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INTRODUCTION
Devices that are used to maintain the airway patency and provide
ventilation by placing just above the glottic opening.
They sit outside the trachea and provide a hands free means of gas
tight airway.
Standard of airway management , filling the niche between
facemask and tracheal tubes.
Dr. Archie Brain developed LMA in 1982 as a modification of
Goldman dental mask with ET tube.
The first commercially available supraglottic airway device was LMA-
Classic(1988).
CLASSIFICATION Based on Generation:-
LMA
First GenerationSimple airway device. Low pressure
pharyngeal seal
May or may not protect
from aspiration.
Have no specific design
to lessen the risk.Eg.-
cLMA
Flexible LMA
All LMs
Laryngeal tube
Cobra perilaryngeal
airway
Second GenerationSpecially designed for
safety.
High pressure pharyngeal
seal.
Reduce the risk of
aspiration.
May be more efficacious
in ventilation.
Eg.-
PLMA,Supreme LMA,
Laryngeal tube suction 2,
Laryngeal tube suction D,i-gel,
SLIPA.
CLASSIFICATION Based on sealing mechanism –
1.Cuffed perilaryngeal sealer:-
Non-directional non esophageal Sealers- cLMA, Flexible LMA, LMA
unique.
Directional Non-esophageal sealing- Fastrach LMA, ALMA.
Directional esophageal sealing- Proseal LMA, Suprem LMA.
2.Cuffed pharyngeal sealer:-
Without esophageal sealing: COPA, PAX.
With esophageal sealing: Combitube, LT, LTS.
3.Cuff less preshaped sealer: -
With esophageal sealing- Baska mask, i-gel.
Without esophageal sealing- SLIPA , AirQ-SP.
CLASSIFICATION
BASED ON THE NUMBER OF LUMEN-
1.Single Lumen Devices:-
LMA-classic, LMA-unique, LMA-flexible, ILMA, C-trach, Soft seal,
Laryngeal Airway Device(LAD), Ambu Laryngeal Mask,
Pharyngeal airway express(PAX), Cobra Perilaryngeal
Airway(CPLA), Laryngeal Tube(LT), Cuffed oropharyngeal airway,
Stream Lined Liner of the Pharyngeal Airway(SLIPA), Glottic
Aperture Seal Device.
2.Double Lumen Devices:- Proseal LMA, Combitube, Laryngeal Tube Suction(LTS), Airway Management Device(AMD).
3.Tripple Lumen Devices:- Elisha Airway Device(EAD).
INDICATION
Alternative airway during GA specially in short surgical
procedures and minor therapeutic or diagnostic procedures
like radiation therapy, diagnostic and interventional
radiology, endoscopy, ECT etc.
Cardiopulmonary resuscitation to secure the airway.
Essential part of difficult airway trolley.
Primary airway device when urgent airway patency is
required in lateral position as lesser time required to place
LMA in the lateral position as against endotracheal intubation
in this position.
Relative indication- in professional singers to avoid vocal cord
trauma.
CONTRAINDICATION
Limited mouth opening (< 2 fingers)
Local pathology in pharynx , larynx or upper airway.
Trismus, facial or upper airway trauma
Increase risk of aspiration- Morbid obese, > 14 week pregnant,
prior opiods medication, delayed gastric empting, acute
abdominal or thoracic injury, history of GERD, and hiatus hernia.
Reduced lung compliance/increase work of breathing
ADVANTAGES Increased speed and ease of
placement.
Less requirement of expertise.
Improved hemodynamic stability at induction and during emergence of anesthesia.
Minimal IOP and ICP changes during insertion.
Increase airway tolerance.
Lower frequency of coughing during emergence.
Improved oxygen saturation during emergence
DISADVANTAGE
Inadequate positive
pressure ventilation.
More chances of aspiration
of gastric content.
Sore throat.
Vascular compression and
nerve damage.
