Supraglottic airway devices

Supraglottic airway devices

1. Supraglottic airway devices DR ZIKRULLAH

2. SUPRAGLOTTIC DEVICES Airway devices that ventilate patients by delivering anaesthetic gases/oxygen above the level of the vocal cords, regardless of the location of the device in relation to the glottis. EXTRAGLOTTIC DEVICES Any airway device with its distal end located outside the glottis

3. history Prior to 1874,little was known about the anatomic causes of upper airway obstruction that frequently terrified the early practitioners of inhalation anaesthesia Howard in 1880,showed that pulling the tongue forward produced a clear airway by elevating its base from the posterior pharyngeal wall . this contrasted the then held view that tongue traction relieved airway obstruction by lifting the epiglottis.

4. In 1870s Joseph Thomas Clover of Britain maintained a patent airway by using a nasopharyngeal tube In 1908,Frederick Hewitt published a paper in Lancet describing the forerunner to many modern oropharyngeal airway devices Over the next 15-20 years ,Clover’s nasopharyngeal airway and Hewitt’s oropharyngeal airway were extensively adapted to allow administration of volatile anaesthesia

5. In 1934,WB Primrose, described a cuffed oropharyngeal throat tube In early 1940’s the fall of extraglottic airway management was primarily due to rapid advances in the quality and availabilty of endotracheal tube equipment The concept of difficult airway arose during this time as a result of the high failure rate of laryngoscope guided tracheal intubation The main non surgical approach to the difficult airway at that time was blind nasal intubation , pioneered by Magill and Rowbotham 20 years earlier .

6. In 1981, Dr Archie Ian Jeremy Brain ,a 39 year old anaesthetist working in London developed the LMA. The cuff of the goldman dental mask was used to make the first laryngeal prototypes. He was born in Japan on july 2,1942. the LMA was his 13 th patent application and was granted in 1982.

7. 1983 : first use for airway rescue 1987 : first use for resuscitation 1993 : included in ASA algorithm for difficult airway 2002 : 150 million uses worldwide

8. Advantages of lma over ett increased speed and ease of placement improved hemodynamic stability at induction and during emergence reduced anesthetic requirements for airway tolerance lower frequency of coughing during emergence improved oxygen saturation during emergence lower incidence of sore throats in adults  

9. Advantages of lma over facemask easier placement by inexperienced personnel improved oxygen saturation less hand fatigue improved operating conditions during minor surgery

10. Disadvantages of LMA over the ETT   lower seal pressure higher frequency of gastric insufflation   Disadvantages of LMA over the FM  esophageal reflux more likely

11. Classification On the basis of lumen Single Lumen Devices : LMA-classic, LMA-unique, LMA-flexi, ILMA, C- Trach , Soft Seal, Laryngeal Airway Device, Pharyngeal Airway Xpress, Cobra Peri Laryngeal Airway, Laryngeal Tube, Cuffed Oropharyngeal Airway, Stream Lined Liner of the Pharyngeal Airway, Glottic Aperture Seal Device. Double Lumen Devices : Proseal LMA , Combitube , Laryngeal Tube Suction, Airway Management Device. Triple Lumen Device : Elisha Airway Device.

12. On the basis of sealing mechanism : CUFFED PERILARYNGEAL SEALERS : a . Non directional sealers – LMA , ILMA , LAD, Soft seal b . Directional sealers – PLMA CUFFED PHARYNGEAL SEALERS : a . Without esophageal sealing – COPA , PAX b . With esophageal sealers – Combitube , LT, LTS CUFFLESS PRESHAPED SEALERS : SLIPA, I gel

13. Laryngeal Mask Airway Family Classic LMA LMA Unique LMA Flexible LMA Fastrach LMA C Trach LMA AirQ LMA ProSeal LMA Supreme

14. Classic lma Latex free, medical-grade silicone -  throat irritation Consists of a curved tube connected to an elliptical spoon-shaped mask at 30 ° angle to facilitate tracheal intubation The airway tube is slightly curved, semi rigid, semi transparent

15. Two flexible vertical A perture bars where the tube enters the mask to prevent the tube being obstructed by the epiglottis. Cuff Pressure- 60 cm H 2 O Reusable 40 times May be inserted blindly without muscle relaxants

16. LMA Classic

17. LMA size selection

18. modifications Short tube LMA Split LMA Double lumen LMA Large bore LMA Barless LMA AMBU LMA MRI compatibility ( Halkey roberts pilot balloon valve with non magnetic silicone spring)

