POLAR-BEAR

POLAR-BEAR: Prophylactic hypothermia trial to Lessen traumatic brain injury – Basal Energy Assessment Research

The POLAR-BEAR Study is a sub-study of 40 patients enrolled into the POLAR-RCT Study (a prospective, randomised controlled trial).

Goal: The primary objective is to assess the daily energy expenditure (as measured by indirect calorimetry) in traumatic brain injury (TBI) patients over the first 72 hours after enrolment in the POLAR-RCT Study so as to compare patients who receive induced hypothermia with those who receive normothermia. The secondary objective is to assess the daily energy expenditure (as measured by indirect calorimetry) in TBI patients who receive either induced hypothermia or normothermia until the end of their period on mechanical ventilation.

Rationale: TBI is one of the leading causes of hospitalisation, death and disability worldwide, particularly in young adults. Hypothermia is one of the most promising interventions to improve outcomes and may well become a standard of care if the POLAR-RCT Study shows improved outcomes due to induced hypothermia. Nutrition therapy is also a powerful intervention although determining the optimal amount remains a challenge especially as the various interventions such as hypothermia that are used can affect the energy expenditure of the TBI patient. By knowing how energy expenditure changes both in response to hypothermia and throughout the course of the post-hypothermia period, clinicians will have significantly more knowledge about nutritional goals. Optimising nutritional delivery requires clinicians to know the patient's nutritional needs accurately so as to meet their true needs as closely as possible, thereby avoiding the complications of over- and under-feeding. This study will provide us with this information so that intensivists and dietitians can improve nutritional delivery, a principle that is vital to improving patient outcomes in the ICU.
Photo of a ventilator and metabolic cart

Study Progress: The POLAR-BEAR Study was conducted in conjunction with the POLAR-RCT Study. Patient recruitment for the POLAR-RCT Study has completed.

Collaboration: The POLAR-BEAR Study was conducted in collaboration with The Alfred Hospital and Auckland City Hospital.

Publications:

Ridley E, Davies AR, Bernard S, McArthur C, Murray L, Paul E, Trapani A, Cooper DJ. Measured energy expenditure in mildly hypothermic critically ill patients with traumatic brain injury: A sub-study of a randomized controlled trial. Clin Nutrition 2021;40:3875-82. https://pubmed.ncbi.nlm.nih.gov/34130035/

Contact: For further information about this study, please contact Dr Emma Ridley at the ANZIC-RC, by email.