LMA- Classic
Comprised of three main components
– Airway Tube
– Mask
– Inflation line
Mask designed to conform to the
contours of the hypopharynx with its
lumen facing the laryngeal opening.
Made of medical grade silicone, it
can be autoclaved and reused many
times.
Seal pressure =25cmH2O
SIZE SELECTIONMask Size Patient size /Body Weight Maximum Cuff
Inflation Volume (Air)
1 Neonates/Infants up to 5 kg Up to 4 mL
1.5 Infants 5–10 kg Up to 7 mL
2 Infants/Children 10–20 kg Up to 10 mL
2.5 Children 20–30 kg Up to 14 mL
3 Children 30–50 kg Up to 20 mL
4 Adults 50–70 kg Up to 30 mL
5 Adults 70–100 kg Up to 40 mL
6 Large Adults over 100 kg Up to 50 mL
PREPARATION PRIOR TO
INSERTION
Select the proper size of LMA.
Inspect the LMA for any tear , blockage .
Slowly deflate the cuff to form a smooth flat wedge shape .
Over inflate: look for leak.
Use a water soluble lubricant to lubricate the posterior surface of LMA just prior to insertion.
Avoid excessive amounts of lubricant
-on the anterior surface of the cuff or
-in the bowl of the mask.
Avoid lignocaine jelly for lubrication .
INSERTION TECHNIQUE
Position: Neck flexed and head extended.
Use non-inserting hand to stabilize occiput.
Jaw should be pulled down by assistant.
LMA tube be grasped like a pen with index
finger pressing the point where tube joins
mask.
Place the tip of the LMA against the inner surface of the patient’s upper teeth.
Aperture facing forward, the tip pressed
upwards against the hard palate.
Mask is advanced into pharynx to ensure
that tip remains flattened and avoids the
tongue.
Continue.. Neck is kept flexed and head extended.
Press the mask into the posterior pharyngeal wall using the index finger.
Continue pushing with your index finger and guide the mask downward into position.
Grasp the tube firmly with the other hand and then withdraw your index finger from the pharynx.
Press gently downward with your other hand to ensure the mask is fully inserted.
Continue.. Inflate the mask with the
recommended volume of air.
Do not over-inflate the LMA.
Normally the mask should be
allowed to rise up slightly out of the hypo pharynx as it is inflated to find
its correct position.
Insert a bite-block or roll of gauze to
prevent occlusion of the tube.
Now the LMA can be secured
utilizing the same techniques as
those employed in the securing of
an endotracheal tube.
OTHER METHODS OF
INSERTION 1. Thumb index method.
2.Partial inflation method.
3.180 degree rotation method.
4.Laryngoscopy aided method.
5.Stylet aided method.
6.Insertion from the side of the mouth opening.
SIGNS OF CORRECT
PLACEMENT The slight outward movement of the tube
upon LMA inflation.
The presence of a smooth oval swelling in the neck around the thyroid and cricoidarea, or no cuff visible in oral cavity.
Ventilate the patient while confirming equal breath sounds over both lungs in all fields and the absence of ventilatory sounds over the epigastrium.
Part of LMA Position
Distal tip of silicone
cuff
Upper esophageal
sphinter
Sides of the cuff Pyriform fossa
Upper part of the cuff Tounge base
PROBLEMS Failure to press the deflated mask up against
the hard palate or inadequate lubrication or deflation can cause the mask tip to fold back on itself.
Once the mask tip has started to fold over, this may progress, pushing the epiglottis into its down-folded position causing mechanical obstruction .
If the mask tip is deflated forward it can push down the epiglottis causing obstruction
If the mask is inadequately deflated it may either
push down the epiglottis
enter the glottis.
INTUBATION WITH C-LMA 1.Blind intubation.
2.Fibrescope guided.
3.retrograde.
4.Lighted stylet guided.
5.Nasotracheal intubation.
DISADVANTAGES:-
1.Standard tube not long enough to insert.
