CI: Calorie/Energy Needs (2007)

Study Design:
- Click here for explanation of classification scheme.
Quality Rating:
Research Purpose:
Assess the relationship between energy balance and outcome in critically ill patients
Inclusion Criteria:
  • Consecutive patients staying for more than 5 days in the SICU
Exclusion Criteria:
  • Short stay
  • Major burns
Description of Study Protocol:

Recruitment Consecutive patients admitted to SICU meeting inclusion criteria

Design Baseline data were collected, nutritional support was given and clinical follow up was provided for 30 days.

Blinding used: NA

Intervention: NA

Statistical Analysis: Data are presented as means, medians, and ranges.  Analyis of daily and weekly values of relevant variables was done using one-way ANOVA.  Non-parametric test was applied.  Multiple linear regressions were performed to identify predictors of energy balance using standar least squares.  Significance was considered at the level of p<0.05.


Data Collection Summary:

Timing of Measurements:

  • At baseline: age, sex, pre-event weight, height, BMI, severity of disease (SAPS II), organ failure.
  • Weekly: weight, organ failure via SAPS II, blood samples for albumin, pre-albumin and c-reactive protein.
  • At 30 days: length of mechanical ventilation, infections, use of antibiotics, duration of ICU stay, complications and mortality.

Dependent Variables

  • Clinical outcome

Independent Variables

  • Energy balance

Control Variables

  •  provided energy based on measured energy expenditure by indirect calorimetry or 30 kcal per kg per day
Description of Actual Data Sample:
Initial N: 48 SICU patients (669 ICU days) (30 men, 18 women)

Age: 57+16 (range 18-82) years

Other relevant demographics: SAPS II score 45+16 (median 46; range 14-94), failing organs 3.2+1.5 (median 3; range 1-4),

Location: Centre Hospitalier Universitaire Vaudois, Lausanne Switzerland


Summary of Results:
  •  Nutrition support was started 3.1+2.2 days after admission, resulting in 101 days without any feeding (15.1%).
  • 75% of subjects were fed exclusively by the enteral route, 23%  received combined enteral and parenteral nutrition and 2% was fed exclusively intravenously (P<0.0001 between enteral and either parenteral or combined routes). 
  • Energy delivery was lowest during the first week.  The difference between energy target and delivery decreased from -1270 Cal/ day as a mean to -625 Cal/day during the 4th week.
  • Length of ICU stay was correlated with cumulated energy deficit (P<0.0001)
  • Energy deficit after 7 days accumulated during the stay correlated with total (P=0.048) and infectious complications (P=0.0049)

Relationship between complications and cumulated energy deficit by regression analysis

Variables P Value
LOS 0.0001
Complications 0.0003
Infections 0.0042
Days on antibiotics 0.0003
Start of nutrition 0.0002
Dats if mechanical ventilation 0.0002


Author Conclusion:

