Original article
Do PICU patients meet technical criteria for performing indirect
calorimetry?
Megan R. Beggs
a, b
, Gonzalo Garcia Guerra
b, c
, Bodil M.K. Larsen
a, b, c, *
a
Nutrition Services, Alberta Health Services, Canada
b
Stollery Children's Hospital, Edmonton, Canada
c
Department of Pediatrics, University of Alberta, Edmonton, Canada
article info
Article history:
Received 14 March 2016
Accepted 13 June 2016
Keywords:
Indirect calorimetry
Energy
Critical care
Infant
Child
Nutrition
summary
Background & Aims: Indirect calorimetry (IC) is considered gold standard for assessing energy needs of
critically ill children as predictive equations and clinical status indicators are often unreliable. Accurate
assessment of energy requirements in this vulnerable population is essential given the high risk of over
or underfeeding and the consequences thereof. The proportion of patients and patient days in pediatric
intensive care (PICU) for which energy expenditure (EE) can be measured using IC is currently unknown.
In the current study, we aimed to quantify the daily proportion of consecutive PICU patients who met
technical criteria to perform indirect calorimetry and describe the technical contraindications when
criteria were not met.
Methods: Prospective, observational, single-centre study conducted in a cardiac and general PICU. All
consecutive patients admitted for at least 96 h were included in the study. Variables collected for each
patient included age at admission, admission diagnosis, and if technical criteria for indirect calorimetry
were met. Technical criteria variables were collected within the same 2 h each morning and include:
provision of supplemental oxygen, ventilator settings, endotracheal tube (ETT) leak, diagnosis of chest
tube air leak, provision of external gas support (i.e. nitric oxide), and provision of extracorporeal
membrane oxygenation (ECMO).
Results: 288 patients were included for a total of 3590 patient days between June 2014 and February
2015. The main reasons for admission were: surgery (cardiac and non-cardiac), respiratory distress,
trauma, oncology and medicine/other. The median (interquartile range) patient age was 0.7 (0.3e4.6)
years. The median length of PICU stay was 7 (5e14) days. Only 34% (95% CI, 32.4e35.5%) of patient days
met technical criteria for IC. For patients less than 6 months of age, technical criteria were met on
significantly fewer patient days (29%, p < 0.01). Moreover, 27% of patients did not meet technical criteria
for IC on any day during their PICU stay. Most frequent reasons for why IC could not be performed
included supplemental oxygen, ECMO, and ETT leak.
Conclusions: In the current study, technical criteria to perform IC in the PICU were not met for 27% of
patients and were not met on 66% of patient days. Moreover, criteria were met on only 29% of days for
infants 6 months and younger where children 24 months of age and older still only met criteria on 40% of
patient days. This data represents a major gap in the feasibility of current recommendations for assessing
energy requirements of this population. Future studies are needed to improve methods of predicting and
measuring energy requirements in critically ill children who do not meet current criteria for indirect
calorimetry.
© 2016 European Society for Clinical Nutrition and Metabolism. Published by Elsevier Ltd. All rights
reserved.
1. Introduction
Critical illness in infants and children is characterized by
metabolic changes involving stress hormones, inflammation,
catabolism, and changing energy requirements [1]. Clinical
* Corresponding author. Stollery Children's Hospital, 3G1.23 Walter C. McKenzie
Centre, 8440-112 Street, Edmonton, T6G 2B7, Alberta, Canada.
E-mail addresses: Megan.Beggs@albertahealthservices.ca (M.R. Beggs),
Gonzalo.Guerra@albertahealthservices.ca (G. Garcia Guerra), Bodil.Larsen@
albertahealthservices.ca (B.M.K. Larsen).
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Clinical Nutrition ESPEN
journal homepage: http://www.clinicalnutritionespen.com
http://dx.doi.org/10.1016/j.clnesp.2016.06.003
2405-4577/© 2016 European Society for Clinical Nutrition and Metabolism. Published by Elsevier Ltd. All rights reserved.
Clinical Nutrition ESPEN 15 (2016) 80e84