Gastric emptying in mechanically ventilated critically ill patients: effect of neuromuscular blocking agent

Enteral feeding tolerance during pharmacologic neuromuscular blockade

A common misperception is that critically ill patients who receive paralytic therapy will not tolerate enteral nutrition. As a result, some clinicians empirically withhold enteral feedings for critically ill patients who receive neuromuscular blocker pharmacotherapy (NMB). The intent of this review is to examine the evidence regarding enteral feeding tolerance for critically ill patients given NMB. Studies evaluating enteral feeding during paralytic therapy are provided and critiqued. Evidence examining enteral feeding tolerance during NMB is limited. Enteral feeding intolerance is more likely attributable to the underlying illnesses and concurrent opioid analgesia, sedation, and vasopressor therapies. Most critically ill patients can be successfully fed during NMB. Prokinetic pharmacotherapy may be warranted in some patients.

Enteral Nutrition Safety and Outcomes of Patients with COVID-19 on Continuous Infusion of Neuromuscular Blockers: A Retrospective Study

Background

Intravenous infusions of neuromuscular blocking agents (NMBAs) and prone positioning are recommended for acute respiratory distress syndrome (ARDS) due to COVID-19. The safety of enteral nutrition (EN) during these treatments is unclear. This study assessed EN tolerance and safety during NMBA infusion in proned and nonproned patients with ARDS due to COVID-19.

Methods

This retrospective study evaluated patients who were admitted to a tertiary-care ICU between March and December 2020, had ARDS due to COVID-19, and received NMBA infusion. We assessed their EN data, gastrointestinal events, and clinical outcomes. The primary outcome was gastrointestinal intolerance, defined as a gastric residual volume (GRV) ≥500 ml or 200-500 ml with vomiting. We compared proned and nonproned patients.

Results

We studied 181 patients (mean age 61.2 ± 13.7 years, males 71.1%, and median body mass index 31.4 kg/m2). Most (63.5%) patients were proned, and 94.3% received EN in the first 48 hours of NMBA infusion at a median dose <10 kcal/kg/day. GRV was mostly below 100 ml. Gastrointestinal intolerance occurred in 6.1% of patients during NMBA infusion and 10.5% after NMBA discontinuation (similar rates in proned and nonproned patients). Patients who had gastrointestinal intolerance during NMBA infusion had a higher hospital mortality (90.9% versus 60.0%; p=0.05) and longer mechanical ventilation duration and ICU and hospital stays compared with those who did not.

Conclusion

In COVID-19 patients on NMBA infusion for ARDS, EN was provided early at low doses for most patients, and gastrointestinal intolerance was uncommon in proned and nonproned patients, occurred at a higher rate after discontinuing NMBAs and was associated with worse outcomes. Our study suggests that EN was tolerated and safe in this patient population.

Gastric feeding intolerance in critically ill patients during sustained pharmacologic neuromuscular blockade

BACKGROUND

The purpose of this study was to assess gastric feeding intolerance for critically ill patients who received sustained neuromuscular blocker (NMB) pharmacotherapy.

METHODS

Adult patients (>17 years of age) admitted to the trauma intensive care unit who received continuous intravenous NMB pharmacotherapy (rocuronium, cisatracurium, vecuronium, or pancuronium) for ≥48 h during continuous intragastric enteral nutrition (EN) were retrospectively evaluated. Gastric feeding intolerance was defined by initiation of a prokinetic agent (metoclopramide, erythromycin, or both) for an elevated gastric residual volume (GRV) >300 ml and with distention of the abdomen by physical examination, observation of regurgitation or emesis, temporary discontinuation of EN with low intermittent gastric suctioning, or initiation of parenteral nutrition (PN). Patients were evaluated for gastric feeding intolerance for the first 3 days of combined EN and NMB pharmacotherapy. A P value < 0.05 was considered statistically significant.

RESULTS

Ten patients of the 47 patients (21%) were intolerant to EN during NMB pharmacotherapy. No statistically or clinically relevant differences in patient characteristics were found between patients who tolerated EN vs those who experienced gastric feeding intolerance, except for a higher median maximum GRV of 125 ml (28, 200) vs 300 (250, 400) ml, respectively (P < 0.001). Five patients responded to prokinetic therapy and five required PN.

CONCLUSION

Most patients tolerated intragastric EN during sustained NMB pharmacotherapy. Presence of NMB pharmacotherapy is not an absolute contraindication for EN.

Enteral nutrition tolerance in patients receiving neuromuscular blockade

BACKGROUND

Nutrition support is an essential part of critical care medicine. It is commonly accepted that for the critically ill patient, enteral nutrition (EN) is favored. For the patient who receives neuromuscular blockades, EN may be held, or initiation delayed, because of concerns for EN intolerance. We hypothesized there would be no difference in EN tolerance between groups receiving cisatracurium while receiving EN compared with those not receiving cisatracurium.

