Association between serum lactate levels and enteral feeding intolerance in septic patients treated with vasopressors: a retrospective cohort study

When can we start early enteral nutrition safely in patients with shock on vasopressors?

Shock is a common critical illness characterized by microcirculatory disorders and insufficient tissue perfusion. Patients with shock and hemodynamic instability generally require vasopressors to maintain the target mean arterial pressure. Enteral nutrition (EN) is an important therapeutic intervention in critically ill patients and has unique benefits for intestinal recovery. However, the initiation of early EN in patients with shock receiving vasopressors remains controversial. Current guidelines make conservative and vague recommendations regarding early EN support in patients with shock. Increasing studies demonstrates that early EN delivery is safe and feasible in patients with shock receiving vasopressors; however, this evidence is based on observational studies. Changes in gastrointestinal blood flow vary by vasopressor and inotrope and are complex. The risk of gastrointestinal complications, especially the life-threatening complications of non-occlusive mesenteric ischemia and non-occlusive bowel necrosis, cannot be ignored in patients with shock during early EN support. It remains a therapeutic challenge in critical care nutrition therapy to determine the initiation time of EN in patients with shock receiving vasopressors and the safe threshold region for initiating EN with vasopressors. Therefore, the current review aimed to summarize the evidence on the optimal and safe timing of early EN initiation in patients with shock receiving vasopressors to improve clinical practice.

Clinical practice guidelines for nutritional assessment and monitoring of adult ICU patients in China

The Chinese Society of Critical Care Medicine (CSCCM) has developed clinical practice guidelines for nutrition assessment and monitoring for patients in adult intensive care units (ICUs) in China. This guideline focuses on nutrition evaluation and metabolic monitoring to achieve optimal and personalized nutrition therapy for critically ill patients. This guideline was developed by experts in critical care medicine and evidence-based medicine methodology and was developed after a thorough review of the system and a summary of relevant trials or studies published from 2000 to July 2023. A total of 18 recommendations were formed and consensus was reached through discussions and reviews by expert groups in critical care medicine, parenteral and enteral nutrition, and surgery. The recommendations are based on currently available evidence and cover several key fields, including screening and assessment, evaluation and assessment of enteral feeding intolerance, metabolic and nutritional measurement and monitoring during nutrition therapy, and organ function evaluation related to nutrition supply. Each question was analyzed according to the Population, Intervention, Comparison, and Outcome (PICO) principle. In addition, interpretations were provided for four questions that did not reach a consensus but may have potential clinical and research value. The plan is to update this nutrition assessment and monitoring guideline using the international guideline update method within 3-5 years.

Serum lactate normalization time associated with prolonged postoperative ileus after surgical management of the small bowel and/or mesenteric injuries

BACK GROUND

Determining the optimal timing of postoperative oral feeding in trauma patients who have undergone abdominal surgery with small bowel and/or mesenteric injuries is challenging. The aim of this study is to investigate serum lactate as a factor that can predict oral feeding tolerance and prolonged postoperative ileus (PPOI) in patients who underwent surgery for small bowel and/or mesenteric injury due to trauma.

METHODS

The single center retrospective observational study was conducted on 367 patients who underwent surgery for small bowel and/or mesenteric injury between January 2013 and July 2021. The patient group was divided into two groups based on whether the peak serum lactate was over 2mmol/L (18 mg/dL). In the group of lactate > 2mmol/L, it was divided into prolonged postoperative ileus (PPOI) groups and groups rather than PPOI.

RESULTS

Patients in the peak serum lactate > 2 group had tendency to use vasopressors, lower initial systolic blood pressure, larger number of packed red blood cells for 24 h, higher injury severity score, higher PPOI incidence, and a tendency for delayed oral intake tolerance. In peak serum lactate greater than 2 mmol/L group, the lactate normalization time (OR 1.699, p = 0.04), quantity of FFP transfusion for 24 h (OR 1.145, p = 0.012), and creatine kinase (OR 1.001, p = 0.023) were related to PPOI. The lactate normalization time had the highest correlation.

CONCLUSION

In patients undergoing surgical management for small bowel and/or mesenteric injury after trauma, serum lactate normalization time affects oral intake tolerance and prolongs postoperative ileus.

