Supplemental parenteral nutrition in critically ill patients: a study protocol for a phase II randomised controlled trial

Effect of Early Versus Delayed Parenteral Nutrition on the Health Outcomes of Critically Ill Adults: A Systematic Review

Objectives

This systematic review aims to evaluate and summarise the findings of all relevant studies which identified the effect of early vs delayed parenteral nutrition (PN), early PN vs early supplemental PN and early PN vs standard care for critically ill adults.

Methods

The literature search was undertaken using PubMed, Embase, Medline, Clinical Key, and Ovid discovery databases. The reference lists of studies published from 2000 till June 2020 were hand searched.

Result

On screening 2088 articles, a total of five RCTs with 6,277 patients were included in this review. Only one clinical trial compared early PN and late PN; the results reported significantly shorter periods in intensive care unit (ICU) stay (p=0.02) and less ICU related infections (p=0.008) in the late PN group compared to the Early PN group. Two trials compared total parenteral nutrition (TPN) and enteral nutrition (EN) +TPN groups. Both found a significantly longer hospital stay duration (p<0.05 and p<0.01) with a higher mortality rate in the TPN group compared to the EN+TPN group. A statistically significant improvement was observed in patients' quality of life receiving early PN compared to standard care (p=0.01). In contrast, no significant difference was found in the supplemental PN vs the standard care group.

Conclusion

The supplemental PN patients had shorter ICU stay and lower mortality rates than TPN. However, these findings should be interpreted carefully as included studies have different initiation timing of nutritional support, and the patients' diagnosis varied.

Measuring nutrition-related outcomes in a cohort of multi-trauma patients following intensive care unit discharge

BACKGROUND

Functional recovery is an important outcome for those who survive critical illness. The present study aimed to assess nutrition provision and nutrition-related outcomes in a multi-trauma cohort following intensive care unit (ICU) discharge.

METHODS

The present study investigated a prospective cohort of patients discharged from an ICU, who had been admitted because of major trauma and required mechanical ventilation for at least 48 h. Nutrition-related outcomes, including body weight, quadriceps muscle layer thickness (QMLT), handgrip strength and subjective global assessment, were recorded on ICU discharge, days 5-7 post-ICU discharge and then weekly until hospital discharge. Nutrition intake was recorded for 5 days post-ICU discharge. Unless otherwise stated, data are presented as the mean (SD).

RESULTS

Twenty-eight patients [75% males, 55 (22.5) years] were included. Intake met 64% (28%) of estimated energy and 72% (32%) of protein requirements over the 5 days post-ICU discharge, which was similar to over the ICU admission. From ICU admission to hospital discharge, the mean reduction in weight was 4.2 kg (95% confidence interval = 2.2-6.3, P < 0.001) and after ICU discharge, the mean reduction in weight and QMLT was 2.6 kg (95% confidence interval = 1.0-4.2, P = 0.004) and 0.23 cm (95% confidence interval = 0.06-0.4, P = 0.01), respectively.

CONCLUSIONS

Patients received less energy and protein than estimated requirements after ICU discharge. Weight loss and reduction in QMLT also occurred during this period.

Physicochemical Compatibility and Stability of Linezolid with Parenteral Nutrition

Patients referred to intensive care units (ICU) require special care due to their life-threatening condition, diseases and, frequently, malnutrition. Critically ill patients manifest a range of typical physiological changes caused by predominantly catabolic reactions in the body. It is necessary to provide the patients with proper nutrition, for example by administering total parenteral nutrition (TPN). The addition of linezolid to TPN mixtures for patients treated for linezolid-sensitive infections may reduce the extent of vascular access handling, resulting in a diminished risk of unwanted catheter-related infections. The compatibility and stability studies were conducted of linezolid in parenteral nutrition mixtures of basic, high- and low-electrolytic, high- and low-energetic and immunomodulatory composition. Mixtures containing linezolid were stored at 4–6 °C and 25 °C with light protection and at 25 °C without light protection for 168 h. In order to evaluate changes in the concentration of linezolid a previously validated reversed-phase HPLC method with UV detection was used. It was found that linezolid was stable at 4–6 °C in the whole course of the study whereas at 25 °C it proved stable over a period of 24 h required for administration of parenteral nutrition mixtures. The TPN mixtures demonstrated compatibility with linezolid and suitable stability, which were not affected by time or storage conditions.