METHODS

This was a retrospective study that included 459 patients from a combined medical and surgical intensive care unit. There were 44 patients who received cisatracurium with EN and 415 who received EN alone. Data collected included gastric residual volume (GRV) and emesis occurrences, new-onset abdominal pain, new or worsening abdominal distention, and bowel ischemia.

RESULTS

There were more patients with new or worsening abdominal distention in the group receiving cisatracurium (31.82% vs 14.94%; P < 0.01) as well as occurrences of GRV > 300 ml (P < 0.01). There was no statistically significant difference between the groups regarding emesis, new-onset abdominal pain, or bowel ischemia.

CONCLUSION

Our findings suggest that it is acceptable to provide patients with EN who are receiving cisatracurium.

Molecular mechanisms of muscular and non-muscular actions of neuromuscular blocking agents in critical illness: a narrative review

Despite frequent use of neuromuscular blocking agents in critical illness, changes in neuromuscular transmission with critical illness are not well appreciated. Recent studies have provided greater insights into the molecular mechanisms for beneficial muscular effects and non-muscular anti-inflammatory properties of neuromuscular blocking agents. This narrative review summarises the normal structure and function of the neuromuscular junction and its transformation to a 'denervation-like' state in critical illness, the underlying cause of aberrant neuromuscular blocking agent pharmacology. We also address the important favourable and adverse consequences and molecular bases for these consequences during neuromuscular blocking agent use in critical illness. This review, therefore, provides an enhanced understanding of clinical therapeutic effects and novel pathways for the salutary and aberrant effects of neuromuscular blocking agents when used during acquired pathologic states of critical illness.

Diet-related complications according to the timing of enteral nutrition support in patients who recovered from out-of-hospital cardiac arrest: a propensity score matched analysis

Background: A proper nutritional plan for resuscitated patients is important in intensive care; however, specific nutritional guidelines have not yet been established. This study aimed to determine the incidence of diet-related complications that were affected by the timing of enteral nutrition in resuscitated patients after cardiac arrest.Methods: This retrospective and 1:1 propensity score matching study involved patients who recovered after nontraumatic, out-of-hospital cardiac arrest at a tertiary hospital. Patients were divided into an early enteral nutrition support (ENS) group and a delayed enteral nutrition support (DNS) group according to the nutritional support time within 48 hours after admission. The incidence of major clinical complications was compared between the groups.Results: A total of 46 patients (ENS, 23; DNS, 23) were enrolled in the study. There were no differences in body mass index, comorbidity, and time of cardiopulmonary resuscitation between the two groups. There were 9 patients (ENS: 4, DNS: 5) with aspiration pneumonia; 4 patients (ENS: 2, DNS: 2) with regurgitation; one patient (ENS: 0, DNS: 1) with ileus; 21 patients (ENS: 10, DNS: 11) with fever; 13 patients (ENS: 8, DNS: 5) with hypoglycemia; and 20 patients (ENS: 11, DNS: 9) with hyperglycemia. The relative risk of each complication during post-resuscitation care was no different between groups.Conclusions: There was a similar incidence of diet-related complications during post cardiac arrest care according to the timing of enteral nutrition.

When is enteral nutrition indicated?

Enteral nutrition (EN) is a vital component of nutrition around the world. EN allows for delivery of nutrients to those who cannot maintain adequate nutrition by oral intake alone. Common questions regarding EN are when to initiate and in what scenarios it is safe. The answers to these questions are often complex and require an evidence-based approach. The Board of Directors of the American Society for Parenteral and Enteral Nutrition (ASPEN) established an Enteral Nutrition Committtee to address the important questions surrounding the indications for EN. Consensus recommendations were established based on eight extremely clinically relevant questions regarding EN indications as deemed by the Enteral Nutrition Committee. These consensus recommendations may act as a guide for clinicians and stakeholders on difficult questions pertaining to indications for EN. This paper was approved by the ASPEN Board of Directors.

Overcoming challenges to enteral nutrition delivery in critical care

PURPOSE OF REVIEW

Existing data and all ICU nutrition guidelines emphasize enteral nutrition (EN) represents a primary therapy leading to both nutritional and non-nutritional benefits. Unfortunately, iatrogenic malnutrition and underfeeding is virtually ubiquitous in ICUs worldwide for prolonged periods post-ICU admission. Overcoming essential challenges to EN delivery requires addressing a range of real, and frequently propagated myths regarding EN delivery.

