CI: Enteral Nutrition Energy Delivery (2012)
Faisy C, Lerolle N, Dachraoui F, Savard JF, Abboud I, Tadie JM, Fagon JY. Impact of energy deficit calculated by a predictive method on outcome in medical patients requiring prolonged acute mechanical ventilation. Br J Nutr. 2009 Apr; 101 (7): 1,079-1,087. PMID: 18778528.PubMed ID: 18778528
To identify determinants of energy balance as determined by an equation and relationship to ICU outcome among severely-ill patients requiring prolonged acute mechanical ventilation and who are exclusively receiving EN.
- Adult patients admitted to the ICU over a one-year period
- Required endotracheal intubation and mechanical ventilation fewer than six hours after ICU admission
- Remained intubated for at least seven days.
Patients were excluded if they were:
- Intubated over six hours after ICU admission
- Intubated for less than seven days
- Not receiving EN due to complete intestinal obstruction or ileus, intractable vomiting or severe diarrhea, intestinal ischemia, gastrointestinal hemorrhage and high-output enterocutaneous fistulas
- Missing or incomplete data.
- Recruitment: Admission to the ICU
- Design: Retrospective cohort (divided into ICU survivors or deaths)
- Intervention: Not applicable.
- Paired T-tests, Mann-Whitney or Fisher's tests were applied for comparison of relevant variables
- Logistic regression was used for multi-variate analysis
- Mantel-Haenszel tests were used to assess the relationship between ICU mortality and quartiles of mean energy balance
- A receiver operating characteristics curve was generated with non-parametric method to determine the best operating point as mean energy deficit threshold for predicting ICU mortality
- Kaplan-Meier curves were used to analyze ICU survival with comparison between groups determined by log-rank tests
- StatView 4.5 and EPI INFO 3.4 software were used to calculate statistical analysis
- Statistical significance was set at P<0.05.
Timing of Measurements
- Main diagnosis
- Simplified Acute Physiology Score II (SAPS II)
- Diagnosis of septic shock in the presence of documented infection (bacteremia, urinary tract infection and pneumonia).
- Each day of mechanical ventilation (retrospectively collected from charts prospectively completed by nurses)
- Weight measured with a mobile electronic scale
- Temperature (mean of four values, measured electronically in the ear at six-hour intervals during the day)
- Minute ventilation (mean of four values, determined with the respiratory device at six-hour intervals during the day).
- Assessed from charts
- Total duration of EN interruptions (expressed as a percentages of survey time) due to:
- Gastrointestinal intolerance (vomiting, severe diarrhea, ileus)
- Diagnostic and therapeutic procedures.
- Estimated total length (percentage of survey time) of conditions that could decrease nutrient absorption or limit the volume of feeding rate prescription:
- Use of sedatives, opioids, neuromuscular blocking agents or vasopressors
- Presence of renal failure (defined as creatinine clearance <50 ml per minute) with fluid overload.
- Total duration of EN interruptions (expressed as a percentages of survey time) due to:
- Prolonged mechanical ventilation.
- Energy balance
- Total energy prescribed, as calculated from glucose infusions and exclusive EN prescriptions
- Energy delivered was determined by documentation by nursing, including EN and glucose infusions actually administered per day
- Recommended energy was the target feeding prescription
- Daily REE was retrospectively calculated with the following predictive equation: (8 x body weight in kg) + (14 x height in cm) + (32 x minute ventilation in liters per minute) + (94 x body temperature in degrees Celsius) - 4,834
- Energy balance (expressed as kJ per day of mechanical ventilation) was calculated as follows: Energy delivered - calculated REE
- Energy deficit was assumed to be the same as negative energy balance.
- EN was to be started within 24 hours of ICU admission
- Target feeding recommendations were 125.5kJ per kg (30kcal per kg) per day or per kg ideal body weight per day if body mass index (BMI) was over 25kg per m2
- Patients received a polymeric isoenergetic solution, delivered by continuous, pump-driving infusion via nasogastric tubes.
- Initial N: 42 of 684 (6%) consecutive patients admitted to the ICU were eligible for analysis; four eligible patients were excluded because of incomplete or missing files; 38 patients were included (55% male)
- Final N: 38
- Age: Mean, 67.1 years
- Ethnicity: Not described.
Other Relevant Demographics
- Mean length of stay before ICU admission: 6.1 days
- Mean SAPS II at ICU admission: 45.6
- Mean length if ICU stay: 28.0 days
- Mean length of invasive ventilation: 23.4 days
- ICU death: 27 patients (72%).
- Mean height at ICU admission: 167.1cm
- Mean weight at ICU admission: 71.6kg.
Other Relevance Characteristics
- 20-bed medical ICU at a tertiary teaching hospital
- Main diagnoses at ICU admission:
- Septic shock (N=19)
- Acute respiratory failure due to congestive heart failure (N=11)
- Acute respiratory distress syndrome (N=4)
- Non-traumatic coma (N=4).
Impact of energy balance on ICU mortality
- ICU mortality was 72%
- Mean energy balance was -5,439±222kJ per day (1,300±53kcal per day)
- Total of 71% of the energy prescribed was delivered
- Mean energy deficit was higher among non-survivors than survivors (P=0.004)
- Energy deficit was independently associated with ICU death (P=0.02)
- Higher ICU mortality was seen as energy deficit increased (P=0.003)
- Higher ICU mortality was observed among patients with a mean energy deficit of at least 5,021kJ per day (1,200kcal per day) of mechanical ventilation after ICU Day 14 (P=0.01).
- EN was interrupted due to procedures or severe gastrointestinal intolerance for 23% of the survey time, which may have explained the differences between delivered and prescribed energy
- Situations (use of sedatives, opioids, neuromuscular blocking agents, vasopressors, renal failure with fluid overload) that limited administration of EN reached 64%.
Large negative energy balance may be an independent determinant of ICU mortality among patients requiring prolonged acute mechanical ventilation, especially when energy deficit exceeds 5,021kJ per day (1,200kcal per day).
|University/Hospital:||Service de Reanimation Medicale, Hopital Europeen Georges Pompidou, Paris, France|
This study may have been under-powered.
Quality Criteria Checklist: Primary Research
|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|
|1.||Was the research question clearly stated?||Yes|
|1.1.||Was (were) the specific intervention(s) or procedure(s) [independent variable(s)] identified?||N/A|
|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?||Yes|
|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?||Yes|
|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?||Yes|
|3.3.||Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.)||N/A|
|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?||Yes|
|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?||N/A|
|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%.)||N/A|
|4.3.||Were all enrolled subjects/patients (in the original sample) accounted for?||Yes|
|4.4.||Were reasons for withdrawals similar across groups?||Yes|
|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?||Yes|
|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.)||Yes|
|5.3.||In cohort study or cross-sectional study, were measurements of outcomes and risk factors blinded?||Yes|
|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?||Yes|
|6.5.||Were co-interventions (e.g., ancillary treatments, other therapies) described?||Yes|
|6.6.||Were extra or unplanned treatments described?||Yes|
|6.7.||Was the information for 6.4, 6.5, and 6.6 assessed the same way for all groups?||Yes|
|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?||Yes|
|7.7.||Were the measurements conducted consistently across groups?||Yes|
|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|