Is the Mallampati score useful for diagnosing Obstructive Sleep Apnea (OSA)?

The Mallampati Score in Diagnosing Obstructive Sleep Apnea

The Mallampati score alone should not be used to diagnose OSA, but it serves as a valuable component of the comprehensive sleep evaluation as a risk factor assessment tool. 1

Role of Mallampati Score in OSA Evaluation

• The Modified Mallampati score is recognized by the American Academy of Sleep Medicine as one of several physical examination features that should be evaluated during a comprehensive sleep assessment 1
• A Modified Mallampati score of 3 or 4 is considered a risk factor for OSA and is included in the MACOCHA score, a validated predictive tool for difficult intubation in ICU patients 1
• The Mallampati score assesses oropharyngeal crowding, which contributes to upper airway narrowing, a fundamental anatomical factor in OSA pathophysiology 2

Limitations as a Diagnostic Tool

• Clinical tools, questionnaires, and prediction algorithms (including Mallampati scoring) should not be used to diagnose OSA in the absence of polysomnography or home sleep apnea testing 1
• The American Academy of Sleep Medicine strongly recommends against using clinical tools alone for OSA diagnosis 1
• Research has shown inconsistent diagnostic value of the Mallampati score, with one study finding no evidence for its diagnostic value in patients suspected of having OSA 3

Proper Diagnostic Approach for OSA

• Polysomnography remains the gold standard diagnostic test for OSA in adults 1, 2
• Home sleep apnea testing with a technically adequate device may be used for diagnosis in uncomplicated adult patients with signs and symptoms indicating increased risk of moderate to severe OSA 1
• If a single home sleep apnea test is negative, inconclusive, or technically inadequate, polysomnography should be performed 1

Evidence Supporting Mallampati as a Risk Factor

• Some studies have found the Mallampati score to be an independent predictor of both the presence and severity of OSA 4
• Research suggests that for every 1-point increase in Mallampati score, the odds of having OSA increased more than 2-fold 4
• The combination of a high Mallampati score and nasal obstruction represents a greater risk factor for worsening of OSA 5, 6

Clinical Application

• The Mallampati score should be assessed as part of a comprehensive sleep evaluation that includes evaluation of symptoms such as witnessed apneas, snoring, gasping/choking at night, and excessive sleepiness 1
• Other physical examination features that should be evaluated include increased neck circumference (>17 inches in men, >16 inches in women), BMI >30 kg/m², retrognathia, lateral peritonsillar narrowing, and nasal abnormalities 1
• The MACOCHA score, which includes Mallampati scoring, can help identify patients at high risk for OSA, particularly in critical care settings 1

Pitfalls and Caveats

• There is significant variability in how the Mallampati examination is performed and interpreted between clinicians 7
• The examination should be performed with the patient sitting upright, mouth fully open, tongue protruded, and without phonation 7
• Relying solely on the Mallampati score for OSA diagnosis may lead to both false positives and false negatives 3
• The diagnostic accuracy of the Mallampati score may be influenced by factors such as obesity, craniofacial abnormalities, and ethnicity 8

In conclusion, while the Mallampati score provides valuable information as part of a comprehensive sleep evaluation and risk assessment, it should not be used in isolation to diagnose OSA. Objective testing through polysomnography or appropriate home sleep apnea testing remains essential for accurate diagnosis and severity assessment of OSA.