RECENT FINDINGS

Key recent data addresses perceived challenges to EN including: Adequately resuscitated patients on vasopressors can and likely should receive trophic early EN and this was recently associated with reduced mortality; Patients paralyzed with neuromuscular blocking agents can and should receive early EN as this was recently associated with reduced mortality/hospital length of stay; Proned patients can safely receive EN; All ICU nutrition delivery, including EN, should be objectively guided by indirect calorimetry (IC) measures. This is now possible with the new availability of a next-generation IC device.

SUMMARY

It is the essential implementation of this new evidence occurs to overcome real and perceived EN challenges. This data should lead to increased standardization/protocolization of ICU nutrition therapy to ensure personalized nutrition care delivering the right nutrition dose, in the right patient, at the right time to optimize clinical outcome.

The efficacy and safety of prokinetics in critically ill adults receiving gastric feeding tubes: A systematic review and meta-analysis

Background

Intolerance to gastric feeding tubes is common among critically ill adults and may increase morbidity. Administration of prokinetics in the ICU is common. However, the efficacy and safety of prokinetics are unclear in critically ill adults with gastric feeding tubes. We conducted a systematic review to determine the efficacy and safety of prokinetics for improving gastric feeding tube tolerance in critically ill adults.

Methods

Randomized controlled trials (RCTs) were identified by systematically searching the Medline, Cochrane and Embase databases. Two independent reviewers extracted the relevant data and assessed the quality of the studies. We calculated pooled relative risks (RRs) for dichotomous outcomes and the mean differences (MDs) for continuous outcomes with the corresponding 95% confidence intervals (CIs). We assessed the risk of bias using the Cochrane risk-of-bias tool and used the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) methodology to rate the quality of the evidence.

Results

Fifteen RCTs met the inclusion criteria. A total of 10 RCTs involving 846 participants were eligible for the quantitative analysis. Most studies (10 of 13, 76.92%) showed that prokinetics had beneficial effects on feeding intolerance in critically ill adults. In critically ill adults receiving gastric feeding, prokinetic agents may reduce the ICU length of stay (MD -2.03, 95% CI -3.96, -0.10; P = 0.04; low certainty) and the hospital length of stay (MD -3.21, 95% CI -5.35, -1.06; P = 0.003; low certainty). However, prokinetics failed to improve the outcomes of reported adverse events and all-cause mortality.

Conclusion

As a class of drugs, prokinetics may improve tolerance to gastric feeding to some extent in critically ill adults. However, the certainty of the evidence suggesting that prokinetics reduce the ICU or hospital length of stay is low. Prokinetics did not significantly decrease the risks of reported adverse events or all-cause mortality among critically ill adults.

Enteral Nutrition Safety With Advanced Treatments: Extracorporeal Membrane Oxygenation, Prone Positioning, and Infusion of Neuromuscular Blockers

This review aims at assessing the safety and efficacy of enteral nutrition in critically ill patients receiving extracorporeal membrane oxygenation, prone positioning, and infusion of neuromuscular blockers. Existing data from randomized controlled trials demonstrate the survival benefit of early enteral nutrition in critically ill patients. Observational data have demonstrated that enteral nutrition in patients receiving extracorporeal membrane oxygenation, prone positioning, and infusion of neuromuscular blockers is generally safe. However, these patients are at increased risk for gastrointestinal complications from enteral nutrition because of critical illness-induced gastrointestinal dysfunction; associated shock; the concomitant use of vasopressor agents, sedatives, and narcotics; possibly mesenteric circulatory compromise; and regurgitation associated with prone positioning. Therefore, early enteral nutrition is generally recommended in these patients in the absence of severe gastrointestinal dysfunction or shock. To reduce the complications, early nutrition should be advanced gradually (trophic feeding or permissive underfeeding), the bed should be tilted to a maximum of 30°, and concentrated nutritional formulae and the use of prokinetics may be considered to treat enteral feeding intolerance. Physicians should be vigilant about monitoring for early signs of acute mesenteric ischemia, which should lead to holding enteral feeding. Parenteral nutrition may be utilized in patients who cannot receive enteral nutrition or are unable to reach their nutrition goals by the end of the first week.

Early Enteral Nutrition in Patients Undergoing Sustained Neuromuscular Blockade: A Propensity-Matched Analysis Using a Nationwide Inpatient Database

OBJECTIVES

Whether enteral nutrition should be postponed in patients undergoing sustained treatment with neuromuscular blocking agents remains unclear. We evaluated the association between enteral nutrition initiated within 2 days of sustained neuromuscular blocking agent treatment and in-hospital mortality.

DESIGN

Retrospective administrative database study from July 2010 to March 2016.

SETTING

More than 1,200 acute care hospitals covering approximately 90% of all tertiary-care emergency hospitals in Japan.

