The relationship between nasal airway resistance and middle ear pressure in subjects with acute upper respiratory tract infection.

Middle ear pressure and nasal airway resistance were measured over 7 1/2h in 8 subjects (age 18-32) with symptomatic acute upper respiratory tract infection. The mean middle ear pressure was -13 +/- 1.5 daPa (s.e.m.) with a range between 65 to -140 daPa. The mean total nasal resistance was 0.4 +/- 0.02 Pa/cm3/s (s.e.m.) with a range between 0.20 to 1.28 Pa/cm3/s. Unilateral nasal airway resistance exhibited reciprocal fluctuations with a range between 0.18-3.60 Pa/cm3/s. The mean difference between the highest and lowest unilateral nasal resistance values for each subject was 1.48 +/- 0.22 Pa/cm3/s (n = 16). No correlation was found between unilateral nasal airway resistance and middle ear pressure. Total nasal airway resistance had an inverse correlation with middle ear pressure r = 0.32, r2 = 0.11, n = 176 (p < 0.001). The results indicate that the generation of a negative middle ear pressure in acute upper respiratory tract infection occurred in a manner consistent with intermittent obstruction of the Eustachian tube and gradual middle ear gas absorption. Rapid increases in middle ear pressure and the generation of a positive middle ear pressure were associated with nose blowing. No evidence was found to support the hypothesis that negative middle ear pressures are associated with sniffing.