Introduction
Mechanism of ventilator-induced lung injury in healthy lungs
Protective ventilation strategies
Tidal volume, positive end-expiratory pressure and recruitment maneuvers
In surgery
Protective ventilation | Standard ventilation | |||||||
---|---|---|---|---|---|---|---|---|
First author, Year[Ref] | No | Design | Patient population | Tidal volume | PEEP(cmH2O) | Tidal volume | PEEP(cmH2O) | Main outcome of protective ventilation |
Chaney 2000 [14] | 25 | RCT | CABG | 6 ml/kg | ≥ 5 | 12 ml/kg | ≥ 5 | Better lung mechanics and less shunt |
Wrigge 2004 [18] | 62 | RCT | Major thoracic or abdominal surgery | 6 ml/kg IBW | 10 | 12 or 15 ml/ kg IBW | 0 | No difference in BAL or plasma cytokines |
Koner 2004 [15] | 44 | RCT | CABG | 6 ml/kg | 5 | 10 ml/kg 10 ml/kg | 50 | No difference in plasma cytokines, better oxygenation in PEEP groups |
Wrigge 2005 [16] | 44 | RCT | CABG | 6 ml/kg IBW | 9a | 12 ml/kg IBW | 7a | No difference in BAL and plasma cytokines |
Zupancich 2005 [17] | 40 | RCT | CABG | 8 ml/kg | 10 | 10 ml/kg | 2-3 | Decrease in BAL and plasma cytokines |
Cai2006 [27] | 16 | RCT | Neurosurgery | 6 ml/kg | 0 | 10 ml/kg | 0 | No difference in amount of atelectasis or gas exchange |
Determann 2008 [26] | 40 | RCT | Abdominalsurgery | 6 ml/kg IBW | 10 | 12 ml/kg IBW | 0 | No difference in BAL and plasma of Clara cell protein, advanced glycation end products and surfactant proteins |
Wolthuis 2008 [19] | 40 | RCT | Abdominalsurgery | 6 ml/kg IBW | 10 | 12 ml/kg IBW | 0 | Attenuated the increase in BAL myeloperoxidase |
Weingarten 2010 [20] | 40 | RCT | Abdominal surgery Age > 65 years | 6 ml/kg PBWb | 12 | 10 ml/kg PBW | 0 | Better intraoperative oxygenation, no difference in biomarkers |
Fernandez-Bustamante 2011 [22] | 429 | Crosssectional | Abdominalsurgery | < 8 ml/kg PBW 8-10 ml/kg PBW | - | 10 mL/kg PBW | - | Obesity, female gender or short height risk factors for receiving large VT |
Sundar 2011 [28] | 149 | RCT | Cardiac surgery | 6 ml/kg PBW | ≥ 5a | 10 ml/kg PBW | ≥ 5a | Less postoperative reintubation and intubated patients at 6-8 hours after surgery. |
Lellouche 2012 [21] | 3434 | Observational | Cardiac surgery | < 10 ml/kg PBW | - | 10-12 ml/kg PBW > 12 ml/kg PBW | - - | VT > 10 ml/kg independent risk factor for organ failure and prolonged ICU stay |
Treschan 2012 [23] | 101 | RCT | Upperabdominalsurgery | 6 ml/kg PBW | 5 | 12 ml/kg PBW | 5 | Did not improve lung function |
Severgnini 2013 [24] | 56 | RCT | Open abdominal surgery | 7 ml/kg IBWb | 10 | 9 ml/kg IBW | 0 | Better pulmonary function test and mCPIS score, fewer chest X-ray findings. |
Futier 2013 [25] | 400 | RCT | Major abdominal surgery | 6-8 ml/kg PBWb | 6-8 | 10-12 ml/kg PBW | 0 | Less postoperative pulmonary and extra pulmonary complications. |
In the intensive care unit
Recent meta-analyses
Meta-analysis including the most recent trials
Protective ventilation | Standard ventilation | |||||||
---|---|---|---|---|---|---|---|---|
First author, Year [Ref] | Number of patients | VT (ml/kg) | N | VT (ml/kg) | N | Setting | Design | Primary outcome |
Lee 1990 [31] | 103 | 6 | 47 | 12 | 56 | ICU | RCT | Duration of MV |
Chaney 2000 [14] | 25 | 6 | 12 | 12 | 16 | Surg | RCT | Lung mechanics |
Wrigge 2004 [18] | 62 | 6 | 30 | 12 | 32 | Surg | RCT | Cytokines in BAL |