2.Pilot tube may kincked.
3.Cricoid pressure make it difficult to pass the tube.
4.Paediatric-largest uncuffed tube too small to allow good seal for PPV.
5.Removal of the LMA disturbs the ET tube
6. PPV not always possible due to moderate pharyngeal seal.
7.More risk of aspiration
Steps to reduce the chance
of aspiration
Avoid in patients who are un-fasted, or have factors predispose to regurgitation.
Routinely test the cuff for defects before use.
Avoid lubricating the anterior surface of the mask, since the lubricant may be aspirated.
Insert the LMA only when adequate depth of anesthesia has been reached.
Avoid disturbing the patient during emergence from anesthesia.
Keep the cuff inflated till the patient is awake.
Action after aspiration
1. Do not attempt to remove
LMA.
2. Disconnect the circuit and
allow to drain the fluid while
head is down & to the side.
3. Suction the LMA & give 100% O2.
4. Ventilate manually with low
gas flow & small TV.
5. Evaluate tracheobronchial
tree & suction the remaining
fluid with FOB.
6. Intubate when aspiration
below vocal cords.
LMA - UNIQUE
Single use , PVC made , cheaper.
Tube – stiffer , Cuff- less
compliant.
Less rise of intracuff presuure
with N2O.
More difficult to insert.
Size same as cLMA.
FLEXIBLE LMA Flexometallic tube- narrower & longer.
Has a rigid preformed angle at the cuff.
Seal pressure=20cmH2O
More difficult to insert.
Introducer helps to stabilize the airway tube during insertion & it is removed once mask is in place.
It has a less incidence of dislodgement once placed.
More useful in head & neck surgeries, ENT and upper torso procedures where need to reposition the airway is prevalent
Problems- Disruption of spiral reinforce wire, Increased airway resistance , limits endoscope & tracheal tube passage , unsuitable for MRI.
AMBU AURA LARYNGEAL
MASK Ambu Auraonce- single-use LM with a
preformed curve.
The Ambu Aura40 is the reusable, silicone version of the Ambu AuraOnce.
The Ambu Aura-i designed to facilitate intubation like ILMA.
Three parts- an airway tube, a mount area, and a bowl including the inflatable cuff..
All these three areas are molded as single unit for extra safety - no separation..
Facilitate insertion without exerting force on the upper jaw in neutral position.
A reinforced tip reduces the risk of the device folding back during insertion.
integrated inflation line and no epiglotticbars at the airway orifice.
SOFT SEAL LARYNGEAL MASK
similar to the single-use LMA.
The ventilation orifice is wider and it is characterized by the absence of mask aperture bars.
Cuff is more elliptical.
insertion with the cuff partially inflated is
recommended.
A maximum intracuff pressure of 60 cm
H2O is recommended.
may be used as an intubation conduit.
The large bowl of the device and its PVC
Construction inhibit easy insertion.
PERILARYNGEAL AIRWAY single use, PVC made, latex free .
It has a breathing tube with a large inner
diameter to increase air flow.
In the proximal end it has a standard 15 mm
connection
Novel head design- Grill of soft bar with Cobra
head shape.
Lies infront of laryngeal inlet.
Tip deflects epiglottis.
Bars allow ventilation & instrumentation.
Internal ramp to guide ETT to wards glottis
Proximal high volume low pressure cuff- seals
hypopharynx.
PLA offers a more effective seal, and a better
fiberoptic score as the c-LMA.
ADVANTAGES
1. Easy to insert.
2. Large lumen allows larger ETT &
fibrescope.
3. Sealing pressure higher than C-
LMA.
4. Can be used for parcutaneousdilatational cricothyroidotomy.
DISADVANTAGES
1. Less airway protection –
as tip lies above the
oesophageal inlet.
