The impact of higher protein dosing on outcomes in critically ill patients with acute kidney injury: a post hoc analysis of the EFFORT protein trial

Association of Geriatric Nutritional Risk Index with short-term mortality in patients with severe acute kidney injury: a retrospective cohort study

OBJECTIVES

Geriatric Nutritional Risk Index (GNRI) is a new and simple index recently introduced to assess nutritional status, and its predictive value for clinical outcomes has been demonstrated in patients with chronic kidney disease. However, the association between the GNRI and prognosis has not been evaluated so far in patients with acute kidney injury (AKI), especially in those receiving continuous renal replacement therapy (CRRT).

METHODS

A total of 1096 patients with severe AKI initiating CRRT were identified for inclusion in this retrospective observational study. Patients were divided into three groups according to GNRI tertiles, with tertile 1 as the reference. The outcomes of interest were the 28- and 90-days of all-cause mortality. The associations between GNRI and clinical outcomes were estimated using multivariate Cox proportional hazards model analysis.

RESULTS

The overall mortality rates at 28- and 90-days were 61.6% (675/1096) and 71.5% (784/1096), respectively. After adjusting for multiple confounding factors, GNRI was identified as an independent prognostic factor for 28-days all-cause mortality (HR, 0.582; 95% CI, 0.467-0.727; p < .001 for tertile 3 vs. tertile 1) as well as 90-days all-cause mortality (HR, 0.540; 95% CI, 0.440-0.661; p < .001 for tertile 3 vs. tertile 1). The observed inverse associations were robust across subgroup analysis, and were more pronounced in elderly patients over 65 years of age. Finally, incorporating GNRI in a model with established risk factors might significantly improve its predictive power for the short-term death.

CONCLUSIONS

GNRI is considered to be a useful prognostic factor in patients with severe AKI initiating CRRT, especially in elderly patients.

The kidney: the critical organ system for guiding nutrition therapy in the ICU-patient?

Most randomized controlled studies on nutrition in intensive care patients did not yield conclusive results or were neutral or negative concerning the primary endpoints but also in most secondary endpoints. However, there is a consistent observation that in several of these studies there was a negative effect of the nutrition intervention on the kidneys in one of the study arms. During the early phase and in unstable periods during further course of disease an inadequate clinical nutrition can damage the kidneys, can elicit or aggravate acute kidney injury and/ or increase requirements of renal replacement therapy (RRT). This relates to total energy intake, glucose intake/hyperglycemia and protein/ amino acid intake at various stages of renal dysfunction. The kidney could present a critical organ system for guiding nutrition therapy, a close monitoring of kidney function should be observed and nutrition therapy may need to be adapted accordingly. The long-held dogma of performing full nutrition and accept an otherwise not necessary RRT is definitely to be refuted.

Early protein delivery in critically ill patients with acute kidney injury: post hoc analysis of a multicenter cluster-randomized controlled trial

Background

There is controversy over the optimal early protein delivery in critically ill patients with acute kidney injury (AKI). This study aims to evaluate whether the association between early protein delivery and 28-day mortality was impacted by the presence of AKI in critically ill patients.

Methods

This is a post hoc analysis of data from a multicenter cluster-randomised controlled trial enrolling newly admitted critically ill patients (n = 2772). Participants without chronic kidney disease and with complete data concerning baseline renal function were included in this study. The primary outcome was 28-day mortality. Cox proportional hazards models were used to analyze the association between early protein delivery, reflected by mean protein delivery from day 3-5 after enrollment, 28-day mortality and whether baseline AKI stages interacted with this association.

Results

Overall, 2552 patients were included, among whom 567 (22.2%) had AKI at enrollment (111 stage I, 87 stage II, 369 stage III). Mean early protein delivery was 0.60 ± 0.38 g/kg/day among the study patients. In the overall study cohort, each 0.1 g/kg/day increase in protein delivery was associated with a 5% reduction in 28-day mortality[hazard ratio (HR) = 0.95; 95% confidence interval (CI) 0.92-0.98, p < 0.001]. The association between early protein delivery and 28-day mortality significantly interacted with baseline AKI stages (adjusted interaction p = 0.028). Each 0.1 g/kg/day increase in early protein delivery was associated with a 4% reduction in 28-day mortality (HR = 0.96; 95%CI 0.92-0.99, p = 0.011) among patients without AKI and 9% (HR = 0.91; 95%CI 0.84-0.99, p = 0.021) among those with AKI stage III. However, such associations cannot be observed among patients with AKI stages I and II.