Supplemental Parenteral Nutrition: Review of the Literature and Current Nutrition Guidelines

Parenteral nutrition has significantly and positively affected the clinical care of patients for >50 years. The 2016 Society of Critical Care Medicine/American Society for Parenteral and Enteral Nutrition guidelines for the provision of nutrition support to adult patients emphasize the role of this therapy in attenuating the stress response and impacting the immune response, among other benefits. Malnutrition in hospitalized patients remains a major problem; it is underdiagnosed and often undertreated. Malnourished patients are more likely to suffer from infections, pneumonia, and pressure ulcers, among other serious concerns. Enteral nutrition is considered first-line therapy in many of these patients; however, data suggest that many patients receive far less than prescribed amounts for a variety of reasons. Supplemental parenteral nutrition (SPN), used to augment nutrition support of appropriate adult patients and better meet nutrition goals, is not often used in the United States. The purposes of this review are to highlight selected studies in the literature that support and question the use and value of SPN in adult patients; propose consideration of 2 definitions for SPN, "early" and "traditional"; and encourage clinicians to consider SPN for appropriate patients.

[Research advances in nutritional support for critically ill children]

Most critically ill children are in a state of serious stress and tend to develop malnutrition, which may reduce the body's ability to fight against diseases and repair damaged tissues and thus aggravate their conditions. Reasonable and effective nutritional support for critically ill children can improve their nutritional status and prognosis, and so it is necessary to offer nutritional support for critically ill children. This article reviews the research on nutritional support for critically ill children and the current status of clinical application. It also introduces the main methods for nutritional support, including enteral nutrition and parenteral nutrition, and elaborates on the new methods for nutritional support, such as early enteral nutrition, enteral immunonutrition, and supplementary parenteral nutrition, in order to provide a reference for nutritional support for critically ill children.

[Research advances in nutritional support for critically ill children]

Most critically ill children are in a state of serious stress and tend to develop malnutrition, which may reduce the body's ability to fight against diseases and repair damaged tissues and thus aggravate their conditions. Reasonable and effective nutritional support for critically ill children can improve their nutritional status and prognosis, and so it is necessary to offer nutritional support for critically ill children. This article reviews the research on nutritional support for critically ill children and the current status of clinical application. It also introduces the main methods for nutritional support, including enteral nutrition and parenteral nutrition, and elaborates on the new methods for nutritional support, such as early enteral nutrition, enteral immunonutrition, and supplementary parenteral nutrition, in order to provide a reference for nutritional support for critically ill children.

What Happens to Nutrition Intake in the Post-Intensive Care Unit Hospitalization Period? An Observational Cohort Study in Critically Ill Adults

BACKGROUND

Little is currently known about nutrition intake and energy requirements in the post-intensive care unit (ICU) hospitalization period in critically ill patients. We aimed to describe energy and protein intake, and determine the feasibility of measuring energy expenditure during the post-ICU hospitalization period in critically ill adults.

METHODS

This is a nested cohort study within a randomized controlled trial in critically ill patients. After discharge from ICU, energy and protein intake was quantified periodically and indirect calorimetry attempted. Data are presented as n (%), mean (SD), and median (interquartile range [IQR]).

RESULTS

Thirty-two patients were studied in the post-ICU hospitalization period, and 12 had indirect calorimetry. Mean age and BMI was 56 (18) years and 30 (8) kg/m² , respectively, 75% were male, and the median estimated energy and protein requirement were 2000 [1650-2550] kcal and 112 [84-129] g, respectively. Oral nutrition either alone (n = 124 days, 55%) or in combination with enteral nutrition (n = 96 days, 42%) was the predominant mode. Over 227 total days in the post-ICU hospitalization period, a median [IQR] of 1238 [869-1813] kcal and 60 [35-89.5] g of protein was received from nutrition therapy. In the 12 patients who had indirect calorimetry, the median measured daily energy requirement was 1982 [1843-2345] kcal and daily energy deficit was -95 [-1050 to 347] kcal compared with the measured energy requirement.