PATIENTS

Mechanically ventilated patients, who had undergone sustained treatment with neuromuscular blocking agents in an ICU, were retrospectively reviewed. We defined patients who received sustained treatment with neuromuscular blocking agents as those who received either rocuronium at greater than or equal to 250 mg/d or vecuronium at greater than or equal to 50 mg/d for at least 2 consecutive days.

INTERVENTIONS

Enteral nutrition started within 2 days from the initiation of neuromuscular blocking agents (defined as early enteral nutrition).

MEASUREMENTS AND MAIN RESULTS

We identified 2,340 eligible patients during the 69-month study period. Of these, 378 patients (16%) had received early enteral nutrition. One-to-three propensity score matching created 374-1,122 pairs. The in-hospital mortality rate was significantly lower in the early than late enteral nutrition group (risk difference, -6.3%; 95% CI, -11.7% to -0.9%). There was no significant difference in the rate of hospital pneumonia between the two groups (risk difference, 2.8%; 95% CI, -2.7% to 8.3%). Length of hospital stay among survivors was significantly shorter in the early compared with the late enteral nutrition group (risk difference, -11.4 d; 95% CI, -19.1 to -3.7 d). There was no significant difference between the two groups in length of ICU stay or length of mechanical ventilation among survivors.

CONCLUSIONS

According to this retrospective database study, early enteral nutrition may be associated with lower in-hospital mortality with no increase in-hospital pneumonia in patients undergoing sustained treatment with neuromuscular blocking agents.

Clinical Practice Guidelines for Sustained Neuromuscular Blockade in the Adult Critically Ill Patient

OBJECTIVE

To update the 2002 version of "Clinical practice guidelines for sustained neuromuscular blockade in the adult critically ill patient."

DESIGN

A Task Force comprising 17 members of the Society of Critical Medicine with particular expertise in the use of neuromuscular-blocking agents; a Grading of Recommendations Assessment, Development, and Evaluation expert; and a medical writer met via teleconference and three face-to-face meetings and communicated via e-mail to examine the evidence and develop these practice guidelines. Annually, all members completed conflict of interest statements; no conflicts were identified. This activity was funded by the Society for Critical Care Medicine, and no industry support was provided.

METHODS

Using the Grading of Recommendations Assessment, Development, and Evaluation system, the Grading of Recommendations Assessment, Development, and Evaluation expert on the Task Force created profiles for the evidence related to six of the 21 questions and assigned quality-of-evidence scores to these and the additional 15 questions for which insufficient evidence was available to create a profile. Task Force members reviewed this material and all available evidence and provided recommendations, suggestions, or good practice statements for these 21 questions.

