Conference Lectures

UNANTICIPATED DIFFICULT AIRWAY
Dr.C.GRaghuram MD.PDC
Professor Head of the Department, Superintendent
Department of Anaesthesiology, Osmania General Hospital
Hyderabad. Telangana State.

UNANTICIPATED DIFFICULT AIRWAY- WHERE DO YOU SEE IT?

  • It is seen in obstetrics, children, emergencies and in patients who are found unconscious at the time of evaluation.
  • WHAT ARE REASONS FOR UNANTICIPATED DIFFICULT AIRWAY?
  • The reasons are multifold viz restricted mouth opening, restricted oral cavity (space), restricted retromandibular space, occluded laryngeal inlet(obstruction, laryngospasm) and occluded tracheobronchial tree(bronchospasm).

 

  • WHAT ARE THE SCENARIOS THAT UNFOLD IN UNANTICIPATED DIFFICULT AIRWAY?
  • There are only two scenarios.
  • Mask ventilation of patient is possible but intubation of trachea is difficult.
  • Both mask ventilation and endotracheal intubation difficult or not possible.
  • WHAT ARE DEVICES USED IN TACKLING A DIFFICULT AIRWAY?
  • Nasopharyngeal Airway.
  • Oropharyngeal Airway.
  • Various types of laryngeal mask airways.
  • Intubating laryngeal mask airways.
  • Gum elastic bougies.
  • Lighted wands .
  • Tube exchangers(Airway Exchangers).
  • Frova’s intubating stylet.
  • Video laryngoscopes, bronchoscopes.
  • Glidescopes.
  • Air traq device.

 

  • Jet ventilation devices.
  • Mini trach sets.
  • Percutaneous tracheostomy sets.
  • 16G Epidural needle with epidural catheter or 3FG ureteric catheter.
  • MCCOY blade laryngoscopes .
  • Combitube.

 

  • WHAT ARE THE BASIC STRATEGIES TO TACKLE A DIFFICULT AIRWAY?
  • Preoxygenation with 100% O2.
  • Prevent or avoid aspiration.
  • If ventilation and intubation turn out to be difficult,  try to recover the patient and restore spontaneous respirations.
  • Left lateral, head down position if patient starts breathing spontaneously after failed ventilation or intubation.
  • Sniffing of morning air position.
  • Should not compromise on depth of anesthesia.
  • Jaw thrust, good face mask seal, adequate reservoir bag squeeze and a clear, secretions free oral cavity should be ensured at all costs.

 

  • WHAT SHOULD BE RULED OUT WHEN THERE IS A FRIGHTENING “CAN’T VENTILATE AND CANT’T INTUBATE” SCENARIO?
  • Blood and secretions in upper airway.
  • Laryngospasm.
  • Bronchospasm

TACKLING LARYNGOSPASM

  • 100% oxygen with facemask and closed expiratory valve.
  • Clear airway by suction.
  • Apply CPAP and manual ventilation to break “ LARYNGOSPASM”.
  • Jaw thrust may clear larynx.
  • I.V Propofol may deepen the patient and clear laryngospasm.
  • Deepen anaesthesia in a spontaneously breathing patient.
  • Superior laryngeal nerve block.
  • Suxamethonium only if haemodynamics are stable.

 

A WORD ABOUT BRONCHOSPASM

  • Usually leads to a difficulty in mask ventilation.
  • Watch out for smokers and asthmatics.
  • Ruleout anaphylactic drug reactions.
  • Undiagnosed mediastinalmasses, lymphnodes or tumors can also lead to a

“Diffcultyin Mask Ventilation”.

  • OTHER CONSIDERATIONS
  • All patients who have unanticipated difficult airway should be informed after their recovery.
  • Full documentation of their airway is a must.

 

  • TACKLING AN UNANTICIPATED DIFFICULT AIRWAY
  • Check whether mouth opening is adequate or not.
  • Check whether insertion of NASOPHARYNGEAL airway or OROPHARYNGEAL airway or both is possible or not.
  • Ensure sufficient space for the airways at the back of the tongue in the retromandibular space.
  • Attempt mask ventilation- If it is feasible, ensure adequate 100% oxygenation before attempting laryngoscopy.
  • Use a MCCOY blade straightway. Nothing is lost by doing that.
  • If laryngeal visualization is still difficult, try inserting a bougie/tube exchanger / FROVA’S stylet.
  • If not successful, go back to mask ventilation ………. Get ready for any LMA/ILMA/PLMA.
  • Ensure ventilation with devices in no(7)……. Try to intubate through them with lighted wands / FOB / FROVA’S / Tube exchanger.
  • If cricothyroid membrane is neatly visualised, even retrograde intubation after local infiltration of Lignocanine with Adrenaline is a viable option. Meanwhile, continue to ensure ventilation with any supraglottic device / facemask.
  • If ventilation with mask/ LMA not possible and intubation also not possible, straight away proceed to thecricothyroid membrane to introduce a 14G or 16G needle / cannula / minitrach / small 3.5cuffed ET Tube through the membrane to access trachea.

 

Try Jet ventilation / oxygen insufflation / anything that is feasible abandon if surgical emphysema ensues in neck.
Close the mouth / nose during inspiration phase of jet ventilation to facilitate better expansion of lungs.

  • Get ready for an emergency percutaneous / surgical tracheostomy in the meanwhile continue whatever form of oxygenation, that is possible / feasible.
  • Never forget laryngospasm / bronchospasm. They have to be ruled out in any given can’t ventilate / can’t intubate scenario.