Daren K Heyland MD MSc FRCPC Professor of Medicine Queens University Kingston General Hospital Kingston Ontario A Randomized Trial of Supplemental Parenteral Nutrition in Under ID: 725379
Download Presentation The PPT/PDF document "The Inter-rater Reliability and Intra-ra..." is the property of its rightful owner. Permission is granted to download and print the materials on this web site for personal, non-commercial use only, and to display it on your personal computer provided you do not modify the materials and that you retain all copyright notices contained in the materials. By downloading content from our website, you accept the terms of this agreement.
Slide1
The Inter-rater Reliability and Intra-rater Reliability of Bedside Ultrasounds of the Femoral Muscle Thickness
Daren K. Heyland, MD, MSc, FRCPCProfessor of MedicineQueen’s University, Kingston General HospitalKingston, OntarioSlide2
A Randomized Trial of Supplemental Parenteral Nutrition in Under
and Over Weight Critically Ill Patients:The TOP UP TrialHypothesis: Increased energy and protein delivery to underweight and overweight critically illpatients (Body Mass Index [BMI] <25 or >35) will result in improved 60 day survival compared to usual care.Multicenter pilot studyRandomized trial of 160 critically ill adult patients from 8 tertiary care ICU’s in Canada, United States, and Europe.
Patients randomized to one of 2 interventions: enteral nutrition (EN) alone or enteral nutrition plus parenteral nutrition (supplemental PN group).
Patients stratified on the
basis of
admission BMI: <25 or
>35, medical or surgical admission diagnosis, by site and if EN was administered between ICU admission and randomization Primary outcome: 60 day mortality. Secondary outcomes: 28 day mortality, hospital mortality, duration of stay (ICU and hospital), multiple organ dysfunction (SOFA and PODS), duration of mechanical ventilation, development of ICU acquired infections, functional status at hospital discharge, and 3 and 6 month survival and health-related quality of life.Slide3
Weekly Ultrasounds
There is emerging evidence that muscle mass and muscle function predict morbidity in surviving patients and that muscle mass at ICU admission may predict length of hospital stay.We propose to evaluate the effect of differential amounts of protein and energy provided to study patients on muscle mass and function. We can postulate that the beneficial effect of enhanced energy and protein provision is mediated by the preservation (or attenuated deterioration) of muscle mass and increased function in these better fed patients, which would ultimately result in positive outcomes.We will evaluate muscle mass in all study patients using non-invasive bedside ultrasound of the femoral muscleSlide4
Testing Ultrasound Reliability before TOP-UP
Before we performed weekly ultrasounds on the study population, we conducted a trial of the ultrasound protocol to allow us to:standardize the training of all Study Investigators performing the ultrasound assessmenttest the feasibility of the procedures determine ‘normal’ values to which we can compare our measures in the study populationdetermine intra-rater (trainer) and the inter-rater (trainee) reliability.The ultrasound reliability trial involved: the 7 participating TOP UP sites
healthy volunteers a standardized protocol: ultrasound trainers were to perform ultrasounds twice on each patient
a trainee repeated the measurement on the same patient
The objective was to evaluate the inter-rater reliability and intra-rater reliability of bedside ultrasounds of the femoral muscle measuring muscle thickness in healthy volunteers before using this tool in detailing overall muscle mass in ICU patients.Slide5
Reliability Protocol
Trainer to complete a 2/3rd and midpoint ultrasound on each leg
Trainer to repeat a 2/3rd
and midpoint ultrasound on each leg (intra-rater reliability
test)
Trainee to complete a 2/3
rd
and midpoint ultrasound on each leg (inter-rater reliability test)
The overall muscle thickness was calculated as the average of the readings measured at the border between the lower third and upper two-thirds between Anterior Superior Iliac Spine (ASIS) and upper pole of the patella as well as the reading at the midpoint between the ASIS and the upper pole of the patella averaged over the right and left legs. Slide6
Volunteers’ Demographics
VariableN
Mean
Std Dev
Minimum
Maximum
Age
Height
Weight
BMI
64
78
78
78
30.6
171.4
71.2
24.1
8.4
11.5
16.4
4.4
21.0
135.0
46.0
16.9
55.0
196.0
136.4
40.7Slide7
Intra-rater Reliability Results
SiteSubjects
Between Subject Variance
Within Subject Variance
ICC
Erasme
University Hospital, Brussels, Belgium
10
0.2307
0.01380
0.94
Grey Nuns Hospital, Edmonton,
Alberta, Canada
0
NA
NA
NA
Royal Alexandra Hospital, Edmonton, Alberta, Canada
10
0.2425
0.001018>0.99Nouvel Hôpital Civil, Strasbourg, France40.25670.000199>0.99University of Alberta HospitalEdmonton, Alberta, Canada120.058660.0031800.95University of Colorado, Aurora, Colorado, USA50.28690.000613>0.99University of Texas Health Science Center, Houston, Texas, USA50.17740.0038370.98Pooled460.26480.0045540.98
ICC: Intra-class correlation coefficient,
ICC = between subject variance / (between subject variance +within subject variance)Slide8
Intra-rater Reliability Results (Continued)
The mean difference between trainer measurements (95% CI) = 0.037 (0.010 to 0.063) p=0.0077Mean difference between trainer measurement 1 and trainer measurement 2Trainer measurement 1
Trainer measurement 2
The paired t-test was used examine the average difference between the first and second trainer measurements.
The paired profile plot visualizes the difference in the paired measures.Slide9
Inter-rater Reliability Results
SiteSubjects
Between Subject Variance
Within Subject Variance
ICC
Erasme
University Hospital, Brussels, Belgium
10
0.2194
0.02900
0.88
Grey Nuns Hospital, Edmonton,
Alberta, Canada
13
0.3217
0.000769
>0.99
Royal Alexandra Hospital, Edmonton, Alberta, Canada
10
0.2305
0.020720.92Nouvel Hôpital Civil, Strasbourg, France180.26230.0099720.96University of Alberta HospitalEdmonton, Alberta, Canada120.035870.013600.73University of Colorado, Aurora, Colorado, USA50.17140.027460.86University of Texas Health Science Center, Houston, Texas, USA50.17040.033340.84Pooled730.25840.015800.94
ICC: Intra-class correlation coefficient,
ICC = between subject variance / (between subject variance +within subject variance)Slide10
Inter-rater Reliability Results (Continued)
There was a small but statistically significant difference between the trainer and trainee results: Mean (95% CI) = -0.061 cm (-0.100 to -0.022), p= 0.0028Mean difference between trainer measurement and trainee measurementTrainer
TraineeThe paired t-test was used examine the average difference between the first trainer and the trainee measurement.
Paired profile plots are provided to visualize the difference in the paired measures.Slide11
Conclusion
There is excellent inter and intra-rater reliability for ultrasound measurements of the femoral muscle to determine overall muscle thickness in healthy volunteers. A sample of ‘normal’ values is now available to compare measures from a study population. Further evaluation of this technique must be validated in critically ill patients. Efforts to link the ultrasound measurements to ICU outcomes should be undertaken. Slide12
Questions