CONCLUSIONS

Energy and protein intake in the post-ICU hospitalization period was less than estimated and measured energy requirements. Oral nutrition provided alone was the most common mode of nutrition therapy.

Enteral versus parenteral nutrition and enteral versus a combination of enteral and parenteral nutrition for adults in the intensive care unit

BACKGROUND

Critically ill people are at increased risk of malnutrition. Acute and chronic illness, trauma and inflammation induce stress-related catabolism, and drug-induced adverse effects may reduce appetite or increase nausea and vomiting. In addition, patient management in the intensive care unit (ICU) may also interrupt feeding routines. Methods to deliver nutritional requirements include provision of enteral nutrition (EN), or parenteral nutrition (PN), or a combination of both (EN and PN). However, each method is problematic. This review aimed to determine the route of delivery that optimizes uptake of nutrition.

OBJECTIVES

To compare the effects of enteral versus parenteral methods of nutrition, and the effects of enteral versus a combination of enteral and parenteral methods of nutrition, among critically ill adults, in terms of mortality, number of ICU-free days up to day 28, and adverse events.

SEARCH METHODS

We searched CENTRAL, MEDLINE, and Embase on 3 October 2017. We searched clinical trials registries and grey literature, and handsearched reference lists of included studies and related reviews.

SELECTION CRITERIA

We included randomized controlled studies (RCTs) and quasi-randomized studies comparing EN given to adults in the ICU versus PN or versus EN and PN. We included participants that were trauma, emergency, and postsurgical patients in the ICU.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed studies for inclusion, extracted data, and assessed risk of bias. We assessed the certainty of evidence with GRADE.

MAIN RESULTS

We included 25 studies with 8816 participants; 23 studies were RCTs and two were quasi-randomized studies. All included participants were critically ill in the ICU with a wide range of diagnoses; mechanical ventilation status between study participants varied. We identified 11 studies awaiting classification for which we were unable to assess eligibility, and two ongoing studies.Seventeen studies compared EN versus PN, six compared EN versus EN and PN, two were multi-arm studies comparing EN versus PN versus EN and PN. Most studies reported randomization and allocation concealment inadequately. Most studies reported no methods to blind personnel or outcome assessors to nutrition groups; one study used adequate methods to reduce risk of performance bias.Enteral nutrition versus parenteral nutritionWe found that one feeding route rather than the other (EN or PN) may make little or no difference to mortality in hospital (risk ratio (RR) 1.19, 95% confidence interval (CI) 0.80 to 1.77; 361 participants; 6 studies; low-certainty evidence), or mortality within 30 days (RR 1.02, 95% CI 0.92 to 1.13; 3148 participants; 11 studies; low-certainty evidence). It is uncertain whether one feeding route rather than the other reduces mortality within 90 days because the certainty of the evidence is very low (RR 1.06, 95% CI 0.95 to 1.17; 2461 participants; 3 studies). One study reported mortality at one to four months and we did not combine this in the analysis; we reported this data as mortality within 180 days and it is uncertain whether EN or PN affects the number of deaths within 180 days because the certainty of the evidence is very low (RR 0.33, 95% CI 0.04 to 2.97; 46 participants).No studies reported number of ICU-free days up to day 28, and one study reported number of ventilator-free days up to day 28 and it is uncertain whether one feeding route rather than the other reduces the number of ventilator-free days up to day 28 because the certainty of the evidence is very low (mean difference, inverse variance, 0.00, 95% CI -0.97 to 0.97; 2388 participants).We combined data for adverse events reported by more than one study. It is uncertain whether EN or PN affects aspiration because the certainty of the evidence is very low (RR 1.53, 95% CI 0.46 to 5.03; 2437 participants; 2 studies), and we found that one feeding route rather than the other may make little or no difference to pneumonia (RR 1.10, 95% CI 0.82 to 1.48; 415 participants; 7 studies; low-certainty evidence). We found that EN may reduce sepsis (RR 0.59, 95% CI 0.37 to 0.95; 361 participants; 7 studies; low-certainty evidence), and it is uncertain whether PN reduces vomiting because the certainty of the evidence is very low (RR 3.42, 95% CI 1.15 to 10.16; 2525 participants; 3 studies).Enteral nutrition versus enteral nutrition and parenteral nutritionWe found that one feeding regimen rather than another (EN or combined EN or PN) may make little or no difference to mortality in hospital (RR 0.99, 95% CI 0.84 to 1.16; 5111 participants; 5 studies; low-certainty evidence), and at 90 days (RR 1.00, 95% CI 0.86 to 1.18; 4760 participants; 2 studies; low-certainty evidence). It is uncertain whether combined EN and PN leads to fewer deaths at 30 days because the certainty of the evidence is very low (RR 1.64, 95% CI 1.06 to 2.54; 409 participants; 3 studies). It is uncertain whether one feeding regimen rather than another reduces mortality within 180 days because the certainty of the evidence is very low (RR 1.00, 95% CI 0.65 to 1.55; 120 participants; 1 study).No studies reported number of ICU-free days or ventilator-free days up to day 28. It is uncertain whether either feeding method reduces pneumonia because the certainty of the evidence is very low (RR 1.40, 95% CI 0.91 to 2.15; 205 participants; 2 studies). No studies reported aspiration, sepsis, or vomiting.

