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ANESTHESIA for Dental & MAXILLOFACIAL SURGERY SAAD A. SHETA MBChB, MA, MD Associate Professor, Anesthesia Dental College KSU Dental Anesthesia I. Out-Patient anesthesia II. Day-Case anesthesia III. In-Patient anesthesia V. Emergency Surgery Out-Patient Dental Anesthesia Dental Chair Anesthesia Out-Patient Dental Anesthesia Dental Chair Anesthesia Out-Patient dental extraction Children (4-10 years): URTI Steadily decreased Out-Patient Dental Anesthesia Induction Inhalational (mask) induction Intravenous Induction Out-Patient Dental Anesthesia Maintenance Inhalational agents/N2O Maintain airway Posture (Supine Position) Less hypotension less bradycardia However high risk of aspiration high risk of Airway obstruction Out-Patient Dental Anesthesia Recovery Left lateral position 100% O2 Suction Observation & monitoring Discharge criteria Instructions Analgesia (NSAIDs) Out-Patient Dental Anesthesia Complications Respiratory Complications Cardiovascular Complications Syncope Allergic Reaction Respiratory Complications Airway Obstruction Respiratory Depression Cardiovascular Complications Hypotension Bradycardia Dysrhythmias Aetiology (Tachy-arrhythmias) (Tooth extraction) High preoperative catecholamines Light anesthesia Airway obstruction & hypoxia Halothane & local anesthesia Local anesthesia with vasopressors Syncope Causes Previous factors (CV, allergic,..) Emotional factors (more common) Aetiology limbic cortex-hypothalamus-reflex vasodilatation Increase parasympathetic activity-bradycardia Management Head down-leg elevated 100% O2 Cessation of anesthesia Allergic Reaction Incidence Very rare More commonly (vaso-vagal, toxic reaction, epinephrine) Aetiology Ig E-mediated reaction Easter-linked: p-amino benzoic acid Amide-linked: preservatives (Paraben) Manifestations Management Day-Case Dental Anesthesia Minor Oral Surgery& Conservative Dentistry Day-Case Dental Anesthesia Concerns Rapid Recovery Minimal Postoperative Morbidity Remote Location Day-Case Dental Anesthesia Minor oral surgery and conservative dentistry Limited surgery No significant risk of complications Standard criteria of patient selection (ASAI&II) Day-Case Dental Anesthesia Anesthetic Technique Induction • Inhalational (pediatrics) or Intravenous (propofol) • Airway Intubation Nasal Endotracheal tube Oral intubation LMA Nasal mask& Nasophryngeal airway NDMR (short acting) Suxamethonium (Postoperative Mylegia) Deep Inhalational Anesthesia Propofol & Alfentanil • Moist Pharyngeal Pack Day-Case Dental Anesthesia Anesthetic Technique Maintenance • Inhalational • Ventilation Sevoflurane Isoflurane Halothane (slow recovery & cardiac arrhythmias) Spontaneous (Short procedure) Controlled ventilation • Extubation Throat pack removed Very light anesthesia (recommended) Patient turned to one side Day-Case Dental Anesthesia Anesthetic Technique Recovery& PO • Minimum 2 hrs • Pain Control NSAIDs (IM diclofenac) Short acting opioids Local analgesic block (2Quadrants only ) Preoperative Dexamethazone • Discharge Assessment (Morbidity) Written instructions Contact telephone number Possible overnight admission In-Patient Dental Anesthesia Major Oral & Fasciomaxillary Surgery In-Patient Dental Anesthesia Classifications: Major Orthognathic Surgery Tumor Surgery Palate Surgery In-Patient Dental Anesthesia Concerns: Altered Airway Anatomy Shared Operative Field Anesthetic Drugs Choice Appropriate Time for Tracheal Extubation Airway Management Anesthetic Management Airway Management Airway Management Choice of the technique depends on several factors: Patient safety Experience of the anesthetist Known difficult airway Requirement: nasal or oral Post operative jaw wiring Airway Management History Physical Examination Further Evaluation Difficult Airway & Algorism Airway Strategies History Documented History of Difficulties with general anesthesia or, more specifically, mask ventilation or endotracheal intubation Congenital Syndromes