اجهزة

• Laryngoscopes


  Consist of a handle and a blade. The latter can be straight or curved.

  
• Laryngoscope bulb


  Either in the blade or in the handle
• Using a straight laryngoscope blade


  1. Advance over the posterior border of the relatively large, floppy V-shaped epiglottis

  2. Lift the epiglottis directly in order to view the larynx

  
• Using a curved (Macintosh) laryngoscope blade

  1. Insert through the right angle of the mouth

  2. Advance gradually, pushing the tongue to the left and away from the view

  3. Tip of the blade reaches the vallecula

  4. Lift the laryngoscope upwards elevating the larynx and allowing the vocal cords to be seen
• McCoy laryngoscope


  • Based on the standard Macintosh blade
  • Has a hinged tip which is operated by the lever mechanism present on the back of the handle
  • Suited for both routine use and in cases of difficult intubation

  
• Flexiblade laryngoscope


  • Whole distal half of the blade can be manoeuvred rather than just the tip, using a lever on the front of the handle
• Laryngoscope blade standards


  ISO 7376/2009 (green system)

  ISO 7376/1 (red system)

  Different dimension hinges and light source positions

  
• The 'green system' is the most commonly used fitting standard
• Problems with laryngoscopes


  • Higher risk of trauma and bruising with straight blades

  Importance of checking function before use

  Difficulty with large breast tissue

  Need for disposable blades and handle decontamination to prevent cross-infection
• Fibreoptic intubating laryngoscope

  Used to perform oral or nasal tracheal intubation, evaluate the airway, confirm tube placement, and perform tracheobronchial toilet
• Fibreoptic laryngoscope mechanism

  Uses light transmitted through glass fibres

  Fibres coated with lower refractive index glass for optical insulation

  Fibres arranged coherently to transmit clear images
• Fibreoptic laryngoscopes have revolutionized airway management in anaesthesia and intensive care
• Additional equipment used with fibreoptic laryngoscopes

  • Endoscopic face mask

  Oral airway

  Bite block

  Defogging agent
• Fibreoptic intubating laryngoscope


  • Used for tracheal intubation, airway evaluation and tracheobronchial toilet
  • Damage to the fibres causes loss of image
• Insertion cord


  Consists of glass fibres arranged in bundles
• Light


  Transmitted through the glass fibres
• Videolaryngoscopes


  • Combine features of flexible fibreoptic scopes and standard rigid laryngoscopes
  • Images are transmitted using fibreoptics or lenses and prisms
  • Cameras offer wide views to see around corners
  • Some designs have a channel that guides the tracheal tube into the trachea
• Videolaryngoscopes


  • Improve the view of the glottis as the camera eye is only centimetres away
  • Require minimal neck movement and can make laryngoscopy and tracheal intubation easier
• Magill forceps


  • Designed for ease of use within the mouth and oropharynx
  • Can be used to direct the tracheal tube towards the larynx and vocal cords
  • Care should be taken to protect the tracheal tube cuff from being damaged
• Intubation aids


  1. Local anaesthetic spray to coat the laryngeal and tracheal mucosa

  2. Bite guard to protect the front upper teeth

  3. Endotrol tube with a ring-pull to adjust the curvature

  4. Nosworthy airway to allow connection of a catheter mount and breathing system
• Introducer or stylet


  Used to adjust the curvature of a tracheal tube to help direct it through the vocal cords
• Gum elastic bougie


  Used when it is difficult to visualize the vocal cords, inserted through the vocal cords so the tracheal tube can be railroaded over it
• Airway exchange catheter (AEC)

  • Allows the exchange of tracheal tubes, can be inserted through a tracheal tube and withdrawn so another tube can be inserted over it
  • Specially designed connectors can be used to provide temporary oxygenation
• Aintree intubation catheter


  • Designed to be used with a fibrescope passed through a laryngeal mask or other supraglottic airway device
  • Allows any appropriate size of tracheal tube to be inserted into the trachea
• Retrograde intubation set


  • Used to assist in placement of a tracheal tube when a difficult intubation is encountered
  • Components: introducer needle, guidewire with J-shaped end, hollow guiding catheter
  • Mechanism: introducer needle inserted through cricothyroid membrane, guidewire advanced cephalically, guiding catheter introduced antegrade into trachea, tracheal tube introduced over guiding catheter
• Ventilators


  Used to provide controlled ventilation (intermittent positive pressure ventilation; IPPV)

  
• Ventilators


  • Can be used in the operating theatre, intensive care unit, during transport of critically ill patients and also at home (e.g. for patients requiring nocturnal respiratory assistance)

  
• Methods of classifying ventilators


  • Method of cycling
  • Inspiratory phase gas control
  • Source of power
  • Suitability for use
  • Paediatrics use
  • Method of operation
  • Sophistication
  • Function

  
• Method of cycling


  Used to change over from inspiration to exhalation and vice versa
• Types of method of cycling

  • Volume cycling
  • Time cycling
  • Pressure cycling
  • Flow cycling
• Volume cycling


  When the predetermined tidal volume is reached during inspiration, the ventilator changes to exhalation

  
• Time cycling


  When the predetermined inspiratory duration is reached, the ventilator changes to exhalation. The cycling is not affected by the compliance of the patient's lungs. Time cycling is the most commonly used method
• Pressure cycling


  When the predetermined pressure is reached during inspiration, the ventilator changes over to exhalation. The duration needed to achieve the critical pressure depends on the compliance of the lungs

  
• Flow cycling


  When the predetermined flow is reached during inspiration, the ventilator changes over to exhalation. This method is used in older design ventilators

  
• Inspiratory phase gas control


  • Volume
  • Pressure
• Volume


  A preset volume is delivered
• Pressure


  A preset pressure is not exceeded
• Source of power


  • Electric
  • Pneumatic
• Suitability for use


  • Operating theatre
  • Intensive care unit
  • Both
• Paediatrics use


  • Yes
  • No