Ent scopies

ANAESTHESIA

1. Dr.D.SUVANKAR ANAESTHESIA IN ENT SCOPIES

2. Bronchoscopy Microlaryngoscopy Esophagoscopy

3. Bronchoscopy Bronchoscopy is an endoscopic technique to visualise the inside of the airways for diagnostic and therapeutic purposes.

4. History Killian- First Rigid bronchoscopy (1898) -Father of bronchoscopy Algernon Coolidge- First successful removal of tracheal foregion body Jackson- Lighted Bronchoscope Szigeti Ikeda- fibreoptic bronchoscope (1967)

5. Types 1.Rigid Bronchoscopy 2.Felxible bronchoscopy

6. Indications for Rigid Bronchoscopy Malignant or benign tumours Foreign bodies Palliative obstruction relief of the main airway Iatrogenic stenosis Extrinsic compression Intra‑ luminal tracheo‑bronchial repair of sealing defects Biopsies and cryotherapy

7. Contraindications Uncontrolled coagulopathy Extreme ventilation and oxygenation demands Tracheal obstruction

8. Challenges in Bronchoscopy Shared area of interest Instrumentation of airway Ventilation Inadequate starvation Depth of Anaesthesia Arrythmias

9. Foreign Body in AIRWAY Where ?? What ? When ?? Starvation?

10. Goals of anaesthesia in Bronchoscopy Maintenance of adequate ventilation and oxygenation Adequate depth of anesthesia, amnesia, analgesia Prevention of pulmonary aspiration Quick return of consciousness, respiratory drive and upper airway reflexes Minimization of secretions.

11. Preoperative evaluation Routine investigations Coagulation profile ABG PFT CT SCAN

12. Intra operative monitoring Pulse oximetry ECG NIBP ABG

13. Premedication Antisialogogues –Atropine Glycopyrrolete Antiemetics-Ondensetron Metoclopramide Benzodiazepines – Midazolam Opioids Bronchodilators

14. VENTILATION STRATEGIES IN BRONCHOSCOPY Apnoeic oxygenation Spontaneous assisted ventilation Controlled ventilation Manual jet ventilation High frequency jet ventilation.

15. 1.Apnoeic ventilation Preoxygenation Patient is hyperventilated to achieve profound hypocapnia Fine catheter is passed through trachea & oxygen insufflated at 15-20 liters/min through out the procedure TIVA & Muscle relaxant Rise in arterial co2 tension Not suitable for prolonged bronchoscopy Not more the 10 minutes procedure Works well in patients without significant pulmonary disease

16. 2.Spontaneous assisted ventilation TIVA Supplemental oxygen is given via rigid bronchoscope and the ventilation is assisted. Bronchoscope is introduced and the patient is ventilated with high flow oxygen manually. Muscle relaxants are not used Anaesthesia is maintained with repeated injections/infusion of intravenous drugs and ventilation assisted in case of apnoea or desaturation .

17. 3.Jet ventilation This method is based on Bernoulli’s principle High pressure gas source that is applied to the open airway in small bursts via a small catheter. Two techniques of jet ventilation A)Manual jet ventilation B)Automated jet ventilation

18. A)Manual jet ventilation Hand operated valve which is connected to 100% oxygen and the pressure is delivered at 50 psi or less . A jet frequency of 8-10 /min is sufficient to allow time for exhalation and prevents air trapping and barotrauma

19. Airway pressure monitoring I:E Ratio -1:4 Monitoring tidal volume is difficult Periodic CO2 and blood gas measurement or transcutaneous capnography may be used to assess ventilation.

20. B)Automated jet ventilation Higher respiratory rates 60-300 / min. The operator controls the applied pressure, respiratory rate and inspiratory time to maintain adequate oxygenation. High respiratory rate and low VT gives a ‘quiet’ procedure field Advantage -can be used in patients with bronchopleural,bronchoesophageal and bronchomediastinal fistula which requires low airway pressures.

