DESIGN: A post hoc subgroup analysis of the effect of higher protein dosing in critically ill patients with high nutritional risk (EFFORT Protein): an international, multicenter, pragmatic, registry-based randomized trial.

SETTING: Eighty-five adult ICUs across 16 countries.

PATIENTS: Patients with obesity defined as a body mass index (BMI) greater than or equal to 30 kg/m 2 ( n = 425).

INTERVENTIONS: In the primary study, patients were randomized into a high-dose (≥ 2.2 g/kg/d) or usual-dose protein group (≤ 1.2 g/kg/d).

MEASUREMENTS AND MAIN RESULTS: Protein intake was monitored for up to 28 days, and outcomes (time to discharge alive [TTDA], 60-d mortality, days of mechanical ventilation [MV], hospital, and ICU length of stay [LOS]) were recorded until 60 days post-randomization. Of the 1301 patients in the primary study, 425 had a BMI greater than or equal to 30 kg/m 2 . After adjusting for sites and covariates, we observed a nonsignificant slower rate of TTDA with higher protein that ruled out a clinically important benefit (hazard ratio, 0.78; 95% CI, 0.58-1.05; p = 0.10). We found no evidence of difference in TTDA between protein groups when subgroups with different classes of obesity or patients with and without various nutritional and frailty risk variables were examined, even after the removal of patients with baseline acute kidney injury. Overall, 60-day mortality rates were 31.5% and 28.2% in the high protein and usual protein groups, respectively (risk difference, 3.3%; 95% CI, -5.4 to 12.1; p = 0.46). Duration of MV and LOS in hospital and ICU were not significantly different between groups.

METHODS: In this post hoc analysis of the EFFORT Protein trial, we investigated the effect of high versus usual protein dose (≥ 2.2 vs. ≤ 1.2 g/kg body weight/day) on time-to-discharge alive from the hospital (TTDA) and 60-day mortality and in different subgroups in critically ill patients with AKI as defined by the Kidney Disease Improving Global Outcomes (KDIGO) criteria within 7 days of ICU admission. The associations of protein dose with incidence and duration of kidney replacement therapy (KRT) were also investigated.

RESULTS: Of the 1329 randomized patients, 312 developed AKI and were included in this analysis (163 in the high and 149 in the usual protein dose group). High protein was associated with a slower time-to-discharge alive from the hospital (TTDA) (hazard ratio 0.5, 95% CI 0.4-0.8) and higher 60-day mortality (relative risk 1.4 (95% CI 1.1-1.8). Effect modification was not statistically significant for any subgroup, and no subgroups suggested a beneficial effect of higher protein, although the harmful effect of higher protein target appeared to disappear in patients who received kidney replacement therapy (KRT). Protein dose was not significantly associated with the incidence of AKI and KRT or duration of KRT.

CONCLUSIONS: In critically ill patients with AKI, high protein may be associated with worse outcomes in all AKI stages. Recommendation of higher protein dosing in AKI patients should be carefully re-evaluated to avoid potential harmful effects especially in patients who were not treated with KRT.