2. Airway obstruction.
INTUBATING LARYNGEAL
AIRWAY medical-grade silicon and latex free.
airway tube is curved similar to the anatomical curve of the upper airway to eliminate the need to bend the tube further during use, which can lead to kinking.
Mask- keyhole outlet to direct ETT to laryngeal inlet.
3 ridges – on inflation of mask, these ridges move against the posterior pharynx and improve anterior mask seal.
After intubation , ILA can be removed without dislodging the ETT using a reusable "ILA Removal Stylet”.
Low airway seal, high risk of aspiration.
INTUBATING LMA A modification of the c-LMA.
A rigid (stainless steel) anatomically
curved,short & wide bored shaft that
follows the anatomical curve of the palate
and the post pharyngeal wall.
An epiglottic elevator bar at the mask
aperture
Armoured flexible ET tube with a
longitudinal and a horizontal black line-
coincides with the epiglottic elevating bar.
The Stabilizer Rod of 25cm.
Seal pressure=60cmof H2O max.
Body
weight
ILMA size Air
volume
Tracheal
Tube
30-50kg 3 20ml 7mm
50-70kg 4 30ml 7.5mm
70-100kg 5 40ml 8mm
INSERTION Position: Neutral
Hold rigid handle parallel to patient’s chest.
Glide the mask along the palate till the straight part of the rigid tube is
parallel to the chin.
Rotate the rigid handle directing towards patient’s nose till it can not
be advanced.
Inflate the cuff & check ventilation.
Introduce FETT with black line faceing rigid handle till 15 cm mark.
Now grip ILMA handle firmly and lift it forward by few mms without
levering.
Advance the tube using clinical judgment.
Inflate the cuff and check for tracheal intubation.
Continue..
After confirmation of tracheal intubation deflate the ILMA cuff.
Remove FETT connector
Insert the stabilizing rod in the FETT to keep it in place.
Remove the ILMA gently over the stabilizing rod until it is clear of the
oral cavity.
Stablize the FETT to prevent accidental extubation.
Remove ILMA and the stabilizing rod.
Reconnect FETT connector and the breathing circuit and
confirm position again
CHANDY’S MANEUVER They increases the seal pressure and aligns the axes of trachea and
FETT.
First step : Rotating ILMA in coronal & sagittal plane in an attempt to
find least resistant ventilation position.
Second step : is to grasp the handle and use it to draw LMA forward
2-5 mm in a lifting action without levering teeth.
ADVANTAGES
Useful in “can’t intubate, can’t ventilate” scenarios.
Allows fast insertion into correct position without moving patient’s head or neck.
Can be used alone or as a guide to intubation.
Facilitates ventilation between ILMA insertion and ETT insertion
Good conduit for fibreopticintubation in presence of blood or clot in oral cavity.
Difficult laryngoscopic view is irrelevent to the success of ILMA intubation.
DISADVANTAGES
More likely to dislodge in head or
neck manipulation.
Unsuitable for MRI.
Difficulty in insertion with limited
mouth opening.
On removal of ILMA , tracheal tube
can be displaced downwards.
PROSEAL LMA
Reusable , silicon made , most specialized modification of c-LMA.
Modifications:-
(i) oesophageal drain tube
(ii) posterior inflatable cuff
(iii) reinforced airway tube
(iv) integral bite block
(v) introducer
Higher leak pressure(35cm of H2O)
than c-LMA(25cm of H2O).
Size- in 7 sizes (1-5) like the C-LMA with
drainage tube of
8,10,10,14,16,16&18 Fr respectively.
INSERTION (i) Standard: identical to the cLMA, but demanding
careful attention to detail.
(ii) Introducer: a metal introducer is attached to the concave side of the device. It is then introduced in the same manner as an intubatingLMA.
(iii) Bougie-guided: a bougie is placed upside down into the oesophagus and the PLMA is railroaded into place via the drain tube (suction catheters or orogastric tubes are alternatives).This technique had a significantly higher success rate.