RESULTS

The Task Force developed a single strong recommendation: we recommend scheduled eye care that includes lubricating drops or gel and eyelid closure for patients receiving continuous infusions of neuromuscular-blocking agents. The Task Force developed 10 weak recommendations. 1) We suggest that a neuromuscular-blocking agent be administered by continuous intravenous infusion early in the course of acute respiratory distress syndrome for patients with a PaO2/FIO2 less than 150. 2) We suggest against the routine administration of an neuromuscular-blocking agents to mechanically ventilated patients with status asthmaticus. 3) We suggest a trial of a neuromuscular-blocking agents in life-threatening situations associated with profound hypoxemia, respiratory acidosis, or hemodynamic compromise. 4) We suggest that neuromuscular-blocking agents may be used to manage overt shivering in therapeutic hypothermia. 5) We suggest that peripheral nerve stimulation with train-of-four monitoring may be a useful tool for monitoring the depth of neuromuscular blockade but only if it is incorporated into a more inclusive assessment of the patient that includes clinical assessment. 6) We suggest against the use of peripheral nerve stimulation with train of four alone for monitoring the depth of neuromuscular blockade in patients receiving continuous infusion of neuromuscular-blocking agents. 7) We suggest that patients receiving a continuous infusion of neuromuscular-blocking agent receive a structured physiotherapy regimen. 8) We suggest that clinicians target a blood glucose level of less than 180 mg/dL in patients receiving neuromuscular-blocking agents. 9) We suggest that clinicians not use actual body weight and instead use a consistent weight (ideal body weight or adjusted body weight) when calculating neuromuscular-blocking agents doses for obese patients. 10) We suggest that neuromuscular-blocking agents be discontinued at the end of life or when life support is withdrawn. In situations in which evidence was lacking or insufficient and the study results were equivocal or optimal clinical practice varies, the Task Force made no recommendations for nine of the topics. 1) We make no recommendation as to whether neuromuscular blockade is beneficial or harmful when used in patients with acute brain injury and raised intracranial pressure. 2) We make no recommendation on the routine use of neuromuscular-blocking agents for patients undergoing therapeutic hypothermia following cardiac arrest. 3) We make no recommendation on the use of peripheral nerve stimulation to monitor degree of block in patients undergoing therapeutic hypothermia. 4) We make no recommendation on the use of neuromuscular blockade to improve the accuracy of intravascular-volume assessment in mechanically ventilated patients. 5) We make no recommendation concerning the use of electroencephalogram-derived parameters as a measure of sedation during continuous administration of neuromuscular-blocking agents. 6) We make no recommendation regarding nutritional requirements specific to patients receiving infusions of neuromuscular-blocking agents. 7) We make no recommendation concerning the use of one measure of consistent weight over another when calculating neuromuscular-blocking agent doses in obese patients. 8) We make no recommendation on the use of neuromuscular-blocking agents in pregnant patients. 9) We make no recommendation on which muscle group should be monitored in patients with myasthenia gravis receiving neuromuscular-blocking agents. Finally, in situations in which evidence was lacking or insufficient but expert consensus was unanimous, the Task Force developed six good practice statements. 1) If peripheral nerve stimulation is used, optimal clinical practice suggests that it should be done in conjunction with assessment of other clinical findings (e.g., triggering of the ventilator and degree of shivering) to assess the degree of neuromuscular blockade in patients undergoing therapeutic hypothermia. 2) Optimal clinical practice suggests that a protocol should include guidance on neuromuscular-blocking agent administration in patients undergoing therapeutic hypothermia. 3) Optimal clinical practice suggests that analgesic and sedative drugs should be used prior to and during neuromuscular blockade, with the goal of achieving deep sedation. 4) Optimal clinical practice suggests that clinicians at the bedside implement measure to attenuate the risk of unintended extubation in patients receiving neuromuscular-blocking agents. 5) Optimal clinical practice suggests that a reduced dose of an neuromuscular-blocking agent be used for patients with myasthenia gravis and that the dose should be based on peripheral nerve stimulation with train-of-four monitoring. 6) Optimal clinical practice suggests that neuromuscular-blocking agents be discontinued prior to the clinical determination of brain death.

Early enteral nutrition in critically ill patients: ESICM clinical practice guidelines

Purpose

To provide evidence-based guidelines for early enteral nutrition (EEN) during critical illness.

Methods

We aimed to compare EEN vs. early parenteral nutrition (PN) and vs. delayed EN. We defined “early” EN as EN started within 48 h independent of type or amount. We listed, a priori, conditions in which EN is often delayed, and performed systematic reviews in 24 such subtopics. If sufficient evidence was available, we performed meta-analyses; if not, we qualitatively summarized the evidence and based our recommendations on expert opinion. We used the GRADE approach for guideline development. The final recommendations were compiled via Delphi rounds.

Results

We formulated 17 recommendations favouring initiation of EEN and seven recommendations favouring delaying EN. We performed five meta-analyses: in unselected critically ill patients, and specifically in traumatic brain injury, severe acute pancreatitis, gastrointestinal (GI) surgery and abdominal trauma. EEN reduced infectious complications in unselected critically ill patients, in patients with severe acute pancreatitis, and after GI surgery. We did not detect any evidence of superiority for early PN or delayed EN over EEN. All recommendations are weak because of the low quality of evidence, with several based only on expert opinion.

Conclusions

We suggest using EEN in the majority of critically ill under certain precautions. In the absence of evidence, we suggest delaying EN in critically ill patients with uncontrolled shock, uncontrolled hypoxaemia and acidosis, uncontrolled upper GI bleeding, gastric aspirate >500 ml/6 h, bowel ischaemia, bowel obstruction, abdominal compartment syndrome, and high-output fistula without distal feeding access.

Electronic supplementary material

The online version of this article (doi:10.1007/s00134-016-4665-0) contains supplementary material, which is available to authorized users.

Lower versus higher dose of enteral caloric intake in adult critically ill patients: a systematic review and meta-analysis

BACKGROUND

There is conflicting evidence about the relationship between the dose of enteral caloric intake and survival in critically ill patients. The objective of this systematic review and meta-analysis is to compare the effect of lower versus higher dose of enteral caloric intake in adult critically ill patients on outcome.

METHODS

We reviewed MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and Scopus from inception through November 2015. We included randomized and quasi-randomized studies in which there was a significant difference in the caloric intake in adult critically ill patients, including trials in which caloric restriction was the primary intervention (caloric restriction trials) and those with other interventions (non-caloric restriction trials). Two reviewers independently extracted data on study characteristics, caloric intake, and outcomes with hospital mortality being the primary outcome.

