LAP before the ASV
The LAP during the inspiratory phase was 4.9 ± 5.4 mmHg and was significantly lower than that during the expiratory phase (14.0 ± 5.2 mmHg, p < 0.01). The average lowest LAP was -2.2 ± 5.1 mmHg (from 7 to -17 mmHg), which was recorded during the inspiratory phase in all patients. Out of a total of 51 patients enrolled, 37 (72.5 %) had a lowest LAP value of ≤ 0 mmHg. A male gender was frequently observed in patients with a lowest LAP value of ≤ 0 mmHg (negative lowest LAP) than in those with a lowest LAP value of > 0 mmHg (33/37 vs. 8/14, p = 0.02). There were no significant differences regarding the BIS index, body-mass index (BMI), prevalence of OSA, obesity (BMI > 25 kg/m2), and other comorbidities between the patients with and without a negative lowest LAP value (Table 3A ). The BIS value at the time of the LAP measurement was similar between the two groups (67.4 ± 12.5 vs. 68.7 ± 14.4, p = 0.54).