EE: Application of RQ (2005)

Citation:

Jeevandandam M, Shamos R, Petersen S. Substrate efficacy in early nutrition support of critically ill multiple trauma victims. JPEN 1992;16(6):511-520.

 
Study Design:
Nonrandom
Class:
C - Click here for explanation of classification scheme.
Quality Rating:
Positive POSITIVE: See Quality Criteria Checklist below.
Research Purpose:

To compare the metabolic and hormonal responses to infusion of glucose alone as the sole nutrient source or the infusion of amino acids and glucose as TPN in severely injured trauma victims during the early catabolic phase of injury.

Definitions

  • RmE: energy expenditure at rest
  • AmE:  active metabolic expenditure
  • SDA: specific dynamic action of ingested nutrients
  • REE: resting energy expenditure, the sum of RmE and SDA.
Inclusion Criteria:
  1. At least one life-threatening major injury and multiple minor injuries with an injury severity score ranging from 22-50.
  2. On mechanical ventilation.
  3. Stable cardiopulmonary condition.
  4. Studied 48-60 hours after injury.
Exclusion Criteria:
  1. Refusal to consent
  2. Not meeting inclusion criteria
  3. Diseases in subjects that were excluded: diabetes, liver dysfunction, renal problems, malignant diseases, infection, recent weight loss.
Description of Study Protocol:

Each pt was studied twice

Study 1: (Trauma-basal) was the early flow phase of injury and they were receiving no calories or N; only electrolytes

Study 2: (Trauma TPN or Trauma Glu) was after 4-6 days of nutrition support.

Whole body lipid kinetic study: A 2-staged (each 70 minutes) primed-constant infusion of glycerol (10% wt/wt) was infused. During the last 10 minutes of each stage, 3 blood samples were drawn and correctly stored for analysis within 1 week.

Whole body protein kinetic study: At the end of this initial study (study 1) nutrition support was instituted and continued for 4-6 days.

Study 2: After 4-6 days of continuous feeding, the protein kinetic study was repeated, followed by the metabolic cart measurements for IC and then a repeat lipid kinetic study.

Control group: Postabsorptive blood samples after overnight fasting and 24-hour urine samples were collected from 14 healthy volunteers. They were not on any relevant medication. There were no activity or diet restrictions, and no kinetic data was obtained from them.

ANTHROPOMETRIC

  • Ht measured? yes
  • Wt measured? yes
  • Fat-free mass measured? No
  • BMI measured? Yes

CLINICAL

  • Monitored heart rate? Not stated
  • Body temperature? Implied since pts were followed for sepsis
  • Medications administered? Yes, no medications that would affect energy and protein metabolism.

24 hour urine collections and morning blood samples for BUN were collected daily.

Resting energy expenditure

  • IC type: Horizon Metabolic Measurement Cart, System 4400, Sensormedics, Anaheim, CA
  • Equipment of Calibration: Before each test, at least two standard calibrating gases were used, and stability was observed for at least a 10 minute equilibration period.
  • Coefficient of variation using std gases: Not stated but see above
  • Rest before measure (state length of time rested if available): Not available
  • Measurement length: 20 minute period of continuous sampling
  • Steady state: 10 minute equilibration
  • Fasting length: Measured b/t 8-9 a.m.; basal only electrolytes and then afer all pt on TPN for 4-6 h
  • Exercise restrictions: On mechanical ventilation
  • Room temp: not addressed
  • No. of measures within the measurement period: not stated
  • Were some measures eliminated? Not stated
  • Were a set of measurements averaged? Likely non steady state
  • Coefficient of variation in subjects measures? Not stated
  • Training of measurer? Yes, see acknowledgement to Rick Wade
  • Subject training of measuring process? Not stated

DIETARY

  • Parenteral: 25% dextrose (4.8±0.6 mg glucose/kg/minute), 8.5% AA (contained 250-300 mg N/kg/d)
  • Energy needs were measured using the Harris-Benedict formula; 8 patients were given glucose alone and 10 were given glucose and amino acids.
Data Collection Summary:

Outcome(s) and other measures

  1. Means of oxygen consumption and carbon dioxide production were used to calculate REE and substrate oxication rates.
  2. Measured urinary nitrogen and ammonia excretion g/24h
  3. Independent variables of weight, height, age, BMI.

Blinding used: No

Description of Actual Data Sample:

Trauma TPN

  • N=10; 7 males, 3 females
  • Mean age, y: 34±5
  • ISS: 32.7±2.7
  • BMI, kg/m2: 28.8±1.9

Trauma Glucose

  • N=8; 6 males, 2 females
  • ISS: 30.9±2.1
  • BMI, kg/m2: 26.6±2.3

The trauma groups were pooled to assess basal values, since they were very similar.

