CI: Blood Glucose Control (2009)

Citation:

Grey NJ, Perdrizet GA. Reduction of nosocomial infections in the surgical intensive-care unit by strict glycemic control. Endocr Pract. 2004 Mar-Apr;10 Suppl 2:46-52.

PubMed ID: 15251640
 
Study Design:
Randomized Controlled Trial
Class:
A - Click here for explanation of classification scheme.
Quality Rating:
Neutral NEUTRAL: See Quality Criteria Checklist below.
Research Purpose:
To test the hypothesis that strict glycemic control will decrease the rate of nosocomial infections in patients in the surgical ICU.
Inclusion Criteria:

Adult patients admitted to a 12 bed surgical ICU requiring treatment of hyperglycemia. 

Exclusion Criteria:

Patients expected to have a brief stay or not expected to survive beyond 48 hours, with active infections, with disseminated cancer or receiving chemotherapy, irradiation or corticosteroids were excluded from the study.

 

Description of Study Protocol:

Recruitment: Patients were recruited from surgical ICU of a large teaching hospital in Hartford, Connecticut.

Study Design: Prospective randomized controlled clinical trial. Randomization to receive standard glucose control or strict glucose control was determined by coin toss

Blinding Used: None

Intervention: Intravenous insulin infusions were administered to maintain serum glucose values in the range of 180-220 mg/dl in the standard control group and from 80-120 mg/dl in the strict control group.

Statistical Analysis: There is no discussion of the statistical methods used, although the investigators report p values. Demographic data, comorbidities, and confounding variables were analyzed. Outcome measures included mean daily serum glucose values, mean insulin doses and number of nosocomial infections during the ICU stay

Data Collection Summary:

Timing of measurements: Frequency of blood glucose measures based on insulin algorithms and supplemented by clinical judgment of nurses at bedside.

Dependent variable: Incidence of nosocomial infection (defined in accordance with CDC classification). Infections were classified as intravascular device infection, bloodstream infection, surgical site infection, pneumonia, or urinary tract infection per 1,000 surgical ICU days.

Independent variable: Serum glucose values

Control Variables: Age, sex, BMI, ethnicity, incidence of diabetes, presence of comorbidities, duration of surgical ICU stay, proportion receiving parental nutrition, APACHE, American Society of Anesthesiologists score, blood transfusion history, initial serum glucose value, and antimicrobial administration.

Description of Actual Data Sample:

Initial N: 61  (69% male gender)

  • standard glucose group n=27 for 663 ICU days
  • strict glucose control group n=34 for 761 ICU days

Attrition: No significant differences between groups for in-hospital mortality

  • standard glucose control group (21%)
  • strict glucose control group (11%)

Age: Mean age standard glucose control 55 ± 22; strict glucose control 56 ± 22.

Ethnicity: Not described

Other relevant demographics: APACHE II: Standard control: 15.6 ± 7.4; Strict control: 15.1 ± 6.5 (p=0.79)

Anthropometrics:

  • Groups were not significantly different on important measures that included mean serum glucose values at time of study enrollment, mean age, female:male, BMI, APACHE II (acute phpysiologic assessment and chronic health evaluation) score, ASA (American Society of Anesthesiologist) score, diabetes, corticosteroids, vasopressor, renal replacement, hospital mortality, mean SICU days.

 Location: Surgical ICU at Hartford Hospital and Univ. of Connecticut Health Sciences Center, Hartford, Connecticut

Summary of Results:

Results:

Variable

Standard glucose control group

Strict glucose control group

P value

Group mean glucose

125 ± 36 mg/dL

179 ± 61 mg/dL

< 0.001

Episodes of hypergycemia

32%

7.4%

<0.001

Other Findings

  • Standard group had 4-fold increase in intravascular device (IVDI) infections and blood stream infections when compared to strict glucose control group (p=0.05);
  • Standard group had 3.5 fold increase in related bloodstream infections and surgical site infections when compared to strict glucose control group (p=0.05)
  • Urinary tract infections and nosocomial pneumonia were not significantly changed.
  • No significant difference for in-hospital mortality (death) between groups.

 

Author Conclusion:

Strict glycemic control is a safe and effective method for reducing incidence of nosocomial infections in a predominantly nondiabetic, general surgical ICU patient population.

Funding Source:
Reviewer Comments:

This paper would have been strengthened by including a section on statistical analyses and including data about infection rates in table rather than figure format. The discussion of findings is very brief. The authors did not address limitations of the study.

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? 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? 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) Yes
  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? 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? No
  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? 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? No
  5.1. In intervention study, were subjects, clinicians/practitioners, and investigators blinded to treatment group, as appropriate? No
  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? 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? Yes
  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? 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? No
  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? No
  7.1. Were primary and secondary endpoints described and relevant to the question? No
  7.2. Were nutrition measures appropriate to question and outcomes of concern? No
  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? No
  7.5. Was the measurement of effect at an appropriate level of precision? No
  7.6. Were other factors accounted for (measured) that could affect outcomes? No
  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? ???
  8.1. Were statistical analyses adequately described and the results reported appropriately? No
  8.2. Were correct statistical tests used and assumptions of test not violated? ???
  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)? No
  8.5. Were adequate adjustments made for effects of confounding factors that might have affected the outcomes (e.g., multivariate analyses)? No
  8.6. Was clinical significance as well as statistical significance reported? No
  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? No
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