Associated With Difficult Endotracheal Intubation Pathologic States That Influence Airway Management Selected Congenital Syndromes Associated With Difficult Endotracheal Intubation SYNDROME Down DESCRIPTION Large tongue, small mouth make laryngoscopy difficult; small subglottic diameter possible Laryngospasm frequent Goldenhar Mandibular hypoplasia and cervical spine abnormality make laryngoscopy difficult Klippel-Feil Neck rigidity because of cervical vertebral fusion Pierre Robin Small mouth, large tongue, mandibular anomaly; awake intubation essential in neonate Treacher Collins (mandibulofacial dysostosis) Laryngoscopy difficult Turner High likelihood of difficult intubation Selected Pathologic States That Influence Airway Management PATHOLOGIC STATE DIFFICULTY Infectious epiglottitis Laryngoscopy may worsen obstruction Abscess (submandibular, retropharyngeal, Ludwig‘s angina) Distortion of airway renders mask ventilation or intubation extremely difficult Croup, bronchitis, pneumonia (current or recent) Airway irritability with tendency for cough, laryngospasm, bronchospasm Maxillary/mandibular injury Airway obstruction, difficult mask ventilation, and intubation; cricothyroidotomy may be necessary with combined injuries Laryngeal fracture Airway obstruction may worsen during instrumentation Cervical spine injury Neck manipulation may traumatize spinal cord Selected Pathologic States That Influence Airway Management PATHOLOGIC STATE DIFFICULTY Upper airway tumors Inspiratory obstruction with spontaneous ventilation Lower airway tumors Airway obstruction not relieved by tracheal intubation Radiation therapy Fibrosis may distort airway or make manipulations difficult Inflammatory rheumatoid arthritis Mandibular hypoplasia, temporomandibular joint arthritis, immobile cervical spine, laryngeal rotation, cricoarytenoid arthritis all make intubation difficult and hazardous Ankylosing spondylitis Direct laryngoscopy maybe impossible Soft tissue, neck injury (edema, bleeding, emphysema) Anatomic distortion of airway Laryngeal edema (postintubation) Irritable airway, narrowed laryngeal inlet Selected Pathologic States That Influence Airway Management PATHOLOGIC STATE Angioedema DIFFICULTY Obstructive swelling renders ventilation and intubation difficult Endocrine/metabolic Large tongue, bony overgrowths acromegaly Diabetes mellitus Reduced mobility of atlanto-occipital joint Hypothyroidism Large tongue, abnormal soft tissue (myxedema) make ventilation and intubation difficult Thyromegaly Extrinsic airway compression or deviation Obesity Upper with loss of consciousness airway obstruction Tissue mass makes successful mask ventilation unlikely Physical Examination Inspection (Obvious Problems) Mouth Opening (3 – 4cm) Oral Cavity Examination Mallampati Score Thyromental Distance (3 large fingers = 5 cm) Neck Movement Further Evaluation PRE-OPERATIVE ASSESSMENT OF THE AIRWAY » Indirect or Fiberoptic Laryngoscopy » X ray: Chest , Cervical Spine » CT or MRI » Flow- Volume Loops » Pulmonary Function Tests Cormack-Lehane Laryngeal View Scoring Difficult Airway Difficult airway The clinical situation in which a conventionally trained anesthesiologist experiences difficulty with mask ventilation, difficulty with tracheal intubation, or both Difficult mask ventilation 1) inability of unassisted anesthesiologist to maintain SpO2 > 90% using 100% oxygen and positive pressure mask ventilation in a patient whose SpO2 was 90% before anesthetic intervention; Or 2) inability of the unassisted anesthesiologist to prevent or reverse signs of inadequate ventilation during positive pressure mask ventilation Difficult Airway Difficult Laryngoscopy Not being able to see any part of the vocal cords with conventional laryngoscopy Difficult Intubation Proper insertion with conventional laryngoscopy requires either : a) > 3 attempts b) > 10min Airway Management Normal Airway Difficult Airway Awake or Sedated Under GA Difficult Airway Awake Under GA/Sedation