Positioning:- The easy passage of an orogastric
tube into the stomach via the oesophageal tube has been shown to correlate with optimal
anatomical airway positioning over the larynx.
ADVANTAGES Increased airway seal improves the PPV.
Decreased chance of aspiration-
1.Oesophageal opening is isolated from the airway.
2.Drain tube vents gas leaked into the oesophagus.
3.On regurgitation drain tube vents the fluid & small solid particles
beyond the pharynx.
4. The large bulk of the PLMA reduces the space available for
regurgitated fluid to ‘pool’.
5. Increased oesophageal and pharyngeal seal decreases the risk
of any pooled fluid entering the laryngeal inlet.
Simple tests enable correct positioning of the PLMA to be confirmed.
The stomach may be accessed with an orogastric tube.
DISADVANTAGES
1. Less suitable as an intubating device as an ILMA b/c narrow
airway tube.
2.Slightly longer time required to insert than C-LMA.
3.Can cause airway obstruction by- compression of supraglottic
structure or cuff in folding.
4.Contraindicated for intraoral surgery .
LMA - SUPREME
Single use, PVC made 2nd
generation LMA.
Has features of P-LMA, I-LMA & LMA unique.
(i) Single use , PVC- (cf.LMA unique).
(ii) Large inflatable plastic cuff, but no posterior cuff (cf. PLMA)
(iii) Oesophageal drain tube
(iv) Preformed semi-rigid tube
(v) Fins in the mask bowl to prevent epiglottic obstruction(cf. PLMA, cLMA)
Pharyngeal seal is intermediate between cLMA and PLMA( 26–30 cm H2O)
Oesophageal seal not reported.
ADVANTAGES
The reinforced tip reduces the risk
of fold-over, compared with the
PLMA.
Anatomic curve that facilitates
easy insertion.
A drain tube to allow gastric
aspiration.
A high volume/ low pressure cuff
which generates higher seal pressure (36.1 vs 27.4cm H20 of
LMA unique).
A built-in bite block and fixation
tab to help secure the airway
4- An oval airway cross section
for improved stability of the
airway
DISADVANTAGES
drain tube runs through the middle
of the airway tube (rather than next to it in the PLMA) dividing it
into two narrow lumens. This limits
its use for airway inspection
and for use as a conduit for
intubation.
Being made of PVC, the SLMA
may cause more trauma than
silicone devices
LMA C-Trach Enables combined ventilation,
visualization, and intubation.
High first attempt intubation success rate
of 91%.
Fiberoptic technology allows real time
visualization of the glottic opening and
of the ET tube passing through the vocal
cords.
Ideal in rescue/difficult airway situations
.
Completely portable and wireless system
weighs less than eight ounces.
Easy to learn and very effective
INSERTION
Inserted exactly the same as the LMA Fastrach.
Once the airway is secured and patient is being ventilated
The viewer is switched on, placed in the magnetic connector and a clear image of the larynx is displayed in real time.
The ET tube can be viewed as it enters the trachea. Once the patient is intubated, the viewer is removed and the mask is removed leaving the ET tube in place.
Problems:-
1. It has a poorer image quality than a flexible fiberoptic endoscope.
2. It cannot be used easily in the patient with a limited mouth
opening.
3. The view may be obstructed by secretions, lubricant, or blood.
i-GEL Novel SAD designed by UK anaesthetist,
Muhammed Nasir.
(i) Single use.
(ii) Cuffless: the mask is made of a soft polymer and is shaped similarly to an inflated LMA posteriorly with its anterior shape designed to ‘fit the perilaryngealstructures’.
(iii) Narrow-bore oesophageal drain tube.
(iv) Short, wide-bore airway tube.
(v) Integral bite block
(vi) Contains an epiglottic rest at the anterior part of the cuff which reduces the possibility of epiglottis ‘down folding’ and airway obstruction.
