DEPARTMENT OF ORAL AND MAXILLOFACIAL SURGERY YENOPOYA DENTAL COLLEGE, MANGALORE
PRESENTED BY DR.MAHABALESHWARA CH.
UNDER THE GUIDENCE OF, DR. BH.SRIPATHI RAO PROF. AND HOD
1. Introduction 2. Anatomy of upper airway 3. Indications for tracheal intubation. 4. Patient assessment 5. Equipment for tracheal intubation 6. Selection of intubation technique oral/nasal 7. Technique for oral intubation 8. Technique for nasotracteal intubation 9. Special technique and aids for intubation 10. 11. 12. 13. 14. 15. Management of difficult airway Complications of tracheal intubation Laryngeal mask airway Emergency airway management Conclusion Reference
Indication for tracheal intubation 1. Upper airway obstruction Foreign body Tumour Infection Laryngosposm Bilateral vocal card paralysis Epiglottis Surgical field avoidance during anaesthesia General Anaesthesia in other than supine position Prolonged anaesthesia Bulbar NM disease Coma Stroke, Drug overdose GA for patient with full stomach GA for prolonged surgical procedure 4. Inability to clear tracheo bronchial secretions N M diseases: - Quadriplegia Myasthenia gravis Pneumonia Respiratory failure Resp. failure Paralysis N M disease Muscular relaxation for surgery
2. Airway control
3. Prevention of aspiration
5. Need for mechanical ventilation
Anatomy of the upper airway 1. Nasal cavity and nasopharynx. 2. Mouth and orpharynx The orpharynx extends from the soft palate superiorly to the epiglottis inferiorly. The sidewall contains tonsils lying between the palatoglossal arch and the palatopharyngeal arch. 3. Laryngopharynx The laryngopharynx extends from the epiglottis to the beginning of the oesophagus at the level of the 6th cervical vertebrae behind the cricoids cartilage. The anterior wall is the inlet and back of the larynx. The cartilage epiglottis is covered by mucous membrane and attached to the base of the tongue by median glossoepiglottic fold in the middle and by the lateral glassoepiglottic fold on each side. Anatomically the epiglottic valleculae are paired depressions between these folds. Clinically entire space between the epiglottis and base of tongue is referred to as the vallecula. Larynx: It is a tubular structure connecting the laryngopharynx with the trachea. It protect lower respiratory tract during deglutition is adapted for phonation. It lies anterior to the 4th, 5th and 6th cervical vertebrae in the adult. It is involved in respiration, phonation, deglutition and effort closure. Interior of the larynx: The entrance of larynx bounded arteriorely by the epiglottis and the median epiglottis ligament. The lateral boundaries are defined by the aryepiglottic folds, which enclose aryepiglottis muscle and the cuneiform and corniculate cartilages. The posterior boarder is the interaretenoid fold of mucous membrane enclosing transverse arytenoids muscle. The piriform fossae are the depressions between the aryepiglottic folds and the lateral wall of the pharynx.
Beyond the inlet of larynx lie the ventricular (false cords) and vocal folds. The vocal folds contain vocal ligaments and vocal process of arytenoids cartilage. Framework of larynx: It is formed by single thyroid, cricoid and epiglottis cartilages and the paired arytenoids, corniculate and cuneiform cartilage. The cricoid cartilage is shaped like signet ring. It forms two joints (with thyroid and arytenoid cartilage). Involvement of these joints cause hoarseness in voice and occasionally difficulty with intubation. Intrinsic muscles of larynx: A. Muscles influencing the inlet 1. Aryepiglottic – close inlet supplied by recurrent laryngeal nerve. 2. 3. Oblique arytenoids – close inlet -- “ – recurrent laryngeal nerve. Throepiglotticus – open inlet -- “ –
B. Muscles influencing rima glottides 1. Posterior cricoarytenoid _ Abduction supplied by recurrent laryngeal n. 2. Lateral cricuocyterid Adult -- “ – 3. Transverse – “ – 4. Thyroarytenoid -Relax vocal ligament– “ – 5. Vocalis- Relax vocal ligament – “ – 2. Cricothyroid- Tense vocal ligament supplied by superior laryngeal nerve. Sensory innervations: The internal branch of SLN (branch of vagus) supplies mucous membrane till vocal folds. After it pierces thyrohyoid membrane, it lies just below the mucosal surface of the piriform fossa. The recurrent laryngeal nerve innervates the mucous membrane below the vocal folds.
