General Anaesthesia for Dental Procedures Dr Walid Zuabi FCA RCSI Consultant Anesthetist JUH

Anaesthesia Terminology: An-  No Esthesia  Sensation

Sensations Peripheral: Pain Temperature Touch deep light Proprioception Special senses Central: Awareness:  Apprehension; Fear and Anxiety

Anaesthesia Implies reversibly rendering the patient unconscious by drugs for the execution of a painful operative procedure - in a titrated & controlled way.

Surgery Trauma  stress Metabolic Response to stress: Neural Component  Autonomic system - Sympathetic - Parasympathetic Endocrine Component  Hormonal System - Growth Hormone - Cortisol - glucagon - Antidiuretic - Renin & Aldosterone

Anaesthesia Modulates the stress response by blocking the afferent limb of the response Pain and awareness are blocked by anaesthetic drugs but other afferent limb factors are not/ Hypovolemia & hypoxemia  Complete medical management of the patient: pre, intra & post-op management.

Anaesthesia Modern Anaesthesia is Composed of: Hypnosis: Controlled Loss of Awareness Analgesia: Loss of Pain (+/-) Muscle Relaxation( Controlled muscle Paralysis)

Hypnosis *Hypnosis: The state of being asleep. Pharmacologically induced: non-physiological very deep level of sleep that deprives the patient from his control. Can and should be titrated according to the level of surgical stimulus

Analgesia * State of freedom from pain Analgesia vs. anaesthesia: Analgesia can be brought about by local or regional techniques, or drugs with specific pain receptors action ( Opioids) without Loss of consciousness.

Muscle Relaxation Paralyzing the patient’s skeletal muscles by use of drugs that block the acetylcholine receptors at the Neuromuscular junction Purposes: Facilitate airway management Prevents aspiration Control of Ventilation Facilitate Surgery Should patients be artificially ventilated!!

Stages of Anesthesia 2- Stage of uninhibited response (Excitement): Divided into Four planes according to the depth and marked by cessation of breathing at its lower end. 1- Stage of analgesia: Diminished pain perception while verbal contact & laryngopharyngeal reflexes and voluntary control Present 2- Stage of uninhibited response (Excitement): LOC, verbal contact & voluntary control  uncontrolled, exaggerated, withdrawal type response to any stimulus Protective laryngopharyngeal reflexes maintained !

Stages of Anesthesia (continued) 3- Stage of Surgical Anaesthesia: Centers of the medulla become progressively depressed (vomiting, striated muscle tone, respiratory) Autonomic reflexes depressed It is this stage at which anaesthesia has depressed both the reticular activating system and selectively the pain synapses of the spinal cord and is the stage at which operations may be performed

Stages of Anesthesia (continued) 4- Stage of Respiratory Arrest * Cessation of Respiration  Cardiac Arrest * Anoxia * Direct Cardiac effects: arrhythmias * Danger of Death

Stages of Anesthesia 1- Stage of analgesia: Diminished pain perception, verbal contact maintained laryngopharyngeal reflexes and present voluntary control. 2-Stage of uninhibited response/ Excitement Consciousness lost, verbal contact and voluntary control lost  uncontrolled, exaggerated, withdrawal type response to any stimulus Protective laryngopharyngeal reflexes maintained! 3- Stage of Surgical Anaesthesia: 4- Stage of Respiratory Arrest

In Dentistry 1- Local Anaesthesia 2- Sedation 3- General Anaesthesia

Dental Procedures Requiring General Anesthesia 1- Oral Surgery: Removal of impacted teeth Multiple extractions - Preprosthetic Surgery - Insertion of Osteointegrated implants

Dental Procedures Requiring General Anesthesia 2- Restorative Dentistry: Multiple dental restorative procedures - Procedures on special needs patients

Dental Procedures Requiring General Anesthesia 3-TMJ: Arthroscopy - Arthroplasty

Dental Procedures Requiring General Anesthesia 4- Maxillofacial Surgery: - Trauma - Tumors - Reconstructive

Dental Procedures Requiring General Anesthesia 5- Special patient groups: Young Children with systemic Diseases (hemophilia & CHD) Patients with poor controlled Seizures - Those with an oral septic focus

