Effects of Hypercaloric Feeding on Nutrition Status and Carbon Dioxide Production in Patients With Long-Term Mechanical Ventilation

Hypercapnia is not excluded by normoxia in neuromuscular disease patients: implications for oximetry

Background

Pulse oximetry is widely used in the assessment of chronic respiratory failure in neuromuscular disease (NMD) patients. Chronic respiratory failure is the major cause of morbidity and mortality, necessitating early diagnosis and intervention. Guidelines suggest that an arterial blood gas (ABG) measurement is indicated if oxygen saturation (S pO2 ) is ≤94% in the absence of lung disease. However, hypercapnia with normoxia (S pO2 ≥95%) has been observed on ABGs of patients with NMD, in particular those with motor neurone disease.

Methods

A single-centre retrospective audit of room-air ABGs in stable hypercapnic chronic respiratory failure patients from 1990 to 2020 was performed. Patients with parenchymal lung disease were excluded. Patients were grouped into three main categories: non-NMD, other NMD and motor neurone disease.

Findings

297 ABGs with hypercapnia from 180 patients with extrinsic restrictive lung disease were analysed. No patients with non-NMD, 54% of patients with other NMD and 36% of motor neurone disease patients demonstrated hypercapnia with normoxia (Chi-squared 61.33; p<0.001). The potential mechanism is proposed to be a difference in calculated respiratory quotient. If the alveolar-arterial gradient is assumed to be normal, the calculated respiratory quotient was significantly higher in motor neurone disease patients and other NMD patients compared with non-NMD patients (estimated marginal mean 0.99, 95% CI 0.94-1.03; 0.86 0.76-0.96; 0.73, 0.63-0.83, respectively; p<0.001) by mixed-model analysis.

Interpretation

Hypercapnia is not excluded with normal oximetry in NMD patients and may be due to an elevated respiratory quotient. This has implications in the diagnosis and monitoring of respiratory insufficiency in NMD patients with oximetry alone.

Markers of respiratory function response to high-carbohydrate and high-fat intake in patients with lung diseases: a systematic review with meta-analysis of randomized clinical trials

BACKGROUND

Macronutrients can differently affect respiratory function markers such as VO₂ , VCO₂ , PaO₂ , PaCO₂ and respiratory quotients (RQ), but systematic appraisal of the evidence on randomized clinical trials (RCTs) is lacking.

OBJECTIVE

To compare the response of respiratory function markers to high-carbohydrate and high-fat intake in patients with lung diseases.

METHODS

Systematic review conducted according to Cochrane Collaboration recommendations, reported following PRISMA 2020. PubMed, EMBASE, Scopus, and Cochrane CENTRAL were searched up to July/2021. Two reviewers selected the RCTs and extracted the data. Risk of bias and the certainty of evidence were assessed by RoB 2 and GRADE, respectively. Statistical and graphical data guided the publication bias investigation. Meta-analyses were conducted.

RESULTS

We included 14 RCTs (362 participants), four of which were parallel. Most studies included patients with COPD. High-fat intake decreased VCO₂ [MD = -35.89(95%CI -45.24; -26.21) ml/min; I²=0%], VO₂ [MD= -29.30(95% CI -40.94, -17.66) ml/min; I² = 0%], PaCO₂ [MD = -4.62(95%CI -7.67; -1.58) mmHg; I²=84%], and RQ [MD = -0.08(95%CI -0.09; -0.06); I² = 0%] in the subset of parallel RCTs. In crossover RCTs, there was generally no evidence of effect except for a greater decrease in RQ [MD = -0.09(95%CI -0.12; -0.02); I² = 96%] in favor of high fat intake.

CONCLUSION

High-fat intake resulted in greater reductions ​​of VCO₂ , VO₂ , PaCO₂ , and RQ in adult patients with lung diseases. The certainty of the evidence is very low/ low, and it precludes a specific recommendation on macronutrients contribution to energy intake of these patients. This article is protected by copyright. All rights reserved.