RESULTS

Twenty-one trials mostly with moderate bias risk were included (2365 patients in the lower caloric intake group and 2352 patients in the higher caloric group). Lower compared with higher caloric intake was not associated with difference in hospital mortality (risk ratio (RR) 0.953; 95 % confidence interval (CI) 0.838-1.083), ICU mortality (RR 0.885; 95 % CI 0.751-1.042), total nosocomial infections (RR 0.982; 95 % CI 0.878-1.077), mechanical ventilation duration, or length of ICU or hospital stay. Blood stream infections (11 trials; RR 0.718; 95 % CI 0.519-0.994) and incident renal replacement therapy (five trials; RR 0.711; 95 % CI 0.545-0.928) were lower with lower caloric intake. The associations between lower compared with higher caloric intake and primary and secondary outcomes, including pneumonia, were not different between caloric restriction and non-caloric restriction trials, except for the hospital stay which was longer with lower caloric intake in the caloric restriction trials.

CONCLUSIONS

We found no association between the dose of caloric intake in adult critically ill patients and hospital mortality. Lower caloric intake was associated with lower risk of blood stream infections and incident renal replacement therapy (five trials only). The heterogeneity in the design, feeding route and timing and caloric dose among the included trials could limit our interpretation. Further studies are needed to clarify our findings.

A Double-Blind Randomized Clinical Trial Comparing the Effect of Neostigmine and Metoclopramide on Gastric Residual Volume of Mechanically Ventilated ICU Patients

BACKGROUND

In critically ill patients, enteral feeding through the nasogastric tube is the method of choice for nutritional support. Gastrointestinal feeding intolerance and disturbed gastric emptying are common challenges in these patients. The aim of this study was to compare the effect of Neostigmine and Metoclopramide on gastric residual volume (GRV) in mechanically ventilated ICU patients.

METHODS

In a double blind, randomized clinical trial, a total of 60 mechanically ventilated ICU patients with GRV >120 mL (3 hours after the last gavage), were randomly assigned into two groups A and B. At baseline and 6 hours later, patients in group A and B received intravenous infusion of neostigmine in a dose of 2.5 mg and metoclopramide in a dose of 10 mg in 100 ml of normal saline, within 30 minutes. Patients' gastric residual volumes were evaluated before the beginning of the intervention, and 3, 6, 9 and 12 hours after the intervention.

RESULTS

After adjusting of other variables (Sex, BMI and ICU stay period) generalized estimating equation (GEE) model revealed that neostigmine treatment increased odds of GRV improvement compare to metoclopramide group (Estimate 1.291, OR= 0.3.64, 95% CI 1.07-12.34). However there is a statistically significant time trend (within-subject differences or time effect) regardless of treatment groups (P<0.001). The median time from intervention to GRV improvement was 6 hours (95% CI 3.75-8.25) and 9 hours (95% CI 7.38-10.17) in neostigmine and metoclopramide groups, respectively. This difference was statistically significant (P<0.05).

CONCLUSION

It seems that neostigmine is more effective than metoclopramide in reducing GRV and improving gastric emptying in mechanically ventilated ICU patients without significant complication and this protocol may be effective on the tolerance of enteral feeding in ICU patients. Further well-designed randomized clinical trials are needed.

Gastric Dysmotility in Critically Ill Children: Pathophysiology, Diagnosis, and Management

OBJECTIVE

We aimed to review gastric dysmotility in critically ill children: 1) its pathophysiology, with a focus on critical care diseases and therapies that affect gastric motility, 2) diagnostic methodologies, and 3) current and future potential therapies.

DATA SOURCES

Eligible studies were identified from PubMed and MEDLINE.

STUDY SELECTION

Literature search included the following key terms: "gastric emptying," "gastric motility/dysmotility," "gastrointestinal motility/dysmotility," "nutrition intolerance," and "gastric residual volume."

DATA EXTRACTION

Studies since 1995 were extracted and reviewed for inclusion by the authors related to the physiology, pathophysiology, diagnostic methodologies, and available therapies for gastric emptying.

DATA SYNTHESIS

Delayed gastric emptying, a common presentation of gastric dysmotility, is present in up to 50% of critically ill children. It is associated with the potential for aspiration, ventilator-associated pneumonia, and inadequate delivery of enteral nutrition and may affect the efficacy of enteral medications, all of which may be result in poor patient outcomes. Gastric motility is affected by critical illness and its associated therapies. Currently available diagnostic tools to identify gastric emptying at the bedside have not been systematically studied and applied in this cohort. Gastric residual volume measurement, used as an indirect marker of delayed gastric emptying in PICUs around the world, may be inaccurate.

CONCLUSIONS

Gastric dysmotility is common in critically ill children and impacts patient safety and outcomes. However, it is poorly understood, inadequately defined, and current therapies are limited and based on scant evidence. Understanding gastric motility and developing accurate bedside measures and novel therapies for gastric emptying are highly desirable and need to be further investigated.

