Gut Motility Issues in Critical Illness

Gastrointestinal Dysmotility in Critically Ill Patients: Bridging the Gap Between Evidence and Common Misconceptions

Disruption of normal gastrointestinal (GI) function in critical illness is linked to increased morbidity and mortality, and GI dysmotility is frequently observed in patients who are critically ill. Despite its high prevalence, the diagnosis and management of GI motility problems in the intensive care unit remain very challenging, given that critically ill patients often cannot verbalize symptoms and the general lack of understanding of underlying pathophysiology. Common clinical presentations of GI dysmotility issues among critically ill patients include: (1) high gastric residual volumes, acid reflux, and vomiting, (2) abdominal distention, and (3) diarrhea. In this review, we discuss the differential diagnosis for intensive care unit patients with symptoms and signs concerning GI motility issues. There are many myths and longstanding misconceptions about the diagnosis and management of GI dysmotility in critical illness. Here, we uncover these myths and discuss relevant evidence in each subject area, with the goal of re-conceptualizing GI motility disorders in critical care and providing evidence-based recommendations for clinical care.

Promotility agents for the treatment of ileus in adult surgical patients: A practice management guideline from the Eastern Association for the Surgery of Trauma

BACKGROUND

Ileus is a common challenge in adult surgical patients with estimated incidence to be 17% to 80%. The main mechanisms of the postoperative ileus pathophysiology are fluid overload, exogenous opioids, neurohormonal dysfunction, gastrointestinal stretch, and inflammation. Management includes addressing the underlying cause and supportive care. Multiple medical interventions have been proposed, but effectiveness is uncertain. A working group of the Eastern Association for the Surgery of Trauma aimed to evaluate the effectiveness of metoclopramide, erythromycin, and early enteral nutrition (EEN) on ileus in adult surgical patients and to develop recommendations applicable in a daily clinical practice.

METHODS

Literature search identified 45 articles appropriate for inclusion. The Grading of Recommendations Assessment, Development and Evaluation methodology was applied to evaluate the effect of metoclopramide, erythromycin, and EEN on the resolution of ileus in adult surgical patients based on selected outcomes: return of normal bowel function, attainment of enteral feeding goal, and hospital length of stay. The recommendations were made based on the results of a systematic review, a meta-analysis, and evaluation of levels of evidence.

RESULTS

The level of evidence for all PICOs was assessed as low. Neither metoclopramide nor erythromycin were effective in expediting the resolution of ileus. Analyses of 32 randomized controlled trials showed that EEN facilitates return of normal bowel function, achieving enteral nutrition goals, and reducing hospital length of stay.

CONCLUSION

In patients who have undergone abdominal surgery, we strongly recommend EEN to expedite resolution of Ileus, but we cannot recommend for or against the use of either metoclopramide or erythromycin to hasten the resolution of ileus in these patients.

LEVEL OF EVIDENCE

Type of Study Therapeutic, level II.

Prognostic capability of the Maximum Acute Gastrointestinal Injury Score and of caloric intake in patients requiring vasopressors: A multicenter prospective cohort study

PURPOSE

Our main objective was to use the Maximum Acute Gastrointestinal Injury Score (AGI_max) to evaluate the prognostic capability of gastrointestinal dysfunction (GID), on hospital mortality in patients on mechanical ventilation (MV) requiring vasopressors. A secondary goal was to analyze the relationship between AGI_max and vasopressor dosage with increasing caloric intake.

MATERIALS AND METHODS

Prospective multicenter cohort study in ten ICUs across Argentina. Consecutive adult patients on MV, requiring vasopressors and receiving enteral nutrition (EN) were included. AGI_max was identified (I-IV) using a modified AGI score. Comparisons of clinical and outcome variables were performed in 3 predetermined EN-groups: <10 kcal/kg/d, ≥10 to <20 kcal/kg/d, or ≥ 20 kcal/kg/d.

RESULTS

A total of 494 patients met all inclusion criteria. Forty-four percent of patients had severe AGI_max and 17% received <10 kcal/kg/day, indicating more severity and higher mortality. Notable independent predictors of mortality were AGI_max, vasopressors, and caloric intake. PN was the only factor which had an inverse relationship to mortality.

CONCLUSIONS

In this population, patients with AGI_max III-IV were significantly associated with lower caloric intake and greater hospital mortality, highlighting the importance of AGI as a prognostic tool. As PN was linked with lower mortality, it could be an option to explore in further studies.