Measured vs Predicted Energy Expenditure in Mechanically Ventilated Adults With Acute, Traumatic Spinal Cord Injuries

BACKGROUND

Research regarding the impact of acute spinal cord injury (aSCI) on energy expenditure is limited. Patients with aSCI are prone to complications of both over- and under-feeding, making appropriate nutrition support pivotal to patient care. The purpose of this study was to describe energy expenditure and assess the performance of predictive equations in mechanically ventilated adults with aSCI.

METHODS

Adult patients admitted to a single trauma center from March 2017 through June 2018 with aSCI and a documented indirect calorimetry (IC) within 6 weeks of injury were included for analysis. Predictive equations evaluated included Penn State 2003b (PS 2003b), the derived Weir equation, 25 kcal/kg and 30 kcal/kg. Sub-set analysis was performed for patients with and without obesity, isolated aSCI, and concomitant traumatic injuries.

RESULTS

On hundres fifteen IC studies in 51 patients were included for analysis. Median energy expenditure was 1747 kcal/day (interquartile range [IQR], 1492-2099 kcal/day), or 22.7 kcal/kg (IQR, 19.3-25.9 kcal/kg). When stratified by hospital day, energy expenditure ranged from 20 to 25 kcal/kg. PS 2003b and the derived Weir equation had similar correlation coefficients (r = 0.81 and 0.82, respectively). The 25 and 30 kcal/kg performed unacceptably (r = 0.61). PS 2003b predicted within 10% of measured energy expenditure most frequently. All equations were biased towards overfeeding, except for PS 2003b in the obese subset.

CONCLUSION

In the absence of IC, PS 2003b or the derived Weir equation may be acceptable predictive equations in this population. However, bedside clinicians should monitor carefully for signs and symptoms of overfeeding.

Caloric intake and the fat-to-carbohydrate ratio in hypercapnic acute respiratory failure: Post-hoc analysis of the PermiT trial

BACKGROUND

The effect of moderate caloric enteral intake in critically ill patients with hypercapnic acute respiratory failure (HCARF) is unclear. We studied the impact of permissive underfeeding (PUF) compared with standard feeding (SF) on various HCARF outcomes.

MATERIALS AND METHODS

The PermiT trial randomized 894 patients to either PUF (40-60% caloric requirement) or SF (70-100% requirement) with similar protein intake and found no difference in mortality, mechanical ventilation (MV) duration and ventilator-free days. In this post-hoc study, we restricted analysis to mechanically-ventilated patients with HCARF (PaCO₂ >45 mmHg on the first two study days) and assessed the impact of trial interventions and fat-to-carbohydrate ratio on outcomes.

RESULTS

One-hundred-twenty patients had HCARF (59 PUF and 61 SF, age 53.7 ± 17.8 years, body mass index 31.1 ± 11.2 kg/m², Acute Physiology and Chronic Health Evaluation II score 21.7 ± 7.1 and day-1 PaCO₂ 61 ± 16 mmHg). Caloric intake was 815 ± 270 kcal/day in PUF group and 1289 ± 407 kcal/day in SF group. The two groups had similar PaCO₂ levels during ICU stay. The 90-day mortality (33.9% versus 35.6%, p = 0.85), MV duration (10.7 ± 6.8 versus 11.1 ± 8.1 days, p = 0.56) and ventilator-free days (52.9 ± 38.6 versus 51.2 ± 38.0 days, p = 0.80) were also similar in PUF and SF groups, respectively. Ventilator-free days and 90-day mortality were similar when the fat-to-carbohydrate ratio was < or ≥ the median value (0.73) in all patients and in PUF and SF groups.

CONCLUSIONS

In patients with HCARF, SF and PUF were associated with similar PaCO₂, MV duration, ventilator-free days and mortality. Fat-to-carbohydrate ratio was not associated with mortality or ventilator-free days.

TRIAL REGISTRATION

ISRCTN Registry: ISRCTN68144998.

Monitoring Nutrition in Critical Illness: What Can We Use?

