General anesthesia in oral and maxillofacial surgery

1. General Surgery
Mosul university- College of dentistry-oral & maxillofacial surgery department
Dr. Ziad H. Delemi
B.D.S, F.I.B.M.S (M.F.)
General Anaesthesia
In Dentistry

2. GENERAL ANAESTHESIA (G.A.)
Mosul university- College of dentistry-oral & maxillofacial surgery department

3. GENERAL ANAESTHESIA (G.A.)
Anaesthesia: (an: no, aesthesia:
sensation) so it is a reversible state of
unconsciousness during which the
reflex response to pain is abolished,
&keep the patient a life & prepare
optimal possible condition for surgery
or diagnosis.
Mosul university- College of dentistry-oral & maxillofacial surgery department

4. Indications of GA for dentistry:
1) Extent of surgery unsuitable for local
anaesthesia.
2) Lack of co-operation: young children, mentally
or physically debilitated patients.
3) Extreme nervousness, dental phobia.
4) Local anaesthetic ineffective (infection) or
contraindicated (allergy to local anaesthetic or
vasoconstrictor).
Mosul university- College of dentistry-oral & maxillofacial surgery department

5. 1. Cardiac disease.
2. Obstructive airways disease.
3. Active or recovering respiratory tract infection.
4. Upper airways obstruction.
5. Diabetes.
6. Anaemia.
7. Obesity.
8. Cerebrovascular disease.
9. Pregnancy.
Contra-indications to outpatient GA:
Mosul university- College of dentistry-oral & maxillofacial surgery department

6. Assessment is by history, observation,
physical examination + laboratory tests,
hemoglobin level (Hb.), chest radiograph
(CXR),electrocardiograph (ECG), blood
group (B.Gp), general urine examination
(G.U.E.), fast blood sugar (F.B.S.), serum
electrolyte.
Preoperative assessment
Mosul university- College of dentistry-oral & maxillofacial surgery department

7. All patients should have starved of clear fluids for
at least 2 hours and of solids for 6 hours prior to
induction of anaesthesia, take shower & cleaning
operated site & shaving the area of the operation if
there is a hair, emptying bladder, Written consent
must have been obtained from the patient, or
parent or legal guardian.
Preoperative preparation
Mosul university- College of dentistry-oral & maxillofacial surgery department

8. I.V. canula as a peripheral line one or more,
ECG leads and a pulse oximeter probe which
measures oxygen saturation and pulse rate are
attached, electocautery shield put under one
of the legs, & always check drugs emergency
kit.
Intraoperative preparation
Mosul university- College of dentistry-oral & maxillofacial surgery department

9. I.V. canula
Mosul university- College of dentistry-oral & maxillofacial surgery department

10. Anaesthetic drugs
Mosul university- College of dentistry-oral & maxillofacial surgery department

11. Artificial airway & IPPV
Mosul university- College of dentistry-oral & maxillofacial surgery department

12. Stage I
Analgesia (cough reflex)
Stage II
Disinhibition excitation (bad stage)
Stage III
Surgical anesthesia (working stage)
Stage IV
Medullary depression (death stage)
Stages of General Anesthesia
Mosul university- College of dentistry-oral & maxillofacial surgery department

13. 1- Sleep induction & loss of consciousness.
Skeletal muscle relaxation.
Intubation : Orotracheal, Nasotracheal, Tracheostomy
Loss of pain responses( analgesia ).
2- Maintenance of anaesthesia
3- Recovery
Technique of general anaesthesia
PHASES OF ANAESTHESIA
Mosul university- College of dentistry-oral & maxillofacial surgery department

14. Premedications
Anxiolyic agents:
-Diazepam 10mg I.V., Promethazine 50mg I.V.
Anticholinergic agents:
-Atropine 0.6mg I.V. , Hyosine 0.4mg I.V.
Analgesic agents:
-Morphine 15mg I.V., Pethidine 50-100mg I.V. Fentanyl 50µg
I.V. or Pentazocine 30 mg I.V.
Antiemetic agents:
-Metoclopramide 10mg I.V.
Antacid agents:
-Cimitidine 200mg I.V.
Mosul university- College of dentistry-oral & maxillofacial surgery department

15. Skeletal muscle relaxation drugs
It is used to get muscle relaxation for endotacheal
intubation.
1- Depolarizing agents:
Suxamethonium (scoline) rapid onset 45sec. Lasts
for 5min, No need for antidot.
2- Non depolarizing agents:
Tubocurarin (curari), Galamine long acting onset
3min. Lasts for 30 min. it need antidot cholinesterase
inhibitor {Neostigmine}so Atropin is needed also.
Mosul university- College of dentistry-oral & maxillofacial surgery department

