Fig. 2From: Prehospital treatment with continuous positive airway pressure in patients with acute respiratory failure: a regional observational studyChanges in SpO2 from arrival at scene to arrival at hospital as a function of initial SpO2 value and according to study group. Grey areas represent 95 % confidence limits. Number of points: 30. CPAP group: N = 136. Non-CPAP group: N = 663Back to article page