacologically induced state of
depressed level of consciousness , from which the
patient is not easily aroused and which may be
accompanied by a partial loss of protective reflexes,
including the ability to maintain a patent airway
independently and/or respond purposefully to
physical stimulation or verbal commands.
Sedation and General Anesthesia Dr.Akram Thabet
General Anesthesia
The elimination of all sensations
accompanied by the loss of consciousness.
Sometimes, the two phrases (GA & Deep
Sedation) refer to one physiologic
state.Sedation and General Anesthesia Dr.Akram Thabet
Sedation and General Anesthesia Dr.Akram Thabet
Sedation and General Anesthesia Dr.Akram Thabet
Sedation and General Anesthesia Dr.Akram Thabet
Risks of Anesthesia
low
high
N20Anxiolysis
LocalAnesthesia
ConsciousSedation
DeepSedation
GeneralAnesthesia
Fundamental Concepts: It is easy to drift from one state to another.
Any anesthetic/sedative/opioid regardless of route of administration can be a general anesthetic (can cause unconsciousness)
Patient state is considered in terms of the level of consciousness rather than the technique involved.
Sedation techniques are not pain-control techniques.
Sedation and General Anesthesia Dr.Akram Thabet
Indications:1- Behaviorally challenged patients (stressful and fearful patients).
2- Young children
3- Mentally retarded Patients
4- Major operations in oral and maxillofacial surgery
5- Stressful Procedure ( multiple 3 rd Molar extractions, Interosseous implants ,complex periodontal surgery)
6- Gagging reflexes
7- Local Anesthesia problems
8- Medically compromised patients
Sedation and General Anesthesia Dr.Akram Thabet
Routes of Administration: Enteral – any technique of administration in which the agent is
absorbed through the gastrointestinal (GI) tract or oral mucosa [i.e., oral, rectal, sublingual].
Parenteral – a technique of administration in which the drug bypasses the gastrointestinal (GI) tract [i.e., intramuscular (IM), intravenous (IV), intranasal (IN), submucosal (SM), subcutaneous (SC), intraosseous (IO)].
Transdermal – a technique of administration in which the drug is administered by patch or iontophoresis through skin.
Transmucosal – a technique of administration in which the drug is administered across mucosa such as intranasal, sublingual, or rectal.
Inhalation – a technique of administration in which a gaseous or volatile agent is introduced into the lungs and whose primary effect is due to absorption through the gas/blood interface.
Sedation and General Anesthesia Dr.Akram Thabet
Sedation
Anxiolysis
Interactive
Arousable
Airway is maintained
Protective reflexes are intact
Responses to command are intact
Sleeplike state
Non-Interactive
Non- arousable(except with tense stimulation)
Inability to maintain airway
Partial loss of reflexes
Difficult to respond to command
Cons. Sedation Deep Sedation Minimally Depressed Consciousness Deeply depressed consciousness
Sedation and General Anesthesia Dr.Akram Thabet
Sedation techniques Non - titrable Technique
Oral SedationRectal SedationIntramuscular SedationSubmucosal SedationIntranasal Sedation
Titrable TechniqueInhalational SedationIntravenous Sedation
Combination Of the two Sedation and General Anesthesia Dr.Akram Thabet
I- Oral Sedation By far, it is the most universally accepted and
easiest method of sedation administration.
The most variable (non-titrable) technique
Recovery time prolonged
Difficult to reverse unwanted effect
Utilizing escort
No repeated doses
Sedation and General Anesthesia Dr.Akram Thabet
Advantages of Oral SedationUniversal acceptabilityEase of administrationLow costIncidence of adverse reactions less than
some other techniquesNo needles, syringes or special techniquesVarious drugs, dosage forms availableAllergic reactions less severe than seen in
parenteral administration No specialized training
Sedation and General Anesthesia Dr.Akram Thabet
Disadvantages of oral Route Reliance on patient cooperation
Prolonged onset
Erratic absorption, unpredictable effect
Inability to titrate to effect
Inability to readily lighten or deepen
Prolonged duration of effect
Adverse interactions of sedative drugsSedation and General Anesthesia Dr.Akram Thabet
Contraindications to oral SedationSevere dental anxiety & fear
High probability of adverse drug interaction
Poor past experience with oral sedation
Allergy to drug being used
Other drug contraindications (pregnancy ,
glaucoma, etc.)