Laryngeal Variations in the infant.
Head Tongue Epiglottis Infant Relatively larger Relatively larger Long thin, stiff trachea Level of Junction Level of Junction Cricoid ring Adult Relatively smaller Relatively smaller ‘U’ Shorter, wider, parallel C4 – trachea C4 Level of junction C5 Level of C6 Rima glottides flat to C5
shaped 45 degree to flexible, Laryngeal inlet Cricoid Narrowest part of larynx C3 C4 – –
Patient assessment and preparations: 1. History 2. Physical examination In assessing patient 4 areas should be evaluated for signs that may suggest difficulty. 1. Limited volume or displacement of tongue during laryngoscopy. a) Short muscular neck with full set of teeth b) Receding mandible with obtuse mandibular angle. c) Long narrow mouth (usually associated with high arched palase) d) Thyroid cartilage to mental distance of less than 6 cm (3 finger’s breadth). 2. Limitation to inserting laryngoscope or obtaining straight line of sight to the glottis. a) Maxillary prognathism b) Large breasts/extreme truncal obesity c) Increased distance from mandibular alveolar ridge to lower mental boarder requiring wide mouth opening. 3. Limitation of mouth opening:
a) Arthritis of bone b) Trismus c) < 4 cm (2 finger breadth) between incisors on mouth opening. 4. Limitation of mobility of cervical spine. a) Lack of ability to flex neck b) Lack of ability to flex or extend head atlanto occipital joint. c) Symptoms cervical nerve encroachment on head extension. d) Reduction of distance between the occipital bone and spinous process of C1 on lateral neck X-ray. Simple clinical tests to assess patients’ airway: 1. Mallampatti test This is a simple test based upon visibility of pharyngeal structure. The patient is seated in front of the observer and asked to protrude tongue. The observer notes the physical structure visible with pen torch. Class I – Soft palase, fauces, uvula anterior and posterior tonsillar pillars are visualised. Class II – Soft palate, fauces, uvula visualised. Class III – Soft palate, base of uvula visualised. Class IV – Soft palate is not visible at all. Class IV and Class III should be suspected as difficult intubation. 2. Patil test This is the measurement of thyromental distance when the head is fully extended. It therefore assesses both the relationship of larynx to jaw and also ability to extend the head. If the distance is greater than 7 cm the intubation should be easy. The measurement of horizontal length of mandible also useful. A length greater than 9 cm correlate with low tongue/strongly suggests visualisation of the larynx by direct laryngoscopy will be relatively easy. 3. The Wilson test
The Wilson test is a risk score based on the assessment of five factors. 1. Body weight 2. Head and neck movements 3. Jaw movements 4. Mandibular recession 5. Presence of bulky teeth 4. Radiological tests: To identify the length and anterior depth of mandible and atlanto occipital distance. Equipment for tracheal intubation: A. Tracheal Tubes Red rubber (reusable) Plastic (Disposable) Uncuffed tube (use in a child) Cuffed tube (Adult) Tubes are available in 0.5 mm increments from 2.5 mm to 10 mm. Length of tube is directly related to diameter of the tube (The larger the tube the longer is diameter). The following rules of thumb can be used to predict tube size in children from 2 to 14 years of age. Tube size: External diameter = diameter of little finger Internal diameter = Age in years 4 + 4.5
For oral tube = Age in years 2
Low residual cuff Cuffed tracheal tubes High residual cuff Type of tracheal tube 1. Preformed tube 2. Armoured tubes 3. Specialized tubes for laryngeal surgery 4. Jet ventilation tube 5. Paediatric tubes 6. Double-lumen tubes. B. Laryngoscopes Chevalies Jackson described the 1st modern laryngoscope in 1906. Types a) Macintosh curved blade b) Straight blade c) Straight blades for infants e) Specialized blades C. Forceps a) McGill forceps b) Allison forceps D. Tracheal tube guide
b) Flexible catheter guide c) Light wands e) Fibreoptic tube guides Selection of intubation technique • The primary indications for nasal intubation are avoidance of surgical field and in difficulty with oral intubation.