The study confirms that

  • negative energy balances are very frequent during severe criticall illness despite nutrition protocols
  • underfeeding is correlated with increasing number of complications, particularly infections
  • energy debt is initiated during the first week after admission
  • delaying the initiation of nutrition support exposes patients to energy deficits that cannot be compensated during the remaining ICU stay
  • combined nutritional support only moderately reversed the building up deficiency
Funding Source:
University/Hospital: Univeritaire Vaudois (Switzerland), CHU de Brest (France)
Reviewer Comments:
Quality Criteria Checklist: Primary Research
Relevance Questions
  1. Would implementing the studied intervention or procedure (if found successful) result in improved outcomes for the patients/clients/population group? (Not Applicable for some epidemiological studies) N/A
  2. Did the authors study an outcome (dependent variable) or topic that the patients/clients/population group would care about? Yes
  3. Is the focus of the intervention or procedure (independent variable) or topic of study a common issue of concern to dieteticspractice? Yes
  4. Is the intervention or procedure feasible? (NA for some epidemiological studies) N/A
Validity Questions
1. Was the research question clearly stated? Yes
  1.1. Was (were) the specific intervention(s) or procedure(s) [independent variable(s)] identified? Yes
  1.2. Was (were) the outcome(s) [dependent variable(s)] clearly indicated? Yes
  1.3. Were the target population and setting specified? Yes
2. Was the selection of study subjects/patients free from bias? Yes
  2.1. Were inclusion/exclusion criteria specified (e.g., risk, point in disease progression, diagnostic or prognosis criteria), and with sufficient detail and without omitting criteria critical to the study? Yes
  2.2. Were criteria applied equally to all study groups? N/A
  2.3. Were health, demographics, and other characteristics of subjects described? Yes
  2.4. Were the subjects/patients a representative sample of the relevant population? Yes
3. Were study groups comparable? N/A
  3.1. Was the method of assigning subjects/patients to groups described and unbiased? (Method of randomization identified if RCT) N/A
  3.2. Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline? N/A
  3.3. Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.) Yes
  3.4. If cohort study or cross-sectional study, were groups comparable on important confounding factors and/or were preexisting differences accounted for by using appropriate adjustments in statistical analysis? N/A
  3.5. If case control study, were potential confounding factors comparable for cases and controls? (If case series or trial with subjects serving as own control, this criterion is not applicable.) N/A
  3.6. If diagnostic test, was there an independent blind comparison with an appropriate reference standard (e.g., "gold standard")? N/A
4. Was method of handling withdrawals described? Yes
  4.1. Were follow-up methods described and the same for all groups? Yes
  4.2. Was the number, characteristics of withdrawals (i.e., dropouts, lost to follow up, attrition rate) and/or response rate (cross-sectional studies) described for each group? (Follow up goal for a strong study is 80%.) Yes
  4.3. Were all enrolled subjects/patients (in the original sample) accounted for? Yes
  4.4. Were reasons for withdrawals similar across groups? N/A
  4.5. If diagnostic test, was decision to perform reference test not dependent on results of test under study? N/A
5. Was blinding used to prevent introduction of bias? N/A
  5.1. In intervention study, were subjects, clinicians/practitioners, and investigators blinded to treatment group, as appropriate? N/A
  5.2. Were data collectors blinded for outcomes assessment? (If outcome is measured using an objective test, such as a lab value, this criterion is assumed to be met.) ???
  5.3. In cohort study or cross-sectional study, were measurements of outcomes and risk factors blinded? No
  5.4. In case control study, was case definition explicit and case ascertainment not influenced by exposure status? N/A
  5.5. In diagnostic study, were test results blinded to patient history and other test results? N/A
6. Were intervention/therapeutic regimens/exposure factor or procedure and any comparison(s) described in detail? Were interveningfactors described? Yes
  6.1. In RCT or other intervention trial, were protocols described for all regimens studied? N/A
  6.2. In observational study, were interventions, study settings, and clinicians/provider described? Yes
  6.3. Was the intensity and duration of the intervention or exposure factor sufficient to produce a meaningful effect? Yes
  6.4. Was the amount of exposure and, if relevant, subject/patient compliance measured? N/A
  6.5. Were co-interventions (e.g., ancillary treatments, other therapies) described? N/A
  6.6. Were extra or unplanned treatments described? N/A
  6.7. Was the information for 6.4, 6.5, and 6.6 assessed the same way for all groups? N/A
  6.8. In diagnostic study, were details of test administration and replication sufficient? N/A
7. Were outcomes clearly defined and the measurements valid and reliable? Yes
  7.1. Were primary and secondary endpoints described and relevant to the question? Yes
  7.2. Were nutrition measures appropriate to question and outcomes of concern? Yes
  7.3. Was the period of follow-up long enough for important outcome(s) to occur? Yes
  7.4. Were the observations and measurements based on standard, valid, and reliable data collection instruments/tests/procedures? Yes
  7.5. Was the measurement of effect at an appropriate level of precision? Yes
  7.6. Were other factors accounted for (measured) that could affect outcomes? ???
  7.7. Were the measurements conducted consistently across groups? N/A
8. Was the statistical analysis appropriate for the study design and type of outcome indicators? Yes
  8.1. Were statistical analyses adequately described and the results reported appropriately? Yes
  8.2. Were correct statistical tests used and assumptions of test not violated? Yes
  8.3. Were statistics reported with levels of significance and/or confidence intervals? Yes
  8.4. Was "intent to treat" analysis of outcomes done (and as appropriate, was there an analysis of outcomes for those maximally exposed or a dose-response analysis)? N/A
  8.5. Were adequate adjustments made for effects of confounding factors that might have affected the outcomes (e.g., multivariate analyses)? Yes
  8.6. Was clinical significance as well as statistical significance reported? Yes
  8.7. If negative findings, was a power calculation reported to address type 2 error? N/A
9. Are conclusions supported by results with biases and limitations taken into consideration? Yes
  9.1. Is there a discussion of findings? Yes
  9.2. Are biases and study limitations identified and discussed? Yes
10. Is bias due to study's funding or sponsorship unlikely? Yes
  10.1. Were sources of funding and investigators' affiliations described? Yes
  10.2. Was the study free from apparent conflict of interest? Yes