Impact of nutrition route on microaspiration in critically ill patients with shock: a planned ancillary study of the NUTRIREA-2 trial.

BACKGROUND: Microaspiration of gastric and oropharyngeal secretions is the main mechanism of entry of bacteria into the lower respiratory tract in intubated critically ill patients. The aim of this study is to determine the impact of enteral nutrition, as compared with parenteral nutrition, on abundant microaspiration of gastric contents and oropharyngeal secretions. METHODS: Planned ancillary study of the randomized controlled multicenter NUTRIREA2 trial. Patients with shock receiving invasive mechanical ventilation were randomized to receive early enteral or parenteral nutrition. All tracheal aspirates were collected during the 48 h following randomization. Abundant microaspiration of gastric contents and oropharyngeal secretions was defined as the presence of significant levels of pepsin (> 200 ng/ml) and salivary amylase (> 1685 UI/ml) in > 30% of tracheal aspirates. RESULTS: A total of 151 patients were included (78 and 73 patients in enteral and parenteral nutrition groups, respectively), and 1074 tracheal aspirates were quantitatively analyzed for pepsin and amylase. Although vomiting rate was significantly higher (31% vs 15%, p = 0.016), constipation rate was significantly lower (6% vs 21%, p = 0.010) in patients with enteral than in patients with parenteral nutrition. No significant difference was found regarding other patient characteristics. The percentage of patients with abundant microaspiration of gastric contents was significantly lower in enteral than in parenteral nutrition groups (14% vs 36%, p = 0.004; unadjusted OR 0.80 (95% CI 0.69, 0.93), adjusted OR 0.79 (0.76, 0.94)). The percentage of patients with abundant microaspiration of oropharyngeal secretions was significantly higher in enteral than in parenteral nutrition groups (74% vs 54%, p = 0.026; unadjusted OR 1.21 (95% CI 1.03, 1.44), adjusted OR 1.23 (1.01, 1.48)). No significant difference was found in percentage of patients with ventilator-associated pneumonia between enteral (8%) and parenteral (10%) nutrition groups (HR 0.78 (0.26, 2.28)). CONCLUSIONS: Our results suggest that enteral and parenteral nutrition are associated with high rates of microaspiration, although oropharyngeal microaspiration was more common with enteral nutrition and gastric microaspiration was more common with parenteral nutrition. TRIAL REGISTRATION: ClinicalTrials.gov, NCT03411447 . Registered 18 July 2017. Retrospectively registered.

Critical illness neuromuscular syndromes.

Critical illness neuromyopathy (CINM) is the most common peripheral neuromuscular disorder encountered in the ICU. Bilateral diffuse weakness predominant in the proximal part of the limbs after improvement of the acute phase of the critical illness is highly suggestive of CINM. Although muscle and peripheral nerve often are involved in combination, muscle involvement alone increasingly is identified on electrophysiological investigation, including direct muscle stimulation. Respiratory muscles also are involved, and CINM may cause delayed weaning and prolonged MV. Besides muscle immobilization and prolonged sepsis-induced multiple organ failure, which are both strong contributors to CINM, hyperglycemia and use of corticosteroids also might have a deleterious effect on the neuromuscular system in critically ill patients.