Need for rapid onset and/or rapid recovery
Sedation and General Anesthesia Dr.Akram Thabet
Factors Influencing Oral Drug AbsorptionLipid solubilitypH of gastric tissuesMucosal surface areaGastric emptying timeDosage form of drugDrug inactivation (“first pass effect”)Presence of food in stomachBioavailability of drugGenetics
Sedation and General Anesthesia Dr.Akram Thabet
II- Inhalational SedationNitrous oxide/oxygen inhalation sedation is
the most commonly used technique in dentistry for sedation .
Nitrous oxide/oxygen (N²O/O²) sedation is a combination of these gases that the patient inhales to help eliminate fear and to help the patient relax.
Sedation and General Anesthesia Dr.Akram Thabet
Equipments
Continuous flow design
with flow meters
Safe delivery of O2 and
N2O.
Pin-indexed yoke system
Efficient scavenger
Sedation and General Anesthesia Dr.Akram Thabet
Nasal Mask
Sedation and General Anesthesia Dr.Akram Thabet
Advantages of Nitrous OxideRapid onset (almost equal to that of IV. administration ) Ability to titrate & to reverseDepth of sedation readily alteredFlexible duration of action Rapid recovery from sedationSafeNo injection requiredVery few side effectsNo adverse effects on vital organsPatient can be discharged aloneNon addictive.Produces stage I anesthesia. Dulls the perception of pain. Sedation and General Anesthesia
Dr.Akram Thabet
Disadvantages of Nitrous Oxide
Initial cost of cumbersome equipment is high
Continuing costs of gases high
Equipment takes up operatory space
Requires constant patient cooperation
Chronic exposure of office personnel can cause
Carcinogenicity , Teratogenicity or Toxicity
Not always effectiveSedation and General Anesthesia Dr.Akram Thabet
Relative Contraindications to Inhalation Sedation:
Severe dental anxiety & fearCompulsive personalitiesPoor past experience with oral sedationPregnancyURI, COPDNasal obstruction: Problems inhaling through the
noseEmphysema: Increased O²
Multiple sclerosis: Breathing difficultiesEmotional stability: Altered perception of reality
Sedation and General Anesthesia Dr.Akram Thabet
Potential Problems Diffusion hypoxia
Vomiting
Toxicity: inhibit vitamin B12 dependent enzymes (Pernicious anemia)
Reproductive Abnormalities
Sedation and General Anesthesia Dr.Akram Thabet
Administration of Inhalation sedationStart with pure oxygen while establishing the
patient’s tidal volume.Slowly titrate the nitrous oxide until the desired
results are achieved. Patients should refrain from talking or mouth
breathing. The N²O/O² analgesia should end with the
administration of 100% O² for 3 to 5 minutes. Obtain postoperative vital signs and compare
them to the preoperative recordings.
Sedation and General Anesthesia Dr.Akram Thabet
How to reduce N²O hazards to dental personnel ??
◦Use a scavenger system. ◦Use a patient mask that fits well.◦Discourage patients from talking. ◦Vent gas outside the building. ◦Routinely inspect equipment and hoses
for leaks. ◦Use an N²O monitoring badge system.
Sedation and General Anesthesia Dr.Akram Thabet
III- Intravenous SedationAntianxiety drugs that are administered
intravenously continuously throughout the procedure at a slower rate, providing a deeper stage I analgesia.
The most rapid technique; onset is approximately 20 to 25 seconds.
