Risk of hypoxemia, hypercarbia and sevoflurane consumption during low-flow anesthesia with fresh gas flow 0.5 or 1 liter / minute using EcoFlow for open abdominal surgery in elderly patients - Risk of hypoxemia of group N0.5 (32.4%) was higher than that of group N1 (0%) with SpO2 = 92% (PaO2 = 64.7 ± 3.8 mmHg) after 97.2 ± 19.6 minutes of LFA.