review airway management

Review

Airway management

Giedrius Laurinėnas

Airway management

A look back: what's learnt from bitter experience

Future trends: a vision of a 'universal soldier'

Lithuania: Go west

Airway management

A look back: what's learnt from bitter experience

Future trends: a vision of a 'universal soldier'

Lithuania: Go west

• Difficult airway is an interdisciplinary problem• The diagnostics wasn't, isn't, and, apparently, won't be accurate • Updated knowledge, vigilance, adequate monitoringand standardization is the key for success:- Standards of Safe Anesthesia Practice (ASA, 1986)- Difficult Airway Algorithm (ASA, 1993)

• Alternative airway devices revolutionized outcomes• Ever growing interest for a proper education

Adverse respiratory events in anesthesia: A closed claims analysis. Caplan RA, Posner KL,

Ward RJ Anesthesiology 75:828, 1990• • •

Adverse respiratory events infrequently leading to malpractice suits. A closed claims analysis.

Cheney FW, Posner KL, Caplan RA Anesthesiology 75:932, 1991

• • •

ASA closed claims project database 1985-2004

The Problem

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

Inadequate ventilation 13%

Esophageal intubation 7%

Difficult intubation 6%

Other respiratory problems 8%

Other claims 34%

N = 1541

Adverse respiratory events in anesthesia: A closed claims analysis. Caplan RA, Posner KL,

Ward RJ Anesthesiology 75:828, 1990• • •

Adverse respiratory events infrequently leading to malpractice suits. A closed claims analysis.

Cheney FW, Posner KL, Caplan RA Anesthesiology 75:932, 1991

• • •

ASA closed claims project database 2002

The Problem

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��Inadequate ventilation 7%

Difficult intubation 6,4%

Esophageal intubation 4.5%Other claims

N = 4459

18%

Anesthesia-related deaths and permanent brain damage

(ASA closed claims project database, 2002)

The Problem

Respiratory adverse eventsCardiovascular adverse eventsTechnical problems

1980-1990N= 570N= 1320

1990-2000

A look back

Monitoring:The Beginning of A New Era

A look back

Inadequate ventilation

Esophageal intubation

Difficultintubation

Mirtys ir CNS pakenkimas dėl anestezijos (ASA closed claims project database, 2004)

Both SaO2 and EtCO2 unavailable

SaO2 monitoring only

SaO2 ir EtCO2 available

Monitoring modalities and respiratory adverse events(ASA closed claims project database)

Monitoring of Ventilation

ASA Standards for basic Anesthetic Monitoring

... Continuous evaluation of qualitative clinical signs such as chest excursion, observation of the breathing bag, and

auscultation is mandatory...

... When an ETT or LMA is inserted, its correct positioning must be verified by identification of carbon dioxide in the expired gas. Continuous capnometry

should be used until extubation...

... Quantitative monitoring of the volume of expired gas is strongly encouraged...

Ventilation monitoring• Exploring Lithuania •

Capnometry in our operating rooms:District hospitals..................................................................42%Regional nonteaching hospitals.............................................55%University hospitals..............................................................70%

OR fully equipped with capnography....................................10%Hospitals without capnography............................................12%Hospitals, where blood gas analysis is unavailable.................0%

Capnometry in our ICUs:ICUs, where capnography is used at least from time to time......8%

Capnometry in our prehospital setting:Ambulances equipped with capnometry devices..............not found

2000American Heart Association

Guidelines for cardiopulmonary resuscitation and emergency cardiovascular care

Qualitative end-tidal CO2 detectors

Esophageal detectors

• Kokybiniai etCO2 detektoriai• Recent advances •

Ventilation monitoring

2004 ?Microstream capnometryDay case surgery

Sleep apnea monitoring Extended cardiovascular uses of capnography

(CPR, electromechanic dissociation ...)Pulmonology

Ventilation monitoring• Recent advances •

One lung ventilation Fiberoptic bronchoscopy

Needle cricothyrotomy Critical care

spontaneous breathing

apnea

Ventilation monitoring• Other uses of capnometry •

Monitoring of Oxygenation

... Adequate illumination and exposure of the patient are necessary to assess

color...

ASA Standards for basic Anesthetic Monitoring

... During all anesthetics, pulse oximetry shall be employed...

... The concentration of oxygen in the breathing system shall be measured with a

low FiO2 alarm in use...