AUTHORS' CONCLUSIONS

We found insufficient evidence to determine whether EN is better or worse than PN, or than combined EN and PN for mortality in hospital, at 90 days and at 180 days, and on the number of ventilator-free days and adverse events. We found fewer deaths at 30 days when studies gave combined EN and PN, and reduced sepsis for EN rather than PN. We found no studies that reported number of ICU-free days up to day 28. Certainty of the evidence for all outcomes is either low or very low. The 11 studies awaiting classification may alter the conclusions of the review once assessed.

Parenteral or enteral nutrition: do you have the choice?

PURPOSE OF REVIEW

The review focuses on the use of parenteral nutrition and enteral nutrition in critically ill patients to optimize the nutrition care throughout the ICU stay. The key message is: you have the choice!

RECENT FINDINGS

Enteral nutrition has been recommended for critically ill patients, whereas parenteral nutrition has been considered harmful and to be avoided. However, recent studies have challenged this theory. They demonstrated that enteral nutrition is frequently associated with energy and protein undernutrition, whereas parenteral nutrition becomes deleterious only if overfeeding is induced. Measuring energy expenditure by indirect calorimetry, in most cases, enables accurate determination of the energy needs to optimize the prescription of nutrition. Protein targets should also be considered for adequate feeding. Parenteral nutrition can be used as a supplement or as an alternative to enteral nutrition in case of gastrointestinal intolerance, to enable adequate energy, and protein provision.

SUMMARY

Parenteral nutrition is a powerful tool to optimize nutrition care of critically ill patients to improve clinical outcome, if prescribed according to the individual needs of the patients. After 3-4 days of attempt to feed enterally, enteral nutrition or parenteral nutrition can be used alternatively or combined, as long as the target is reached with special attention to avoid hypercaloric feeding.

Supplemental parenteral nutrition versus usual care in critically ill adults: a pilot randomized controlled study

Background

In the critically ill, energy delivery from enteral nutrition (EN) is often less than the estimated energy requirement. Parenteral nutrition (PN) as a supplement to EN may increase energy delivery. We aimed to determine if an individually titrated supplemental PN strategy commenced 48–72 hours following ICU admission and continued for up to 7 days would increase energy delivery to critically ill adults compared to usual care EN delivery.

Methods

This study was a prospective, parallel group, phase II pilot trial conducted in six intensive care units in Australia and New Zealand. Mechanically ventilated adults with at least one organ failure and EN delivery below 80% of estimated energy requirement in the previous 24 hours received either a supplemental PN strategy (intervention group) or usual care EN delivery. EN in the usual care group could be supplemented with PN if EN remained insufficient after usual methods to optimise delivery were attempted.