Awake Laryngoscopy Different Laryngoscopes, Stylets Awake Fiberoptic LMA/ I LMA/FO Tracheostomy Fiberoptic Retrograde Intubation Tracheostomy Blind Nasal Intubation AWAKE TECHNIQUES Difficult Airway Awake Awake Laryngoscopy Awake Fiberoptic Tracheostomy Retrograde Intubation AWAKE TECHNIQUES Glosso-Pharyngeal Nerve IX Nerve Posterior pharyngeal fold at its midpoint, 1 cm deep to the mucosa of the lateral pharyngeal wall AWAKE TECHNIQUES Superior Laryngeal Nerve Pyriform Fossa External :1 cm medial to the superior cornu of the Hyoid Bone to pierce the thyrohyoid membrane AWAKE TECHNIQUES Trachea & Vocal Cord Atomizer Injection AWAKE TECHNIQUES Laryngoscope Blades AWAKE TECHNIQUES McCoy AWAKE TECHNIQUES AWAKE TECHNIQUES FIBER OPTIC INTUBATION AWAKE TECHNIQUES SURGICAL AIRWAY Under General Anesthesia Chidren / Uncoaperative Adults / Sepsis Assess / Anticholinergic / Anxiolytic ( if any) 1) Inhalational / asses: Ventilation / Veiw 2) Stillete / Different Laryngeoscopes (=/- short acting MR) 3) LMA / LMA + F.O. Face Mask + F.O. + Modified Oral AW 4) F.O using Sedation Or light GA 5) Tracheosyomy under light GA 6) Blind Nasal Technique GA TECHNIQUES Laryngoscope Blades GA TECHNIQUES McCoy GA TECHNIQUES Laryngeal Mask Airway (LMA) GA TECHNIQUES LIGHTED STYLETS/LIGHTWAND Well Circumscribed Glow GA TECHNIQUES Unconventional LMA F.O. + LMA Fast Track LMA GA TECHNIQUES Blind Nasal Intubation 90% successful but may need several attempts Contraindicated in fractured base of skull Cervical collar in situ GA TECHNIQUES FIBER OPTIC INTUBATION GA TECHNIQUES Rigid Fiberoptic laryngoscope Retromolar Fiberscope GA TECHNIQUES BULLARD LARYNGOSCOPE GA TECHNIQUES SURGICAL AIRWAY Classification According to Mouth Opening Awake or Sedated Normal mouth opening SLN block +Transtracheal LA Limited Retrograde Intubation Extremely limited Awake Intubation with F.O. Awake Intubation Under Anesthesia Spontaneously Risk of apnea with breathing awake difficulty mask patient without the risk ventilation of apnea Suitable for patients Suitable for patients with no obstructive with obstructive symptoms symptoms Needs patient’s cooperation Success rate in good experienced hands Risk of complications from nerve block Incase of failure , can be postponed for reconsideration Failure to intubate may result in fatal outcome Multiple attempts may lead to bleeding and/or aspiration Blind Technique Blind technique such as BNI, Light wand, Retrograde wire intubation, LMA, and Combi tube are C/I in tumor patients because of the risk of bleeding and tumor dislodgement. Techniques Under Vision Awake Laryngoscopic Fiberoptic Intubation Under GA Tracheostomy Blind Techniques Retrograde Wire Intubation Lighted Stylet/ Light wand Combi-Tube Blind Nasal Intubation Modified Techniques Wu Scope Bullard Laryngoscope NEVER PARALYSE UNTILL POSSIBLE VENTILATION HAS BEEN ESTABLISHED RECENT SUCCESSFUL INTUBATION DOESNOT MEAN FUTURE POSSIBLE INTUBATION FULL RANGE OF DIFICULT INTUBATION EQUIPMENT MUST BE AVAILABLE ALL PHYSICIANS RESPONSIBLE FOR AIRWAY MANAGEMENT SHOULD BE PRACTICED IN AT LEAST ONE ALTERNATE TO BAG & MASK VENTILATION. THESE ALTERNATIVE INCLUDES THE FOLLOWING: LARYNGEAL MASK AIRWAY COMBI TUBE TRANSTRACHEAL TECHNIQUES LMA PROVIDE RESCUE VENTILATION IN 94% OF CASES OF UNANTICIPATED DIFFICULT INTUBATION HAVING DISCUSSED ALL THE MANAGEMENT STRATEGIES AWAKE TECHNIQUE IN GENERAL & AWAKE FIBER OPTIC TECHNIQUE ESPECIALLY, IS THE MOST COMMONLY USED & SAFE TECHNIQUE ANESTHESIA MANAGEMENT Special Consideration Preoperative Management Intraoperative Management Post operative Management PRE-OPERATIVE PROBLEMS Elderly, Chronically Debilitated Patients Malnourished H/O Heavy Smoking with Resultant COPD H/O Alcoholism Co-existing disease such as HTN,D.M, IHD, etc. PRE-OPERATIVE MANAGEMENT Adequate pre-operative work-up of Cardiac Status & Pulmonary Functions should be carried out using various diagnostic modalities with the objective of optimizing patient’s condition RECONSTRUCTIVE MAXILLOFACIAL