Enhanced exclusive enteral nutrition delivery during the first 7 days is associated with decreased 28-day mortality in critically ill patients with normal lactate level: a post hoc analysis of a multicenter randomized trial

BACKGROUND AND AIMS

Exclusive enteral nutrition (EN) is often observed during the first week of ICU admission because of the extra costs and safety considerations for early parenteral nutrition. This study aimed to assess the association between nutrition intake and 28-day mortality in critically ill patients receiving exclusive EN.

METHODS

This is a post hoc analysis of a cluster-randomized clinical trial that assesses the effect of implementing a feeding protocol on mortality in critically ill patients. Patients who stayed in the ICUs for at least 7 days and received exclusive EN were included in this analysis. Multivariable Cox hazard regression models and restricted cubic spline models were used to assess the relationship between the different doses of EN delivery and 28-day mortality. Subgroups with varying lactate levels at enrollment were additionally analyzed to address the potential confounding effect brought in by the presence of shock-related hypoperfusion.

RESULTS

Overall, 1322 patients were included in the analysis. The median (interquartile range) daily energy and protein delivery during the first week of enrollment were 14.6 (10.3-19.6) kcal/kg and 0.6 (0.4-0.8) g/kg, respectively. An increase of 5 kcal/kg energy delivery was associated with a significant reduction (approximately 14%) in 28-day mortality (adjusted hazard ratio [HR] = 0.865, 95% confidence interval [CI]: 0.768-0.974, P = 0.016). For protein intake, a 0.2 g/kg increase was associated with a similar mortality reduction with an adjusted HR of 0.868 (95% CI 0.770-0.979). However, the benefits associated with enhanced nutrition delivery could be observed in patients with lactate concentration ≤ 2 mmol/L (adjusted HR = 0.804 (95% CI 0.674-0.960) for energy delivery and adjusted HR = 0.804 (95% CI 0.672-0.962) for protein delivery, respectively), but not in those > 2 mmol/L.

CONCLUSIONS

During the first week of critical illness, enhanced nutrition delivery is associated with reduced mortality in critically ill patients receiving exclusive EN, only for those with lactate concentration ≤ 2 mmol/L.

TRIAL REGISTRATION

ISRCTN12233792, registered on November 24, 2017.

Different definitions of feeding intolerance and their associations with outcomes of critically ill adults receiving enteral nutrition: a systematic review and meta-analysis

BACKGROUND

A unified clinical definition of feeding intolerance (FI) is urged for better management of enteral nutrition (EN) in critically ill patients. We aimed to identify optimum clinical FI definitions based on reported evidence.

METHODS

We searched clinical studies comparing FI with non-FI with a clear definition, summarized the evidence by random-effect meta-analyses, and rated the certainty of evidence by the Grading of Recommendations Assessment, Development and Evaluation frameworks.

RESULTS

Five thousand five hundred twenty-five records were identified, of which 26 eligible studies enrolled 25,189 adult patients. Most patient-centered outcomes were associated with FI overall. Low to very low certainty evidence established FI defined as large gastric residual volume (GRV) ≥ 250 ± 50 mL combined with any other gastrointestinal symptoms (GIS) had a significant association with high mortalities in particular all-cause hospital mortality (odds ratio [OR] 1.90, 95% confidence interval [CI] 1.40-2.57), the incidence of pneumonia (OR 1.54, 95% CI 1.13-2.09) and prolonged length of hospital stay (mean difference 4.20, 95% CI 2.08-6.32), with a moderate hospital prevalence (41.49%, 95% CI 31.61-51.38%). 3-day enteral feeding (EF) delivered percentage < 80% had a moderate hospital prevalence (38.23%, 95% CI 24.88-51.58) but a marginally significant association with all-cause hospital mortality (OR 1.90, 95% CI 1.03-3.50).

CONCLUSIONS

In critically ill adult patients receiving EN, the large-GRV-centered GIS to define FI seemed to be superior to 3-day EF-insufficiency in terms of both close associations with all-cause hospital mortality and acceptable hospital prevalence (Registered PROSPERO: CRD42022326273).

TRIAL REGISTRATION

The protocol for this review and meta-analysis was registered with PROSPERO: CRD42022326273. Registered 10 May 2022.

