dentalDocument from Aditya.pptx Islam Irish

Italian halal

1. ANESTHESIA FOR DENTAL PROCEDURES Presenter : Dr . Jyotsna Moderator : Dr . Rajeshwar Reddy

2. Dental anesthesia Anesthesia started with dentistry Horace wells administered himself nitrous oxide – his colleague extracted his tooth in 1844 . In 1846, morton did it again !! Three types of anesthesia Out - patient anesthesia Day - care anesthesia In - patient anesthesia

3. Out - patient anesthesia Dental chair anesthesia Simple extraction of teeth (exodontia) especially in children. Conservative dentistry. Simple and short duration procedures. Incision and drinages . Indications:- Children Anxious/ apprehensive patients Mentally retarded Failure of local anesthesia Sedation for out patient dentistry: Conscious sedation, is a carefully controlled technique in which a single intravenous drug or combination of oxygen and nitrous oxide is used, but allows verbal contact with patients to be maintained at all the time.

4.   Problems in dental chair Venous return decrease Venous embolism Unprotected airway Aspiration of blood or mucus  Adrenaline in local anesthetic can cause arrhythmias in presence of halothane. Higher incidence of  arrhythmias due to stimulation of 5th cranial nerve. Fainting due to cerebral hypoxia. Difficulty in initiating CPR once cardiac arrest occurs. Foreign body obstruction of the airway by needles or dentures, necessitating removal by bronchoscopy.

5. Day - care anesthesia Patient goes through formal admission to hospital but is discharged home later in day . Usually adults Procedures - limited dental extraction, such as impacted wisdom teeth - minor oral surgical procedures In case of emergency if airway management is needed , naso -tracheal intubation tray must be ready along with bite block and throat pack.

6. In - patient anesthesia Impacted wisdom teeth where considerable surgery is anticipated. Extraction of 4 wisdom teeth together. Major oral and maxillofacial surgeries involving :- - major orthognathic surgery for skeletal malocclusion. - facial trauma & fractures . Eg :- mandibular fractures & midfacial fractures - radical cancer surgeries . Eg :- maxillectomy & mandibulectomy

7. Operative procedures require cutting through sensitive structures, producing extreme discomfort and pain. Pain is a result of stimulation of nociceptors that are receptors preferentially sensitive to a noxious stimulus ( Aδ , C fiber afferent axons ) Local anesthetics (LA) cause : reversible block sensory nerve conduction of noxious stimuli from periphery to the CNS.

8. Anesthesia techniques Local anesthetics Topical infiltration - Small nerve endings in the small area of soft tissue or bone are flooded with small amount of local anesthetic solution Regional nerve blocks - The local anesthetic solution is given within close proximity to a main peripheral nerve. Field blocks - Local anesthetic is deposited near a larger nerve trunks. Conscious sedation General anesthesia

9. Local infiltration :- The effectiveness of local anesthetics is improved by the addition of a vasoconstrictor: Decrease absorption of local anesthetic into blood, thus increasing duration of anesthesia & decreasing toxicity. Generally performed by operating dentist Local anesthetics with or without adrenaline is used to perform various techniques & nerve blocks These can be combined with conscious sedation. Role :- Decrease intraoperative and postoperative pain. Decrease amount of general anesthetics used in the OR Increase patients cooperation Diagnostic testing/examination

10. Oral nerve blocks Indications : Dento - alveolar abscess Tooth ache, pulpitis, or root impaction Orofacial laceration repair Post extraction pain, including dry socket Dento -alveolar trauma or fractures Maxillary & mandibular fractures

11. Maxillary Nerve Anesthesia Pulpal anesthesia : is given via the apical foramen to anesthetize the pulp tissue. Periodontal : through the interdental and inter radicular branches Palatal : soft and hard tissues of the palatal periodontium (e.g. gingiva, periodontal ligaments, alveolar bone) PSA block : recommended for maxillary molar teeth and associated buccal tissues in ONE quadrant MSA block : recommended for maxillary premolars and associated buccal tissues ASA block : recommended for maxillary canine and the incisors in ONE quadrant Greater palatine block : recommended for palatal tissues distal to the maxillary canine in ONE quadrant Nasopalatine block : recommended for palatal tissues between the right and left maxillary canines

12. PSA Block Anesthetize the pulps and periodontal ligaments of the maxillary molars, corresponding buccal alveolar bone and gingival tissue and posterior portion of the maxillary sinus. Technique - between 1st and 2nd molar at a height of insertion of mucobuccal fold, angle at 45° superiorly and medially.