16. 1- Induction (rendering the patient unconscious)
1-Inhalational induction: anaesthesia is induced with a mixture
of gases, oxygen (minimum 30%) &nitrous oxide &one of the
volatile anaesthetics (Halothane) the patient loses consciousness at
which stage it is important to prevent airway obstruction with the
tongue by lifting the jaw.
2-Intravenous induction: following injection of one of the
intravenous anaesthetic agents such as (propofol or Na+ thiopental
or Ketamine) the patient becomes unconscious in 30-45s. All of
these drugs cause respiratory depression and the patient’s
respiration may need to be assisted after their use.
PHASES OF ANAESTHESIA
Mosul university- College of dentistry-oral & maxillofacial surgery department

17. 2-Maintenance of anaesthesia (keeping the patient
unconscious) by inhalation of oxygen, nitrous oxide &
vapour, usually Halothane in lower concentrations than
those used at induction. However during dental surgery th
cannot be given by a full face mask covering the mouth
because the operator needs access to the mouth. This
problem is overcome by using one of three methods:
-Nasal mask
-Laryngeal mask
-Endotracheal intubation
PHASES OF ANAESTHESIA
Mosul university- College of dentistry-oral & maxillofacial surgery department

18. Monitoring the patient’s condition is of vital
importance. The patient’s color & respiration
& color of blood are observed. The pulse is
felt. As well as the ECG & pulse oximetry the
blood pressure is measured in longer cases,
before starting the procedure put the
pharyngeal pack.
Monitoring
Mosul university- College of dentistry-oral & maxillofacial surgery department

19. 3- Recovery
At the end of the operation the inhaled anaesthetic mixture is
replaced with 100% oxygen.. the pharyngeal pack should be
removed, The patient is placed on their side with the head down
and the jaw well supported.
In the recovery area the patient is still at risk of airway
obstruction, inhalation of blood/vomit , respiratory depression,
arrhythmias and hypotension. Recovery must be supervised by
trained staff who look after the patient continually until full
consciousness occurs. All patients should be nursed in the
recovery position with the jaw supported and with oxygen given
by mask and a pulse oximeter attached until they awake. Suction
must be available at all times.
Recovery
Mosul university- College of dentistry-oral & maxillofacial surgery department

20. 1-Airway obstruction - caused by the tongue falling back or dental
packs. In addition if foreign material touches the vocal cords they
may go into laryngospasm.
2-Respiratory depression - all the commonly used anaesthetic
drugs may cause respiratory depression. The anaesthetist must be
ready to reduce the amount of anaesthetic or assist respiration
wherever appropriate.
3-Inhalation of blood and debris - unconscious patient cannot
protect their airway due to a depressed cough or gag reflex. The
dental pack may not be properly placed or it may become soaked
with blood & become ineffective.
Complications
Mosul university- College of dentistry-oral & maxillofacial surgery department

21. Complications
4-Arrhythmias (abnormal heart rhythm) - these were very
common during dental extraction under halothane anaesthesia.
5-Hypotension (low blood pressure) - this is a side-effect of most
anaesthetic drugs. The effect is lessened by anaesthetizing the
patient in the supine position.
Remember that problems associated with anaesthesia such as
anaphylaxis, malignant hyperpyrexia, and post-operative nausea
and vomiting may occur in the dental surgery too.
Mosul university- College of dentistry-oral & maxillofacial surgery department

22. Rare, genetically susceptible
Tachycardia, hypertension, hyperkalemia, muscle
rigidity, and hyperthermia
Due to massive release of Ca++
Treat with dantrolene (Dantrium), lower elevated
temperature, and restore electrolyte imbalance
Malignant Hyperthermia
Mosul university- College of dentistry-oral & maxillofacial surgery department

23. Halothane (Fluothane):
 Volatile liquid
 Narrow margin of safety
 Less analgesia and muscle relaxation
 Hepatotoxic
 Reduced cardiac output leads to decrease in mean
arterial pressure
 Increased sensitization of myocardium to
catecholamines (local anaesthesia carpol)
Major types of G.A. agents
Mosul university- College of dentistry-oral & maxillofacial surgery department

24. Ketamine (Ketalar):
Dissociative anesthesia:
analgesia, and amnesia without loss of consciousness
Post-op emergence phenomena:
disorientation, illusions, vivid dreams
Cardiac stimulant
Major types of G.A. agents
Mosul university- College of dentistry-oral & maxillofacial surgery department