19. AMBU LMA Latex free, extra soft cuff Special curve that replicates human anatomy Reinforced tip does not bend during insertion

20. LMA unique Made of PVC Tube is stiffer and the cuff less compliant Helpful to warm it prior to insertion Intracuff pressure increases significantly less in the LMA Unique when nitrous oxide is used

21. LMA Unique No risk of cross infection Convenient, single-use, disposable Sizes available from 1 to 6

22. Flexible LMA It has a long flexible, wire reinforced tube The cuff sizes are the same A single use version is also available Surgery on the head, neck & upper torso

23. Increased airway resistance

24. Soft Seal LMA Similar to LMA Unique Cuff is softer, blunter & less permeable to N 2 O Integrated inflation line No epiglottic bars Wider ventilation orifice Sizes 1-5

25. LMA Fastrach U Although the LMA- Fastrach has been designed to facilitate tracheal intubation, it can also be used as a primary airway device. It is especially useful for the anticipated or unexpected difficult airway It can be used with the patient in the lateral position. Enables ventilation during intubation attempts

26. A difficult laryngoscopy view is irrelevant to successful ILMA intubation No cervical spine movement is required Placement does not require the operator to be above the patients head

27. Air-Q Specifically engineered for use both as a stand-alone laryngeal mask airway (LMA) and as a rescue device The air-Q™ Disposable allows for intubation using standard oral endotracheal tubes, sizes 5.5 to 8.5. Clinicians can easily remove the air-Q™ Disposable with the Removal Stylet without dislodging the ET tube. The Removal Stylet is reusable up to 10 times. The stylet is not autoclavable .

28. Available in 4 colour -coded sizes: 1.0, 1.5, 2.0, 2.5, 3.5, 4.5. Single patient use Sizing Chart Max. TT Size   4.5Adults 70 - 100 kg 8.5    3.5Adults 50 - 70 kg 7.5    2.5Children/Adults 20 - 50 kg 6.5      1.5Pediatric 5.5

29. LMA CTrach ™  intubation success rates in difficult airways Built-in fiberoptics provide a direct view of the larynx Real time visualization of the ET passing through the vocal cords Sizes 3, 4, and 5 and is reusable up to 20 times Poorer image quality than a flexible fiberoptic endoscope

30. ProSeal LMA The airway tube of the LMA- ProSeal is shorter and smaller in diameter than that of the LMA-Classic Dorsal cuff pushes the mask anteriorly to provide a better seal around the glottic aperture and helps to anchor the device in place The dorsal cuff is not present on sizes 1 1 / 2 to 2 1 / 2

31. LMA Proseal Introducer Cuff Deflator 1 ½, 2, 2½, 3, 4, 5

32. Additional features Improve the laryngeal seal without increasing mucosal pressures Separate the respiratory and alimentary tracts Higher airway seal pressures for PPV Built-in bite block Drain tube Introducer for Insertion

33. LMA Supreme Disposable Double lumen tubes Hybrid of PLMA and ILMA The airway tube has a gentle curve and oblong shape Easy insertion and stable placement molded fins in the bowl of the mask to prevent epiglottic down folding

34. Predictors of difficult placement Disrupted upper airway( trauma,ingestion of caustics) Restricted mouth opening(<2 cm) Obstruction of the upper airway (mass, foreign body,edema ) Poor lung or thoracic compliance

35. Placement of lma Preoxygenation Coinduction Assessment of depth Insertion,cuff inflation and fixation Assessment of function and anatomic position

36. Preoxygenation All patients undergoing iv induction must be preoxygenated . Technique is unimportant provided there is a good seal. Normal tidal volume for 3 minutes 3 vital capacity breaths End tidal O2 90-95%

37. Coinduction agents Facilitate LMA insertion Topical lignocaine is more effective than iv lignocaine - unpleasant - during application protective reflexes can be activated -once protective reflexes are obtunded the risk of aspiration may be increased Use of even minidose of muscle relaxants improves insertion

38. induction Unpremedicated adults require atleast 2mg/kg of propofol and children atleast 4mg/kg. MAC LMA insertion for sevoflurane for 50% and 95% of patients is about 1.5-2% and 2-2.5%respectively It is reduced in additive fashion by N 2 O MAC LMA insertion for halothane is 1.4-1.7% Ketamine given in dose of 3-3.5mg/kg

39. Iv or inhalational induction Thiopentone similar to propofol when combined with coinduction agent Propofol and sevoflurane provide similar insertion condition . But hypotension more common with propofol .

