A randomized controlled pilot study to evaluate the effect of an enteral formulation designed to improve gastrointestinal tolerance in the critically ill patient—the SPIRIT trial

BACKGROUND: Diarrhea is frequent in patients in intensive care units (ICU) and is associated with discomfort and complications and may increase the length of stay and nursing workload. METHODS: This was a prospective, double-blind, randomized, controlled single-center pilot study to assess the incidence and frequency of diarrhea and the respective effects of a modified enteral diet (intervention: Peptamen® AF, rich in proteins, medium chain triglycerides and fish oil) compared to a standard diet (control: Isosource® Energy) in 90 randomized adult patients (intervention, n = 46; control, n = 44) with an ICU stay ≥5 days and tube feeding ≥3 days. Tube feeding was initiated within 72 h of ICU admission and continued up to 10 days. The caloric goal was adjusted to needs by indirect calorimetry. Gastrointestinal function, nutritional intake, and nursing workload were recorded. Follow-up was until 28 days after randomization. RESULTS: Median age was 63.3 (interquartile range (IQR) 51.0–73.2) years and Simplified Acute Physiology Score (SAPS) II was 61.0 (IQR 47.8–74). Time to reach caloric goal (intervention: 2.2 (0.8–3.7) days (median, IQR); control: 2.0 (1.3–2.7) days; p = 0.16), length of time on study nutrition (intervention: 5.0 (3.6–6.4) days; control: 7.0 (5.3–8.7) days; p = 0.26), and calorie intake (intervention: 18.0 (12.5–20.9) kcal/kg/day; control 19.7 (17.3–23.1) kcal/kg/day; p = 0.08) did not differ between groups, with a higher protein intake for Peptamen® group (1.13 (0.78–1.31) g/kg/day vs 0.80 (0.70–0.94); p < 0.001). No difference in diarrhea incidence (intervention group: 29 (64%); control group: 31 (70%); p = 0.652), use of fecal collectors (23 (51%) vs. 24 (55%); p = 0.83), or diarrhea-free days (161 (64%) vs 196 (68%); p = 0.65) was found. Nursing workload and cost for diarrhea care were not different between the groups. In a post-hoc analysis, adjusted for treatment group, age, sex, and SAPS II score, diarrhea was associated with length of mechanical ventilation (9.5 (6.0–13.1) vs. 3.9 (3.2–4.6) days; p = 0.006) and length of ICU stay (11.0 (8.9–13.1) vs. 5.0 (3.8–6.2) days; p = 0.001). CONCLUSIONS: In this pilot study, we found a high incidence of diarrhea, which was not attenuated by Peptamen® AF. Patients with diarrhea stayed longer in the ICU. TRIAL REGISTRATION: ClinicalTrials.gov identifier, NCT01581957. Registered on 18 April 2012. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s13054-017-1730-1) contains supplementary material, which is available to authorized users.