BACKGROUND

Nutrition monitoring in the context of critical care presents unique challenges. Traditionally used anthropometric and biochemical markers may be difficult to obtain or confounded by factors such as fluid status and the inflammatory response. A previous survey identified 15 parameters in common use, all of which have confounding influences during critical illness.

MATERIALS AND METHODS

A literature search was conducted to assess current use of commonly used nutrition-monitoring parameters and to explore other possible methods that might be more useful. More than 1000 journal articles were reviewed to identify indicators of nutrition status or nutrition progress that have been used in ICU studies. The most recent 200 articles were examined to quantify the number of occurrences for each indicator. Each parameter was rated for availability and feasibility in the ICU.

RESULTS

There were 53 parameters found, including the 15 already identified as commonly used; 27 were used in ≥3 recent studies. Less-well-established nutrition indicators with potential for use in the ICU (moderate or high feasibility and availability) included ultrasound measurement of arm or leg muscle thickness, fatigue scoring with the Chalder scale, urinary creatinine assay, and serum insulin-like growth factor 1 level. None of these was among the commonly used indicators in recent studies.

CONCLUSION

This study identifies commonly used nutrition-monitoring parameters and discusses their feasibility and availability in the critical care setting. Further investigation of nutrition indicators in ICU is needed, ideally as part of a randomized trial to reduce the effect of the many possible confounding factors.

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.

Use of metabolic monitors in a multidisciplinary Intensive Care Unit: A prospective pilot study of 20 patients

Introduction:

Caloric intake of critically ill patients are usually calculated using predictive equations. Recent advances in gas exchange measurements have the potential to estimate energy expenditure at the bedside and at different time periods.

Materials and Methods:

Energy needs of critically ill patients were estimated over a period of 3 months using simplistic formula of 25 kcal/kg/day estimated energy expenditure (EEE), Harris–Benedict equation (HBE) (Basal energy expenditure [BEE]) and M-COVX™ metabolic monitor resting energy expenditure (REE) on day 4 of Intensive Care Unit (ICU) admission. Calculations based on HBE were taken as standard, and percentage errors (PE) were calculated for each patient for values derived from simplistic formula and metabolic monitor. Adequacy of nutritional intake in ICU was also assessed.

Results:

Metabolic monitor could be used in only 20/70 patients. The mean age of patients was 40 years, 65% were males, and average body mass index was 23.69 kg/m². Intermittent intolerance to feeds was reported in 50%. Values of REE and EEE were greater than BEE in 70% of patients. A significant difference was reported in values of PE of ≤20% and ≥30%; P = 0.0003 and 0.0001, respectively estimated using REE and EEE.

Conclusions:

It is not feasible to use metabolic monitors in all patients. Variability in readings is large and further studies are needed to establish the validity of its measurements. Calculations using simplistic formulas are much closer to values obtained using HBE.

Impact of Individualized Diet Intervention on Body Composition and Respiratory Variables in Children With Respiratory Insufficiency: A Pilot Intervention Study

OBJECTIVES

Diet modification may improve body composition and respiratory variables in children with respiratory insufficiency. Our objective was to examine the effect of an individualized diet intervention on changes in weight, lean body mass, minute ventilation, and volumetric CO2 production in children dependent on long-term mechanical ventilatory support.

DESIGN

Prospective, open-labeled interventional study.

SETTING

Study subjects' homes.

PATIENTS

Children, 1 month to 17 years old, dependent on at least 12 hr/d of transtracheal mechanical ventilatory support.

INTERVENTIONS

Twelve weeks of an individualized diet modified to deliver energy at 90-110% of measured energy expenditure and protein intake per age-based guidelines.