40. Assessment of depth Lack of response to jaw thrust is a reliable clinical indicator Loss of verbal contact and eyelash unreliable Insertion should be timed to coincide with maximum anaesthesia effect. This occurs 2 minutes after completion of injection using propofol During this time nonirritant inhalational agent with low blood /gas solubility should be administered via facemask

41. Insertion technique Standard technique: -midline -lateral -thumb

42. Choose the appropriate size and check the cuff for leaks Cuff deflated,lubricate the posterior surface With rim facing posteriorly.hold with dominant hand like pen Sniffing position. Nondominant hand behind occiput Inspect mouth. Flatten against palate

43. Index finger pressed towards occiput.finger and wrist flexed Jaw should not be held open once the mask is in the mouth Follow palatopharyngeal curve. lateral approach if resistance Finger straightens and wrist internally rotates as LMA advances Finish insertion when resistance encountered

44. Alternative techniques Change in cuff volume Laryngoscope guided Reverse / guedel technique Alternative finger position Manipulation of jaw, mouth ,head and neck -jaw thrust (reduces the frequency of epiglottis downfolding but does not increase insertion success) -extra mouth opening -external manipulation of neck (TRIPLE AIRWAY MANEUVRE )

45. Artificial palates -Spoons -modified oral airways( dingleys artificial palate) Intra and extra tube insertion tools - intratube : stylet , bougie,Trachlite - extratube : blades, forceps Drain and airway tube Active swallowing

46. Cuff inflation Should be inflated to 2/3 rd of maximum recommended volume and then adjust to just seal volume Should not be less than 1/4 th of the maximum recommended volume(at this seal with GIT fails)

47. overinflation Efficacy of seal with repiratory tract: - most effective @1/3 rd -2/3 rd of the maximum recommended volume -after this little further increase with increase in volume - overinflation may eject the cuff from pharynx Seal with GIT: -most effective seal with GIT is at higher volume than respiratory tract but follows a similar pattern

48. increased pharyngolaryngeal morbidity May interfere with surgical field Anatomic distortion - carotid compression - IJV displaced -displacement of pathology -surgical misdiagnosis Esophageal sphincter tone -LES tone unaffected,UES tone may be decreased Emergence charachteristics are generally unaffected by cuff volume

49. underinflation Ineffective seal with respiratory tract /GIT PPV fails when seal is < 10-15 cm of H2O Airway protection from above the cuff fails when seal is less than 15 cm H2O

50. Bite blocks To prevent compression of tube and damage to teeth In edentulous patients stability is improved Ideal bite block : Should prevent tube occlusion and dental damage Should be easy to insert and remove Not stimulate or traumatize the patient Should not disturb the position of LMA

51. Rolled gauze serves the purpose well Guedel’s airway is used but not recommended Best location : between back teeth as front teeth are easily damaged if biting occurs during removal

52. Fixation(ram’s horn fixation technique)

53. Assessment of function Ventilatory capability -observation of thoraco abdominal movement - capnography -auscultation of neck and chest -peak airway pressure(should be low and not associated with leaks) -maintenance of oxygen saturation -expired tidal volume( quantitative)

54. Efficacy of seal with respiratory tract a rough rapid idea about periglottic seal can be obtained by squeezing the reservoir bag and noting the pressure at which an oropharyngeal leak occurs Efficacy of seal with GIT epigastric auscultation does not usually provide information about the hypopharyngeal seal because most air leaks occur into the mouth rather than esophagus for PLMA it can be assessed by testing for airleaks upto the drain tube

55. Clinical indicators of cuff position Quality of insertion The length,orientation and movement of the tube Inspection of the mouth Observation of the neck Assessment of function Drain tube airleak and patency test( for PLMA)

56. Non - Laryngeal Mask Airways Oe sophageal combi tube Laryngeal tube airway Laryngeal tube airway suction SLIPA Pharyngeal X Press Perilaryngeal airway Elisha I-gel

57. Oesophageal Tracheal Combitube Developed by Dr Frass in Austria in 1980’s, though prototype of the invention was developed in the 1960s by Drs. Don Michael, Lambert (of the Lambert-Eaton syndrome), and Mehran . Disposable double lumen tube (tracheal & pharyngeal) With two inflatable balloons Pharyngeal lumen Blocked distally with a blue proximal standard 15mm connector Eight oval-shaped holes(7X3mm) Tracheal lumen Open at distal end Shorter, clear proximal portion with a standard 15mm connector