Results

There were 100 patients included in the study and 99 analysed. Overall, 71% of the study population were male, with a mean (SD) age of 59 (17) years, Acute Physiology and Chronic Health Evaluation II score of 18.2 (6.7) and body mass index of 29.6 (5.8) kg/m². Significantly greater energy (mean (SD) 1712 (511) calories vs. 1130 (601) calories, p < 0.0001) and proportion of estimated energy requirement (mean (SD) 83 (25) % vs. 53 (29) %, p < 0.0001) from EN and/or PN was delivered to the intervention group compared to usual care. Delivery of protein and proportion of estimated protein requirements were also greater in the intervention group (mean (SD) 86 (25) g, 86 (23) %) compared to usual care (mean (SD) 53 (29) g, 51 (25) %, p < 0.0001). Antibiotic use, ICU and hospital length of stay, mortality and functional outcomes were similar between the two groups.

Conclusions

This individually titrated supplemental PN strategy applied over 7 days significantly increased energy delivery when compared to usual care delivery. Clinical and functional outcomes were similar between the two patient groups.

Trial registration

Clinical Trial registry details: NCT01847534 (First registered 22 April 2013, last updated 31 July 2016)

Electronic supplementary material

The online version of this article (10.1186/s13054-018-1939-7) contains supplementary material, which is available to authorized users.

Nutrition support in hospitalised adults at nutritional risk

BACKGROUND

The prevalence of disease-related malnutrition in Western European hospitals is estimated to be about 30%. There is no consensus whether poor nutritional status causes poorer clinical outcome or if it is merely associated with it. The intention with all forms of nutrition support is to increase uptake of essential nutrients and improve clinical outcome. Previous reviews have shown conflicting results with regard to the effects of nutrition support.

OBJECTIVES

To assess the benefits and harms of nutrition support versus no intervention, treatment as usual, or placebo in hospitalised adults at nutritional risk.

SEARCH METHODS

We searched Cochrane Central Register of Controlled Trials (CENTRAL) in the Cochrane Library, MEDLINE (Ovid SP), Embase (Ovid SP), LILACS (BIREME), and Science Citation Index Expanded (Web of Science). We also searched the World Health Organization International Clinical Trials Registry Platform (www.who.int/ictrp); ClinicalTrials.gov; Turning Research Into Practice (TRIP); Google Scholar; and BIOSIS, as well as relevant bibliographies of review articles and personal files. All searches are current to February 2016.

SELECTION CRITERIA

We include randomised clinical trials, irrespective of publication type, publication date, and language, comparing nutrition support versus control in hospitalised adults at nutritional risk. We exclude trials assessing non-standard nutrition support.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane and the Cochrane Hepato-Biliary Group. We used trial domains to assess the risks of systematic error (bias). We conducted Trial Sequential Analyses to control for the risks of random errors. We considered a P value of 0.025 or less as statistically significant. We used GRADE methodology. Our primary outcomes were all-cause mortality, serious adverse events, and health-related quality of life.