Continue…
Mask is made of a thermoplastic elastomer (SEBS-Styrene Ethylene
Butadiene Styrene) that has the flexibility and feel of human tissue. . After placement, body heat from the patient activates the gel component of this airway which expands to fill the void in the hypopharynx where the device rests.
Advantages:-
1. easy to insert: due to a combination of a very,very low coefficient
of friction when lubricated & absence of cuff.
2. truncated tip, with the aim of reducing post-use dysphagia.
3. wide lumen make it well worth for both airway rescue and as a
conduit for assisted intubation.
4. A gastric channel allows for suctioning and placement of a nasogastric tube.
5.Though oesophageal seal is low but enough (according to the manufacturer).
LARYNGEAL TUBE
multiuse, latex-free, single-lumen silicon tube
two low pressure cuffs (proximal and distal).
The distal balloon (esophageal balloon) seals the airway distally
The proximal balloon (oropharyngeal balloon) seals both the oral and nasal cavity.
Two anterior ,oval ventilating vents between the cuffs.
Cough pressure 60cmH2O
4 types- LT, LT-D, LTS-II, LTs-D
INSERTION Open the mouth app. 3 cm using
the thumb and index finger technique in neutral position of head.
Hold like a pen in the area of the teeth marks (three black marks).
Insert centrally along the hard palate into the hypopharynx.
Advance until a slight resistance is felt. The center black line should n be level with the upper front teeth.
Inflate the cuffs considering the respective colour code.
Connect bag to the 15 mm standard connector.
place the tube deeper, inflate the cuffs and withdraw until ventilation is optimized results in the best depth of insertion because tissue is retracted away from the laryngeal inlet.
ADVANTAGES
1. Easy insertion.
2. 2.High ventilation pressure can
be used.
3. Better protection from
aspiration.
4. Can be used to intubate the
trachea.
DISADVANTAGES
1.Airway obstruction.
2.Displacement on head &
neck movement.
3. Cuff rupture
4. Trauma to pharynx.
ESOPAHGEAL- TRACHEAL
COMBITUBE PVC double lumen supraglottic
airway device with two inflatable balloons
2 Lumens: tracheal and pharyngeal
Ventilation -either tracheal or esophageal intubation
95% of cases tube enters the esophagus
Proximal balloon-seals the oral and the nasal cavity
Distal balloon - seals either the esophagus or the trachea, depending on which of these the ETC has been sited.
Size- 37 Fr for height up to 5 ft.
41 Fr for height above 5.5 ft.
Between 5-5.5ft – either of these.
INSERTION Neutral position. Lift the tongue and
lower jaw upward to open the oropharynx .
Lubricate the tube with sterile, water soluble lubricant.
Insert the Combitube so that it curves in the same direction as the natural curvature of the pharynx .
If resistance is met, withdraw tube and attempt to reinsert.
Advance tube until the patient’s teeth are between the two black lines.
Inflate the blue pilot cuff with 100ml of air from the large syringe.
Inflate the white pilot cuff with 15ml of air from the small syringe.
Begin ventilation through the longer tube . If auscultation of breath sounds is good and gastric inflation is negative, continue and vice versa.
INDICATION
1. Patients in irreversible
respiratory arrest (i.e.
narcotic overdose,
hypoglycemia).
2. Patients in cardiac arrest.
3. Ventilation in
normal/abnormal airways
4. Failed intubation
5. Unconscious patients without
a gag reflex, and in need of
ventilatory support
CONTRAINDICATION1. Intact gag reflex
2. Under 4 feet tall & Under 16
years of age
3. Conscious – arouseable
patient
4. Known esophageal disease (cancer, varices)
5. Ingestion of caustic
substances
6. Stoma or functional surgical
airway
7. Partial or complete FBAO
8. CONSIDER: Latex Allergy
ADVANTAGES
1. Requires minimal training
2. May be more useful in non-
fasted patients
3. Successful passage and
ventilation in many patients via
esophageal route
4. Portable, useful in remote
setting
5. Functions in either the trachea
or esophagus
DISADVANTAGES1. Only adult and small adult
sizes
2. Potential for esophageal
trauma
3. Problems maintaining
seal in some patients
EASY TUBE The Easy Tube is new disposable,
polyvinyl -chloride, double-lumen, latex-free, supra-glottic airway device.
