THE DIFFICULT AIRWAY

THE DIFFICULT AIRWAY The Key is to maintain: Oxygenation Ventilation

The Difficult Airway A difficult airway can be defined as a clinical situation in which a conventionally trained ALS provider experiences difficulty with mask ventilation, difficulty with tracheal intubation or both.

THE DIFFICULT AIRWAY Definition: Difficult to oxygenate and ventilate Difficult to intubate

Complexity The difficult airway represents a complex interaction between patient factors, the prehospital/clinical setting, and the skills of the EMS provider.

Difficult Mask Ventilation Not possible for the EMS provider to maintain the SpO2 >90% using 100% oxygen and positive pressure mask ventilation. It is not possible for the EMS provider to prevent or reverse signs of inadequate ventilation during PPV.

THE DIFFICULT AIRWAY Difficult to oxygenate and ventilate (BMV) Beard Obese No Teeth Elderly Snores

The Difficult Airway Difficult to intubate Look at head and neck Evaluate ability to open mouth/access oropharynx Mallampati or Cormack Scales Obstruction Neck Mobility

Look at head and neck: Anatomical Features Recessed Chin Buck teeth Short neck or “no neck” Signs of previous surgery

Difficult Endotracheal Intubation Proper insertion of the tracheal tube with conventional laryngoscopy requires more than three attempts Proper insertion of the tracheal tube with conventional laryngoscopy requires more than 10 minutes.

Intubation Difficulty May Be Due To: Incorrect position of the patient Inadequate or improper equipment Unusual or abnormal anatomy Pathologic causes

Evaluate Access to Oral Cavity Opening of mouth <20 mm predisposes to difficult airway

Evaluate Access to Oral Cavity Rule of thumb: an opening of at least two large finger breadths between upper and lower incisors in the adult is desirable

Mallampati Scale

Assessing the Oral Cavity

Cormack Scale

Difficult Laryngoscopy It is not possible to visualize any portion of the vocal cords with conventional laryngoscopy.

Factors Contributing to Difficult Laryngoscopy The following factors may be contributors to a difficult airway: Obstruction Infections Trauma Rheumatoid Arthritis Congenital Problems Pregnancy

Obstruction Foreign body airway obstruction is a common cause of failed airways. Direct laryngoscopy must be used with caution as it may result in further advancement of the foreign body into the airway

Obstruction Obstruction of the airway can also be anatomical or pathological, causing narrowing or complete blockage of the airway.

Infections Infectious processes such as abscesses, croup, bronchitis, and pneumonia can distort normal anatomy.

Trauma Maxillofacial or head trauma may distort normal airway anatomy, resulting in clenched teeth and edema.

Obesity Obesity results in airway and respiratory problems secondary to altered respiratory pathophysiology and distorted upper airway anatomy.

Rheumatoid Arthritis Patients with rheumatoid arthritis and other connective tissue diseases often limit ROM of the cervical spine.

Tumors Tumors of the neck and airway can distort anatomy, limiting the space for instrumentation.

Congenital Disorders Congenital disorders may be associated with airway difficulty due to mandibular hypoplasia, cervical abnormalities, large tongue or a cleft palate.

Pregnancy Pregnancy is associated with a difficult upper airway, an increased risk of aspiration and limited tolerance to apnea.

The Most Difficult Airway The one the EMT or Paramedic insists that he can “get it” Almost a guarantee the patient will die

Summary The difficult airway is a significant problem to the patient and EMS provider in terms of mortality, morbidity and cost.

Summary It is imperative to be aware of the factors that contribute to a difficult airway so that: EMS providers may improve their ability to be prepared The morbidity and mortality of difficult airway patients can be minimized Patient outcome can be improved upon

Questions?

THE DIFFICULT AIRWAY BIBLIOGRAPHY Walker LA: Using Rapid Sequence to Facilitate Tracheal Intubation. Emergency Med Reports 14:125-132, 1993. Chari R: Drugs for Conscious Sedation and Neuromuscular Paralysis. Emergency Med Reports 19:9-20, 1998 McAllister JD, Gnauck KA: Rapid Sequence Intubation of the Pediatric Patient. Ped Clin NA 46:1249-1276, 1999. Pousman RM: Rapid Sequence Induction for Prehospital Providers. Www.ispub.com/journals/IJEICM/Vo14N1/rapid.htm.