Summary of Fasting Recommendations

Summary of Fasting Recommendations Clear liquids 2 Hrs

Summary of Fasting Recommendations Clear liquids 2 Hrs Solids 6 Hrs

Summary of Fasting Recommendations Clear liquids 2 Hrs Solids 6 Hrs Nonhuman milk 6 Hrs

Summary of Fasting Recommendations Clear liquids 2 Hrs Solids 6 Hrs Nonhuman milk 6 Hrs Infant formula 6 Hrs

Summary of Fasting Recommendations Clear liquids 2 Hrs Solids 6 Hrs Nonhuman milk 6 Hrs Infant formula 6 Hrs Light meal 6 Hrs

Summary of Fasting Recommendations Clear liquids 2 Hrs Solids 6 Hrs Nonhuman milk 6 Hrs Infant formula 6 Hrs Light meal 6 Hrs Breast milk 4 Hrs

Preoperative Pharmacologic Interventions GI stimulants (metoclopramide) Block of gastric acid secretion H2 antagonists (cimetidine, ranitidine) PPI (omeprazole, lansoprazole) Antacids (sodium citrate) Antiemetics (ondansetron) Anticholinergics (atropine, glycopyrrolate)

Problems Related to Dental Anaesthesia 1- In & Outpatient selectivity 2- Competition for the Airway by both Dentist and Anaesthetist 3- Patients are often young 4- Mentally handicapped patients

Conduct of Anaesthesia Pre-Operative Assessment Intra-Operative Management Post-Operative Care

Pre-Operative Assessment - History: medical, surgical, anaesthetic & Allergy - Physical Examination - Investigations: accordingly.. INR or ECHO! - Informed Consent: signed by patient or guardian

Risk classification ASA I : A normal Healthy patient 0.06-0.08% ASA II : A patient with mild systemic disease 0.27-0.40% ASA III: A patient with severe systemic disease 1.8 - 4.3% ASA IV: A patient with severe systemic disease that is a constant threat to life 7.8 - 23% ASA V: Moribund patient who is not expected to survive without the operation 9.4-51% ASA VI: A declared brain dead patient whose organs are being removed for donor purposes “E” For Emergency surgery

Intra-Op Management 1- Establishing Monitoring: Heart Rate, Blood Pressure, Electrocardiogram, Pulse Ox & ETCO2 2- Induction of Anesthesia : Hypnosis => - Intravenous Drugs: (e.g. Sodium Thiopentone , Propofol, Etomidate, Ketamine Analgesia => - Nitrous Oxide gas - Opioid Drugs: Morphine, Pethidine, Fentanyl, Alfentanyl, Sufentanyl, Remifentanyl Muscle Relaxation => - Short Acting: Suxamethonium - Intermediate: Atracurium, Cisatracurium, Vecuronium, Rocuronium, - Long Acting: d-tudocurarine, Pancuronium

Intraoperative Management continued 3- Maintenance of Anaesthesia => - IV infusion for short acting drugs - Inhalational Agents for Hypnosis: (e.g. Halthane, Sevoflurane, Isoflurane , Enflurane, etc ) - Intermittent doses for intermediate or long acting muscle relaxants and analgesics

Intraoperative Management continued 4- Securing the Airway : * Using a Cuffed Endotracheal Tube - Orally - Nasally for surgical access * Throat pack * Meticulous Suctioning

Endotracheal Tube

Intraoperative Management continued 5- Securing Ventilation - Spontaneous Breathing - Manual ventilation - Ventilator/ PPV 6- Surgery Starts * Continuous Monitoring for - A,B,C - Adequate Anaesthesia -Necessary management

Intra-operative Issues Loose Teeth Surgical Debris Bleeding Secretions Use of Throat Pack Endocarditis Prophylaxis

Postop Management By anaesthetist 1- Emergence from Anesthesia * Anaesthetics off Recovery in Lateral Position * * Reversal of residual Muscle relaxation Anti-dote: Neostigmine with atropine * Extubation 2- PACU: Monitoring and Active Management 3- Assessment before Discharge By anaesthetist

Recovery Room Issues - Nursing in Lateral position - Management of complications: Pain, N&V, bleeding & hypoxia etc.. - Oral analgesia if sent home - NOT to Drive or operate machinery for 24 hours AND making sure that there is somebody to escort patient home.

In summary Understanding the concept, limits & limitations. The pharmacology of drugs used, when to & when not to use them. Pts selection & preparation. NPO Recognizing troubles and managing them. Postop care.