Oxygenation monitoring• Exploring Lithuania •

Pulse oximetry in operating rooms:District hospitals...................................................................59%Regional nonteaching hospitals..............................................46%University hospitals...............................................................73%

Hospitals, fully equipped with pulse oximetry.........................4%Hospitals, where pulse oximetry is unavailable.......................0%

Pulse oximetry in ICUs:District hospitals...................................................................57%Regional nonteaching hospitals..............................................51%University hospitals...............................................................60%

Pulse oximetry in the prehospital setting:Ambulances, equipped with pulse oximeters.............a recent victory

Equipment Status Monitoring

... Anesthesia apparatus check-up is an essential part of any anesthesia ...

... Unreliable and unsecure anesthesia equipment should not be used ...

... There shall be in continuous use a device that is capable of detecting

disconnection of components of the breathing system ...

Equipment status monitoring• Obsolescence criteria •

ASA Guidelines for Determining

Anesthesia Machine Obsolescence

• Necessary and approved replacement parts are impossible to obtain

• No standard connections

• Evident leakage in the breathing system

• Absent oxygen supply alarm, no FiO2 detector

• Absent automatic O2/N2O ratio device, no "fail-safe" system

• Absent airway pressure (P-peak, PEEP, negative pressure) alarm*

• Impractical equipment (e.g.,, no possibility to utilize other vaporizers or to perform a low flow anesthesia)*

• A significant possibility of human error due to tremendous technological differencies when compared with modern anesthesia machines*

(...)* Relative criteria

It's the responsibility of the anesthesiologist to determine if a machine’s failure to meet newer equipment standards represents a threat to patient

safety

Anesthesia equipment• Exploring Lithuania •

Stationary anesthesia machines in the OR:District hospitals...................................................................85%Regional nonteaching hospitals..............................................89%University hospitals...............................................................89%

Newer (<5 years) anesthesia machines:District hospitals...................................................................16%Regional nonteaching hospitals..............................................16%University hospitals................................................................9%

Older (>10 years) anesthesia machines:District hospitals....................................................................31%Regional nonteaching hospitals...............................................25%University hospitals................................................................13%

Provision with ventilators of our ICUs:District hospitals...................................................................48%Regional nonteaching hospitals..............................................49%University hospitals...............................................................59%

Newer (<5 years) ventilators in ICU:District hospitals...................................................................26%Regional nonteaching hospitals..............................................21%University hospitals...............................................................40%

Older (> 10 years) ventilators in ICU:District hospitals...................................................................53%Regional nonteaching hospitals..............................................17%University hospitals...............................................................10%

Ventilation equipment• Exploring Lithuania •

Deaths and brain damage related to difficult airway

(ASA closed claims project database, 2003)

A look back

0

50

100

Desperate attempts of intubation only

Alternative airway devices used

A look back

Searching for a perfect one

(Airway)ABCDA

Alternative airway management devices• Laryngoscopes •

BladesHandles

McCoy laryngoscope

Alternative airway management devices• Laryngoscopes •

Bullard laryngoscopeFlexiblade

Wu scope Upsher laryngoscope

Alternative airway management devices• Intubation adjuncts •

Flexible stylets Lighted stylets

Guminis elastinis bužasGum elastic bougie ETT with controllable tip

Alternative airway management devices• Supraglotic devices •

Oropharyngeal airwayNasopharyngeal airway

COPA (cuffed oropharyngeal airway)

Esophageal obturator airway

Laryngeal mask airway (LMA)

Laryngeal tube Combitube

Intubation LMA (Fastrach)

Alternative airway management devices• Supraglotic devices •

Alternative airway management devices• Infraglotic devices •

Transtracheal jet ventilation Cricothyrotomy

Tracheostomy Translaryngeal tracheostomy

(Breathing)ABCDB

Ventilation devices• Primary survey •

Faceshield (Microshield)

Pocket face mask

Ventilation devices• Advanced •

Bag-valve device Demand valve Ventilation via Combitube

Emergency transportventilator

ICU ventilatorsVentilation via LMA

Searching for an ideal one• What should I choose? •

• It's the main factor influencing one's decision. Many alternative techniques, however, could be relatively easily learnt.

• Intubation is still considered a "gold standard". One should maintain acceptable intubation skills.