21. 4)Controlled ventilation The bronchoscope is used like an endotracheal tube for positive pressure ventilation. Other ports are closed of rigid scope and packing of the oropharynx is done to minimize the leak Manual bag ventilation Limitations- operator judgement lack of control of FiO2with high flow rate and inappropriate delivery of inhalational agents

22. TIVA Opiods -to suppress airway reflexes and blunt adrenergic responses to pain Propofol or thoipentone can be used ,after induction propofol infusion of 100-200 ug /kg /min can be used to maintain depth of anaesthesia Muscle relaxants

23. Flexible Bronchoscopy

24. Anaesthesia for flexible bronchoscopy Antisialogogues Minimal sedation with benzodiaepines and opioids Dexmedetomidine Topical anaesthesia Blocks- Glossopharyngeal Block -Superior laryngeal nerve Block - Translaryngeal Block

25. Indications for flexible bronchoscopy Aspiration of retained secretions Bronchopulmonary lavage Placement of endotracheal tube in a difficult situation Laser resection of tumour Placement of airway stent Removal of foreign body Evaluation of airway

26. Contraindications- Absolute- Inability to maintain adequate oxygenation Operator inexperience Relative- Profound refractory hypoxemia Severe bleeding diathesis uncorrectable prior to the procedure

27. Anaesthesia for flexible bronchoscopy Antisialogogues Minimal sedation with benzodiaepines and opioids Dexmedetomidine Topical anaesthesia Blocks- Glossopharyngeal Block -Superior laryngeal nerve Block - Translaryngeal Block

28. Rigid bronchoscopy Flexible bronchoscopy Pros Compromised airway patency Can be done bedside Topical anaesthesia Better visualistion Sponataneous ventilation Done in upright position Cons Done in operating room Requires ventilation Teeth may be damaged Limited visualisation Bleeeding Perforation Risk of laryngeal oedema , bleeding and pneumothorax Needs fragmentation of foreign body before removal Small size of aspiration channel

29. Complications of bronchoscopy Oral trauma Bleeding Dysrrythmias Hypoxia Perforation of airway

30. Microlaryngoscopy Larynx is visualised through microscope Allows magnified vision of larynx Indications A)Diagnostic 1.Hoarseness of voice cannot be diagnosed on direct or indirect laryngoscopy 2.Biopsy of laryngeal lesion 3.assesment of laryngeal trauma

31. B)Therapeutic 1.Removal of foreign bodies 2.laser cordectomy in ca vocal cord 3.Dilatation of subglottic stenosis 4.Arytenoidectomy in cases of abductor cord palsy 5.Excision of vocal cord cysts ,nodules and haemangiomas

32. Advantages over direct laryngoscopy Magnified binocular vision Both hands of operating surgeon are free Exact precision achieved when performing laser or crayosurgery Video attachment

33. Microlaryngeal tracheal surgery(MLT) tubes- Smaller external diameter Large high volume low pressure cuff

34. Esophagoscopy Esophagoscopy is a procedure in which a flexible or rigid endoscope is inserted through the mouth or, more rarely, through the nares and into the esophagus

35. Indications Foreign body or food bolus impaction Evaluation of GERD Screening of barrets esophagus Treatment of varices Evaluation and management of dysphagia Biopsy of lesion Dilatation of esophagus

36. In ENT esophagoscopy is done mainly for foregion body removal. In adult patients it can be done in minimal sedation But for paediatric patients general anaesthesia with endotracheal intubation is recommended. Foreign body can get dislodged in airway while removing

37. Symptoms- Most common site of impaction is cricopharynx Starvation Preoperative evaluation- X ray neck Induction Small sized endotracheal tube Intra operative monitoring

38. Intraoperative Complications 1. Esophageal perforation which may lead to pneumothorax (Right > Left). 2.Mediastinitis 2. Compression of endotracheal tube. 3. Dysrhythmia . 4. Aspiration. 5. Accidental extubation . 6. Stridor secondary to subglottic edema