The nasal route is also preferred for prolonged intubation because it provides more stable tube fixation with less chance for kinking and is more comfortable in the awake patient. Disadvantages of nasal intubations are the need to use a smaller tube, making pulmonary toilet more difficult; pressure on the nasal mucosa; and the possibility of precipitating bleeding or blocking sinus/middle ear drainage leading to infection.
Intubation under anaesthesia: For short-term intubation in the elective surgical procedures, oral intubation under general anaesthesia with paralysis is most often used. A common approach is to have the patient breath 100% oxygen for 5 minutes before inducing anaesthesia with a short acting IV agent. After demonstrating that ventilation can be accomplished by mask, a short acting NM blocker, usually suxamethonium is given and intubations performed when the patient becomes relaxed, about 60 seconds later. Use of NM agent: Is to relax the skeletal musculature to aid in laryngoscopy and to minimize reflex responses to intubations such as laryngeal spasm and coughing. Intubation of the awake patient: It should be considered whenever a 1) Difficult airway is encountered 2) When there is a risk of aspiration and when tolerance of general anaesthetic questioned. Disadvantages:
Longer time it takes for the process and increased difficulty due to an uncomfortable nervous patient who may gag, swallow, close the mouth/adduct the cords. • • • • Procedure and approach should be discussed thoroughly with the patient. Pre treatment with antisialogogue agent is used to reduce secretions Sedation with anxiolytics such as benzodiazepines given as premedication or titrated i.v at the time of procedure. The thorough topical anesthesia of nose and mouth, local anaesthesia by SLN block are provided to remove pain and reflex responses to procedure. • The procedure is conducted with gentleness and the patient is kept informed of what is being done and what to expect next. Technique for oral intubation: Head Position: • • • To visualize the glottis successfully the axis of mouth, pharynx and larynx must be aligned. By elevating the head approximately 10 cm on a pad, the base of neck flexed bringing laryngeal and pharyngeal axes into alignment. The extension of head about atlanto occipital joint will now bring the oral axis into near alignment with other axis. This position is commonly called as “SNIFFING POSITION” . The final alignment of the oral axis is accomplished by lifting the tongue with laryngoscope blade.
Laryngoscopy • The laryngoscope held in the left hand and inserted in to the right side of the patients mouth. Extension of head by applying pressure on brow/using scissors motion using right hand fingers by placing thumb on the lower molars and the third finger on the upper molar will enable wide mouth opening. • • The laryngoscope blade is advanced through the right side of the mouth, care being taken to keep the tongue to the left of the flange. When the tonsillar fossa is reached, a curved blade is slipped in to valleculae. Traction along the axis of the handle of the laryngoscope will lift the base of tongue, stretch the hyoepiglotic ligament and expose the larynx. Intubation: • When the glottis is visualized the laryngoscope is held firmly in the midline and trached tube is introduced with right hand into the right corner of the mouth (retraction of corner of mouth by assistant may help insertion). • • • The tube is inserted between vocal cords and advanced until the cuff lies approximately 2 cm beyond the cords. The laryngoscope is removed, taking care to prevent damage to the teeth during withdrawal. The cuff should be inflated with just enough air to seal during positive pressure ventilation. The visual inspection of chest and auscultation over both lung field and the epigastrium during positive pressure ventilation confirms proper placement. An alternative is to check CO2 on end-tidal CO2 monitor. • The tube is seewely fixed in place, noting the distance of insertion at the lips.