In children under 6 years, the incidence of untoward effects is increased
Sedation and General Anesthesia Dr.Akram Thabet
Drugs for sedations :
Either one drug or combinations of IV drugs
Commonest combinationsBenzodiazepines & opioidsPropofol & opioids
Sedation and General Anesthesia Dr.Akram Thabet
Valium (Diazepam)BenzodiazepineProduces sleepiness and relief of apprehensionOnset of action 1-5 minutesHalf-life
◦ 30 hours◦ Active metabolites
Average sedative dose◦ 10-12 mg
Sedation and General Anesthesia Dr.Akram Thabet
Versed (Midazolam)Short acting benzodiazepine
◦ 4 times more potent than ValiumProduces sleepiness and relief of apprehensionOnset of action 3-5 minutesHalf-life
◦ 1.2-12.3 hoursAverage sedative dose
◦ 2.5-7.5 mg
Sedation and General Anesthesia Dr.Akram Thabet
Demerol (Meperidine)NarcoticPain attenuation and some sedationOnset of action
◦3-5 minutesHalf-life
◦30-45 minutesAverage dose
◦20-50 mg
Sedation and General Anesthesia Dr.Akram Thabet
Fentanyl (Sublimaze)Narcotic/Opiod agonist
◦100 times more potent than MorphinePain attenuation and some sedationOnset of action around 1 minuteHalf-life
◦30-60 minutesAverage dose
◦0.05 – 0.06 mg
Sedation and General Anesthesia Dr.Akram Thabet
Additional MedicationsLikely to be seen in scenarios where
deeper levels of sedation are being performed◦Propofol (Diprivan)◦Robinul (Glycopyrrolate)
Sedation and General Anesthesia Dr.Akram Thabet
Propofol (Diprivan)Intravenous anesthetic/sedative hypnoticSedative, anesthetic and some antiemetic
propertiesOnset of action within 30 secondsHalf-life
◦2-4 minutesAverage sedative dose
◦Varies
Sedation and General Anesthesia Dr.Akram Thabet
Robinul (Glycopyrrolate)Anticholinergic
◦Heart rate increases◦Salivary secretions decrease
Dose 0.1-0.2 mgOnset of action within 1 minute
Sedation and General Anesthesia Dr.Akram Thabet
General anesthesia
Stages of General AnesthesiaStage I “Conscious Sedation”
◦AnalgesiaStage II
◦DeliriumStage III (“Deep Sedation/General Anesthesia)◦Surgical anesthesia
Stage IV◦Medullary paralysis
Sedation and General Anesthesia Dr.Akram Thabet
Four Stages of Anesthesia:Stage I: Analgesia is the stage at which a
patient is relaxed and fully conscious. The patient is able to keep his or her mouth open without assistance and is capable of following directions. The patient will have a sense of euphoria and a reduction in pain. Vital signs are normal. Depending on the agent used, the patient can move into different levels of analgesia.
Sedation and General Anesthesia Dr.Akram Thabet
Stage II: Excitement is the stage at which a patient is less aware of his or her immediate surroundings and can start to become unconscious. The patient can become excited and unmanageable. Nausea and vomiting can occur. This is an undesirable stage.
Sedation and General Anesthesia Dr.Akram Thabet
Stage III: This stage of General anesthesia in which the patient becomes calm after stage II. This is the favorable stage for doing surgery. The patient feels no pain or sensation. The patient will become unconscious. This stage of anesthesia can be met only under the guidance of an anesthesiologist in a controlled environment such as a hospital.
Sedation and General Anesthesia Dr.Akram Thabet
Stage IV: Respiratory failure or cardiac arrest is the stage at which the lungs and heart slow down or stop functioning. If this stage is not reversed quickly, the patient will die.
Sedation and General Anesthesia Dr.Akram Thabet
Intubation in GA. For maintenance of respiration :
Sedation and General Anesthesia Dr.Akram Thabet
Sedation and General Anesthesia Dr.Akram Thabet
Types of General AnestheticsInduction agents( begins the anesthesia)
◦ Induction agents usually administered IV ◦can be inhalational for those who do not
tolerate IV access
Maintenance agents (maintain the anaestheisa)◦Maintenance agents usually administered
inhalationally or IV with bolus or continuous infusion technique
Sedation and General Anesthesia Dr.Akram Thabet
Routes for Delivery of General Anesthetics
Intravenous (IV)
Inhalational
Sedation and General Anesthesia Dr.Akram Thabet
Structural formulas of anesthetic drugs.Sedation and General Anesthesia Dr.Akram Thabet
General Anesthetics-Intravenous Agents
Primary role as induction agents Maintenance with total intravenous anesthesia
◦ Rapid redistribution◦ Shorter half lives◦ Environmental risk of inhalational agents
Rapid distribution to vessel rich tissues High lipid solubility allows for rapid induction When redistributed out of the brain, the effect decreases Advantages
◦ Rapid and complete induction◦ Less CV depression
Sedation and General Anesthesia Dr.Akram Thabet
General Anesthetics-Intravenous Agents
The most commonly drugs used in GA:1- Benzodiazepines2- Opioids3- Ketamine4- Methohexital5- Propofol
Sedation and General Anesthesia Dr.Akram Thabet
General Anesthetics-Inhalational Agents
1- Nitrous Oxide2- Sevoflurane3- Desflurane4- Isoflurane (Forane)5- Halothane
Sedation and General Anesthesia Dr.Akram Thabet
Technician Responsibilities
Pre anesthetic Evaluation‐
“Never treat a stranger”
Never do anesthesia on a patient you have
not previously evaluated.