SURGERY Problems: Major problem: Airway Management Extensive, long operation Significant blood loss Poor nutritional status Micro-vascular surgery » » » » Caution with Vasoconstrictors Caution with Transfusion Caution with Diurresis Blood Rheology (Hct:25-27) INTRA-OPERATIVE Routine Monitoring NIBP ECG SPO2 ETCO2 TEMPERATURE Choice of Volatile Agent Choice of Anesthesia INTRA-OPERATIVE MANAGEMENT SPECIAL CONSIDERATIONS Two large bore canulae Invasive blood pressure monitoring Central venous pressure monitoring Use of muscle relaxants Induced hypotension Blood loss & transfusion Haemodynamic changes Venous air embolism INTRA-OPERATIVE MANAGEMENT Two Large Bore Canulae After induction of anesthesia, two large bore canulae can be put in large veins so that rapid fluid replacement can be carried out in case need arises. INTRA-OPERATIVE MANAGEMENT Invasive Blood Pressure Monitoring is indicated due to following reasons : Blood loss may be rapid secondary to Neck dissection Pre operative radiotherapy Surgery close to big vessels of neck Frequent fluctuations in the blood pressure due to manipulation in the area of carotid body and sinus. INTRA-OPERATIVE MANAGEMENT Central Venous Pressure Monitoring Risk of venous air embolism during neck dissection As a guide to the management of fluid therapy The site of insertion is either: Antecubital vein Femoral vein INTRAOPERATIVE MANAGEMENT Use of Muscle Relaxants During surgery IPPV is carried out without muscle relaxant as surgeons need to identify the nerves during surgery INTRAOPERATIVE MANAGEMENT Induced Hypotension Mild degree of hypotension is required during surgery to reduce the blood loss. This can be achieved by following: » » » » 15-30 degree head up tilt Increasing the conc. of volatile anesthetics Use of peripheral vasodilators Use of beta blockers INTRAOPERATIVE MANAGEMENT Blood Transfusion Before the decision of blood transfusion the following points should be considered Patient’s underlying medical condition Possibility of risks of transfusion hazards Increased risk of post-transfusion cancer recurrence as a result of immune suppression INTRAOPERATIVE MANAGEMENT Haemodynamic Changes During radical neck dissection, the traction or pressure on the carotid sinus and / or stellate ganglion can cause following:» Brady-dysrhythmias » Sinus arrest leading to asystole » Wide swings in blood pressure » Prolonged QT Interval INTRAOPERATIVE MANAGEMENT Haemodynamic Changes “Treatment” Immediate cessation of the stimulus Blockage of the sinus with local anesthetic by the surgeon Vagolysis by atropine INTRAOPERATIVE MANAGEMENT Venous Air Embolism When the venous pressure in neck veins is low and these veins are open to atmosphere, air is sucked in causing air embolism. Diagnosis » » » » Early Detection Hypoxia Hypotension Hypocarbia INTRAOPERATIVE MANAGEMENT Venous Air Embolism Treatment Compression of neck veins Positive pressure ventilation Place the patient in the left lateral position Aspiration of air through the central venous catheter Ionotropes POST-OPERATIVE CARE I. ROUTINE CARE II. SPECIAL CONSIDRATIONS ICU care & Possible mechanical Ventilation Hemodynamic Instability Analgesia Tracheostomy POST-OPERATIVE CARE ICU Care & Possible Mechanical Ventilation Patient should be kept in the intensive care unit for 24-48 hours Prolonged Surgery Airway Oedema Co-existing diseases Risk of bleeding and/or neck hematoma POST-OPERATIVE CARE Haemodynamic Instability As bilateral neck dissection may result in post-operative hypertension and hypoxic drive because of the denervation of the carotid sinus and carotid body POST-OPERATIVE CARE Analgesia Non Steroidal Anti-inflammatory Agents should be used as opioids cause respiratory depression in spontaneously breathing patients When patient is on ventilator opioid analgesia can be given POST-OPERATIVE CARE Tracheostomy Care Humidified Oxygen Intermittent Suction Sterile Precautions Adjustment of cuff pressure to15-20 mmHg Complications THANK YOU