Mean PaCO2 value in 2 groups Group Time PaCO2 (mmHg) X ± SD (min - max) p JV n = 41 AIV n = 44 T1 42, 13 ± 6, 56 (28 - 57) 41, 27 ± 10, 14 (28 - 73) > 0, 05 T2 38, 69 ± 10, 06 (24 - 77) 41, 94 ± 10, 54 (25 - 79) > 0, 05 T3 45, 6 ± 10, 23 (28 - 65) 52, 53 ± 11, 96 (32 - 82) < 0, 05 11 T3' 52, 15 ± 11, 06 * (30 - 74) 58, 91 ± 13, 52 * (38 - 89) < 0, 05 T4 37, 77 ± 5, 58 (26 - 50) 39, 42 ± 6, 04 (28 - 62) > 0, 05 T5 44, 87 ± 8, 69 (18 - 62) 42, 69 ± 7, 33 (27 - 59) > 0, 05 T6 44, 44 ± 5, 86 (29 - 56) 42, 49 ± 5, 35 (24 - 53) > 0, 05 T7 43, 49 ± 5, 74 (35 - 56) 45, 14 ± 6, 22 (33 - 66) > 0, 05 T8 43, 85 ± 6, 00 (33 - 65) 45, 09 ± 5, 57 (31 - 60) > 0, 05 * p < 0.05 compared to T2 After 30 minutes using jet ventilation or intermittent apnea, PaCO2 increased in both groups.