The risk of hypercarbia Table 3.19: Number of patients with hypercarbia and the time from the beginning of LFA to the appearance of hypercarbia Parameters Group N0.5 (n = 37) Group N1 (n = 37) Number of patients with hypercarbia n (%) 7 (18.9) 0 (0.0) Time (Min) X ± SD Min - Max 72.3 ± 22.7 50 - 20 - Comments: After 72.3 ± 22.7 minutes of low flow anesthesia, group N0.5 had 18.9% of patients with hypercarbia and EtCO2 increasing 45 mmHg.