Airway difficulty in Mallampati 'class zero' patients: a prospective double-blind observational study

Area of Science:

• Anesthesiology
• Airway Management

Background:

• Mallampati class assessment is crucial for preoperative airway evaluation.
• Higher Mallampati classes correlate with increased intubation difficulty.
• Airway complications in Mallampati class zero patients are infrequently reported.

Purpose of the Study:

• To assess tracheal intubation difficulty in Mallampati class zero patients.
• To correlate intubation difficulty with indirect laryngoscopy findings.
• To determine the incidence of Mallampati class zero airways and mask ventilation difficulty in Indian patients.

Main Methods:

• Prospective, double-blind observational study.
• Inclusion of 33 Mallampati class zero patients (1.7% of 1937) aged 18+ undergoing elective surgery.
• Evaluation of indirect and direct laryngoscopy, intubation difficulty (Cormack & Lehane grades), and mask ventilation.

Main Results:

• All 27 analyzed patients with Mallampati class zero had predicted easy airways and easy tracheal intubation (Cormack & Lehane grade 1 or 2).
• Two patients experienced difficult mask ventilation.
• A large or overhanging epiglottis was noted in 37% of patients but did not predict difficult intubation.

Conclusions:

• Mallampati class zero alone does not predict a difficult airway.
• Other contributing airway characteristics are necessary for difficult intubation.
• A large epiglottis in Mallampati class zero patients rarely leads to airway complications.