Koner 2004 [15] | 44 | 6 | 15 | 10 | 29 | Surg | RCT | Cytokines in blood |
Wrigge 2005 [16] | 44 | 6 | 22 | 12 | 22 | Surg | RCT | Cytokines in BAL |
Zupancich 2005 [17] | 40 | 8 | 20 | 10 | 20 | Surg | RCT | Cytokines in BAL |
Michelet 2006 [43] | 52 | 5 | 26 | 9 | 26 | Surg | RCT | Cytokines in blood |
Cai 2007 [27] | 16 | 6 | 8 | 10 | 8 | Surg | RCT | Atelectasis |
Wolthius 2008 [19] | 40 | 6 | 21 | 12 | 19 | Surg | RCT | Pulmonary Inflammation |
Determan 2008 [26] | 40 | 6 | 21 | 12 | 19 | Surg | RCT | Cytokines in BAL |
Weingarten 2010 [20] | 40 | 6 | 20 | 10 | 20 | Surg | RCT | Oxygenation |
Determann 2010 [33] | 150 | 6 | 76 | 10 | 74 | ICU | RCT | Cytokines in BAL |
Pinheiro de Oliveira 2010 [32] | 20 | 6 | 10 | 12 | 10 | ICU | RCT | Cytokines in BAL |
Sundar 2011 [28] | 149 | 6 | 75 | 10 | 74 | Surg | RCT | Duration of MV |
Treschan 2012 [23] | 101 | 6 | 50 | 12 | 51 | Surg | RCT | Spirometry |
Severgnini 2013 [24] | 55 | 7 | 27 | 9 | 28 | Surg | RCT | Change in mCPIS |
Futier 2013 [25] | 400 | 6-8 | 200 | 10-12 | 200 | Surg | RCT | Pulmonary and extrapulmonary complications |
Protective ventilation (n= 682) | Standard ventilation (n= 680) | p | |
---|---|---|---|
Age, years | 61 (8.4) | 61 (7.7) | 0.96 |
Weight, kg | 77.5 (10.1) | 77.2 (9.5) | 0.82 |
Tidal volume, ml/kg | 6.1 (0.63) | 10.7 (1.2) | 0.00 |
PEEP, cm H2O | 7.6 (2.4) | 2.5 (2.6) | 0.00 |
Plateau pressure, cm H2O | 17.2 (2.2) | 19.9 (3.9) | 0.03 |
Respiratory rate, breaths/min | 16.7 (3.2) | 10.1 (3.5) | 0.00 |
PaO2/FiO2 | 331.6 (62.3) | 332.5 (64.3) | 0.94 |
PaCO2, mmHg | 42.6 (5.5) | 38.4 (4.8) | 0.01 |
pH | 7.37 (0.3) | 7.40 (0) | 0.01 |
Author, year [ref] | Serpa Neto et al. 2012[38] | Hemmes et al. 2013[40] | Our meta-analysis | |||
---|---|---|---|---|---|---|
Number of studies | 20 articles | 8 articles | 17 articles | |||
Number of RCTs | 15 articles | 6 articles | 17 articles | |||
Populations | ICU and surgical patients | Only surgical patients | ICU and surgical patients | |||
Search strategy until (year) | 2012 | 2012 | 2013 | |||
Statistical analysis | Fixed effect + Mantel and Haenszel | Fixed effect + Mantel and Haenszel | Fixed effect + Mantel and Haenszel, when P > 25 % random effect plus DerSimonian and Laird | |||
Number of patients | 2833 | 1669 | 1362 | |||
PV group | CV group | PV group | CV group | PV group | CV group | |
VT (ml/kg) | 6.5 | 10.6 | 6.1 | 10.4 | 6.1 | 10.7 |
PEEP (cm H2O) | 6.4 | 3.4 | 6.6 | 2.7 | 7.6 | 2.5 |
Plateau pressure (cmH2O) | 16.6 | 21.4 | 16.6 | 20.5 | 17.2 | 19.9 |
Main outcome
| ||||||
ALI | RR 0.33; 95 %CI 0.23-0.47 | RR 0.40; 95 % CI 0.22-0.70 | RR 0.27; 95 % CI 0.12-0.59 | |||
Pulmonary infection | RR 0.52; 95 %CI 0.33-0.82 | RR 0.64; 95 % CI 0.43-0.97 | RR 0.35; 95 % CI 0.25-0.63 | |||
Atelectasis | RR 0.62; 95 %CI 0.41-0.95 | RR 0.67; 95 % CI 0.47-0.96 | RR 0.76; 95 % CI 0.33-1.37 | |||
Mortality | RR 0.64; 95 %CI 0.46-0.86 | No data | RR 1.03; 95 % CI 0.67-1.58 | |||
ICU length of stay | No data | No data | WMD -0.40; 95 %CI -1.02; 0.22 | |||
Hospital length of stay | No data | No data | WMD 0.13; 95 %CI -0.73; 0.08 | |||
Homogeneity test
| Found heterogeneity in pulmonary infection outcome | Found heterogeneity in atelectasis outcome | Found heterogeneity in atelectasis, ICU length of stay and hospital length of stay outcome |