Technique of nasotracheal intubation:
Patient position and preparation: • • It is performed with Direct laryngoscopy Blind Awake Anaesthetized • In general, a tube size 0.5 mm smaller than indicated for oral intubation is necessary to pass easily through nasal cavity (The tube should be well lubricated, taking care not to let lubricant obstruct lumen). • • The head and neck should be positioned in “sniffing” position. The tube may be passed on either noses; the least obstructed/larger passage is chosen. While passing tube excessive pressure should be avoided. Once the tube reaches the oropharynx, the continuation of procedure depend on whether the tube is to be placed with direct laryngoscopy/blindy. Nosotracheal intubation with direct laryngoscopy It is performed under general anaesthesia with NM blockade because it does not depend upon spontaneous ventilation/pt. Cooperation. 1. When the tracheal tube has been passed into the oropharynx, direct laryngoscopy is performed and tube is advanced to glottis under direct vision. 2. If the tube enters piriform fossa it can be moved to midline by rotating the tube at proximal end. 3. Backward/lateral pressure on the thyroid cartilage by an assistant can help direct the glottis toward the tip of the tube. 4. McGill forceps/Allison’s forceps are used to pass tube to larynx if necessary.
5. Alternatively, flexing the head and neck to bring trachea more in line with the tube usually allows the tube to pass easily. 6. The tube is advanced into the trachea until cuff is approximately 2 cm beyond the cords in the adult/the pre-determined distance to have the tip in the mid-trachea. The cuff is inflated just enough to seal with positive pressure ventilation. 7. Auscultation of both lateral lung fields and the epigastrium and end-tidal carbon dioxide concentration in exhaled gas are checked to ensure proper placement. 8. The tube is securely fixed in place. Blind nasotracheal intubation: • • • • • • This is most commonly used in awake patient. General anaesthesia is used; it should be light enough to obtain laryngeal reflexes. When the tube reaches oropharynx breath sound should be audible through the tubes. Closing the mouth, occluding opposite noses improves hearing the breath sounds. As the tube is slowly advanced breath sounds become louder as the laryngeal in let is approached. Ideally the cords are passed quickly during the latter part of inspiration when the cords are most widely separated. Successful intubation is heralded by continuous breath sounds through the tube, loss of ability to phonate in the awake patient and coughing if the trachea has not been anaesthetized. • • When the tube enters trachea it is advanced to a distance from the noses predicted to place the tip in the mid trachea. Placement of tube in the trachea confirmed by auscultation over epigastrium lung fields and checking end-tidal carbon dioxide concentration of inhaled gas.
Special techniques and aids to intubation: 1. Specialized blades: a) Bizzari guffrida blade b) Macintosh blade or short handle c) Howland adapter d) Polio blade. 2. Malleable styletes 3. Flexible catheter guides 4. Light wand 5. Malleable fibre optic laryngoscope 6. Flexible fibre optic laryngoscope/bronchoscope. • • • It can be used with the patient awake/anaesthetized using same considerations and pharmacological adjunct to other techniques. The fibre scope should be well lubricated with a water-jelly. For nasal intubation 3 techniques are employed. 1. The tracheal tube may be placed as far possible and the instrument guided through the nose and into the trachea before advancing tube. 2. Another method is to guide the instrument to pharynx, advance the tracheal tube into oropharynx before inserting fibre scope and then proceed with laryngoscopy. 3. Third technique is to pass the tracheal tube into oropharynx before inserting the fibre scope. As the fibre scope advanced the epiglottis identified, as it is passed, the cords are seen and entered. Placement in the trachea is identified by a clear view of tracheal rings.
If the view through the fibre scope becomes blurred and red, either the piriforon fossa/the oesophagus has been entered/the tip has become covered with secretions.
Oral intubation carried out in a similar manner. through the oral cavity.
Use Of “Oral
intubation airway” improves control of instrument as it passes 7. Retrograde Intubation: With this technique a guide is threaded in a retrograde direction through the cricothyroid membrane, out through mouth and nose and tracheal tube is inserted over the guide into the trachea (Epidural and central venous catheter, seldinger wire, plastic tubes and silk/nylon thread are used). 8. Needle cricothyrotomy: 1951 Jacob – It is the procedure that can provide oxygenation and ventilation in special elective situations in an emergency when intubation cannot be performed. Management of difficult airway: • • • • The true incidence of difficult intubation is estimated to be 1 – 3% of intubation in anesthetic practice. Only ¼ of anticipated difficult intubations may actually be difficult. Nearly 50% of difficult intubation is unexpected. Approximately 85 – 90% of difficult intubation is managed by experienced practitioners. Unexpected airway difficulty: 1. Anesthesia induced in usual (iv) fashion Mask ventilation attempted and successful Muscle relaxants administered Intubation attempted but unsuccessful.
