AIRWAYS, LARYNGOSCOPES, NRVS AND CONNECTORS (II)Anjali PingleARC 2009

Modifications of the Macintosh Blade

Left sidedImproved vision

Tull

OxiportOxiport

English Macintosh

MCCOY

The 'McCoy-style' blade is based on the standard Macintosh blade. It has a hinged tip that is operated by a lever mechanism on the back of the handle. It allows elevation of the epiglottis while reducing the amount of force required. This blade has been shown to improve the view at laryngoscopy in difficult intubations and in patients wearing cervical hard collars.Reference:

[i] Laryngoscopy using the McCoy laryngoscope after application of a cervical collar. Gabbott DA. Anaesthesia. 1996 Sep;51(9):812-4. 

Changing View with the McCoy

Flexiblade

Trigger lies along the front

6 segments -3.5 to 10 cm from tip

Variable flexion Mc 2,3,4 blades Tongue laceration Tip dislocation Faulty assembly

Blade and handle modifications

Yentis adaptor

Patil-Syracuse handle

Polio blade

Bizzari- Giuffrida

Flangeless Macintosh Flange is removed,

except for a small part that encases the light bulb

Limits damage to the upper teeth

Limited mouth opening, prominent incisors, receding mandible, short and thick neck, or anterior larynx.

Bainton Blade

Unique Straight blade Pathology causing

obliteration of hypopharynx

Distal 7 cm tubular Creates space 8.0 ETT Intraluminal light

OPTICS Huffman’s prism Refraction 30deg, add 80deg Stylet required Metal clip Plexiglas Viewmax blade Optic side port on a standard

Macintosh blade 20 degrees Allows for a more anterior

view from a position 1 cm behind the left tip of the blade

Allows the standard direct view

DISPOSABLE SCOPES, BLADES AND SHEATHS

Dorges Universal Straight – 11mm,

125mmAngle of blade tipmwith handle is 76

Combines features of both the Miller and Macintosh blades

Flange has a lower height(15mm) and the curve of the blade is less.

It has 10- and 20-kg markings on the blade.

RIGID FO AND VIDEO-ASSISTED

Bullard

Upsher

Wu Glide-scope

Bullard Upsher Wu

Age Adult/paed/neo Adult Adult/large adult

Awake

Route Oral/nasal Oral/nasal Oral

Tube Rae/DLT 8.5,9.5

Working channel Y N Y, catheter

Stylet •Wire3.3 mm,•MFIS- hollow – airway exchange cath

Bougie Suction cath

Blade L,6.4mm J,15mm Tubular, Curved, Bivalve element, 16-18mm

Better, quicker, Unaffected by cricoid

Upsher handle required

Decreased space in hypopharynx

BULLARD LARYNGOSCOPE

UPSHER SCOPE

WU SCOPE

OPTICAL STYLETS

40 deg ant curvature 5 mm 1.2mm working

channel Retromolar

Tube stop Oxy insuffulation J shaped Malleable – 120deg

Bonfil’s

Shikani

NON-REBREATHING VALVES

Unidirectional flow of gases Inspiration - gas flows out of the bag & only

into the patient port Exhalation- gas escapes through the

expiratory port without mixing with the fresh gas stored in the bag

several components

IDEAL NRV

minimal dead space minimal resistance no forward / backward leak light weight transparent easy to clean & sterilize non noisy non sticky compact and inexpensive minimal opening pressure

NON REBREATHING VALVES

Identify Classify Description – material, parts Functional Analysis Dead space Resistance Advantages Disadvantages Sterilization

UNIDIRECTIONAL VALVESFishmouth Centre mounted flap

Edge mounted flap Spring-disc

BAG INLET VALVE

one-way valve that is opened by negative pressure inside the bag

When the bag is squeezed, the valve closes.

This prevents escape of gas through the inlet.

A simple flap or spring-disc valve

This valve is usually located at the opposite end of the bag from the nonrebreathing valve but may be at the same end and may be combined with the nonrebreathing valve.

Spring-disc unidirectional valve

In the closed position, the spring holds the disc against the seat.

When the pressure to the left of the disc increases above the pressure of the spring, the disc is forced away from the seat.

When the pressure to the left of the disc drops, the valve closes.

