Dysregulated alveolar function and complications in smokers following oesophagectomy

Acute respiratory distress syndrome (ARDS) has a significant impact on post-operative morbidity and mortality following oesophagectomy. Smoking is a risk factor for the development of ARDS, although the mechanism is unclear. We examined the effect of smoking on alveolar and systemic inflammation, in addition to alveolar–capillary permeability, leading to ARDS in patients undergoing oesophagectomy. We compared clinical, biomarker and PiCCO system data between current smokers (n=14) and ex-smokers (n=36) enrolled into a translational substudy of the BALTI-P (Beta Agonist Lung Injury Trial Prevention) trial. Current smokers compared with ex-smokers had significantly higher numbers of circulating neutrophils, elevated bronchoalveolar lavage (BAL) interleukin (IL)-1 receptor antagonist (IL-1ra), soluble tumour necrosis factor receptor-1 and pre-operative plasma soluble intercellular adhesion molecule-1, and lower BAL vascular endothelial growth factor and post-operative plasma IL-17 (p<0.05). On post-operative day 1, current smokers had higher extravascular lung water index (9.80 versus 7.90; p=0.026) and pulmonary vascular permeability index (2.09 versus 1.70; p=0.013). Current smokers were more likely to develop ARDS (57% versus 25%; p=0.031) and had a significantly reduced post-operative median survival (421 versus 771 days; p=0.023). Smoking prior to oesophagectomy is associated with dysregulated inflammation, with higher concentrations of inflammatory mediators and lower concentrations of protective mediators. This translates into a higher post-operative inflammatory alveolar oedema, greater risk of ARDS and poorer long-term survival.