Objective: Appropriate body positioning is crucial for maximizing the effectiveness of mechanical ventilation in patients with obesity. The ramped position is generally used for patients who are difficult to intubate, especially patients with severe obesity. We hypothesized that the ramped position would also improve ventilation and oxygenation in patients with obesity vs the semi-Fowler position.
Methods: This retrospective study compared data from 17 total patients with obesity (body mass index ≥35 kg/m2) who underwent intubated general anesthesia in the ramped position vs the semi-Fowler position. Differences in 2 indices of respiratory function, alveolar-arterial oxygen gradient (P(A-a)DO2; ventilation) and arterial partial pressure of oxygen/fraction of inspired oxygen (P/F ratio; oxygenation), were measured during the maintenance of general anesthesia between the 2 groups.
Results: The mean (SD) P(A-a)DO2 was significantly lower in the ramped group (168.83 [54.18] mm Hg) than in the semi-Fowler group (273.33 [39.72] mm Hg; P = .012), and the mean (SD) P/F ratio was significantly higher in the ramped group (354.44 [88.88]) than in the semi-Fowler group (225.40 [67.49]; P = .002).
Conclusion: The ramped position was associated with improved ventilation and pulmonary oxygenation vs the semi-Fowler position during mechanical ventilation in patients with obesity.
Keywords: Mechanical ventilation; Oxygenation; Ramped position; Severe obesity.