EXPERIENCE

• Factors to consider: aspiration risk, possible ventilation difficulties, risks associated with patient transportation

• LMA and Combitube are effective when one needs to establish airway patency quickly, in nonstandard position or in case of difficult intubation

SITUATION

• LMA is the best known alternative airway device in elective as well as in emergency anesthesiology

• Endotracheal intubation is preferred during prolonged procedures, in case of nonstandard positioning of the patient

SURGICAL INTERVENTION

• The indications of alternative devices in airway management is only partly defined. There are, however, well-established contraindications.

• Only few specific recommendations for suspected cervical spine injury, presence of dangerous infections have been developed

PATIENT

Prehospital setting• What should I choose? •

The manner in which a patient's airway is

maintained often influences how effectively ventilation

and transportation is accomplished

Prehospital setting

Despite constantly increasing selection of alternatives, an ideal airway device for prehospital airway does not yet exist

Difficult intubations are more common in prehospital circumstancies. Poor intubation

experience, errors in tube position diagnostics and lack of monitoring are

detrimental

Oxygenation and effective ventilation are the main priorities

Prehospital setting• Exploring Lithuania •

Anesthesiologists in prehospital setting

Alternative airway devices availableCombitube..............................................................................rarityLaryngeal mask...........................................................................noSuccinylcholine............................................................................no

Fully equipped ambulances ('reanimobiles')

it's a minority

usually up to 100 km away

FAILED PREHOSPITAL INTUBATIONS: AN ANALYSIS OF EMERGENCY DEPARTMENT COURSES AND OUTCOMES Henry E. Wang et al, Prehospital Emergency Care 2001;5:134–141

592 prehospital intubations•••

AN ANALYSIS OF INVASIVE AIRWAY MANAGEMENT IN A SUBURBAN EMERGENCY MEDICAL SERVICES SYSTEM

Prehosp Disaster Med 1992; 7:121-126

278 prehospital intubations

Prehospital setting• Endotracheal intubation issues •

• Knowledge of indications for endotracheal intubation is of paramount importance• The incidence of difficult intubation subsides remarkably if muscle relaxants are used. Although rare, potential complications could be lethal. A great deal of experience is required when using these pharmacological adjuncts.• There is still no clearly defined and internationally supported indications for their use in prehospital setting• Intubation with iv sedation seems to be a reasonable choice• There is no clear consensus on the number of intubations required to train prehospital personnel adequately and maintain their skills. A figure of approximately 10 per year is often cited.

Prehospital setting• Endotracheal intubation issues •

AHA Guidelines 2000 for cardiopulmonary resuscitation and emergency cardiac care

Emergency and transport

ventilators

Demand valve Pocket face mask

Bag - mask ventilation

Prehospital setting• Ventilation priorities •

Prehospital setting• Ventilation priorities •

Bag-mask onlyCombitube + bag-mask

Laringinė kaukė + bag-mask

AHA Guidelines 2000 for cardiopulmonary resuscitation and emergency cardiac care

CombitubeAn ideal option for our ambulances?

Prehospital setting• Combitube •

760 prehospital insertions of Combitube

Use of the Esophageal Tracheal Combitube by basic emergency medical technicians. Resuscitation 2002 Jan;52(1):77-83)

• insertion successful 95,4%• ventilation successful 91,4%• sucutaneous emphysema (18)• tension pneumothorax (5)• pharyngeal bleeding (15)• airway edema (3)

No Combitube related injuries established at autopsy

CombitubeIndications Advantages

• Difficult intubation (especially useful in case of bleeding from upper airways and gastrointestinal tract or profuse vomiting as well)

• Quick establishment of airway is needed (especially useful in prehospital setting)

• Elective surgery, especially in case of deformities of neck and face. Also recommended for actors and singers

• No experience is required

• No 'sniffing' position is needed

• No preparation is needed -Combitube is ready for immediate use

• Suitable in case of 'full stomac'. Minimal aspiration risk if inserted correctly

• Fixation is unnecessary

Contraindications Disadvantages• Conscious patient or the presence of gag reflex

• Small (<1.52 m) adults

• Children (up to sixteen years old) ?

