Therapeutic intravascular normothermia reduces the burden of metabolic crisis

We aim to investigate whether therapeutic-induced normothermia (TIN) ≤ 37.5 °C, by means of intravascular cooling devices is more efficacious than standard medical therapy (MED) in alleviating metabolic crisis (MC) acutely following traumatic brain injury (TBI).

We retrospectively analyzed data from 62 patients with severe TBI, GCS ≤ 8. We divided the cohort into two groups. (1) Patients who had temperature controlled via standard medical therapies (n = 52), (2) TIN group (n = 10). For each group, we analyzed the percent time spent in normothermia, and in MC. Furthermore, we focused the investigation on pre-TIN versus post-TIN comparing temp, intracranial pressure (ICP), sedation, and MC before and after intravascular cooling.

TIN patients had a better temperature control than MED group (60.72 ± 19.53 vs 69.75 ± 24.98 %, p < 0.001) and spent shorter time in MC (22.60 ± 20.45 vs 32.17 ± 27.25 %, p < 0.001). Temperature control was associated with reduced incidence of MC in TIN (OR 0.51, CI 0.38-0.67, p < 0.001, p < 0.001) but not in MED (OR 0.97, CI 0.87-1.1, p = 0.63). Within TIN group analysis, following TIN both temperature and incidence of MC improved from 37.62 ± 0.34 versus 36.69 ± 0.90 °C (p < 0.005) and 41.95 ± 27.74 % before to 8.35 ± 9.78 % (p = 0.005) after, respectively. ICP was well controlled both before and after intravascular cooling (13.07 vs 15.83 mmHg, p = 0.20).

Therapeutic normothermia, using intravascular cooling, results in a reduction in the burden of MC. This differential effect occurs despite equivalent control of ICP in both TIN and MED treatments. These results demonstrate proof of concept of normothermia, when applied in a controlled manner, being neuroprotective.