Paracetamol After Traumatic Brain Injury (PARITY) study

Worldwide, traumatic brain injury (TBI) is the leading cause of disability in adults under 40 years of age and 10 million people each year are hospitalised with TBI. There remains a significant lack of coherent evidence about effective therapies in the acute care of patients with TBI. Therapies that are widely available and inexpensive warrant investigation, as they may be applicable to patients in low and middle income countries, as well as high-income countries, if efficacy and safety were to be demonstrated.

In acute ischaemic stroke, observational studies have demonstrated that raised body temperature (>37.5°C) in the first few days after stroke is associated with larger infarct volume, poorer functional outcome and increased mortality. An additional meta-analysis of observational data also suggested that a raised body temperature after stroke or TBI was associated with adverse morbidity and mortality. These data from stroke and TBI may suggest that interventions that induce small temperature differences after neuronal injury warrant further investigation in randomised-controlled trials.


The primary aim of the PARITY study is to determine whether the early administration of intravenous paracetamol reduces core body temperature following severe traumatic brain injury compared to placebo (normal saline).

The study will establish whether a definitive phase III trial is feasible and justifiable, and will provide essential information on the cost and estimated sample size for such a trial.


The PARITY study is a prospective, phase 2b, multi-centre, blinded, randomised placebo-controlled trial, designed to answer the research question of the efficacy (and safety) of intravenous paracetamol in reducing body temperature after TBI.


Adult intensive care patients aged 18 to 65, with a clinical diagnosis of acute traumatic brain injury (confirmed by CT) admitted to ICU within 48 hours of injury will be eligible for inclusion. Patients will also require an existing (or imminent placement of) an arterial cannula and an Alanine transferase level of < 100. Patients must meet all eligibility criteria for enrolment into the PARITY Study. Informed consent will be obtained from the patient or their substitute decision maker prior to enrolment.


Recruitment has been completed with data queries and cleaning underway. Data analysis and the publication of results are expected by the end of 2014.