• Corrosive injuries of gastrointestinal tract

• Foreign bodies

• Tracheostomy

• Esophageal abnormalities

• Requires ablation of consciousness

• Its insertion can evoke cardiovascular reactions

• Serious complications (esophageal trauma, subcutaneous emphysema, pneumomediastinum etc)

• Difficulties if bronchoscopy is needed


1139 prehospital insertions of Combitube

Complications associated with the use of the Esophageal-Tracheal Combitube. Vezina D et al. Can J Anaesth 1998

8 Combitube-related subcutaneous emphysema

4 Combitube-related esophageal lacerations

CombitubeWhere is the tip?

Bag ventilation via blue port

Chest rises, breath sounds are present, no gurgitation

Chest does not rise, gurgitation in epigastrium is heard

Unable to ventilate via either port, no sounds heard

Deflate cuffsWithdraw 2-3 cm

ReinflateRecheck

Ventilation via blue portGastric tube via white port

Drugs via blue port?

Ventilation via white portObserve, listen, lookDrugs via white port

• Always use capnography, esophageal detectors or end-tidalcarbon dioxide detectors. Recheck position during transportation• Do not overfill the distal cuff • Consider endotracheal intubation

If situation does not changes, reinsert Combitubeonce more. If unsuccessful,

consider other airway devices


172 prehospital airway emergencies

Comparison of a conventional tracheal airway with the Combitube in an urban emergency medical services system run by physicians. Rabitsch W et al. Resuscitation, 2003;57(1):27

A: Endotracheal intubation• Successful 94%

• Failed 6%

B: Combitube insertion• 98% successful

• 2% failed

Combitube and endotracheal intubation could act as a substitute of each other. Intubation success rate increases, if these devices are

used concomitantly

Prehospital setting• Combitube vs LMA •

• So far, there are no well-controlled, randomized, prospective studies

• Success rates for insertion of both the Combitube and the LMA depend on adequate initial training and frequent practice. Those that were trained in the OR had much higher success rates for insertion of the LMA

A choice of airway device for 12,020 cases of non-traumatic cardiac arrest in Japan. Tanigawa K et al.

Prehosp Emerg Care 1998.

Overall successful insertion and ventilation rates Combitube 73.5% vs 64% LMA

Both of these devices provide good options for airway rescue in the event of failed intubation, but in prehospital studies neither have consistently high success rates for

insertion and ventilation

Hospital setting

Despite better equipment, monitoring, and extensive experience of hospital staff,

perioperative respiratory adverse events are still common

Noncompliance with standardized action plan as well as the absence of preplanned strategy in case of difficulties seems to be

the main problem

Hospital: An underused source of knowledge and experience for the

prehospital care staff

Hospital setting• Suggested portable storage unit (ASA, 2003) •

Alternative laryngoscope blade (McCoy, Miller, Bullard)

Endotracheal tubes of assorted sizes Tracheal tube guides (semirigid stylets, tube changer,

lighted stylet, Magill forceps)

Laryngeal mask airway of assorted sizes and typesFlexible fiberoptic intubation equipment

Retrograde intubation equipmentNoninvasive ventilation devices (Combitube, hollow jet

ventilation stylet, transtracheal jet ventilation)Emergency invasive airway access (cricothyrotomy

equipment)Exhaled carbon dioxide detectors

Availability of a portable kit for difficult airways

0%

Hospitals without any alternative deviceDistrict hospitals....................................................................63%Regional nonteaching hospitals...............................................33%University hospitals................................................................12%

Hospitals equipped with all required devices

0%

Hospital setting• Exploring Lithuania •

Hospital setting• Exploring Lithuania •

Most common alternative airway devices:

Laryngeal mask...............................................24%

Cricothyroidotomy kit.....................................18%

Fiberoptic bronchoscope.................................18%

Combitube.........................................................8%

Rigid bronchoscope...........................................8%

Alternative blades of laryngoscopes.................5%

COPA..................................................................4%

Intubating LMA..................................................2%

Laryngeal maskThe essential tool

Currently available items

LMA

Disposable LMA Wire - reinforced LMAClassical LMA

Dual-lumen LMA Intubating LMA LMA accessoires

Laryngeal mask ADVANTAGES

Easy insertion technique

Multifunctional device (a ventilatory device or conduit for tracheal intubation)

Placement success is not influenced by anatomic abnormalities

A first choice device in case intubation has failed

Minimal cardiovascular response after insertion

'Smooth' awakening

Minor vocal cord dysfunction

Well tollerated in awake patients

Reusable

DISADVANTAGES

Risk of aspiration

Risk of gastric distention

Risk of dislodgement

Isn't suitable in case of any gross laryngeal abnormality

Drug administration via LMA is a bit problematic

LMA performs adequately even when it is used

poorly.