Fishmouth unidirectional valve

As pressure to the left increases, the leaflets open, allowing gas to flow through the valve. An increase in pressure to the right pushes the leaflets together, closing the valve and preventing backflow of gas.

Edge-mounted flap unidirectional valve

Increased pressure upstream of the flap pushes the flap away from the seat, opening the valve.

When the pressure downstream of the flap increases above the pressure upstream, the flap is forced back against the seat, blocking the flow of gas.

Center-mounted flap unidirectional valve

The flap valve is secured by a tab at the center

The tab is secured by a retainer, which is attached to the valve body.

Spring-disc NRV – Ruben Valve(Bobbin)

The disc is held on the seat by the spring

When the bag is squeezed, the disc moves to the left, closing the expiratory port

At the end of inspiration, the spring forces the disc to the right so that the patient exhales to atmosphere and not into the bag

A guide pin keeps the disc in the center. A spontaneously breathing patient can inhale room air unless a valve is placed over the expiratory port to prevent air entrainment.

Fishmouth-flap NRV - Laerdal

The circular flap and fishmouth valves are attached, around the periphery

When the bag is squeezed, the flap valve is seated against the exhalation ports, and the fishmouth portion of the valve opens

During expiration, the fishmouth closes and the flap falls away from the exhalation channel

A second flap valve over the exhalation ports prevents air from being inspired during spontaneous respiration.

Mushroom-flap valve – Ambu Hesse

This valve contains a mushroom-style diaphragm that is inflated when the pressure in the pressure channel increases

This occurs during inspiration. When the mushroom is inflated, it blocks the exhalation channel, allowing the lungs to be inflated. When the pressure inside the mushroom drops at the end of inspiration, it opens the channel and allows the exhaled gases to pass out of the exhalation channel

The flap valve prevents backflow of exhaled gases into the bag.

Diaphragm-flap valve

During inspiration, when the bag is squeezed, the pressure to the right increases and the diaphragm is pushed to the left, closing the exhalation channel. At the same time, the flaps at the edge of the diaphragm open, allowing gas from the bag to flow to the patient connector. When inspiration ends, the diaphragm moves away from the exhalation channel and the flaps close, blocking the inspiratory port.

Nonrebreathing valve with two flap valves

During inspiration, the center-mounted flap valve opens, and the peripheral flap closes over the exhalation ports. During exhalation, the central flap valve closes, and the peripheral flap falls away from the exhalation ports. This valve has an oxygen inlet and two bag inlet valves, which open if the oxygen flow is not sufficient to prevent a negative pressure from developing in the space to the left.

AmbuR

E E2 Hesse Paed Laerdal Ruben Lewis-Leigh

Type R D D D D D D D

Housing Polycarbonate, polysulphonate

Polycarbonate, polysulphonate

Polycarbonate, polysulphonate

Polycarbonate, polysulphonate

Polycarbonate, polysulphonate

Polycarbonate, polysulphonate

Plastic Polycarbonate, polysulphonate

Fittings Silicone Silicone Silicone Silicone Silicone

Silicone Metal fittings

Silicone

Mech Spring, pin, disc

2 labial flaps

Single labial flap

Mushroom, 2 flap valves

2 labial flaps

Fish mouth, circular flange, exp flap

Spring loaded bobbin,

Flap

Diaphragm

Dead Space

10 ml 10 ml 10 ml 14 ml

7 ml 7 ml 9 ml

Insp res Exp res (cm H2O)

0.6-2

0.6-2

0.6 -2

0.6-2

0.6 -2

0.6-2

0.2-0.7

0.2-0.9

0.32-1

0.16-2.83

0.9

1

Forward leak

Low resistance

Fast switching action

High back leak

Gravity dep

Back leak(%TV)

2.8-9 .9-7.3 10-29,

76%

CONNECTORS

A connector is a fitting intended to join together two or more components

An adaptor is a specialized connector that establishes functional continuity between otherwise disparate or incompatible components

ORAL AND NASAL CONNECTORS

Magill’s - Acute and Obtuse angled

Noseworthy – No angulation, minimal resistance

Universal connector – 15 mm

SUCTION UNIONS

Corrugated end to the tube

Right angle to circuit Magill’s – Funnel

shaped Cobb’s – Obturator

secured with chain or link

Loflo-A

ThankYou!!

anupritaa@yahoo.com