Educational Blog about Anesthesia, Intensive care and Pain management

Laryngeal Mask Airway

Laryngeal Mask Airway (LMA)

1-The LMA-Classic™:



-It is a reusable LMA™ airway for general anesthesia.
-The LMA-Classic™ is available in eight sizes: (1, 1½, 2, 2½, 3, 4, 5, and 6).

Advantages:

-A safe and effective alternative to the endotracheal tube and the facemask.

-Over 100 million uses worldwide.

-Leaves the anesthetist's hands free to attend, to monitoring and record keeping.

-Latex-free and exceptionally well tolerated.

-A reusable device that can be cleaned and steam sterilized up to 40 times before being discarded.

2-LMA-Unique™ (Single-use):



-The LMA-Unique™ is a convenient, single-use LMA™ airway suitable for general anesthesia procedures.

-The LMA-Unique™ is available in sizes: (1, 1½, 2, 2½, 3, 4, and 5).

-The LMA-Unique™ is a disposable, single-use device, made to the same design specifications as the LMA-Classic™.

Advantages:

-Packaged sterile - ready for use.

-Suitable for use on emergency vehicles.

-Suitable where access to sterilization facilities is limited.

-Made of medical-grade PVC.

3-LMA-Flexible™:



-The LMA-Flexible™ is a reinforced LMA™ airway with a flexible airway tube.

-The LMA-Flexible™ is available in sizes: (2, 2½, 3, 4, 5, and 6).

-The LMA-Flexible™ is a re-usable device that can be cleaned and steam sterilized up to 40 times before being discarded.

Advantages:

-Designed for ENT, dental, and head surgery.

-Allows extreme flexion.

-Guaranteed kink and crush-proof.

-Latex-free.

4-LMA Flexible (Single-use):



-The LMA Flexible™ Single Use is ideal for use in ENT, ophthalmic, dental, and other head and neck cases and extends the LMA™ Airway benefits of hemodynamic stability and smoother emergence to more procedures.

5-LMA-ProSeal™:



-The LMA-ProSeal™ is an advanced LMA™ airway suitable for general anesthesia.

-It has a unique double cuff arrangement that provides an exceptionally effective, 'hands-free' airway seal, at low intracuff pressures.

-The LMA-Proseal™ is available in sizes: (1½, 2, 2½, 3, 4, and 5).

-The LMA-Proseal™ is a re-usable device that can be cleaned and steam sterilized up to 40 times before being discarded.

Advantages:

-A new double tube design separates the respiratory and alimentary tracts, providing a safe escape channel for regurgitated fluids in the event of unexpected regurgitation.

-The mask is designed to be a minimally stimulating airway device, whose cuff tip presses against the upper oesophageal sphincter when it is correctly positioned. The sides of the mask face the pyriform fossae and the upper border rests against the base of the tongue.

-Latex-free.

6-LMA Supreme™ (Single-use):



-The first and only single-use laryngeal mask with a built-in drain tube.
-The integrated drain tube is designed to channel fluid and gas safely away from the airway. Several simple and quick tests help verify accurate positioning.
-An improved curve for easy insertion. Subtle refinements in the mask make correct placement easier.

7-LMA Fastrach™ & LMA Fastrach™ ETT:



-The design of the LMA-Fastrach™ facilitates rapid insertion from any position, even if space is limited, and moving the patient is a possible hazard.

-The device is self-positioning with the rigid tube designed to fit the curvature of the palatopharyngeal arch, enabling a firm seal to be achieved.

-The LMA-Fastrach™ is available in sizes: (3, 4, and 5).

-The LMA-Fastrach™ is a reusable device that can be cleaned and steam sterilized up to 40 times before being discarded.

Advantages:

The LMA-Fastrach™ has additional features to those of the LMA-Classic™:

-Designed specifically for the anatomically difficult airway.

-Ideal in emergency situations.

-Can be used as an intubating tool, with no interruption of patient oxygenation.

-Allows insertion in the neutral position, in limited space.

-No need to move the patient.

-No need to insert fingers into the patient's mouth.

8-LMA Fastrach™ & LMA Fastrach™ ETT (Single-use):

9-LMA CTrach™:



-The only difficult airway device that allows ventilation, visualization, and intubation.