Conclusions

Increased early protein delivery (up to close to the guideline recommendation) was associated with reduced 28-day mortality in critically ill patients without AKI and with AKI stage III, but not in those with AKI stage I or II.

Association between protein intake and functional capacity in critically ill patients: A retrospective cohort study

BACKGROUND

Intensive care unit (ICU) protein benchmarks are based on mortality and morbidity; whether these targets also support functional recovery is unknown. We assessed whether different protein doses influenced patients' functional capacity, measured by the Chelsea Physical Assessment score (CPAx).

METHODS

Single-center retrospective cohort study on ICU survivors with length of stay ≥7 days admitted between October 2014 and September 2020. Eligible patients were divided according to protein intake (g/kg/day): low (<0.8), medium (0.8-1.19), high (1.2-1.5), and very high (>1.5). Protein dose effect on CPAx was assessed at ICU discharge with analysis of covariance adjusting for age, illness severity, hospital length of stay before ICU admission, time to start nutrition support, and mechanical ventilation duration. We also investigated effect modification by energy intake and nutrition status.

RESULTS

Enrolled patients (n = 531) were similar for age, nutrition status, and illness severity across groups. CPAxs were nonlinearly associated with protein doses and similar among low, medium, and very high groups. The CPAx for the high group was statistically different (P = 0.014), indicating that the data of three groups could be pooled. Mean CPAx difference remained statistically significant after adjusting for confounding variables (3.9 ± 1.8, P = 0.029 in the four-group model, and 2.7 ± 0.9, P = 0.003 in the pooled two-group model). Energy intake was equivalent between groups and did not modify CPAx. The high group had superior CPAx in both well-nourished and malnourished patients, indicating nutrition status was not an effect modifier.

CONCLUSION

Protein dose 1.2-1.5 g/kg/day was associated with superior functional capacity at ICU discharge compared with other doses. Neither energy intake nor nutrition status modified functional capacity across groups; therefore, the results appear to be influenced by 1.2-1.5 g/kg/day.

Nutritional Prescription in ICU Patients: Does it Matter?

Background

The nutritional status of the patients before critical illness and nutrition support given during the critical illness play an important role in the recovery. We aimed to evaluate the nutritional prescription and its effect on ICU mortality.

Materials and methods

This was a prospective observational study conducted after institutional ethical committee approval (IEC 94/2018, CTRI/2018/06/014625) in a case-mixed (medical and surgical) ICU. Patients admitted to the ICU were enrolled within 24 hours of admission. The amount of calories and proteins prescribed and received by the patients was collected for 7 days. The primary outcome was ICU mortality.

Results

A total of 100 patients were included. The mean age was 48.63 (16.25) years, and 62% were males. The acute physiology and chronic health evaluation (APACHE II), sequential organ failure assessment (SOFA), and modified Nutric (mNUTRIC) scores were comparable between the two groups. The ICU mortality was 30%. The calorie and protein deficits were comparable between survivors and non-survivors. Among the secondary outcomes, a significant time effect (p = 0.013) and interaction effect (p = 0.004) were noted for maximum glucose levels. The glucose variability calculated by coefficient of variation (CV) was significantly higher in non-survivors than survivors (p = 0.031).

Conclusion

The calorie and protein deficits did not affect ICU mortality. The maximum glucose variability and CV were significant parameters associated with ICU mortality.

How to cite this article

Havaldar AA, Selvam S. Nutritional Prescription in ICU Patients: Does it Matter? Indian J Crit Care Med 2024;28(7):657-661.