Development of a prediction model for enteral feeding intolerance in intensive care unit patients: A prospective cohort study

BACKGROUND

Enteral nutrition (EN) is essential for critically ill patients. However, some patients will have enteral feeding intolerance (EFI) in the process of EN.

AIM

To develop a clinical prediction model to predict the risk of EFI in patients receiving EN in the intensive care unit.

METHODS

A prospective cohort study was performed. The enrolled patients’ basic information, medical status, nutritional support, and gastrointestinal (GI) symptoms were recorded. The baseline data and influencing factors were compared. Logistic regression analysis was used to establish the model, and the bootstrap resampling method was used to conduct internal validation.

RESULTS

The sample cohort included 203 patients, and 37.93% of the patients were diagnosed with EFI. After the final regression analysis, age, GI disease, early feeding, mechanical ventilation before EN started, and abnormal serum sodium were identified. In the internal validation, 500 bootstrap resample samples were performed, and the area under the curve was 0.70 (95%CI: 0.63-0.77).

CONCLUSION

This clinical prediction model can be applied to predict the risk of EFI.

Prevalence and risk factors of enteral nutrition intolerance in intensive care unit patients: a retrospective study

BACKGROUND

Feeding intolerance (FI) among intensive care unit (ICU) patients undergoing early continuous enteral nutrition (EN) is related to poor outcomes. This study aimed to explore the prevalence and risk factors of FI in ICU patients.

METHODS

We retrospectively enrolled 1057 patients who received early continuous EN via a nasogastric tube between January 2014 and August 2019. The prevalence of FI during the first 7 days of ICU stay was calculated, and the risk factors were investigated using multivariate logistic regression analysis.

RESULTS

The prevalence of FI during the first 7 days of ICU stay was 10.95%. FI occurred in 159 of 1057 (15.04%) patients on ICU day 2, 114 of 977 (11.67%) patients on ICU day 3, and 86 of 715 (12.03%) patients on ICU day 7. Mechanical ventilation (MV) (odds ratio [OR]: 1.928, 95% confidence interval [CI]: 1.064-3.493, P  = 0.03) was an independent risk factor for FI defined by a gastric residual volume (GRV) of 200 mL and/or vomiting, and acute renal failure (OR: 3.445, 95% CI: 1.115-10.707, P  = 0.032) was an independent risk factor of FI defined by a GRV of 500 mL and/or vomiting. Continuous renal replacement therapy (CRRT) was an independent predictor regardless of the FI defined by a GRV of 200 mL (OR: 2.064, 95% CI: 1.233-3.456, P  = 0.006) or 500 mL (OR: 6.199, 95% CI: 2.108-18.228, P  = 0.001) in the ICU patients.

CONCLUSIONS

FI occurs frequently in early ICU days, especially in patients receiving MV and CRRT. However, further investigation of a consensus definition of FI and risk factors is still warranted in future studies.

Development and validation of a predictive model for feeding intolerance in intensive care unit patients with sepsis

BACKGROUND

Feeding intolerance in patients with sepsis is associated with a lower enteral nutrition (EN) intake and worse clinical outcomes. The aim of this study was to develop and validate a predictive model for enteral feeding intolerance in the intensive care unit patients with sepsis.

METHODS

In this dual-center, retrospective, case-control study, a total of 195 intensive care unit patients with sepsis were enrolled from June 2018 to June 2020. Data of 124 patients for 27 clinical indicators from one hospital were used to train the model, and data from 71 patients from another hospital were used to assess the external predictive performance. The predictive models included logistic regression, naive Bayesian, random forest, gradient boosting tree, and deep learning (multilayer artificial neural network) models.

RESULTS

Eighty-six (44.1%) patients were diagnosed with enteral feeding intolerance. The deep learning model achieved the best performance, with areas under the receiver operating characteristic curve of 0.82 (95% confidence interval = 0.74-0.90) and 0.79 (95% confidence interval = 0.68-0.89) in the training and external sets, respectively. The deep learning model showed good calibration; based on the decision curve analysis, the model's clinical benefit was considered useful. Lower respiratory tract infection was the most important contributing factor, followed by peptide EN and shock.

CONCLUSIONS

The new prediction model based on deep learning can effectively predict enteral feeding intolerance in intensive care unit patients with sepsis. Simple clinical information such as infection site, nutrient type, and septic shock can be useful in stratifying a septic patient's risk of EN intolerance.