Background The application of therapeutic hypothermia (TH) for 12 to 24 hours
following out-of-hospital cardiac arrest (OHCA) has been associated with
decreased mortality and improved neurological function. However, the optimal
duration of cooling is not known. We aimed to investigate whether targeted
temperature management (TTM) at 33 ± 1 °C for 48 hours compared to 24 hours
results in a better long-term neurological outcome. Methods The TTH48 trial is
an investigator-initiated pragmatic international trial in which patients
resuscitated from OHCA are randomised to TTM at 33 ± 1 °C for either 24 or 48
hours. Inclusion criteria are: age older than 17 and below 80 years; presumed
cardiac origin of arrest; and Glasgow Coma Score (GCS) <8, on admission. The
primary outcome is neurological outcome at 6 months using the Cerebral
Performance Category score (CPC) by an assessor blinded to treatment
allocation and dichotomised to good (CPC 1–2) or poor (CPC 3–5) outcome.
Secondary outcomes are: 6-month mortality, incidence of infection, bleeding
and organ failure and CPC at hospital discharge, at day 28 and at day 90
following OHCA. Assuming that 50 % of the patients treated for 24 hours will
have a poor outcome at 6 months, a study including 350 patients (175/arm) will
have 80 % power (with a significance level of 5 %) to detect an absolute 15 %
difference in primary outcome between treatment groups. A safety interim
analysis was performed after the inclusion of 175 patients. Discussion This is
the first randomised trial to investigate the effect of the duration of TTM at
33 ± 1 °C in adult OHCA patients. We anticipate that the results of this trial
will add significant knowledge regarding the management of cooling procedures
in OHCA patients