[Analyst note: only Trauma TPN group appraised for RQ question]

Control group

  • N=14; No age range given.
  • Statistical tests: Student’s t-test for unpaired samples (comparison of the means between the groups) and paired data analysis (comparison of values before and during nutrition therapy) were used. Significant differences were reported if P<0.05.
Summary of Results:

Comparison of Trauma-basal (pooled) with normal controls confirmed hypoaminoacidemia, hyperglycemia, hyperketonemia, elevated levels of counterregulatory horrnones and decreased levels of anabolic hGH and IGF-1.

Compared to Trauma basal, nutrition treatment raised the RQ but it never exceeded 1.0, indicating the absence of net lipid synthesis and the efficient disposal of glucose.

Group mean basal RQ before TPN intitiaion was 0.73±0.03; 4-6 days after isocaloric continuous TPN to meet 100% measured REE, group mean RQ was 0.82±0.04.

[Analyst note: assuming normality, 98% of pts had a RQ that fell within 0.54-0.92 to XX for basal and 0.567-1.073 after 4-6 days of continuous TPN (without lipids).]

Calculations

  • v10x0.03=0.095 (1 SD)
  • 0.095x2=0.19 (2 SD)
  • v10x0.04=0.126 (1 SD)
  • 0.126x2=0.253 (2 SD)

ANTHROPOMETRIC

Mean±SEM TPN    Glu

Wt, kg 

86.5±6.9   40±9

Ht, m   

not given
BMI      28.8±1.9   26.6±2.3

BSA   

1.98±0.09      1.89±0.05
          

Author Conclusion:

As stated by the authors in body of report

“...during the early catabolic flow phase of injury, infusion of hypertonic glucose alone restores PSE, spares labile protein pool, significantly diminishes lipolysis, fat oxidation, and reesterification rates, and provides a favorable hormonal environment.

“Pt were given nonprotein calories not to exceed their measured REE adjusted to the activity evneryg expenditure (7-10% of REE) will be just enough in this postinjury period. This calorie provision may not result in the diversion of glucose to fat synthesis as indicated by the RQ, which is less than 1.0 and the O2consumption is minimally changed whether glucose is given with or without amino acids.

Addition of adequate amino acids to the same glucose load could not improve the above metabolic responses. The results suggest that the injured patient could not efficiently accept the protein load at this stage of injury, and hence its provision could be avoided without metabolic consequences. Thus, the recommended nutrition therapy should be time dependent with the administration of glucose alone (not to exceed REE) during the first 5 posttrauma days, followed by conventional TPN…in the late catabolic and early anabolic stages of injury recovery.”
Funding Source:
Government: Arizona Disease Control Research Commission
Reviewer Comments:

Strengths 

  • Clinically relevant
  • Meticulously detailed.
  • Credible use of statistics.

Generalizability/Weaknesses

  • Limitations were not discussed.
  • Small sample size
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) Yes
  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) Yes
 
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? N/A
  1.2. Was (were) the outcome(s) [dependent variable(s)] clearly indicated? N/A
  1.3. Were the target population and setting specified? N/A
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? N/A
  2.2. Were criteria applied equally to all study groups? N/A
  2.3. Were health, demographics, and other characteristics of subjects described? N/A
  2.4. Were the subjects/patients a representative sample of the relevant population? N/A
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? N/A
  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? 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? No
  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? N/A
  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? No
  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.) N/A
  5.3. In cohort study or cross-sectional study, were measurements of outcomes and risk factors blinded? N/A
  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? N/A
  6.3. Was the intensity and duration of the intervention or exposure factor sufficient to produce a meaningful effect? N/A
  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? N/A
  7.2. Were nutrition measures appropriate to question and outcomes of concern? N/A
  7.3. Was the period of follow-up long enough for important outcome(s) to occur? N/A
  7.4. Were the observations and measurements based on standard, valid, and reliable data collection instruments/tests/procedures? N/A
  7.5. Was the measurement of effect at an appropriate level of precision? N/A
  7.6. Were other factors accounted for (measured) that could affect outcomes? N/A
  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? N/A
  8.2. Were correct statistical tests used and assumptions of test not violated? N/A
  8.3. Were statistics reported with levels of significance and/or confidence intervals? N/A
  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)? N/A
  8.6. Was clinical significance as well as statistical significance reported? N/A
  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? N/A
  9.2. Are biases and study limitations identified and discussed? N/A
10. Is bias due to study's funding or sponsorship unlikely? Yes
  10.1. Were sources of funding and investigators' affiliations described? N/A
  10.2. Was the study free from apparent conflict of interest? N/A