58. Small adult ETC 37 F Large adult ETC 41 F CONTRAINDICATIONS ABSOLUTE : complete airway obstruction RELATIVE : disease of the esophagus and after the patient has ingested caustic( if inserted without visual check) body size of the patient

59. Instructions for use Free the upper airway of obstruction if necessary( vomit,foreign bodies) Test the integrity of two cuffs Lubricate the tube Place the head in neutral position (positioning the tube may be more difficult in sniffing position) Hold the tube above the proximal and below the distal cuff and bend to 90 degrees for few seconds Open the patients mouth by inserting the thumb of one hand deeply while pushing the patients tongue forward.

60. Introduce the tube slowly along the tongue till the upper ring lies on the upper row of teeth. Inflate the proximal cuff with 80 ml of air Inflate the distal cuff with 10 ml of air Ventilate via the long tube. Check for position( auscultation of the chest,ETCO2 monitoring) If positive-continue the same If negative- ventilate via the short tube If both negative the tube may have been advanced too far

61. Laryngeal Tube airway Shorter version of the Combitube with shaped seal pharyngeal ends Cuffs inflated by a single line Latex free, double lumen with oropharyngeal and oesophageal low pressure-cuffs Ventilation outlet in between and a second tube placed posteriorly to the respiratory lumen

62. LTA with a drain tube and reshaped cuff is known as LTS

63. Airway Management Device Hybrid oesophageal tracheal combitube /laryngeal mask airway intubator Translucent silicone tube Two silicone cuffs, inflated by separate pilot balloons Distal cuff when inflated occludes a small lumen Anteriorly facing oval ventilation orifice Resusable and can be steam autoclaved at 134 °C

64. Cobra Pharyngeal Lumen Airway Alternative to a facemask Alternative and useful device in a “ difficult to intubate /difficult to ventilate” scenario Does not provide protection against regurgitation and aspiration Sizes 8 (0.5- 6)

65. Pharyngeal airway express Non inflatable gilled conical tip at the distal end forms a no pressure seal in hypopharynx,prevents regurgitation and gastric insufflation Distal half of the vent has three vertical gills to prevent airway obstruction Advantages It is a sterile, single use latex free device Accommodates up to a 7.5 mm ID TT

66. SLIPA TM Looks like a slipper Soft, hollow, blow-molded plastic airway that is shaped like a boot Toe sits in the hypopharynx Bridge with its two lateral bulges, fits into the pyriform fossae Heel of the chamber anchors the SLIPA TM

67. Elisha Airway Device It is unique as it combines three functions; ventilation, blind and/or fiberoptic -aided intubation without interruption of ventilation and gastric tube insertion New reusable device and is made up of latex-free medical-grade silicone

68. i -gel Anatomical seal of pharyngeal, laryngeal and perilaryngeal structures Latex free, cuffless , easy to insert, single use Soft gel like material – thermoplastic elastomer Separates resp & GI tracts Minimal tissue compression

69. complications An increased risk of airway problems Gastric insufflation Regurgitation & pulmonary aspiration Stimulation of pharyngolaryngeal reflexes Trauma to pharyngeal structures Compression of neurovascular elements Fragmentation or herniation of the LMA

70. Contraindications ABSOLUTE cannot open mouth complete airway obstruction RELATIVE increases risk of aspiration Prolonged bag and mask ventilation Morbid obesity Second and third trimester pregnancy Upper GI bleed Abnormality in supraglottic airway Need for high airway pressure Patients who have not fasted

71. Cleaning and sterilization Dilute solution of( 8-10%w/v) sodium bicarbonate,soapy water may be used Formaldehyde, glutarldehyde , ethylene oxide not to be used Prolonged immersion in chlorhexidine to be avoided

72. Cuff should be deflated immediately prior to autoclaving as spontaneous reinflation occurs over a few hours No residual air/fluid should be left in the cuff It was seen that if residual air was 0.25ml elasticity of the cuff decreased considerably. If it was 1 ml 10% of the cuffs ruptured.

73. Minimum exposure time for steam sterilization at 132-135 ◦ C Autoclave wrapped unwrapped Gravity 10-15 mins 10 mins Prevaccum 3-4 mins 4 mins

74. Thank you