MEASUREMENTS AND MAIN RESULTS

During a multidisciplinary home visit, we obtained baseline values of height and weight, lean body mass percent by bioelectrical impedance analysis, actual energy and protein intake by food record, and measured energy expenditure by indirect calorimetry. An individualized diet was then prescribed to optimize energy and protein intake. After 12 weeks on this interventional diet, we evaluated changes in weight, height, lean body mass percent, minute ventilation, and volumetric CO2 production. Sixteen subjects, mean age 9.3 years (SD, 4.9), eight male, completed the study. For the diet intervention, a majority of subjects required a change in energy and protein prescription. The mean percentage of energy delivered as carbohydrate was significantly decreased, 51.7% at baseline versus 48.2% at follow-up, p = 0.009. Mean height and weight increased on the modified diet. Mean lean body mass percent increased from 58.3% to 61.8%. Minute ventilation was significantly lower (0.18 L/min/kg vs 0.15 L/min/kg; p = 0.04), and we observed a trend toward lower volumetric CO2 production (5.4 mL/min/kg vs 5.3 mL/min/kg; p = 0.06) after 12 weeks on the interventional diet.

CONCLUSIONS

Individualized diet modification is feasible and associated with a significant decrease in minute ventilation, a trend toward significant reduction in CO2 production, and improved body composition in children on long-term mechanical ventilation. Optimization of respiratory variables and lean body mass by diet modification may benefit children with respiratory insufficiency in the ICU.

Cilostazol administration with combination enteral and parenteral nutrition therapy remarkably improves outcome after subarachnoid hemorrhage

OBJECTIVE

In order to prevent cerebral vasospasm (VS) following aneurysmal subarachnoid hemorrhage (SAH), we introduced combined enteral nutrition (EN) and parenteral nutrition (PN) with oral cilostazol administration to the postoperative patient after SAH and investigated the effect on VS.

METHODS

After aneurysmal SAH, 130 postoperative patients were enrolled in this study between April 2008 and March 2012. The patients enrolled before April 2010 were treated by conventional therapy (control group). The patients enrolled after April 2010 were administrated cilostazol 200 mg/day and received EN and PN simultaneously (combined group).

RESULTS

The combined group consisted of 62 patients and the control group of 68 patients. Angiographic VS occurred in 33.9 % (n = 21) of the combined group and in 51.5 % (n = 35) of the control group (p = 0.051, Fisher exact test). The incidence of symptomatic VS was significantly lower in the combined group (p = 0.001). The incidence of new cerebral infarctions was also significantly lower in the combined group (p = 0.0006). Clinical outcome at discharge was also significantly better in the combined group than in control group (p = 0.031).

CONCLUSIONS

Cilostazol administration with combination EN and PN is remarkably effective in preventing cerebral VS after aneurysmal SAH.

Metabolic monitoring in the intensive care unit: a comparison of the Medgraphics Ultima, Deltatrac II, and Douglas bag collection methods

BACKGROUND

The accuracy of oxygen consumption measurement by indirect calorimeters is poorly validated in mechanically ventilated intensive care patients where multiple confounders exist. This study sought to compare the Medgraphics Ultima (MGU) and Deltatrac II (DTII) devices, and the Douglas bag (DB) technique in mechanically ventilated patients at rest.

METHODS

Prospective comparison of oxygen consumption measurement using three indirect calorimetry techniques in stable, resting mechanically ventilated patients at rest. Oxygen consumption (VO2), carbon dioxide production (VCO2), resting energy expenditure (REE), and respiratory quotient (RQ) were recorded breath-by-breath by the MGU over a 30-75 min period. During this time, simultaneous measurements were taken using the DTII, the DB, or both.

RESULTS

While there was no systematic error (bias) between measurements made by the three techniques (VO2: MGU vs DTII 3.6%, MGU vs DB 3.3%), the limits of agreement were wide (VO2: MGU vs DTII 33%, MGU vs DB 54%).

CONCLUSIONS

Resting oxygen consumption values in stable mechanically ventilated patients measured by the three techniques showed acceptable bias but poor precision. There is an important clinical and research need to develop new indirect calorimeters specifically tailored to measure oxygen consumption during mechanical ventilation.

Resting energy expenditure after Fontan surgery in children with single-ventricle heart defects

BACKGROUND

Data on resting energy expenditure (REE) and oxygen consumption (VO(2)) after pediatric cardiopulmonary bypass (CPB) will facilitate optimal nutrient prescription.