Try it!

Failed insertion

LMA

0,4-6%

Failed insertion

LMA

Wrong pressure direction Insufficient deflation Excessive deflation

Folded mask Wrong LMA sizeEntrapped epiglottis

The role of LMA in case of difficult airway

LMA

....Chadwick IS et al. Anaesthesia for emergency caesarean section using the brain laryngeal airway (letter). Anaesthesia 1989. McClune S et al. Laryngeal mask airway for caesarean section. Anaesthesia 1990. Priscu V et al. Laryngeal mask for failed intubation in emergency caesarean section (letter). Can J Anaesth 1992; De Mello WF et al. The laryngeal mask in failed intubation (letter). Anaesthesia 1990 Storey J et al. The laryngeal mask for failed intubation at caesarean section (letter). Anaesth Intensive Care 1992; Williams AR et al. The laryngeal mask airway--suboptimal availability, a cause for concern (letter). Anaesthesia 1992. Denny NM et al. Laryngeal mask airway for emergency tracheostomy in a neonate (letter). Anaesthesia 1990. Wheatley RS et al Intubation of a one-day old baby with the pierre-robin syndrome via a laryngeal mask (letter). Anaesthesia 1994; Myles PS, Venema HR, Lindholm DE: Trauma patient managed with the laryngeal mask airway and percutaneous tracheostomy after failed intubation (letter). Med J Australia 1994. Brain AIJ: The laryngeal mask airway--a possible new solution to airway problems in the emergency situation. Arch Emer Med 1984; Brain AIJ: Three cases of difficult intubation overcome by the laryngeal mask airway. Anaesthesia 1985; Calder I, Ordman AJ, Jackowski A, Crockard HA: The brain laryngeal mask airway: An alternative to emergency tracheal intubation. Anaesthesia 1990; Lim W, Wareham C, de Mellow WF, Kocan M: The laryngeal mask in failed intubation (letter). Anaesthesia 1990; Owen G, Browning S, Davies CA, Saunders M, Thomas TA: The laryngeal mask (letter). BE Med J 1993; Gature PS, Hughes JA: The laryngeal mask airway in obstetrical anaesthesia. Canadian J of Anaesth 1995....

An endless evidence in all

age groups

Universal algorithm(ASA, 1993 - 2004)

National algorithm(Italy, France etc)

National database(Austria)

Difficult Airway Clinic (Michigan, USA, 1987)

Local algorithm

Difficult Airway Algorithms• In the world •

Difficult Airway Algorithm• Exploring Lithuania •

Approved algorithms for difficult airway:Local hospitals......................................................................43%Regional nonteaching hospitals..............................................50%University hospitals...............................................................83%

Algorithms adopted:ASA 'Difficult Airway Algorithm (1993-2004)...........................10%Local algorithms...................................................................38%Algorithms are under development..........................................2%No algorithm available..........................................................50%

Difficult airway algorithms

Most of difficult intubations could be foreseen

Awake airway management is a mainstay of all difficult airway algorithms

Oxygenation is the highest priority

Established indications and priority range for alternative airway devices

A difficult intubation should be communicated to the patient. Appropriate records are made as well.

Portable unit for difficult airway is highly recommended

Difficult airway algorithms

0,5-20% depending on type of surgery, skills and facilities

3rd degree laryngoscopy 0,05% (1:2000)

4th degree laryngoskopy < 0,05%

Failed intubation -?

Failed mask ventilation - ?

Cannot ventilate, cannot intubate 0,01% (1:10000)

• Official statistics is contradictory

• Unofficial statistics: 15-30%90% of cases are preventable with more careful airway status

assessment

Difficult Airway Algorithm• Incidence •

Difficult Airway Algorithm• Problem 1: Poor sensitivity •

Lingual tonsil hyperplasia: an unexpected

catastrophe

Effects of posture, phonation and observer on Mallampati classification. Tham EJ et al. Br J Anaesthesia, 1992

Difficult Airway Algorithm• Problem 2: Nonstandardized technique •

Predictors• Deformities, burns, scars, trauma

• Beard

• Absence of teeth

Definition• Air leak is evident

• No chest rise

• SaO2 < 90% when ventilating with 100% O2

• Necessity to increase flow up to 15 l/ min or to use a by-pass button more than twice

