Incidence and Predictors of Difficult and Impossible Mask Ventilation

Abstract

The authors observed the incidence of grade 3 MV to be 1.4%, similar to studies with the same definition of difficult MV. Presence of a beard is the only easily modifiable independent risk factor for difficult MV. The mandibular protrusion test may be an essential element of the airway examination.

The incidence, success rate, and complications of awake tracheal intubation in 1,554 patients over 12 years: an historical cohort study

“…Even if the need for awake intubation had been diminished by more frequent use of VL, it is also conceivable that such a decrease could have been masked by a concomitant rise in awake intubation for an increasing population of obese patients 10 in whom a higher incidence of anticipated difficult airway management might be expected. [11][12][13][14][15][16][17][18][19][20] While the overall incidence of awake tracheal intubation was 1.06% of GETA cases, there was substantial variability in the rate (0-3.4 per 100 GETA cases) at which individual attending staff performed the procedure. These results were not controlled for subspecialty practice (e.g., anesthesiologists performing mainly regional vs neuroanesthesia), although anecdotally, the four individuals with the two lowest and the two highest rates of awake intubation had similar practice profiles (data not shown).…”

La prise en charge des voies aériennes et l’oxygénation du patient obèse

“…10 A review of 22,660 mask ventilation attempts identified BMI [ 30 kgÁm -2 to be an independent predictor of difficult mask ventilation and an independent predictor of difficult or impossible mask ventilation and difficult tracheal intubation. 11 Nevertheless, a further study of over 50,000 anesthetics failed to show obesity as an independent predictor of impossible mask ventilation. 12 In this study, 12 radiotherapy to the neck, male sex, presence of a beard, and Mallampati scores 3 or 4 were identified as independent predictors of impossible mask ventilation.…”

S1 guidelines on airway management

“…If the results of several authors with large groups of patients are summarized irrespective of the various divergent definitions, the incidence of difficult mask ventilation in an unselected group of elective patients is 2 % [6][7][8]. The incidence of impossible mask ventilation is 0.15 % (1:670) [6].…”

“…An unexpected "cannot intubate, cannot ventilate" situation is to be expected with a probability between 0.008 % (1:13,000) and 0.004 % (1:25,000) [6,8].…”

“…Table 1 shows typical predictors for a difficult or impossible mask ventilation [6][7][8]. The combination of several factors increases the risk of difficult mask ventilation.…”