METHODS

The authors measured continuous REE and VO(2), using an in-line indirect calorimetery (IC) in 30 consecutive children with single-ventricle physiology immediately after Fontan surgery. REE during steady state at 8 hours after surgery was compared with standard equation-estimated energy expenditure (EEE). Patients were classified into 3 groups: hypermetabolic (measured REE [MREE]/EEE ratio >1.2), hypometabolic (MREE/EEE ratio <0.8), and normometabolic (MREE/EEE ratio 0.8-1.2). Demographic, anthropometric, and perioperative clinical characteristics were examined for their correlation with metabolic status.

RESULTS

In 26 of 30 patients with completed IC, mean REE at 8 hours after surgery was 57 ± 20 kcal/kg/d, and mean VO(2) was 110 ± 35 mL/min. Mean values of VO(2) and REE did not change within the first 24 hours after surgery. There was poor correlation between MREE at 8 hours and the EEE using the World Health Organization equation (r = 0.32, P = .11). Most patients (n = 19, 73%) were either normometabolic or hypometabolic. Lack of hypermetabolism was significantly associated with higher intraoperative serum lactate level and positive fluid balance compared with the rest of the group.

CONCLUSIONS

The authors report a low prevalence of hypermetabolism in children with single-ventricle defects after Fontan surgery. Measured REE had poor correlation with equation-estimated energy expenditure in a majority of the cohort. The absence of increased energy expenditure after CPB will influence energy prescription in this group.

Nutrition support for the acute lung injury/adult respiratory distress syndrome patient: a review

Support for Acute Lung Injury (ALI) and Adult Respiratory Distress Syndrome (ARDS) in many ways represents the summation of all intensive care unit nutrition modalities. Basic tenets of management are based on those established for the general population of mechanically ventilated patients. As a marker of critical illness however, patients with ALI/ARDS suffer from other organ dysfunctions that require advanced support. Specific issues to be considered in this population include carbon dioxide production, prevention of aspiration, and modulation of the inflammatory response. These particular areas, with special attention paid to the role of lipids in ALI/ARDS, will be reviewed.

Predictive equations over-estimate the resting energy expenditure in amyotrophic lateral sclerosis patients who are dependent on invasive ventilation support

BACKGROUND

Amyotrophic lateral sclerosis (ALS) is a form of degenerative motor neuron disease. At the end stage of the disease artificial feeding is often required. Nevertheless, very little is known about the energy demand of those ALS patients who are chronically dependent on tracheostomy intermittent positive pressure ventilation. The objective of our study was to clarify the resting energy expenditure (REE) in mechanically ventilated ALS patients.

METHODS

We measured the REE of five ALS patients (four men, one female) twice during a 12 month-period using indirect calorimetry with two sampling flow settings (40 L/min and 80 L/min). The measured REEs (mREE) were compared with values calculated using five different predictive equations.

RESULTS

The mean (± SD) of all mREEs was 1130 ± 170 kcal/d. The measurements with different flow settings and at different time instances provided similar results. The mean of mREEs was 33.6% lower, as compared to the mean calculated with five different predictive equations REE (p < 0.001). Each of the predictive equations over-estimated the REE.

CONCLUSIONS

The mREE values were significantly lower for every patient than all the predicted ones. Determination of daily nutrition with predictive equations may therefore lead in mis-estimation of energy requirements. Because ALS patients may live years with artificial ventilation their nutritional support should be based on individual measurements. However, further study is needed due to the small number of subjects.

Changes in prealbumin, nutrient intake, and systemic inflammation in elderly recuperative care patients

OBJECTIVES

To determine the relationship between prealbumin, nutrient intake, and indicators of inflammation for recuperative and rehabilitative care patients.

DESIGN

Prospective cohort.

SETTING

Recuperative Care Unit within a Veterans Administration Nursing Home Care Unit.

PARTICIPANTS

One hundred eleven men (100 white; mean age 80, range 64-93).