Measurement of gastric emptying in the critically ill

BACKGROUND & AIMS

Enteral nutrition is important in critically ill patients and is usually administered via a nasogastric tube. As gastric emptying is frequently delayed, and this compromises the delivery of nutrient, it is important that the emptying rate can be quantified.

METHODS

A comprehensive search of MEDLINE/PubMed, of English articles, from inception to 1 July 2014. References of included manuscripts were also examined for additional studies.

RESULTS

A number of methods are available to measure gastric emptying and these broadly can be categorised as direct- or indirect-test and surrogate assessments. Direct tests necessitate visualisation of the stomach contents during emptying and are unaffected by liver or kidney metabolism. The most frequently used direct modality is scintigraphy, which remains the 'gold standard'. Indirect tests use a marker that is absorbed in the proximal small intestine, so that measurements of the marker, or its metabolite measured in plasma or breath, correlates with gastric emptying. These tests include drug and carbohydrate absorption and isotope breath tests. Gastric residual volumes (GRVs) are used frequently to quantify gastric emptying during nasogastric feeding, but these measurements may be inaccurate and should be regarded as a surrogate measurement. While the inherent limitations of GRVs make them less suitable for research purposes they are often the only technique that is available for clinicians at the bedside.

CONCLUSIONS

Each of the available techniques has its strength and limitations. Accordingly, the choice of gastric emptying test is dictated by the particular requirement(s) and expertise of the investigator or clinician.

Nutrition Management of the Critically Ill Pediatric Patient

Provision of optimal nutritional support to children in the pediatric intensive care unit (PICU) is important for optimizing nutritional management, yet challenging because of a variety of factors. Previous nutritional status, degree of malnutrition, and variability in disease states differ significantly among PICU patients. Although there are numerous benefits for enteral nutrition (EN) in critically ill children, obstacles exist within the PICU that prevent the initiation and delivery of appropriate EN and parenteral nutritional (PN) support. Evidence-based nutrition care guidelines have been established to promote optimal nutrition support practice in PICU patients, including identification of those at greatest nutritional risk, initiating EN or PN in a timely manner, and providing EN as the preferred nutrition support modality for children with a functioning gastrointestinal tract. Strategies can be implemented to minimize avoidable delays or interruptions to the optimal delivery of PN and EN, including establishing nutrition support guidelines to promote consistency in practice, promoting clear and consistent communication among the PICU team via direct communication, unit rounds, and the medical record. The education of frontline PICU staff by trained professionals such as pediatric registered dietitians board certified in pediatric nutrition or nutrition support practice can also help promote improved nutritional support practice and outcomes. Specific strategies to optimize nutritional support and EN initiation and delivery at the author’s institution are also presented.

Identifying the factors that influence energy deficit in the adult intensive care unit: a mixed linear model analysis

BACKGROUND

Critically ill patients frequently receive inadequate nutrition support as a result of under- or overfeeding. Malnutrition in intensive care unit (ICU) patients is associated with increased morbidity and mortality. The present study aimed to identify the significant factors that influence energy deficit in the ICU.

METHODS

ICU patients with a length of stay of ≥3 days were studied for 30 days over two consecutive years at a large university teaching hospital. Fifty-six Patients were studied, with a total of 530 records of feeding days. Information was collected for: day when feed initiated, age, gender, length of stay, Acute Physiological and Chronic Health Evaluation score (APACHE II), fed within 24 h, speciality, type of ventilation, feeding route, outcome (survived/died), diarrhoea (yes/no), aspirate volume, dietitian observed nutritional status (malnourished/not), sedation, estimated energy requirements and energy received. Mixed linear models for longitudinal data were used with energy deficit (energy received - energy requirements) as the dependent variable.

RESULTS

Factors that were found to have a significant association with energy deficit were: day feeding was initiated (P<0.001), whether fed within 24 h (P<0.001) and whether sedated (P<0.001). Furthermore, three combined effects were found: ventilation mode and aspirate volume (P<0.007), fed within 24 h and ventilation mode (P<0.001), fed within 24 h and sedation (P<0.017).

CONCLUSIONS

The number of days after feeding was initiated, initiation of feeding within 24 h and sedation have been identified as factors that predict energy deficit during ICU stay. Efforts to initiate feeding as soon as possible and minimise interruptions to feeding may reduce energy deficits in these vulnerable patients.