• Persistent hypoventilatrion

• Necessity to constantly change patient's positioning

• Obesity

• Snoring

• Advanced age

• Obstructive sleep apnea

Incidence• 0,07 % El-Ganzouri AR. Anesth Analg 1996• 0,9 % Rose DK. Can J Anaesth 1994• 1,4 % Asai T. Br J Anaesth 1998• 5 % Francon D. AFAR 97, Langeron O. Anesthesiology 2000• 15 % Williamson JA. Anaesth Intens Care 1993

Difficult Airway Algorithm• Problem 3: Predictors of difficult mask ventilation ? •

Difficult ventilation predicts difficult intubation

•••

Ventilation is more complex in difficult intubations

Difficult Airway Algorithm• Problem 3: Predictors of difficult mask ventilation •

Patient's drama

Anesthesiologist's drama

Circumstancies

Difficult Airway Algorithm• Everybody is involved •

Expected difficult airway

Anesthesia-related deaths and brain damage(ASA closed claims project database, 2004)

A look back

0

50

100

Unexpected difficult airway


• An informed consent is mandatory• Awake intubation techniques are employed. Sedation monitoring is highly recommended (Ramsay 3)• Techniques: FOB, intubation in local anesthesia, retrograde witre intubation. A new alternative: intubating LMA, Bullard laryngoscope• Uncooperative patient is a great problem. FOB is relatively contraindicated, elective surgical airway seems to be a reasonable choice• Risky: regional anesthesia, mask anesthesia without any back-up plan in case the necessity of intubation ensues• Not recommended: classical LMA, blind intubation through the LMA, FOB in general anesthesia• If failed:

consider re-preparation of the patient for awake intubation or cancel caseuse different blades, LMA as a FOB conduit, retrograde intubation, face

mask and other anesthesia methodssurgical airway (elective or emergency)

Expected difficult airway• General considerations •

ASA Difficult Airway Algorithm


Difficult airway

Expected Expected in an uncooperative patient

Induction of general anesthesia

Call for help. Ventilation via face mask

Ventilationineffective

Alternative noninvasive approaches(bronchoscopy, retrograde intubation...)

Unexpected

As atemporary ventiliation

device

As a definitive ventiliation

device

Failed intubation

Ventilation effective

Proper preparationAwake intubation

Failed

LMA

LMA failure

A conduit for fiberoptic intubationCombitube

Noninvasive and surgical airway access techniques

Flexiblefiberoptic intubation

Availability of fiberoptic bronchoscopesLocal hospitals......................................................................10%Regional nonteaching hospitals..............................................64%University hospitals...............................................................75%

Rigid bronchoscopyAvailability.............................................................................8%Nevertheless, nobody is experienced in rigid bronchoscopy.....50%

If available, FOB service is provided by Anesthesiologists....................................................................47%Other physicians....................................................................35%Nobody is experienced in FOB................................................18%

Bronchoscopy• Exploring Lithuania •

Fiberoptic intubationContraindications and drawbacksIndications

• Expected difficult intubation• Unexpected difficult intubation in a non hypoxic patient• Airway obstruction (foreign bodies, neoplasm..)• Unstable or immobile cervical spine • Endobronchial intubation• Aspiration• Airway hygiene• Tracheostomy (percutaneous, surgical)

• Uncooperative patient

• Hypoxia

• Obscure view anticipated (incontrollable secretions etc)

• Profuse bleeding if uncontrollable with active suctioning

• Hypersensitivity to local anesthetics (for an awake patient)

•Inexperience of the operator

The most common problems

Flexible fiberoptic intubation

• Toxicity of local anesthetics• Complications of oxygen insufflation• Absence of any back-up plan in case of failure / complications• No alternative airway device available• Hang-up (inability to pass an ETT through the vocal cords)• ETT placed too deep• Lost landmarks due to inexperience• Obstructing base of tongue or epiglottis• Reflex closure of the glottis, bronchospasm, vomiting, severe cardiovascular reaction• Inadequate sedation of the awake patient• Hypersecretion, epistaxis• Fogging of the FOB

Retrograde wire intubationAn underused alternative

Retrograde wire intubationContraindications and drawbacksIndications

• An alternative to FOB in case of expected difficult airway

• Poor visualization of anatomic structures (blood, hypersecretion, deformities etc) in a nonhypoxic patient

