How much underfeeding can the critically ill adult patient tolerate?

Critical illness leads to significant metabolic alterations that should be considered when providing nutritional support.Findings from key randomized controlled trials(RCTs)indicate that underfeeding(<70%of energy expenditure[EE])during the acute phase of critical illness(first 7 days of intensive care unit[ICU]admission)may not be harmful and could instead promote autophagy and prevent overfeeding in light of endogenous energy production.However,the optimal energy target during this period is unclear and full starvation is unlikely to be beneficial.There are limited data regarding the effects of prolonged underfeeding on clinical outcomes in critically ill patients,but recent studies show that oral food intake is suboptimal both in the ICU and following discharge to the acute care setting.It is hypothesized that provision of full nutrition(70–100%of EE)may be important in the recovery phase of critical illness(>7 days of ICU admission)for promoting recovery and rehabilitation;however,studies on nutritional intervention delivered from ICU admission through hospital discharge are needed.The aim of this review is to provide a narrative synthesis of the existing literature on metabolic alterations experienced during critical illness and the impact of underfeeding on clinical outcomes in the critically ill adult patient.

Implementation of enteral feeding protocol in an intensive care unit: Before-and-after study

AIM To determine the effects of implementing an enteral feeding protocol on the nutritional delivery and outcomes of intensive care patients.METHODS An uncontrolled, observational before-and-after study was performed in a tertiary mixed medical-surgical intensive care unit(ICU). In 2013, a nurse-driven enteral feeding protocol was developed and implemented in the ICU. Nutrition and outcome-related data from patients who were treated in the study unit from 2011-2012(the Before group) and 2014-2015(the After group) were obtained from a local electronic database, the national Population Registry and the hospital's Infection ControlService. Data from adult patients, readmissions excluded, who were treated for at least 7 d in the study unit were analysed. RESULTS In total, 231 patients were enrolled in the Before and 249 in the After group. The groups were comparable regarding demographics, patient profile, and severity of illness. Fewer patients were mechanically ventilated on admission in the After group(86.7% vs 93.1% in the Before group, P = 0.021). The prevalence of hospitalacquired infections, length of ICU stay and ICU, 30-and 60-d mortality did not differ between the groups. Patients in the After group had a lower 90-d(P = 0.026) and 120-d(P = 0.033) mortality. In the After group, enteral nutrition was prescribed less frequently(P = 0.039) on day 1 but significantly more frequently on all days from day 3. Implementation of the feeding protocol resulted in a higher cumulative amount of enterally(P = 0.049) and a lower cumulative amount of parenterally(P < 0.001) provided calories by day 7, with an overall reduction in caloric provision(P < 0.001). The prevalence of gastrointestinal symptoms was comparable in both groups, as was the frequency of prokinetic use. Underfeeding(total calories < 80% of caloric needs, independent of route) was observed in 59.4% of the study days Before vs 76.9% After(P < 0.001). Inclusion in the Before group, previous abdominal surgery, intraabdominal hypertension and the sum of gastrointestinal symptoms were found to be independent predictors of insufficient enteral nutrition.CONCLUSION The use of a nurse-driven feeding protocol improves the delivery of enteral nutrition in ICU patients without concomitant increases in gastrointestinal symptoms or intra-abdominal hypertension.

Key details of the duodenal-jejunal bypass in type 2 diabetes mellitus rats

AIM: To investigate which surgical techniques and perioperative regimens yielded the best survival rates for diabetic rats undergoing gastric bypass. METHODS: We performed Roux-en-Y gastric bypass with reserved gastric volume, a procedure in which gastrointestinal continuity was reestablished while excluding the entire duodenum and proximal jejunal loop. We observed the procedural success rate, long-term survival, and histopathological sequelae associated with a number of technical modifications. These included: use of anatomical markers to precisely identify Treitz's ligament; careful dissection along surgical planes; careful attention to the choice of regional transection sites; reconstruction using full-thickness anastomoses; use of a minimally invasive procedure with prohemostatic pretreatment and hemorrhage control; prevention of hypo-thermic damage; reduction in the length of the procedure; and accelerated surgical recovery using fast-track surgical modalities such as perioperative permissive underfeeding and goal-directed volume therapy. RESULTS: The series of modif ications we adopted reduced operation time from 110.02 ± 12.34 min to 78.39 ± 7.26 min (P < 0.01), and the procedural success rate increased from 43.3% (13/30) to 90% (18/20) (P < 0.01), with a long-term survival of 83.3% (15/18) (P < 0.01). CONCLUSION: Using a number of fast-track and damage control surgical techniques, we have successfully established a stable model of gastric bypass in diabetic rats.

The influence of metabolic imbalances and oxidative stress on the outcome of critically ill polytrauma patients: a review

The critically ill polytrauma patient presents with a series of associated pathophysiologies secondary to the traumatic injuries. The most important include systemic inflammatory response syndrome (SIRS), sepsis, oxidative stress (OS), metabolic disorders, and finally multiple organ dysfunction syndrome (MODS) and death. The poor outcome of these patients is related to the association of the aforementioned pathologies. The nutrition of the critically ill polytrauma patient is a distinct challenge because of the rapid changes in terms of energetic needs associated with hypermetabolism, sepsis, SIRS, and OS. Moreover, it has been proven that inadequate nutrition can prolong the time spent on a mechanical ventilator and the length of stay in an intensive care unit (ICU). A series of mathematical equations can predict the energy expenditure (EE), but they have disadvantages, such as the fact that they cannot predict the EE accurately in the case of patients with hypermetabolism. Indirect calorimetry (IC) is another method used for evaluating and monitoring the energy status of critically ill patients. In this update paper, we present a series of pathophysiological aspects associated with the metabolic disaster affecting the critically ill polytrauma patient. Furthermore, we present different non-invasive monitoring methods that could help the intensive care physician in the adequate management of this type of patient.