Challenges to optimal enteral nutrition in a multidisciplinary pediatric intensive care unit

OBJECTIVE

To describe nutrient intake in critically ill children, identify risk factors associated with avoidable interruptions to enteral nutrition (EN), and highlight opportunities to improve enteral nutrient delivery in a busy tertiary pediatric intensive care unit (PICU). Design, Setting, and Measurements: Daily nutrient intake and factors responsible for avoidable interruptions to EN were recorded in patients admitted to a 29-bed medical and surgical PICU over 4 weeks. Clinical characteristics, time to reach caloric goal, and parenteral nutrition (PN) use were compared between patients with and without avoidable interruptions to EN.

RESULTS

Daily record of nutrient intake was obtained in 117 consecutive patients (median age, 7 years). Eighty (68%) patients received EN (20% postpyloric) for a total of 381 EN days (median, 2 days). Median time to EN initiation was less than 1 day. However, EN was subsequently interrupted in 24 (30%) patients at an average of 3.7 +/- 3.1 times per patient (range, 1-13), for a total of 88 episodes accounting for 1,483 hours of EN deprivation in this cohort. Of the 88 episodes of EN interruption, 51 (58%) were deemed as avoidable. Mechanically ventilated subjects were at the highest risk of EN interruptions. Avoidable EN interruption was associated with increased reliance on PN and impaired ability to reach caloric goal.

CONCLUSIONS

EN interruption is common and frequently avoidable in critically ill children. Knowledge of existing barriers to EN such as those identified in this study will allow appropriate interventions to optimize nutrition provision in the PICU.

Prokinetic Drugs in the Intensive Care Unit: Reviewing the Evidence

Delay in gastric emptying is common in the critically ill, and can lead to abdominal distension, diarrhoea or constipation, and vomiting, and may contribute to increased incidence of reflux and nosocomial infection. Prokinetic agents increase the rate of luminal transit as well as the force of contraction, and are commonly used in the intensive care unit. This article summarises the current state of knowledge about the use of prokinetics and explores potential agents which might be used in the future in this group of patients.

Gastrointestinal motility and prokinetics in the critically ill

PURPOSE OF REVIEW

Enteral nutrition is frequently unsuccessful in the critically ill due to gastrointestinal dysfunction. Current treatment strategies are often disappointing. In this article upper gastrointestinal function in health together with abnormalities seen during critical illness are reviewed, and potential therapeutic options summarized.

RECENT FINDINGS

Reflux oesophagitis occurs frequently due to reduced or absent lower oesophageal sphincter tone. In the stomach a number of motor patterns contribute to slow gastric emptying. The fundus has reduced compliance, there are less frequent contractions in both the proximal and distal stomach, isolated pyloric activity is increased and the organization of duodenal motor activity is abnormal. In response to nutrients, enterogastric feedback is enhanced, fundic relaxation and subsequent recovery is delayed, antral motility is further reduced and localized pyloric contractions stimulated. Elevated concentrations of hormones such as cholecystokinin and peptide YY are potential mediators for these phenomena. Rapid tachyphylaxis occurs with the commonly used prokinetics, metoclopramide and erythromycin, and novel agents are under investigation. Independent of gastric emptying, nutrient absorption is reduced.

SUMMARY

There has been considerable progress in understanding the pathogenesis of mechanisms causing feed intolerance in critical illness, but this is yet to be translated into therapeutic benefit.

Use of a feeding protocol to improve nutritional support through early, aggressive, enteral nutrition in the pediatric intensive care unit

OBJECTIVE

To evaluate the effects of instituting a feeding protocol with inclusive bowel regimen on tolerance and time to accomplish goal feeding in the pediatric intensive care unit.

DESIGN

Retrospective comparison chart review before and after the initiation of a feeding protocol.

PATIENTS

A total of 91 patients in the year 2000, before the initiation of the protocol, who received nasogastric feedings and 93 patients in year 2002 after the protocol was initiated.

MEASURES AND MAIN RESULTS

Patients were selected for review if they received nasogastric tube feedings while in the pediatric intensive care unit. The data were reviewed from time of admission in the pediatric intensive care unit through 7 days of goal feedings or discharge from the pediatric intensive care unit. Data examined included: days in the pediatric intensive care unit and hospital, time to goal feedings, concomitant use of cardiovascular medications, sedation, analgesia, episodes of feedings held, vomiting, diarrhea, and constipation. The protocol group achieved goal nutrition in an average of 18.5 hrs and a median of 14 hrs. The retrospective group achieved goal feedings at an average of 57.8 hrs and a median of 32 hrs (p < .0001). Also noted were a reduction in the percentage of patients vomiting from 20% to 11% and a reduction in constipation from 51% to 33%.

CONCLUSION

This comparison study suggests that the institution of a feeding protocol will not only achieve goal feedings at a substantially reduced time but also improve tolerance of enteral feedings in patients admitted to the pediatric intensive care unit.