Pulmonary levels of biomarkers for inflammation and lung injury in protective versus conventional one-lung ventilation for oesophagectomy: A randomised clinical trial

BACKGROUND: It is uncertain whether protective ventilation reduces ventilation-induced pulmonary inflammation and injury during one-lung ventilation. OBJECTIVE: To compare intra-operative protective ventilation with conventional during oesophagectomy with respect to pulmonary levels of biomarkers for inflammation and lung injury. DESIGN: Randomised clinical trial. SETTING: Tertiary centre for oesophageal diseases. PATIENTS: Twenty-nine patients scheduled for one-lung ventilation during oesophagectomy. INTERVENTIONS: Low tidal volume (VT) of 6 ml kg predicted body weight (pbw) during two-lung ventilation and 3 ml kgpbw during one-lung ventilation with 5 cmH2O positive end expired pressure versus intermediate VT of 10 ml kgpbw during two-lung ventilation and 5 ml kgpbw body weight during one-lung ventilation with no positive end-expiratory pressure. OUTCOME MEASURES: The primary outcome was the change in bronchoalveolar lavage (BAL) levels of preselected biomarkers for inflammation (TNF-α, IL-6 and IL-8) and lung injury (soluble Receptor for Advanced Glycation End-products, surfactant protein-D, Clara Cell protein 16 and Krebs von den Lungen 6), from start to end of ventilation. RESULTS: Median [IQR] VT in the protective ventilation group (n = 13) was 6.0 [5.7 to 7.8] and 3.1 [3.0 to 3.6] ml kgpbw during two and one-lung ventilation; VT in the conventional ventilation group (n = 16) was 9.8 [7.0 to 10.1] and 5.2 [5.0 to 5.5] ml kgpbw during two and one-lung ventilation. BAL levels of biomarkers for inflammation increased from start to end of ventilation in both groups; levels of soluble Receptor for Advanced Glycation End-products, Clara Cell protein 16 and Krebs von den Lungen 6 did not change, while levels of surfactant protein-D decreased. Changes in BAL biomarkers levels were not significantly different between the two ventilation strategies. CONCLUSION: Intra-operative protective ventilation compared with conventional ventilation does not affect changes in pulmonary levels of biomarkers for inflammation and lung injury in patients undergoing one-lung ventilation for oesophagectomy. TRIAL REGISTRATION: The 'Low versus Conventional tidal volumes during one-lung ventilation for minimally invasive oesophagectomy trial' (LoCo) was registered at the Netherlands Trial Register (study identifier NTR 4391)