13. MSA Block Can be indicated for surgery on maxillary pre-molars and buccal root of 1st molar. Target area : MSA nerve block is given at the apex of the maxillary 2nd premolar - needle inserted into the mucobuccal fold

14. ASA Block U sed in conjunction with an MSA block The ASA nerve can cross the midline of the maxilla onto the opposite side . Used in procedures involving the maxillary canines and incisors and their associated facial tissues Anesthetize the pulp tissue + the gingiva, periodontal ligaments and alveolar bone in that area. Target site : ASA nerve block is given at the apex of mucobuccal fold of maxillary canine.

15. Greater Palatine Nerve Block Anesthetize all palatal mucosa of the side injected and lingual gingiva posterior to the maxillary canines and corresponding bone. Technique - on the hard palate between the 2nd & 3rd molars approximately 1cm medially. Nasopalatine Nerve Block Anesthetize the anterior maxillary six teeth from canine one side to canine on other side. Technique - Drug injected approximately 1.5 cm posterior to the alveolar crest between the central incisors.

16. Mandibular nerve Blocks  Infiltration is not as successful as maxillary anesthesia substantial variability in the anatomy of landmarks when compared to the maxilla Pulpal anesthesia Periodontal : through the interdental and inter radicular branches. Inferior alveolar block : for mandibular teeth + associated lingual tissues and for the facial tissues anterior to the mandibular 1st molar. Buccal block: tissues of the mandibular molars Mental block : facial tissues anterior to the mental foramen (mandibular premolars and anterior teeth) Incisive block : for teeth and facial tissue anterior to the mental foramen Gow -gates: most of the mandibular nerve for quadrant dentistry.

17. Inferior Alveolar Nerve Block F or extractions and restorative lingual periodontal anesthesia, facial periodontal anesthesia of anterior mandibular teeth and premolars. Target : Anesthetic solution is injected at the retromolar triangle which is a triangular area located near to the distal side of the lower third molar.

18. Mental & Incisive Nerve Block : Nerves anesthetized: Mental & incisive nerves. Regions anesthetized: Lower lip, Mucosa anterior to mental foramen, teeth anterior to second premolar . Gow -Gates Nerve Block : It is an intraoral mandibular nerve block given at neck of condyle & provides hard & soft tissue anesthesia of mandible upto the midline. Mandibular nerve & its branches are blocked including its auriculotemporal subdivision.

19. Local anesthetics complications Tachycardia, hence this should be avoided in patients at risk of cardiovascular disease particularly when used with a vaso -constrictor. Post injection hyper-occlusion, pain and chewing soreness are other symptoms reported. Allergic reaction :- More common with ester based local anesthetics. Most allergies are due to preservatives in local anesthetics. Methylparaben Sodium metabisulfite

20. Local anesthesia complications Needle breakage Pain on injection Burning on injection Nerve injury (Persistent anesthesia/ parathesia ) Trismus (Trauma to muscles) Hematoma Infection Edema Tissue sloughing Facial nerve paralysis ( Intraglandular injections) LAST

21. Nerve Injury Paresthesia (loss of sensation) commonly involve the tongue and lower lip. Hyperesthesia (increased sensitivity to painful stimuli ) Xerostomia (reduced salivation) - the chorda tympani is traumatized Ocular and extraocular symptoms : The passive diffusion of anesthetic through the orbit leads to ocular and extraocular symptoms: - paralysis extraocular muscle - diplopia - temporary blindness - Horner´s syndrome ( enophthalmos , miosis , palpebral ptosis)

22. LOCAL ANESTHETIC SYSTEMIC TOXICITY Adverse reactions proportional to plasma concentration. All system are affected but specially CNS & CVS. CNS TOXICITY :- LA produces stimulation followed by CNS depression as inhibitory neurons are blocked first. CLINICAL FEATURES: CNS excitation – agitation, confusion, twitching, seizures, convulsions CNS depression – drowsiness, coma, apnea . NON specific CNS- metallic taste, circumoral parathesia , tinnitus, dizziness CVS SIGN – initially – hypertension, tachycardia or hypotension or bradycardia CVS hallmark- ventricular ectopic, multiform ventricular tachycardia, ventricular fibrillation . progressive hypotension and bradycardia leading to Asystole and later to cardiac arrest.