• A hypoxic patient• Difficulties in identifying the cricothyroid (obesity, neck trauma and tumors etc)• Laryngotracheal stenosis• Disorders of bleeding• Infection

Complications

• Hoarseness (14)

• Bleeding (11)

• Subcutaneous emphysema, pneumomediastinum, pneumothorax (6)

• Esophageal trauma

• N. trigeminus injury (1)

Retrograde wire intubation

Possible ways: a small ETT-over-a guidewire, a guidewire-through- Murphy Eye, a guidewire-through-a FOB

Important notes

• A local anesthesia of the trachea, nasal and oral cavity is recommended, if time allows• The needle is advanced over the mid-cricothyroid membrane at an angle of 45° to the chest while maintaining neck extension• J - shaped introducer is at least 2,5 times the length of a standard ETT(typically 1,1-1,2m) • Coughing typically heralds caudad travelling of the wire• Obstruction is usually overcome if the position of head and neck is changed

Unexpecteddifficult airway

• Oxygenation is the first priority. Reevaluate the oxygenation status before any subsequent attemp. Ventilation status should be constantly surveyed as well.• If mask ventilation becomes inadequate, the aspiration issues are not considered• It's highly recommended to refer to Cormack-Lehane laryngoscopy scale. • Persistent attempts of intubation are detrimental. Three attempts are usually allowed, but try once in case of the most difficult laryngoscopy grade• LMA and Combitube is the first choice devices if ventilation becomes ineffective. Do not defer the insertion of LMA. Later, it will be of little value due to progressive posttraumatic edema. If failed, consider transtracheal oxygenation.• FOB should be immediately available. It is used when the patient awakes. • Blind intubation through the LMA and blind nasal intubation is no longer recommended

Unexpected difficult airway• Priorities •

ASA Difficult Airway Algorithm

Unexpected difficult airway

Difficult airway

Expected


Failed

Awaken Cancel case

Postpone case

Expected in an uncooperative patient Unexpected


LMA

Failed intubation





LMA as definitive ventiliation

device

LMA as atemporary ventiliation

deviceLMA failure

Combitube


A conduit for fiberoptic bronchoscope

Intubatinglaryngeal mask

Its role in the management of difficult airway

Intubating LMA

Use of the Intubating LMA-Fastrach™ in 254 Patients with

Difficult-to-manage Airways Anesthesiology, 2001

The overall success rates for blind and fiberoptically guided intubations through the LMA-Fastrach™at three attempts were

96,5 - 100%

Advantages

Intubating LMA

• One of the most effective airway devices in case of difficult intubation and/or extubation

• Hypersecretion, blood, edema usually do not influence the success rate

• Positioning of physician is an unimportant issue

• One hand remains free

• Safe in case of suspected unstable cervical spine (no 'sniffing' position is needed)

• No contact with a dangerous infection

• Accomodation of large-lumen ETT (8,0 mm)

• Very suitable for bronchoscopy

Disadvantages

• Special endotracheal tubes are needed for intubation

• Complicated ILMA removal

• No suitable for prolonged procedures

• Possibility of trauma and dislodgement if patient's position is changed

• Contraindicated in case of pharyngolaryngeal abnormalities

• Possible difficulties if mouth opening is reduced

The place of LMA in ASA Difficult Airway Algorithm

Intubating LMA

Difficult airway

Expected Expected in an uncooperative patient


Failed

Unexpected


Intubating LMA

Failed intubation





LMA as atemporary ventiliation

device

ILMA as a conduite for FOBi

LMA as definitive ventiliation

deviceLMA failure

Combitube


The Last Chance

• Consider LMA, Combitube, rigid bronchoscope. If failed, percutaneous cricothyrotomy is the procedure of choice.

• Decision to do it should not be delayed or postponed. Most physicians hesitate at potentialy grave risk to the patient

• Tracheostomy is never an emergency procedure. If indicated (eg., a laryngeal neoplasm-related obstruction), it is performed electively using a local anesthesia

• Every anesthesiologist should be familiar with basic transtracheal oxygenation techniques. Practicing on mannequins is shown to be effective and therefore it's strongly recommended

Difficult Airway Algorithm • Cannot intubate, cannot ventilate •

1. Percutaneous cricothyroidotomy

Cannot ventilate, cannot intubate

1. If difficult intubation is expected, potential puncture site should be identified, dressed and anesthetized

2. The right-handed clinician stands on the right side of patient, the trachea is fixated with nondominant hand.

3. Needle is advanced at right angle in the caudad third of the membrane. Constant aspiration is applied until the trachea is entered.

