Table 1 Characteristics of included randomised controlled trials
Author (Year) | Study design | Inclusion criteria | Number of patients (% male)a | Age, year, mean ± SD | BMI, kg/m−2, mean ± SD | Intervention |
|---|---|---|---|---|---|---|
Cressey. (2001) [41] | RCT | Age > 18 years; BMI > 35; patient received elective surgery; ASA I–III | V: 10 (0) C: 10 (0) | V: 34 ± 8 C: 47 ± 11 | V: 45 ± 7.0 C: 44 ± 5.6 | V: CPAP 7.5 cm H2O × 3 min C: Spontaneous breathing with Mapleson A breathing system 8 L/min |
Herriger (2004) [46] | RCT | Age 16–60 years; BMI < 25; patient received elective surgery; ASA I–II | V: 20 (60) C: 20 (55) | V: 34 ± 13 C: 36 ± 8 | V: 22 ± 2 C: 22 ± 2 | V: CPAP 6 cm H2O with PEEP 6 cm H2O × 5 min C: Spontaneous breathing without CPAP or PEEP |
Coussa (2004) [42] | RCT | Age 20–65 years; BMI > 35; patient received elective bariatric surgery; ASA II–III | V: 9 (22.2) C: 9 (0) | V: 41 ± 14 C: 37 ± 8 | V: 42 ± 6 C: 44 ± 7 | V: CPAP 10 cm H2O × 5 min C: Spontaneous breathing |
Gander (2005) [43] | RCT | Age 18–60 years; BMI > 35; patient received elective surgery; ASA II–III | V: 12 (25) C: 15 (13.3) | V: 35 ± 8 C: 38 ± 12 | V: 46 ± 7 C: 47 ± 6 | V: CPAP 10 cm H2O × 5 min C: Spontaneous breathing |
Delay (2008) [28] | RCT | Age > 18 years; BMI > 40; patient received abdominal surgery | V: 14 (21.4) C: 14 (14.3) | V: 36.6 ± 11.7 C: 42.9 ± 11.6 | V: 47.1 ± 6.2 C: 52.3 ± 13.7 | V: PSV 6 cm H2O with PEEP 4 cm H2O during the first 20 s, then PSV 8–10 cm H2O with PEEP 6 cm H2O to achieve VTe of 8 mL/kg × 5 min C: Spontaneous breathing |
Futier (2011) [48] | RCT | Age > 18 years; BMI > 40; patient received LSG or Roux-en-Y gastric bypass; ASA II–III | V: 22 (27.2) VR: 22 (36.3) C: 22 (22.7) | V: 42 ± 10 VR: 43 ± 11 C: 41 ± 9 | V: 46 ± 2 VR: 45 ± 5 C: 46 ± 4 | V: PSV < 18 cm H2O with PEEP 6–8 cm H2O × 5 min VR: PSV < 18 cm H2O with PEEP 6–8 cm H2O with RM × 5 min C: Spontaneous breathing |
Georgescu (2012) [50] | Crossover RCT | Age 18–75 years; BMI > 30; patient received elective surgery | V1 + V2: 30 (53.3) | V1 + V2: 49.6 ± 14.0 | V1 + V2: 36.5 ± 5.3 | V1: NIPPV 4 cm H2O with PEEP 4 cm H2O × 3 min, and then spontaneous breathing V2: Spontaneous breathing; then NIPPV 4 cm H2O with PEEP 4 cm H2O × 3 min |
Harbut (2014) [51] | RCT | Age > 18 years; BMI > 35; patient received elective gastric bypass surgery; ASA II–III | V: 22 (N/P) C: 22 (N/P) | V: 46.9 ± 12.9 C: 42.1 ± 12.4 | V: 43 ± 6.3 C: 44.1 ± 6.0 | V: CPAP 5 cm H2O/PSV 5 cm H2O with PEEP 7 cm H2O × 2 min C: Spontaneous breathing |
Hanouz (2015) [44] | RCT | Age > 18 years; patient received elective surgery; ASA I–II | V: 50 (60) Vp: 47 (46.8) C: 49 (55.1) | V: 45 ± 20 Vp: 40 ± 17 C: 45 ± 18 | V: 25 ± 6 Vp: 23 ± 4 C: 25 ± 5 | V: NIPPV 12 cm H2O with PEEP 6 cm H2O to obtain 90% FeO2 Vp: NIPPV 12 cm H2O without PEEP C: Spontaneous breathing |
Edmark (2015) [47] | RCT | Age 24–49 years; BMI 35–50; patient received elective LGBP; ASA I–II | V: 10 (10) C: 20 (35) | V: 42.9 [44.1–44.6] C: 38.1 [36.1–41.2] | V: CPAP 10 cm H2O with PEEP 10 cm H2O × 3 min C: Spontaneous breathing | |
Baltieri (2015) [49] | RCT | Age 25–55 years; BMI 40–55; patient received Roux-en-Y gastric bypass bariatric surgery through laparotomy | V: 10 (20) C: 20 (20) | V: 42 ± 11.2 C: 40.7 ± 10.6 | V: 44.8 ± 2.8 C: 45.72 ± 4.08 | V: BiPAP 12 cm H2O with PEEP 8 cm H2O × 1 h C: Spontaneous breathing |
Sreejit (2015) [45] | RCT | Age 18–70 years; BMI < 25; patient received elective surgery; ASA I–II | V: 20 (55) C: 20 (55) | V: 42.75 ± 11.97 C: 45.65 ± 12.22 | V: 20.97 ± 2.29 C: 21.01 ± 2.38 | V: CPAP 5 cm H2O with a fixed PEEP device × 5 min C: Spontaneous breathing with the same device |
Abou-Arab (2016) [40] | RCT | Age > 18 years; BMI > 35; patient received ENT pan-endoscopy; ASA I–III | V: 25 (16) C: 25 (48) | V: 58 ± 13 C: 58 ± 13 | V: 23.3 ± 4.7 C: 25.1 ± 6.1 | V: NIPPV 4 cm H2O with PEEP 4 cm H2O until EtO2 exceeded 90% C: Spontaneous breathing |