23. TREATMENT Early recognition Immediately stop LA administration Call for help Secure airway & 100% O2 supplement – intubate if required. Control seizures – benzodiazepines - inj. Midazolam 0.2mg/kg bolus repeat after 5 min infusion 2mg/kg/hr. Shock – use IV fluid and vasopressin Ventricular arrhythmia – I nj amiodarone 150 mg over 10 minutes. INTRA-LIPID TREATMENT • Mechanism- increase clearance by extraction of LA from cardiac tissue. Inj . 20% intralipid – 1.5ml/kg over 1 minutes (100ml) I nfusion @ 0.25ml/kg/min ( 500ml over 30 mins) . Infuse for minimum 30 mins.

24. Conscious sedation A minimally depressed level of consciousness, that retains the patient’s ability to maintain an airway independently & respond appropriately to physical stimulation & verbal commands. Indications: In anxious patient in combination with nerve blocks with local anesthesia. Complex dental work Those patients with movement disorders with physical/mental defects unlikely allowing safe completion of treatment. For patients with severe gag reflex To avoid general anesthesia to avoid risks related to GA Medical conditions potentially aggravated by stress & affecting the patient’s ability to cooperate. Types : Inhalational sedation Intravenous sedation Oral sedation

25. General anesthesia It is required for three main groups of patients: ( i ) Patient with learning difficulties ( ii) For extraction of permanent molars more complex or extensive dental work ( iii) In-patient anesthesia for maxillofacial surgery (Congenital, cosmetic, Traumatic and Neoplasm)

26. Conduct of anesthesia for facio -maxillary surgeries Preoperative Assessment All patients require an appropriate and adequate preoperative assessment to define: The extent of disease progression, in particular, looking for indicators of potential airway compromise, Anticipated difficulties in airway management, and Significant comorbidities and selected pathological conditions that influence airway management e.g cervical instability in trauma , Associated hemodynamics unstability . Other concerns regarding trauma ,intraoperative blood loss ,post operative airway problems(airway edema)

27. Airway management in Facio -maxillary surgery Choice of the airway managment technique depends on several factors: Patients factors(Known difficult airway ) Experience of the anesthetist Surgical requirements (nasal or oral ) Ultimately depends on the patient’s safety

28. Physical Examination Besides from general and systemic examination detailed airway assesment is must.

29. Airway strategies LMA Oral intubation Nasal intubation Retromolar intubation Submental intubation Retrograde intubation Fiberoptic aided intubation Trans-tracheal catheter and jet ventilation Planned tracheostomy

30. Nasal intubation Nasal intubation with a flexometallic ETT or a preformed nasal (north facing) preferred Nasal patency should be checked Nasal passage is well prepared with a vasoconstrictor .   Contraindications Midface instability (Le fort II & III) Suspected basilar skull fracture CSF rhinorrhea Coagulopathy Disadvantages : The presence of nasotracheal tube can interfere with the surgical reconstruction of naso - orbital - ethmoid (NOE) complex. Postoperative ventilation or suctioning are difficult through a nasal tube owing to its length and contour. Bleeding , sinusitis and pharyngeal abscess are occasional complications.

31. Retromolar intubation The retromolar space -space behind the last erupted upper and lower molar teeth. The retromolar tube - stabilized in position by fixation to 1st or 2nd molar tooth . Advantages : Adequate space for intubation when mouth opening restricted. Can be performed in complete mandibular occlusion . Provides a nobel alternatives to tracheostomy.

32. Submento -tracheal intubation Provides a secure airway, optimal field, allows maxillo -mandibular fixation while avoiding the drawbacks and complications of nasotracheal intubation and tracheostomy. After induction of general anesthesia - orotracheal intubation is achieved with an armoured tracheal tube (with a detachable connector). 1.5cm skin incision - made in the submental region just medial to the lower border of mandible. Artery forceps - introduced through the submental incision towards the floor of the mouth.