Never sedate or aesthesis
on first patient visit
Always have a consultation first!
Sedation and General Anesthesia Dr.Akram Thabet
Pre anesthetic Examination‐
Physical examination Evaluation of anxiety level Review of medical history Review medications and drug allergies Assign ASA classification Review prior sedation / anesthetic history Obtain informed consent Give pre sedation/ anesthesia instructions‐
Sedation and General Anesthesia Dr.Akram Thabet
Medical historyDiseases to evaluate: HTN;, asthma, COPD, URI, DMPregnancy; psychiatric renal; hepatic problems Obesity; sleep apnea; etc Medications Prior anesthetic experience Allergies Hospitalizations
Sedation and General Anesthesia Dr.Akram Thabet
Physical Examination Vital signs Appearance Height, Weight, & BMI (Body Mass Index) Mental & psychological status Cardiac & pulmonary level ;Exercise tolerance (“if they can walk up 2
flights of stairs to your office, they’re probably ok for anesthesia”)
Airway evaluationSedation and General Anesthesia Dr.Akram Thabet
Airway Evaluation BMI (Body Mass Index)History of obstructive sleep apnea, snoring Mallampati scoreProtrusive (ask: “bite your upper lip with your
lower teeth”) TMJ range of motion (oral opening) Neck circumference
Sedation and General Anesthesia Dr.Akram Thabet
Airway patency
Sedation and General Anesthesia Dr.Akram Thabet
ASA Physical Classification IA normal healthy patient
II A patient with mild systemic disease
III A patient with severe systemic
IVA patient with severe systemic
disease that is a constant threat to life
VA moribund patient who is not expected
to survive without the operationSedation and General Anesthesia Dr.Akram Thabet
Pre-Procedure Patient Assessment◦ Investigations :◦ECG, echo ◦Chest – x-ray◦CBC◦BT,CT ,PT T, PT ,INR◦Na , k◦R.B.S or F.B.S◦LFT◦KFT ◦HBs-Ag◦HIV Sedation and General Anesthesia
Dr.Akram Thabet
Medical Consultations
After doing the medical and physical
examination with the full investigations; the
patient should be evaluated by a medical
doctor or anesthetist to do a medical
fitness for him to receive the anesthesia.
Sedation and General Anesthesia Dr.Akram Thabet
Informed Consent It’s a process, not a piece of paper.Verbal and written informed consent must be given at the
pre op consultation appointment, not the day of surgery‐Cannot be obtained once medications are administered.New written consent must be obtained for each procedure
or sedation.Consent to surgery does not imply consent for sedation;
sedation needs to be specified.Consent must be obtained by the doctor in face to face ‐ ‐
meeting, not a staff member.
Sedation and General Anesthesia Dr.Akram Thabet
Pre Sedation/anesthetic Instructions‐
Give both verbally and in writing
Fasting (“NPO”) instructions (if needed) “Vested” escort to accompany patient Patient’s other medications
Sedation and General Anesthesia Dr.Akram Thabet
Pre Procedure Fasting (“NPO”)‐
The patient must be fasted minimum 2-3
hours for clear liquids and 6 hours for
solid food to prevent vomiting causing
Suffocation and aspiration pneumonia.
Sedation and General Anesthesia Dr.Akram Thabet
Psychological preparation Psychological preparation of the patient for the sedation or
GA is paramount.
Explain the different types of sedation available and GA
techniques
Tell them they will be “relaxed, drowsy, comfortable,” and
“aware and in control.”
Give realistic expectations to patient and explain that every
patient reacts differently, and they may need more / less
medication or different technique at future appointments. Sedation and General Anesthesia Dr.Akram Thabet
Intraoperative Responsibilities ◦ Informed consent signed prior to sedation◦ Name, dose, route and time of all medications
documented◦ Procedure begin and end times◦ Prior adverse reactions◦ Pre-medication time and effect◦ Vital Signs
BP Heart Rate Respiratory Rate Oxygen Saturation Level of Consciousness
Sedation and General Anesthesia Dr.Akram Thabet
Monitoring
Level Of ConsciousnessClinical ObservationPulse OximetryPericardial/pretracheal StethoscopeBPECGMonitoring oxygenation
Sedation and General Anesthesia Dr.Akram Thabet
Sedation and General Anesthesia Dr.Akram Thabet
RecoveryPatients may continue to be at significant risk of
developing complications after procedure is completed.