2. Anesthesia induced in the usual (iv) fashion mask ventilation attempted but inadequate/impossible intubation attempted but unsuccessful. 3. Anesthesia induced in the usual (iv) fashion mask ventilation not attempted/not guaranteed muscle relaxants administered intubation attempted but unsuccessful. 1. In the 1st instance as long as ability to ventilate is maintained, the patient faces no danger. Manual ventilation should be maintained until anesthesia agents and muscle relaxants have either worn off. 2. In the 2nd scenario describes an anaesthetized patient who cannot be adequately ventilated by mask and who cannot be intubated by usual fashion. An organised approach to diagnose the cause for inadequate mask ventilation may prove helpful. • • If upper airway obstruction is the cause it is relived by oronasal airway/readjustment of the patients head into better position. If laryngospasm is the primary cause for inability to ventilate, continuous positive airway pressure and the use of succinyl choline will be corrective. • • • If broncho spasm due to reactive airway discease is the cause, deepening anaesthetic will be effective. Anatomic derangements in airway patency will require surgical correction. Until patients awaken and maintain spontaneous ventilation with the ability to support their own airway they remain at risk. 3. The third type of unanticipated failure to intublate is the worst. The patient is unconscious, the patient is paralysed, the anaesthetist cannot ventilate the patient by mask, and end tracheal intubation proves impossible.
Immediate action must be taken to provide oxygenation otherwise severe hypoxia with irreversible sequelae is certain. ASA’s task force on the difficult airway recommends transtracheal jet ventilation at this juncture. Once ventilation is guaranteed, a decision can be made concerning further airway invasion (Cricothyroidotomy/ alternative intubation technique) versus awakening the patient and rescheduling the surgical procedures. Complications of tracheal intubations: I. Complications at the time of intubation 1. Trauma to structures surrounding the airway a) Laceration and confusions b) Retropharyngeal abscess c) Subcutaneous and mediastinal emphysema d) Pneumothorax e) Epistaxis f) Nasal polyps and adenoid tonsils g) Arytenoid cartilage dislocation h) Damage to teeth. 2. Hypertension and tachycardia 3. Hypoxia and hypercapnia 4. Increased intracranial pressure 5. Fracture and subluxation of the cervical spine 6. Bronchospasm 7. Aspiration. 8. Oesophageal and endotractial intubation. II. Complications while intubated. 1. Obstruction of tracheal tube. 2. Displacement of tracheal tube. 3. Aspiration, increased work of breathing and tracheal rupture. III. Complications at/following extubation.
The Laryngeal Mask Airway:
History: LMA was designed in 1981 by British anaesthesiologist Archie.I.J.Brain. It is an alternate way to connect the natural airway with an artificial airway and minimize complications. The commercially developed LMA became available in the United Kingdom in 1988 and United States in 1991. The LMA differed from traditional airway technique by its extra tracheal location within hypophrynx. End to end opposition of the LMA with the larynx provided a more effective seal than facemasks yet was less invasive than endotracheal intubatin. Physiology of insertion: Insertion of LMA mimics swallowing. The back surface of the LMA is lubricated with a water-soluble gel then pushed by index finger upward and backward along the palatal curves. The LMA is directed in to the hypo pharynx where resistance is met at the level of UES. The size and shape of LMA prevent further passage of the LMA in to the esophagus. LMA types and size: 1. LMA – Classic • Constructed from medical grade silicone.
• • • •
It consists of elliptical masks attached to a breathing tube. It is entirely latex free LMA is available in 7 sizes. 1, 1.5, 2, 2.5, 3, 4 and 5. Appropriate size is determined by weight of the patient. As a general rule the size 4 LMA can be used in the woman, size 5 in the most men.