33. Through the given incision the deflated pilot tube cuff along with the tube is pulled out through the submental incision. Connector is reattached and ventilation is checked. At the end of the surgery, the tube is pulled back into the oral cavity and extubated when patient is awake. Requires adequate mouth opening for the initial orotracheal intubation.

34. Retrograde intubation Catheter-over-needle with attached syringe is inserted through cricothyroid membrane in a cephalad direction. Entering the lower airway allows more space for advancing the tube. Free air aspiration confirms the location . Local anesthesia should be injected through the syringe. The needle and syringe are removed, and a guide wire is inserted through the catheter. Guide wire is advanced cephalad until it emerges at the oral cavity or nares. Tracheal tube can be threaded over the guide wire, with either through the Murphy eye or main lumen. The tracheal tube is advanced until it reaches the point where the guide wire enters the airway. The guide wire is removed from above and the tracheal tube inserted to a proper depth.

35. Fiberoptic Aided intubation Indications Anticipated difficult intubation Unanticipated difficult intubation Lower and upper airway obstructions Unstable or fixed cervical spine disease Contraindications Hypoxia Significant airway secretions not relieved with anti-sialagogues and suction. Airway bleeding not relieved by suction. LA allergy Inability to cooperate

36. Glosso -Pharyngeal Nerve Block : - It is most easily blocked where it crosses the palatoglossal arch. It can be blocked using one of three methods: Topical spray application, Direct mucosal contact of soaked pledgets , Direct infiltration by injection.

37. Superior Laryngeal Nerve Block Direct infiltration is accomplished at the level of the thyrohyoid membrane inferior to the cornu of the hyoid bone. A reliable block with a definite endpoint is effected by retracting the needle marginally after contacting the greater cornu and injecting 2mL of local anesthetic after negative aspiration.

38. Transtracheal block Translaryngeal block of the recurrent laryngeal nerve is accomplished at the level of the cricothyroid membrane . A 10-mL syringe with a needle is advanced until air is aspirated into the syringe. 4 ml of local anesthetic was injected, inducing coughing that disperses the local anesthetic.

39. Monitoring and Equipment's Minimum ASA monitoring standards must be met. Etco2 :to confirm tracheal intubation , to detect disconnection ,detect Venous air embolism. Urine output monitoring: in extensive surgery A full range of resuscitation equipment and drugs must be available. Difficult airway trolley should be checked and immediately available . Invasive lines : Neck dissection, Major prolonged surgery.

40. Intraoperative concerns and Management 1 . Eye Protection : Pads, shields or surgical covers. 2 . Remote location in relation to airway : Adequate fixation of the airway and circuit connections For north-facing tubes or LMAs,- gauze padding on the forehead under nasal tubes. South-facing airways-taped securely away from the surgical site. Tube holders to stabilize the circuit. 3 . Airway edema : Injection dexamethasone 4 . Positioning : Once drapes are applied to the patient, head is supported and stabilized in a horseshoe support or head ring, with a bolster under shoulders to extend the neck. P ressure points protected and vascular access points made accessible.

41. 5 . Anti-emetics : Prophylaxis of PONV :- 5 HT3 Blockers- Ondansetron 6 . Lower airway needs protection against soiling from blood and debris intra operatively - throat packing is done. 7 . Substantial blood loss : Extensive blood supply to mid-face (maxillary artery/Pterygoid venous plexus) Methods to decrease : Slight head-up positioning Controlled hypotension(Hypotensive anesthesia) Local infiltration with adrenaline Tranexamic acid .

42. Emergence and recovery Antagonizing n euromuscular blocking agents. 100% oxygen administered and any anesthetic agents discontinued . Pharyngeal packs should be removed and the pharynx cleared of secretions and debris by suction. The patient should be turned into the lateral position, possibly with a degree of head- down tilt to encourage the drainage of any blood or secretions away from the larynx. Possibility of post-operative tissue edema - Careful assessment of tongue and pharynx. Cuff leak test.

43. Postoperative Management Supplemental oxygenation . Adequate pain control with opioids, NSAIDS, acetaminophen. PONV issues treated with antiemetic. Airway problems continuously monitored-for airway edema ,hematoma compressing neck in case of surgery involving neck. Airway compromised state-continue intubation and mechanical ventilation postoperatively. Ongoing/extensive bleeding may need to be replaced. Fluid and electrolyte supplementation. Nutrition supplement.

44. Thank you