Decreased procedural stimulation, delayed drug absorption, and slow drug elimination, may contribute to residual anesthesia or sedation and respiratory depression during the recovery period.
Patient must be kept in office under observation until completely recovered.
Sedation and General Anesthesia Dr.Akram Thabet
Post-operative Responsibilities ◦Vital Signs at least every 5 minutes
BP Heart Rate Respiratory Rate Oxygen Saturation Level of Consciousness
Sedated/ Anesthetized patients must be continuously monitored until discharged
Sedation and General Anesthesia Dr.Akram Thabet
Recommended Alarm Limits
Sedation and General Anesthesia Dr.Akram Thabet
Low High
Systolic BP 85150
Diastolic BP 50100
Oxygen Saturation 92100
Respiratory Rate 10 16
Heart Rate 60 90
Medical Emergency
SyncopeHypoglycemiaHypotensionHypertensionBronchospasm
LaryngospasmApneaMyocardial infarctionStroke
Sedation and General Anesthesia Dr.Akram Thabet
Medical Emergency
Know how to prevent, recognize, and treat
syncope (fainting)
◦Supplemental O2
◦Elevation of lower extremities
◦Trendelenburg
Be prepared to assist in airway management
Sedation and General Anesthesia Dr.Akram Thabet
Emergency DrugsFlumazenil (Romazicon)Naloxone (Narcan)Esmolol (Brevibloc)EphedrineEpinephrineAtropine
Sedation and General Anesthesia Dr.Akram Thabet
Flumazenil (Romazicon)Benzodiazepine antagonist
◦Versed reversal agentInitial dose – 0.2mg
◦May repeat at 1 minute intervals to dose of 1mg
Onset of action within 1-2 minutesMust monitor for re-sedation
◦May be repeated at 20 minute intervals as needed
Sedation and General Anesthesia Dr.Akram Thabet
Naloxone (Narcan)
Narcotic antagonist
◦Fentanyl reversal agent
Initial dose – 0.4mg
◦May repeat every 2-3 minutes at doses of
0.4-2mg
Monitor for re-sedation
Sedation and General Anesthesia Dr.Akram Thabet
Esmolol (Brevibloc)
Antihypertensive
Beta blocker
Initial dose 0.25 –1.0 mg/kg over 30
seconds
◦Short half-life of approximately 10 minutes
Sedation and General Anesthesia Dr.Akram Thabet
Ephedrine
Used for hypotension
Sympathomimetic
Initial dose 5-10mg
Action may not be seen for several
minutes
Sedation and General Anesthesia Dr.Akram Thabet
Atropine
Significant bradycardia
◦Slow heart beat or NO heartbeat
Anticholinergic
Initial dose 0.25 – 1.0 mg
◦May repeat every 3-5 minutes
◦Maximum total dose .03 mg/kg
Sedation and General Anesthesia Dr.Akram Thabet
Epinephrine
True emergency medication
Administration should be preceded by
activation of the emergency response
system
Sedation and General Anesthesia Dr.Akram Thabet
Discharge CriteriaVital signs normal (within 20% baseline) Airway patency uncompromised Patient awake, or awake on command Can breathe deeply Protective reflexes intact (can cough on command) Adequate hydration, able to drink Patient can speak normally Patient can sit unaided Patient can walk with minimal assistanceResponsible, “vested,” adult escort is availableNo pain, no nausea or vomiting,
Sedation and General Anesthesia Dr.Akram Thabet
Post sedation Instructions‐Verbal and written instructions must be given to
the escort upon discharge from the officeShould include:– Potential and anticipated post sedation effects‐–Limitation of activity (driving, machinery) x 24 hrs– Dietary precautions and suggestions– No other sedatives x 24 hrs– 24 hour contact number for practitioner
Sedation and General Anesthesia Dr.Akram Thabet
Thank You
Sedation and General Anesthesia Dr.Akram Thabet