It has a close design to the Combitube, intended to be more friendly to use.
Allows ventilation in either esophageal or tracheal position, however it is expected to enter the esophagus in most cases.
However, the Easy Tube had a better fiberoptic view and a shorter time to achieve an effective airway, with similar ventilatory performances with the ETC
STREAMLINED LINER OF THE
PHARYNGEAL AIRWAY Plastic made, uncuffed, disposable ,2nd
generation SAD.
Anatomically pre-shaped to line the pharynx.
Hollow & boot shaped distal part-
1. Toe- rest in the oesophageal entrance.
2. Bridge- fits to the pyriform fossa.
3. Heel- anchor in correct position & connect the airway tube.
4. Two lateral bulges- relieve pressure on Hypoglossal& recurrent laryngeal NV.
5. Large capacity chamber-store regurgited fluid.
Available in 6 sizes- relate to dimension across the bridge: 47, 49, 51, 53, 55, and 57 mm.
ADVANTAGES
1. Easy to insert.
2. Greater airway sealing pressure.
3. N2O has no effect on sealing
pressure- as no cuff.
4. Effective protection against
aspiration during PPV
CONTRAINDICATEDUpper airway
abnormality.
CUFFED OROPHARYNGEAL
AIRWAY PVC made , single use ,1st generation.
The distal cuff inflate below the soft palate, behind the tongue, above the epiglottis, and within the oropharynx.
Available in five sizes: 7, 8, 9, 10, and 11 cm length with cuff inflation volume of 20, 25, 30, 35, and 40 ml respectively.
Insertion like Gudel’s oropharyngealairway.
COPA is recommended for use in spontaneously breathing patients with no risk factors for aspiration.
It is quick and easy to place.
Easy size selection & low cost.
Less airway protection
ELISHA AIRWAY DEVICE
Silicon made , latex free, latest.
three separate channels for ventilation,
intubation, and gastric tube insertion.
Ventilation channel (VC) and Intubation channel (IC) are side-by-side but join at the ventilation outlet situated in front of the laryngeal inlet.
The VC has a standard 15 mm
connector at th proximal end.
The IC allows passage of an 8.0 mm ET
tube for blind or fiberoptic-guided
intubation.
Gastric tube channel (GTC) has an
outlet located in the distal end of the
device.
Two high-volume, low-pressure cuffs.
Proximal cuff seals the oropharynx and nasopharynx & distal
cuff seals esophagus.
Both are inflated through a single pilot port with 50 cc of air
resulting in an intra-balloon pressure of approximately 70 cm
H2O.
Provide combination of 3 functions in a single device:
ventilation, intubation (blind and/or fiberoptic-aided) without
interruption of ventilation, and gastric tube insertion.
EFFICACY VS SAFETY
For the evaluation of efficacy (absolute & relative ) small clinical
trials can be used.
Contrary, evaluations of safety (like ventilation failure rates , more
pertinently the risk of aspiration ) may need studies in larger scale
with larger populations.
Therefore the risk profile of a new device (unless it is particularly
unsafe) is unlikely to be established for several years after
introduction.
SUMMARY
There is no solid evidence of any device performing better than the classic LMA among the first generation SADs.
In the second-generation SADs- The PLMA proved top be very efficacious and safe in both routine and advanced uses
SAD with a drain tube has become the first choice as the standard of care.
Other newer SADs like i-gel, SLMA, and LTS-II have increasing positive evidence of their superiority.
All these developments in the field of SAD paved the way to take an ever larger role in modern airway management.
Recommended