2. LMA – Unique Constructed from PVC Single use Relatively inexpensive Ideal for emergency room settings. 1990 by Alexander Introduced in USA in 1996 Modified LMA with a wire wrapped flexible breathing tube. The flexibility allowed LMA to be used during dental extraction and for tonsillectomy without compromising surgical exposure. 4. The intubacting LMA/LMA Fastrach Became available in the 1998 USA This modification of LMA was designed to facilitate tracheal intubation, particularly in the difficult airway situation. It consists of standard LMA mask attached to a short, wide bore stainless steel tube. The mask differs from the LMAs by replacing dual aperture bars with a single, V – shaped epiglottic elevating bar. The bar lifts the epiglottis out of the way as an endotracheal tube passes in to the trachea. The tube is available in 3 sizes – 7, 7.5 and 8 mm internal diameter. Care, Cleaning and Cost: LMA are reusable
3. LMA – flexible
Are cleaned with warm water and a dilute (8% to 10%) sodium bicarbonate solution/mild detergent. Sterilized by steam autoclave with heat < 1350 C It costs $ 200 - $ 300 per unit
Indications and Advantages It is latex free and may provide the appropriate airway for allergic patients. The LMA is ideal for use in the ambulatory surgical seeking for elective surgical procedures that do not require endotracheal intubation. • LMA is easy to learn. After limited training inexperienced medical staff, nurses were able to plan successfully LMAafter two attempts as 97% 100% vivo situations. • • • The LMA is inserted without laryngoscopy or use of muscle relaxants. LMA maintains natural cord function and has been recommended as the airway of choice in professional singers. Insertion of LMA less stimulating than endotracheal interbation, and the device is well tolerated at lighter level of anaesthesia. Advantage of LMA over facemask includes hands – free operation, better seal, fewer hypoxic episodes and less environmental contamination form escaped aesthetic gases. • LMA provides conduit to facilitate passage of endotracheal tube and guide wires exchange catheters/fibereoptic bronchoscopes in difficult airway situations. Contra-indications and Disadvantages: • • Use of LMA (lies outside trachea) does not guarantee long protection from aspiration of gastric contents. Its usage is contraindicated in patients who are at risk for regurgitation/aspiration, including patients with such conditions such
as morbid obesity, hiatal hernia with/without reflex esophagitis, pregnancy, acute abdominal injury and intestinal obstruction and patient who have not pasted. • LMA is contra indicated as a primary device for patients with high airway resistance (bronchospasm), Limited palmonay compliance (palmonay fibrosis), phayngeotracheal pathology (epiglotitis, tumor, abscess, hematona, stricture).
Anaesthetic technique: The LMA may be placed satisfactorily after either i.v/inhalational induction of anesthesia. Anesthetic depth must obtained oropharyngeal and lid reflexes adequately. Complications: 1. Mild and self-limiting complications like sore throat, coughing, hiccups, gagging and dysphagia. 2. Rare neurovascular complication like tongue cyanosis sec. to LMA cuff pressure. Paralysis of lingual, recurrent laryngeal and glossopharyngeal nerves. 3. Transient enlargement of parotid/submandibular gland. 4. Major complications include regurgitation – 0.08% to 23%. Aspiration Bronhospasm Clinical use during Oral and maxillofacilal surgery: • • The ability to insert LMA through interincisal opening of 12 mm may be useful in patients with TMJ dysfunction. Woodcock compared laryngeal mask, nasal mask and nasonpharynged airway for paediatric dental extractions. They found
better surgical areas and easier airway maintains with the LMA than with the other airways. • The flexible LMA has particular application for OMFS.
The airway requirements for OMFS are the provision of a stable, unobstructured airway, minimal interference with the surgical field, and low complication rate and lung protection from aspiration. The LMA fulfils the 1st three of these requirements. However, in situations that pose increased risk for aspiration/in which absolute airway control is necessary, endotracheal intubation remains the standard of care.
