Auditory discrimination improvement predicts awakening of postanoxic comatose patients treated with targeted temperature management at 36 °C

Abstract

These results suggest that tracking of auditory discrimination over time is informative of good recovery independent of the temperature target. This quantitative test provides complementary information to existing clinical tools by identifying patients with high chances of recovery and encouraging the maintenance of life support.

Somatosensory and auditory deviance detection for outcome prediction during postanoxic coma

“…The experimental protocol was approved by the ethical committees of the Cantons Bern, Fribourg, Valais and Vaud and all methods were carried out in accordance with relevant guidelines and regulations. Based on our previous studies showing similar prognostic performance of our method across patients receiving TTM at different target temperatures for the present study we included both patients receiving TTM at 36°C (75 patients) and patients receiving TTM at 33°C (20 patients;). TTM was applied for 24 h using ice packs or intravenous ice‐cold fluids together with a feedback controlled cooling device (Arctic Sun System, Medivance, Louisville or Thermogard XP; ZOLL Medical, Zug, Switzerland) followed by removal of TTM after 24 h. Propofol (2–3 mg/kg/h), Midazolam (0.1 mg/kg/h) and Fentanyl (1.5 μ g/kg/h) were given for analgesia‐sedation, and Vecuronium, Rocuronium, or Atracurium for controlling shivering.…”

“…second CA, multiorganic failure, or intracerebral bleeding) unrelated to the initial CA was diagnosed only after our recordings, and caused death within 3 months. As our approach is based on EEG recordings during the first 2 days following CA, our method cannot foresee such secondary events (for similar approach see). Thus, the number of patients included for the analysis was 66 (15 treated with TTM at 33°C, 23%).…”

“…auditory deviance detection) is typically reported in comatose and disorders of consciousness patients who will eventually survive . The brain mechanisms underlying auditory deviance detection might still be preserved during early stages of coma and further improve over time in long‐term survivors, whereas deviance detection appears to degenerate over time in those patients who eventually die (see for a discussion).…”

“…Based on these observations in healthy subjects, we hypothesized that diffuse cerebral injury in comatose patients might differently impair deviance detection for auditory and somatosensory stimuli. Thus, we hypothesized that the assessment of somatosensory deviance detection might provide complementary information to auditory deviance detection for increasing the number of predicted survivors and thereby improving coma‐outcome prediction …”

“…Specifically, we implemented an auditory mismatch negativity (MMN) protocol (i.e. reported previously) and a tactile MMN protocol where the stimuli were differentiated by their duration, a stimulus feature allowing a direct comparison between the two modalities.…”