• Large - bore (3.5-6 mm) access

Ventilation and oxygenation with low-pressure system is adequate. A 1-1,5 cm vertical skin incision is needed. Insertion direction is 45°caudad. A Seldinger technique may be used to pass a dilator with the catheter

1. Percutaneous cricothyroidotomy


• Low pressure system

Ambu bag or anesthesia circuit is used. This cannot provide enough flow to expand the chest adequately, but it's a temporary oxygenation mean while a more definitive airway is secured.

• High pressure system

Jet ventiliator or "O2 flush" is used. Vt 400-700 ml is achievable via a 16G catheter. Insufflations 1-1,5 secevery 5 sec. Mouths and nose closure is often needed during insufflation (but not exhalation)

2. Surgical emergency airway access


• Complication rate is 20-40% higher when compared to transtracheal jet ventilation

• Reported complications: laryngeal stenosis, voice changes (10-15%), bleeding (up to 8%), tube misplacement

3. Teaching problem


Comparison of Cricothyrotomy Methods Performed by Inexperienced Clinicians. Eisenburger et al. Anesthesiology, March 2000

40 first-time cricothyroidotomies

Surgical cricothyrotomy vs Seldinger technique

.

Successful placement 60%

Failure due to kinking of guidewire

Successful placement 70%

Failure due to subcutaneous, paratracheal and esophageal tube placement

3. Teaching problem


What Is the Minimum Training Required for Successful Cricothyroidotomy?: A Study in Mannequins.

Wong DT et al. Anesthesiology, 2003

102 anesthesiologists performing cricothyroidotomies on mannequins

.By the fifth attempt, 96% of participants were able to

successfully perform the cricothyroidotomy in 40 s or less

The problem of teaching

Difficult Airway

Training Guidelines in Anaesthesia of the European Board of Anaesthesiology, Reanimation and Intensive Care (2001)

• For most manual skills, a necessary number of cases per procedure has been determined to achieve an optimal rate of success. As concernes difficult airway situations, no prospective study has established the minimum number of training sessions required.

• Nevertheless, European Academy of Anesthesiology strongly suggests the use of anesthesia simulators and mannequins during the training process.

• Prehospital and emergency medicine is an important advance in contemporaneous residency training program.

Teaching airway skills• Exploring Lithuania •

Survey of sixteen ex-residents (2001-2004)


Experience of difficult intubation with a compromised oxygenation

94%What guides you in case of difficulties?

Local algorithm of difficul intubation....................................14% My own experience.............................................................20%ASA Difficult Airway Algorithm ............................................66%

It must have been a preventable disaster in....... 53%


Airway techniques performedLMA..........................................................................................100%Endobronchial intubation..............................................................87%Awake intubation........................................................................75%Nasal intubation..........................................................................69%Modified laryngoscopes (McCoy, Miller etc)...................................56%Tracheostomy.............................................................................50%Combitube..................................................................................13%Fiberoptic intubation....................................................................13%Retrograde wire intubation (incl. on a mannequin)..........................6%Cricothyrotomy (incl. on a mannequin)...........................................6%Lighted stylet (incl. on a mannequin)..............................................6%Gum elastic bougie or similar device...............................................0%


Evident lack of experienceFiberoptic intubation.............................................................100%Gum elastic bougie and other stylets.......................................87%Nasal intubation.....................................................................69%Modified laryngoscopes (McCoy, Miller blades etc)....................44%Awake intubation...................................................................19%LMA......................................................................................13%Combitube.............................................................................13%

Gaps in the residency programFiberoptic intubation..............................................................100%Alternative airway devices.......................................................87%Simmulators and mannequins..................................................50%

Room for improvement

Difficult Airway

• Better knowledge of an appropriate plan / algorithm • Being prepared to perform awake intubation more often• More practice in fiberoptic intubation• Always having an appropriate sized LMA immediately available• All anesthesiologists knowing, and practicing on mannequins, how to oxygenate via the cricothyroid membrane• All anesthesiologists knowing that a difficult intubation should be communicated to the patient


20042003


2003 2004

2005A Year of Airway Management ?

The Happy End

review airway management

Documents