MAIN RESULTS

We included 244 randomised clinical trials with 28,619 participants that met our inclusion criteria. We considered all trials to be at high risk of bias. Two trials accounted for one-third of all included participants. The included participants were heterogenous with regard to disease (20 different medical specialties). The experimental interventions were parenteral nutrition (86 trials); enteral nutrition (tube-feeding) (80 trials); oral nutrition support (55 trials); mixed experimental intervention (12 trials); general nutrition support (9 trials); and fortified food (2 trials). The control interventions were treatment as usual (122 trials); no intervention (107 trials); and placebo (15 trials). In 204/244 trials, the intervention lasted three days or more.We found no evidence of a difference between nutrition support and control for short-term mortality (end of intervention). The absolute risk was 8.3% across the control groups compared with 7.8% (7.1% to 8.5%) in the intervention groups, based on the risk ratio (RR) of 0.94 (95% confidence interval (CI) 0.86 to 1.03, P = 0.16, 21,758 participants, 114 trials, low quality of evidence). We found no evidence of a difference between nutrition support and control for long-term mortality (maximum follow-up). The absolute risk was 13.2% in the control group compared with 12.2% (11.6% to 13%) following nutritional interventions based on a RR of 0.93 (95% CI 0.88 to 0.99, P = 0.03, 23,170 participants, 127 trials, low quality of evidence). Trial Sequential Analysis showed we only had enough information to assess a risk ratio reduction of approximately 10% or more. A risk ratio reduction of 10% or more could be rejected.We found no evidence of a difference between nutrition support and control for short-term serious adverse events. The absolute risk was 9.9% in the control groups versus 9.2% (8.5% to 10%), with nutrition based on the RR of 0.93 (95% CI 0.86 to 1.01, P = 0.07, 22,087 participants, 123 trials, low quality of evidence). At long-term follow-up, the reduction in the risk of serious adverse events was 1.5%, from 15.2% in control groups to 13.8% (12.9% to 14.7%) following nutritional support (RR 0.91, 95% CI 0.85 to 0.97, P = 0.004, 23,413 participants, 137 trials, low quality of evidence). However, the Trial Sequential Analysis showed we only had enough information to assess a risk ratio reduction of approximately 10% or more. A risk ratio reduction of 10% or more could be rejected.Trial Sequential Analysis of enteral nutrition alone showed that enteral nutrition might reduce serious adverse events at maximum follow-up in people with different diseases. We could find no beneficial effect of oral nutrition support or parenteral nutrition support on all-cause mortality and serious adverse events in any subgroup.Only 16 trials assessed health-related quality of life. We performed a meta-analysis of two trials reporting EuroQoL utility score at long-term follow-up and found very low quality of evidence for effects of nutritional support on quality of life (mean difference (MD) -0.01, 95% CI -0.03 to 0.01; 3961 participants, two trials). Trial Sequential Analyses showed that we did not have enough information to confirm or reject clinically relevant intervention effects on quality of life.Nutrition support may increase weight at short-term follow-up (MD 1.32 kg, 95% CI 0.65 to 2.00, 5445 participants, 68 trials, very low quality of evidence).

AUTHORS' CONCLUSIONS

There is low-quality evidence for the effects of nutrition support on mortality and serious adverse events. Based on the results of our review, it does not appear to lead to a risk ratio reduction of approximately 10% or more in either all-cause mortality or serious adverse events at short-term and long-term follow-up.There is very low-quality evidence for an increase in weight with nutrition support at the end of treatment in hospitalised adults determined to be at nutritional risk. The effects of nutrition support on all remaining outcomes are unclear.Despite the clinically heterogenous population and the high risk of bias of all included trials, our analyses showed limited signs of statistical heterogeneity. Further trials may be warranted, assessing enteral nutrition (tube-feeding) for different patient groups. Future trials ought to be conducted with low risks of systematic errors and low risks of random errors, and they also ought to assess health-related quality of life.

Clinical effects of supplemental parenteral nutrition in critically ill patients

AIM

To investigate the clinical value of supplemental parenteral nutrition (SPN) in critically ill patients.

METHODS

The clinical data of 108 critically ill patients hospitalized at our hospital from June 2014 to June 2016 were analyzed retrospectively. According to the method of nutrition used, the patients were divided into an enteral nutrition (EN) group (control group) and an EN combined with SPN group (observation group). The clinical effects were compared between the two groups.

RESULTS

After 1 wk of SPN, serum albumin, prealbumin and hemoglobin were significantly higher in the observation group than in the control group (P < 0.05). The upper arm circumference between the two groups had no significant differences (P > 0.05). The incidence of infection and hospitalization time in the observation group were significantly lower than those of the control group (P < 0.05). The mortality of two groups was not statistically different (P > 0.05).

CONCLUSION

SPN can effectively improve the nutritional status of critically ill patients, reduce the incidence of infection, and shorten the length of hospital stay.