Impact of early high protein intake in critically ill patients: a randomized controlled trial

BACKGROUND

Conflicting findings regarding the impact of High protein intake during the early phase in critically ill patients have been reported. Therefore, we aimed to assess the influence of higher early protein intake on the prognosis of critically ill patients.

METHODS

This randomized controlled trial involved 173 critically ill patients who stayed in the Intensive Care Unit/Emergency ICU (ICU/EICU) for at least 7 days. The Low group (n = 87) and High group (n = 86) received protein supplementation of 0.8 g/kg.d and 1.5 g/kg.d, respectively, within 1-3 days of enteral nutrition (EN) initiation, with both groups transitioning to 1.5 g/kg.d on the 4th day. The serum prealbumin (PA), blood urea nitrogen/creatinine, and rectus femoris muscle thickness and cross-sectional area of all patients was measured on the 1th, 3rd, 5th, 7th day, and the day of ICU/EICU discharge.

RESULTS

Patients in both Low and High groups showed no significant differences in age, APACHE II scores, or other demographic and baseline characteristics. There were also no significant differences in the primary outcome (28-day mortality rate) and secondary outcomes (incidence rate of refeeding syndrome and EN tolerance score) between the two groups. However, the Low group exhibited a significantly higher 28-day mortality rate (HR = 2.462, 95% CI: 1.021-5.936, P = 0.045) compared to High group, as determined by Cox proportional hazards models incorporating the time factor. The High group exhibited significantly shorter durations of mechanical ventilation and ICU stay compared to the Low group. Serum PA levels were higher, and rectus femoris muscle atrophy rates were lower in the High group. Furthermore, for septic patients, high protein intake significantly reduced the 28-day mortality rate despite a small sample size (n = 34).

CONCLUSIONS

Our study indicates that increasing early protein intake to 1.5 g/kg.d may be safe and help improve the nutritional status and prognosis of critically ill patients.

TRIAL REGISTRATION

This study was registered with the Chinese Clinical Trial Registry (ChiCTR2000039997, https://www.chictr.org.cn/ ).

Bioimpedance-assessed muscle wasting and its relation to nutritional intake during the first week of ICU: a pre-planned secondary analysis of Nutriti Study

BACKGROUND

Muscle mass evaluation in ICU is crucial since its loss is related with long term complications, including physical impairment. However, quantifying muscle wasting with available bedside tools (ultrasound and bioimpedance analysis) must be more primarily understood. Bioimpedance analysis (BIA) provides estimates of muscle mass and phase angle (PA). The primary aim of this study was to evaluate muscle mass changes with bioimpedance analysis during the first 7 days after ICU admission. Secondary aims searched for correlations between muscular loss and caloric and protein debt.

METHODS

Patients with an expected ICU-stay ≥ 72 h and the need for artificial nutritional support were evaluated for study inclusion. BIA evaluation of muscle mass and phase angle were performed at ICU admission and after 7 days. Considering the difference between ideal caloric and protein targets, with adequate nutritional macronutrients delivered, we calculated the caloric and protein debt. We analyzed the potential correlation between caloric and protein debt and changes in muscle mass and phase angle.

RESULTS

72 patients from September 1st to October 30th, 2019 and from August 1st to October 30th, 2021 were included in the final statistical analysis. Median age was 68 [59-77] years, mainly men (72%) admitted due to respiratory failure (25%), and requiring invasive mechanical ventilation for 7 [4-10] days. Median ICU stay was 8 [6-12] days. Bioimpedance data at ICU admission and after 7 days showed that MM and PA resulted significantly reduced after 7 days of critically illness, 34.3 kg vs 30.6 kg (p < 0.0001) and 4.90° vs 4.35° (p = 0.0004) respectively. Mean muscle loss was 3.84 ± 6.7 kg, accounting for 8.4% [1-14] MM reduction. Correlation between caloric debt (r = 0.14, p = 0.13) and protein debt (r = 0.18, p = 0.13) with change in MM was absent. Similarly, no correlation was found between caloric debt (r = -0.057, p = 0.631) and protein debt (r = -0.095, p = 0.424) with changes in PA.

