Background: Severe injury triggers a complex systemic immune response which may result in significant respiratory compromise, including the development of acute respiratory distress syndrome (ARDS). No randomized clinical trial has assessed the role of nutritional interventions to limit respiratory complications.
Methods: This was a single-center, prospective, randomized, comparative, double-blind, controlled study of patients with severe trauma requiring mechanical ventilation. Patients were randomly assigned to receive either a control formula (n = 58) or a formula enriched with eicosapentaenoic acid (EPA), gamma-linolenic acid (GLA) and antioxidants (n = 62) at time of admission to the intensive care unit (ICU). Primary outcome measures included the level of oxygenation (PaO2/FiO2 ratio, PF ratio) on days 4 and 8, incidence of acute lung injury (ALI) and/or ARDS and length of ventilation. The development of infectious complications and fatty acid red blood cell membrane composition were also assessed.
Results: In this intention-to-treat population, no significant differences between the control and study groups were found for the PF ratio at day 4 (213.7 ± 85.6 vs. 227.2 ± 67.7, respectively; P = 0.24) and day 8 (187.8 ± 65.2 vs. 188.9 ± 56.0, respectively; P = 0.82), the incidence of ARDS/ALI (24.1 vs. 29.0 %, respectively; P = 0.68), length of ventilation time (13.6 ± 10.7 vs. 17.0 ± 15.1 days, respectively; P = 0.15), duration of ICU stay (16.4 ± 11.3 vs. 19.5 ± 15.3 days, respectively; P = 0.21) and 28-day mortality (8.6 vs. 12.9 %, respectively P = 0.56). While the study group showed a significant increase in EPA and GLA concentrations at day 4 (P = 0.05) and day 8 (P < 0.001), the Omega-3 Index (O-3I) failed to reach those suggested as being optimal to obtain clinical efficacy. The significantly higher incidence of bacteremia noted in the study group (P = 0.03) was associated with a higher number of patients with multiple trauma and a higher red blood cell transfusion requirement (P = 0.008).
Conclusion: This study failed to show a significant benefit for the preemptive use of the study formula in patients with severe trauma. Additional studies need to be performed in which the amount of supplementation is targeted to a potentially measurable endpoint, e.g. the O-3I.
- Enteral nutrition
- Multiple trauma
- Omega 3 fatty acids
- Respiratory complications