Emergency Airway Management
The airway is at risk in the trauma patient/in unconscious patient/in foreign body airway obstruction. The unconscious patient may be UN able to maintain airway owing to backward prolapse of the tongue and obstruction of hypo pharynx. Direct trauma to larynx/maxillofacial area may lead to mechanical obstruction at airway/haemorrhage and further compromise airway. During dental treatment the potential is great that objects may fall into particular portion of the oral cavity and subsequently into pharynx (head of paedodontic hand piece, mouth mirror, head and gold crown, rubber dam clamps, enobontic instruments, post and core etc). National safety council of USA estimated that approximately 3100 individuals died as a result of acute airway obstruction. >90% occur in children < 5 years. Prevention: 1. Use rubber dam 2. Oral packing in sedated patient 3. Chair position:
When patient swallows object, the patient should be turned on to the side and leaned into a head down position with upper body over the side of the dental chair. This position uses gravity to the patient advantage, allowing the object to fall from patients’ mouth. 4. Dental assistant and suction. 5. Magil intubation forceps 6. Ligature Management: 1. Management of visible objects: a) If assistant is present place patients in trendelenburg position use magill intubation forceps/sucion. b) If assistant is not present instruct the patient to bend over arm of dental chair with head down encourage the patient to cough. 2. Management of swallowed objects: Consult radiologist obtain appropriate radiographs to determine location of object initiate medical consultation with appropriate specialist. Recognition of Airway obstruction: Acute upper airway obstruction occurs in conscious most oftenly when eating. It is also associated with common factors like a) Large poorly chewed piece of food. b) Elevated blood alcohol level c) Laughing/talking while eating d) Upper/Lower denture (Cafe coronary syndrome) Other causes of airway obstruction: • • Congenital structural abnormality of the airway Infections such as epiglotittis
• • • • • • Signs:
Tonsillitis Ludwig’s angina and laryngitis Tumours and haematomas Vocal cord pathologic process (laryngospasm and paralysis) Inflammatory processes (Angioneurotic edema and anaphylaxis) Sleep apnea
Complete airway obstruction: Inability to speak Inability to breath Inability to cough Universal sign of choking Panic
First phase (1 – 3 min) Patient is conscious. Universal choking sign, struggling paradoxical respirations without air movement or voice, increased blood pressure and pulse. Second Phase (2 – 5 min) Loss of consciousness, decreased respiration, BP and pulse. Third Phase (>4 – 5 min) coma, absent vital signs, diluted pupils. Partial airway obstruction: Individual with good airflow Forceful cough Wheezing between coughs Ability to breath Weak ineffectual cough “Crowing” sound on inspiration Paradoxical respiration Absent/altered voice sounds
Individual with poor air exchange
Possible cyanosis Possible lethargy Possible disorientation
Basic airway Manoeuvres These steps are designed to eliminate the most common cause of airway obstruction – the tongue. 1. Position supine position with the feet elevated. 2. Head tilt – chin lift – 80% cases in which tongue is the cause of the airway obstruction, this procedure effectively opens the airway. 3. Look, listen, feel technique 4. Jaw thrust manoeuvres if indicated. 5. Artificial ventilation if needed. Establishment of emergency airway I. Non invasive procedure 1. Back blows – remains integral part of the protocol for obstructed airway management in infants. 2. Heimlich manoeuvre • 1975 by Dr. Henry J. Heimlich, it is recommended primary technique for relief of foreign body airway obstruction in adults and children. • It is also known as the sub diaphragmatic abdominal thrust/abdominal thrust. 3. Chest Thrust It is an alternative in special situation only to Heimlich manoeuvre. It is indicated in infant (< 1 year), Pregnant victim, extremely obese victim. Contra indications are in older victim. 4. Finger sweep. II. Invasive procedures: 1. Needle cricothyroidotodomy.
2. Surgical cricothy roidotomy 3. Tracheotomy
The maintenance of airway required during the induction of anesthesia, maintainence of anaesthesia. The skill in providing, managing airway is needed in treating many life threatening airway obstruction
References: 1. Operative maxillofacial surgery Langdon & Patel 2. Short practice of surgery Baily & Love 3. Medical emergency in dental practice Stanley Malamed 4. OMFS clinics of North America Vol.II – No.4 Nov. 1999 5. Complications of Head & Neck Surgery Wesslers & Pillsbury 6. Anaesthesia for Burns, MFS & Plastic Surgery H.Patel