Measuring the Metabolic Cost of Fever (IGUANA)

Measuring Energy Expenditure Before and After Fever in Critically Ill Children

Fever is part of the body's immune response, often triggered by infection. Fever is commonly treated with medicines such as paracetamol, mainly because people feel unwell with fever. However fever does have a role in fighting infection: it enables the rest of the immune system to function more efficiently, and may directly stop bacteria and viruses from multiplying. In most cases however treating fever does not matter because the rest of the immune system can cope well enough to fight the infection (with or without additional treatment, like antibiotics).

In critically ill patients however any advantage in the fight against infection may be crucial. In a large observational study of adult patients in the intensive care unit, patients who developed an early fever with temperature between 38.5-39.5 degrees C fared relatively better than patients who were colder. So it is possible that in critical illness fever may be beneficial. However in critical illness the body does have limited energy resources. In order to raise the body temperature energy is required. However the investigators do not know how much energy is required to generate a fever in critically ill children. This study will aim to try and measure the energy required to generate a fever in a critically ill child. The investigators will measure energy expenditure directly in children admitted to the intensive care unit by measuring the levels of oxygen and carbon dioxide they breathe in and out (a method called indirect calorimetry). This will enable the investigators to judge whether the benefits of a fever can be justified by the energy costs in the energy depleted state that is critical illness.

Study Overview

• Status: Terminated
• Conditions: Critical Illness; Child; Fever
• Intervention / Treatment: Device: Indirect calorimetry

• Study Type: Observational
• Enrollment (Actual): 12

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 1 second to 15 years (Child)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Probability Sample

Study Population

Critically ill children admitted on the intensive care unit at risk of developing fever

Description

Inclusion Criteria:

- all children on the paediatric intensive care unit at Great Ormond Street Hospital who

1. are likely to or have developed a fever (suspected infection, following trauma, post major surgery)
2. are over 10kg (approx 1 year of age)
3. are invasively ventilated

Exclusion Criteria:

- Children who

1. have a brain injury, where active temperature control may be instituted
2. patients post cardiac surgery
3. patient with or at risk of cardiac arrhythmias
4. patients post cardiac arrest
5. patient with refractory status epilepticus
6. children with a greater than 5% leak around the endotracheal tube
7. children with a fraction of inspired oxygen >0.6

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Febrile critically ill children; Children above 10kg admitted to the paediatric intensive care unit at Great Ormond Street Hospital who are mechanically ventilated and have a high likelihood of developing a fever. Energy expenditure will be measured using indirect calorimetry at baseline, and continuously during fever, until fever subsides.	Device: Indirect calorimetry; Indirect calorimetry measurement at baseline (stable state), at onset of fever and continued till fever dehiscence

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Percentage Change in Energy Expenditure Per Degree Celsius During Fever and Defervescence	Children at risk of fever will have energy expenditure measured by indirect calorimetry at baseline, when the develop a fever, and continuously until fever dehisces. Change in energy expenditure during fever to be calculated as difference in energy expenditure at the maximum temperature minus the energy expenditure at baseline, divided by the difference in temperature. Change in energy expenditure during defervescence to be calculated as difference in energy expenditure at the maximum temperature and the lowest temperature following the fall in temperature, divided by the difference in temperature. Both will also be expressed as a % of the starting energy expenditure (i.e. from baseline for change during fever, from maximum temperature during defervescence)	6 hours

Collaborators and Investigators

• Sponsor: Great Ormond Street Hospital for Children NHS Foundation Trust
• Investigators: Principal Investigator: Mark J Peters, MBBCh PhD, UCL Great Ormond Street Institute of Child Health

Study record dates

Study Major Dates

• Study Start (Actual): November 1, 2016
• Primary Completion (Actual): November 1, 2017
• Study Completion (Actual): November 1, 2018

Study Registration Dates

• First Submitted: October 11, 2016
• First Submitted That Met QC Criteria: October 18, 2016
• First Posted (Estimate): October 20, 2016

Study Record Updates

• Last Update Posted (Actual): June 25, 2021
• Last Update Submitted That Met QC Criteria: June 24, 2021
• Last Verified: October 1, 2016

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Pathologic Processes; Disease Attributes; Body Temperature Changes; Critical Illness; Fever
• Other Study ID Numbers: 209010

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No