There is a high percentage of smokers among trauma patients. Cigarette smoking has been associated with the development of acute lung injury and the adult respiratory distress syndrome in critically ill patients. It is also known that nicotine exerts immunosuppressive and anti-inflammatory effects with chronic use. Trauma patients who are smokers usually go through acute nicotine withdrawal after the traumatic event and during their stay in ICU. How the smoking status and acute nicotine withdrawal affect outcomes after trauma is unknown. This question was addressed in this study by analyzing the incidence of sepsis, septic shock and multiple organ dysfunction syndrome, and other outcomes in smoking and nonsmoking trauma patients.
A retrospective cohort of trauma patients who met the criteria was randomly selected from the trauma registry. Individual charts were reviewed to confirm documented smoking status. Criteria for selection included the following: Injury Severity Score ≥20, age 18 to 65 years, hospital length of stay >72 hours. Patients with COPD/emphysema, diabetes mellitus, cardiac disease, malignancy, pregnancy, or steroid use were excluded.
Overall, 327 patient charts were reviewed: 156 smokers and 171 nonsmokers. Men outnumbered women in the smoking group fourfold (p = 0.003 versus nonsmokers). Age, Injury Severity Score, the presence of shock on admission, the type of trauma (blunt or penetrating), ICU and hospital length of stay, and the duration of ventilator support were similar between smokers and nonsmokers. There were no differences in the incidence of sepsis, pneumonia, adult respiratory distress syndrome, or multiple organ dysfunction syndrome. Mortality was low (1.2% in smokers; 0.6% in nonsmokers) and did not differ significantly between the groups.
The smoking status plays a minimal role in the outcome of healthy trauma patients. This suggests that the acute nicotine withdrawal that usually occurs in critically ill patients has no clinically significant implications after injury.