-The LMA CTrach™ is designed to increase intubation success rates in difficult airways. The LMA CTrach™ mask enables ventilation during intubation attempts while built-in fiber optics provide a direct view of the larynx and real-time visualization of the ET tube passing through the vocal cords.

-The LMA CTrach™ can be inserted exactly the same as the LMA Fastrach™, however, unlike the LMA Fastrach™, once the airway is secured and the 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.

10-i-gel™:



-The i-gel supraglottic airway device accurately and naturally positions itself over the laryngeal framework to provide a reliable peri-laryngeal seal without the need for an inflatable cuff.

-i-gel is made from a medical-grade thermoplastic elastomer, i-gel has been designed to create a non-inflatable, anatomical seal of the pharyngeal, laryngeal, and peri-laryngeal structures whilst avoiding compression trauma.

-i-gel is currently available in sizes: (1, 1½, 2, 2½, 3, 4, and 5), and is supplied in an innovative, color-coded polypropylene ‘cage pack’.

Advantages:

-No inflatable cuff offers easy, rapid insertion.

-An integral bite block reduces the possibility of airway occlusion.

-A buccal cavity stabilizer aids rapid insertion and eliminates potential rotation.

-Made from a unique, soft, gel-like material to allow ease of insertion and reduced trauma.

-Gastric channel designed to improve and enhance patient safety.

-Reduces the possibility of epiglottis downfolding and obstructing the airway.

-Unique packaging protects the i-gel in transit and ensures that it maintains its anatomical shape.

Ventilators

 Ventilators



-Early ventilators consisted of the generation of negative pressure around the whole of the patient’s body except the head and neck; these were called Cabinet or Iron lung ventilators.

-A negative pressure could also be applied over the thorax and abdomen: Cuirass Ventilators.

Classification:

1. Pattern of gas flow during inspiration:

a) Pressure generators:

Constant pressure is produced by bellows or a moderate weight which produces a decreasing inspiratory flow which alters with changes in lung compliance

b) Flow generators:

Constant flow is produced by a piston, heavyweight, or compressed gas. Flow is unaltered by changes in lung compliance although pressures will vary. These ventilators have a high internal resistance to protect the patient from high working pressures.

2. Power:

Pressure generators are low powered whereas flow generators are high powered.

3. Cycling:

Change from inspiration to expiration may be determined by:

a) Time:

Most common method. The duration of inspiration is predetermined, with the constant flow it may be necessary to preset a Tv; when this has been delivered there is an inspiratory pause (improves distribution) before the inspiratory cycle ends.

b) Pressure:

Used as a pressure limit on other modes. Ventilator cycles into expiration when preset airway pressure is reached (delivers a different Tv if compliance or resistance changes). Inspiratory time varies according to compliance and resistance.

c) Volume:

Usually used with an inspiratory flow restrictor. Cycles into expiration whenever a preset Tv is reached.

d) Flow:

Older ventilators.

4. Sophistication:

Newer ventilators can function in many of the above modes, and also have weaning modes such as SIMV, PS, and CPAP.

5. Function:

a) Minute volume dividers:

Fresh gas flow powers the ventilator. Minute volume equals the FGF divided into pre-set tidal volumes, thus determining the frequency.

b) Bag squeezers:

Replaces the hand ventilation of a Mapleson D or circle system. It needs an external power source.

c) Lightweight portable:

Powered by compressed gas and consists of the control unit and patient valve.

Charcot-Marie-Tooth Disease

Charcot-Marie-Tooth Disease (CMT)



-Charcot-Marie-Tooth disease (CMT) is a neuromuscular disorder characterized by length-dependent degeneration of the motor and sensory nerve fibers, with a prevalence of 1 in 2,500 (about 200,000 patients in the European Union).

-Anesthesia is administered to this population more frequently than to normal people, as CMT patients often need orthopedic surgery to correct muscle imbalance and limb deformities, and for osteosynthesis of bone fractures as they are prone to falls.

Anesthetic Management Complications:

1-Malignant hyperthermia.

2-Prolonged responses to neuromuscular blocking drugs.

3-Drug toxicity is caused by inappropriate doses in case of severe muscle wasting.

4-Medication-induced exacerbation of neuropathy.

5-Associated deformities such as scoliosis.