LEMON Assessment
L= Look Externally
- Dysmorphic Features: Syndromes, retrognathia, micrognathia, coarse facial features (e.g., Mucopolysaccharidosis), anotia, microtia, short neck, protruded teeth, hemangioma masses over face or neck.
- Hydrocephalus
- Trauma
- Mouth Breather
- Tracheostomy (especially uncuffed)
- Obesity
MPS
E= Evaluate
A typical patient can open their mouth sufficiently to permit placement of three patient sized fingers held together between the incisors. (inter-incisor distance). Adequate mouth opening facilitates both insertions of the laryngoscope and obtaining a direct view of the glottis.
Chin to hyoid bone distance =3 finger or not< than 6 cm A typical patient can place three patient sized fingers held together on the floor of the mandible between the mental angle and the neck near the hyoid bone. (hyoid-mental distance).
Thyroid notch to floor of the mouth =2 fingers A typical patient can place two patient sized fingers held together in the superior laryngeal notch.(hyoid-thyroid cartilage distance)
A likely indication of difficult intubation is present if the inter-incisor(mouth opening ) or hyoid-mental distance is less than three fingers or the hyoid-thyroid cartilage distance is less than two fingers.
3-3-2 Rule
- Mouth Opening: 3 fingers breadths.
- Chin to Hyoid Bone Distance: 3 fingers or not less than 6 cm.
- Thyroid Notch to Floor of the Mouth: 2 fingers.
Thyromental Distance (TMD):
- is defined as the distance from the chin (mentum) to the top of the notch of the thyroid cartilage with the head fully extended
- It is extra test other than 3-3-2 rule and easy to assess in the patient
- If it is less than 6 cm that mean possible difficult intubation
M= Mallampati
The Mallampati classification is a simple scoring system that relates the amount of mouth opening to the size of the tongue and provides an estimate of space available for oral intubation by direct laryngoscopy.
This test is performed while the patient is in the sitting position, awake and cooperative.
Simply have the patient open his mouth maximally with out phonation and stick out his tongue while his head is in neutral position and assess based upon the pharyngeal structures that are visible.
- Classification: Relates the amount of mouth opening to the size of the tongue and provides an estimate of space available for oral intubation by direct laryngoscopy.
AIRWAY ASSESSMENT FOR PROCEDURAL SEDATION AND ANALGESIA
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Classes:
- Class I: Hard palate, soft palate, uvula, and pillars are visible.
- Class II: Hard palate, soft palate, uvula are visible.
- Class III: Hard palate, soft palate, and base of the uvula are visible.
- Class IV: Only the hard palate is visible.
In class III and IV patients , difficult ventilation and intubation should be anticipated and expert consultation is required
O= Obstruction
- Trauma: Burn
- Infection: Epiglottis, Croup
- Oedema: Allergy
N= Neck Mobility
- Neck collar = difficult mobility
- DM
- RA
- Syndromes (MPS)
- Old burn or Radiotherapy to Head & neck