MEASUREMENTS

Prealbumin and seven markers of inflammation (C-reactive protein (CRP), tumor necrosis factor, and interleukin-6 (IL-6) and their soluble receptors) were measured at admission and discharge (median length of stay 23 days, interquartile range 15-40 days). Detailed calorie counts were performed daily, and intake was expressed as a percentage of estimated requirements for protein (1.5 g/kg body weight per day) and energy (Harris-Benedict equation). The study objective was examined using least-squares regression analysis.

RESULTS

Discharge prealbumin and the change in prealbumin were positively correlated with protein and energy intake and inversely correlated with markers of inflammation, particularly CRP and IL-6. When all covariates were included in a multivariable regression analysis, the markers of inflammation predominantly accounted for the variance in prealbumin change (56%), whereas discharge protein intake accounted for 6%.

CONCLUSION

For older recuperative care patients, prealbumin and its change during hospitalization are positively associated with protein intake, but inflammation or changes in inflammation appear to exert a much more-powerful influence on prealbumin concentration. Given the potential confounding effects of inflammation, monitoring the change in prealbumin is not an adequate substitute for a more-detailed nutritional assessment in this population.

Is it now time to promote mixed enteral and parenteral nutrition for the critically ill patient?

BACKGROUND

Intensive care outcome measured by morbidity and mortality is altered in the severely malnourished ICU patient, and nutritional support of the critically ill is accepted as a standard of care. Current recommendations suggest starting enteral feeding as soon as possible whenever the gastrointestinal tract is functioning. The disadvantage of enteral support is that inadequate energy and protein intake can occur. The present commentary focuses on some recent findings regarding the nutritional support of critically ill patients and proposes to promote mixed nutrition support by enteral nutrition (EN), and by parenteral nutrition (PN) whenever EN is insufficient.

RECENT FINDINGS

An increasing nutrition deficit during a long ICU stay is associated with increased morbidity (increased infection rate or impaired wound healing). Evidence shows that EN can result in underfeeding and that nutrition goals are reached only after 5-7 days. Contrary to former beliefs, recent meta-analyses of studies in the ICU showed that PN is not related to excess mortality but may even be associated with improved survival.

CONCLUSIONS

Optimising the increased substrate requirement for the critically ill by initiating timely nutrition support and ensuring tight glycaemic control with insulin is now considered central for improved intensive care outcomes. Supplemental PN combined with EN could be an effective alternative to achieve 100% of energy and protein targets at day 4, when EN alone fails to achieve goals greater than 60% by day 3. Whether such combined nutrition support provides additional benefit on overall outcome has to be ascertained in further studies.

Resting energy expenditure during mechanical ventilation and its relationship with the type of lesion

BACKGROUND

Resting energy expenditure (REE) of critically ill patients is usually calculated according to basal energy expenditure obtained from Harris-Benedict equations traditionally corrected by different stress factors, resulting in a variable accuracy for the individual patient. The objective of this study was to investigate whether or not the type of lesion affects the metabolism level of critically ill patients treated with mechanical ventilation. We performed a retrospective study measuring the REE of critically ill patients with 3 different types of lesions (trauma, medical, surgical) who were treated with mechanical ventilation and sedation. Each lesion group of patients was matched with another group, differing in the type of lesion, according to gender, age, and weight.

METHODS

Eighty-seven from a database of 175 critically ill patients undergoing indirect calorimetry were necessary for matching. Twenty matched pairs of patients for each of the following different type of lesion were obtained: medical vs surgical, medical vs trauma, and surgical vs trauma.

RESULTS

The mean REE difference was 52 kcal/d (95% confidence interval [CI] of -136 -241 kcal/d) for the medical vs surgical group, 5 kcal/d (95% CI -236 -247 kcal/d) for the medical vs trauma group and 43 kcal/d (95% CI of -132-219 kcal/d) for the surgical vs trauma group. No statistically significant differences between groups were found in the measured REE. We did not find statistically significant differences in the measured REE of patients with and without infection.

CONCLUSIONS

Critically ill patients with different types of lesion treated with mechanical ventilation have similar measured REE.