CONCLUSIONS

bioimpedance analysis demonstrated that muscle mass and phase angle were significantly lower after 7 days in ICU. The total amount of calories and proteins does not correlate with changes in muscle mass and phase angle.

High protein intake and nitrogen balance in patients receiving venovenous extracorporeal membrane oxygenation: A descriptive cohort study

BACKGROUND

This retrospective cohort study sought to describe the ability of high protein regimens to achieve nitrogen equilibrium in patients receiving venovenous extracorporeal membrane oxygenation (VV ECMO).

METHODS

Patients aged ≥18 years with a documented nitrogen balance study (NB) on VV ECMO between February 2018 and December 2021 were included. Studies with incomplete 24-h urine collections or changes in blood urea nitrogen ≥10 mg/dl were excluded. Data were summarized, correlation between first NB and potentially contributing variables was assessed with Kendall tau. Subanalysis described findings after stratifying for weight class (obese vs nonobese) and duration of VV ECMO at the time of NB.

RESULTS

A total of 68 NBs in 30 patients were included; 47% of the cohort had obesity. The number of NBs per patient was 2.2 ± 1.1, which were completed on a median of 31.5 (interquartile range: 16, 53.8) days receiving ECMO. Nitrogen equilibrium or positive balance was achieved in 72% of studies despite elevated nitrogen excretion. Patients received 87.9 ± 16.8% of prescribed protein on NB days for average intakes of 2.4 ± 0.4 g/kg of actual weight per day and 2.4 ± 0.5 g/kg of ideal weight per day in patients without and with obesity. Median NB in patients without obesity was -1.46 (-8.96, 2.98) g/day and -0.21 (-10.58, 4.04) g/day in patients with obesity. A difference in median NB after stratification for timing was observed (P = 0.029).

CONCLUSION

Nitrogen equilibrium can be achieved with high protein intake in adults receiving VV ECMO. NB monitoring is one tool to individualize protein prescriptions throughout the course of VV ECMO.

The effects of higher versus lower protein delivery in critically ill patients: an updated systematic review and meta-analysis of randomized controlled trials with trial sequential analysis

BACKGROUND

A recent large multicentre trial found no difference in clinical outcomes but identified a possibility of increased mortality rates in patients with acute kidney injury (AKI) receiving higher protein. These alarming findings highlighted the urgent need to conduct an updated systematic review and meta-analysis to inform clinical practice.

METHODS

From personal files, citation searching, and three databases searched up to 29-5-2023, we included randomized controlled trials (RCTs) of adult critically ill patients that compared higher vs lower protein delivery with similar energy delivery between groups and reported clinical and/or patient-centred outcomes. We conducted random-effect meta-analyses and subsequently trial sequential analyses (TSA) to control for type-1 and type-2 errors. The main subgroup analysis investigated studies with and without combined early physical rehabilitation intervention. A subgroup analysis of AKI vs no/not known AKI was also conducted.

RESULTS

Twenty-three RCTs (n = 3303) with protein delivery of 1.49 ± 0.48 vs 0.92 ± 0.30 g/kg/d were included. Higher protein delivery was not associated with overall mortality (risk ratio [RR]: 0.99, 95% confidence interval [CI] 0.88-1.11; I2 = 0%; 21 studies; low certainty) and other clinical outcomes. In 2 small studies, higher protein combined with early physical rehabilitation showed a trend towards improved self-reported quality-of-life physical function measurements at day-90 (standardized mean difference 0.40, 95% CI - 0.04 to 0.84; I2 = 30%). In the AKI subgroup, higher protein delivery significantly increased mortality (RR 1.42, 95% CI 1.11-1.82; I2 = 0%; 3 studies; confirmed by TSA with high certainty, and the number needed to harm is 7). Higher protein delivery also significantly increased serum urea (mean difference 2.31 mmol/L, 95% CI 1.64-2.97; I2 = 0%; 7 studies).

CONCLUSION

Higher, compared with lower protein delivery, does not appear to affect clinical outcomes in general critically ill patients but may increase mortality rates in patients with AKI. Further investigation of the combined early physical rehabilitation intervention in non-AKI patients is warranted.

PROSPERO ID

CRD42023441059.