Seven Deadly Sins of Nutrition Therapy in Critically Ill Patients

This article presents 7 nutrition steps that, if not followed by the clinical staff, may be metaphorically considered as "7 deadly sins" of nutrition therapy. In this review, we suggest approaches that must be avoided or accomplished to increase compliance with the "Ten Commandments" of good nutrition practice in the intensive care setting. Multiple aggressive and simultaneous sets of therapies are implemented in the intensive care setting, which include nutrition and metabolic support as important components in these therapies. "Sins" should be remembered as a mnemonic device for nutrition standard care in the intensive care unit; this incorporates nutrition adequacy and protocol adherence.

Optimal Time and Target for Evaluating Energy Delivery after Adjuvant Feeding with Small Bowel Enteral Nutrition in Critically Ill Patients at High Nutrition Risk

Small bowel enteral nutrition (SBEN) may improve nutrient delivery to critically ill patients intolerant of gastric enteral nutrition. However, the optimal time and target for evaluating SBEN efficacy are unknown. This retrospective cohort study investigates these parameters in 55 critically ill patients at high nutrition risk (modified NUTRIC score ≥ 5). Daily actual energy intake was recorded from 3 days before SBEN initiation until 7 days thereafter. The energy achievement rate (%) was calculated as follows: (actual energy intake/estimated energy requirement) × 100. The optimal time was determined from the day on which energy achievement rate reached >60% post-SBEN. Assessment results were as follows: median APACHE II score, 27; SOFA score, 10.0; modified NUTRIC score, 7; and median time point of SBEN initiation, ICU day 8. The feeding volume, energy and protein intake, and achievement rate (%) of energy and protein intake increased significantly after SBEN (p < 0.001). An energy achievement rate less than 65% 3 days after SBEN was significantly associated with increased mortality after adjusting for confounding factors (odds ratio, 4.97; 95% confidence interval, 1.44⁻17.07). SBEN improves energy delivery in critically ill patients who are still at high nutrition risk after 1 week of stomach enteral nutrition.

Constipation in critical care patients: both timing and duration matter

OBJECTIVE

Most of the studies have defined constipation as a period without stool after ICU admission. We aimed to test the impact of both duration and timing of infrequent defecation in critical care patients.

PATIENTS AND METHODS

We performed a prospective, bi-center, observational study. Patients were divided into three subgroups: 'not constipated', '3-5 days', and 'at least 6 days' (longest period without stool passage, respectively, shorter than 3 days, 3-5 days, and ≥6 days). Furthermore, 'early' constipated patients were defined as those for whom the longest time to stool passage occurred just after ICU admission, whereas for 'late' constipated patients the longest period without stool occurred later during ICU stay.

RESULTS

A total of 182 patients were included: the mean age was 67.2 years (54.4-78.9 years), 80 were women, and simplified acute physiology score II was 42 (34-52). In all, 42 (23.1%), 82 (45.1%), and 58 (31.8%) belonged to the nonconstipated, 3-5 days, or greater than or equal to 6 days subgroup of patients, respectively. Time spent under mechanical ventilation and ICU length of stay was longer in the greater than or equal to 6 days subgroups as compared with both other subgroups. ICU stay was longer in the 3-5 days subgroup as compared with the not constipated patients. Furthermore, the late patients of the greater than or equal to 6 days subgroups exhibited worse survival as compared with all other patients.

CONCLUSION

Both timing and duration of infrequent defecation seem to have an impact on critical care patient's outcome, and should therefore be included in the diagnostic criteria.

Critically ill patients and gut motility: Are we addressing it?

Gastrointestinal (GI) dysmotility is a common problem in the critically ill population. It can be a reflection and an early sign of patient deterioration or it can be an independent cause of morbidity and mortality. GI dysmotility can be divided for clinical purposes on upper GI dysmotility and lower GI dysmotility. Upper GI dysmotility manifests by nausea, feeding intolerance and vomiting; its implications include aspiration into the airway of abdominal contents and underfeeding. Several strategies to prevent and treat this condition can be tried and they include prokinetics and post-pyloric feeds. It is important to note that upper GI dysmotility should be treated only when there are clinical signs of intolerance (nausea, vomiting) and not based on measurement of gastric residual volumes. Lower GI dysmotility manifests throughout the spectrum of ileus and diarrhea. Ileus can present in the small bowel and the large bowel as well. In both scenarios the initial treatment is correction of electrolyte abnormalities, avoiding drugs that can decrease motility and patient mobilization. When this fails, in the case of small bowel ileus, lactulose and polyethylene glycol solutions can be useful. In the case of colonic pseudo obstruction, neostigmine, endoscopic decompression and cecostomy can be tried when the situation reaches the risk of rupture. Diarrhea is also a common manifestation of GI dysmotility and the most important step is to differentiate between infectious sources and non-infectious sources.