Time to awakening after cardiac arrest and the association with target temperature management.
AIM
Target temperature management (TTM) at 32-36 °C is recommended in unconscious survivors of cardiac arrest. This study reports awakening in the TTM-trial. Our predefined hypotheses were that time until awakening correlates with long-term neurological outcome and is not affected by level of TTM.


METHODS
Post-hoc analysis of time until awakening after cardiac arrest, its association with long-term (180-days) neurological outcome and predictors of late awakening (day 5 or later). The trial randomized 939 comatose survivors to TTM at 33 °C or 36 °C with strict criteria for withdrawal of life-sustaining therapies. Administered sedation in the treatment groups was compared. Awakening was defined as a Glasgow Coma Scale motor score 6.


RESULTS
496 patients had registered day of awakening in the ICU, another 43 awoke after ICU discharge. Good neurological outcome was more common in early (275/308, 89%) vs late awakening (142/188, 76%), p < 0.001. Awakening occurred later in TTM33 than in TTM36 (p = 0.002) with no difference in neurological outcome, or cumulative doses of sedative drugs at 12, 24 or 48 h. TTM33 (p = 0.006), clinical seizures (p = 0.004), and lower GCS-M on admission (p = 0.03) were independent predictors of late awakening.


CONCLUSION
Late awakening is common and often has a good neurological outcome. Time to awakening was longer in TTM33 than in TTM36, this difference could not be attributed to differences in sedative drugs administered during the first 48 h.
['Lybeck|Anna|A|', 'Cronberg|Tobias|T|', 'Aneman|Anders|A|', 'Hassager|Christian|C|', 'Horn|Janneke|J|', 'Hovdenes|Jan|J|', 'Kjærgaard|Jesper|J|', 'Kuiper|Michael|M|', 'Wanscher|Michael|M|', 'Stammet|Pascal|P|', 'Wise|Matthew P|MP|', 'Nielsen|Niklas|N|', 'Ullén|Susann|S|', 'Friberg|Hans|H|', '|||']
D000368:Aged D001831:Body Temperature D003128:Coma D005260:Female D006801:Humans D006993:Hypnotics and Sedatives D007036:Hypothermia, Induced D008297:Male D008875:Middle Aged D058687:Out-of-Hospital Cardiac Arrest D016037:Single-Blind Method D013997:Time Factors D014851:Wakefulness D028761:Withholding Treatment
Awakening Cardiac arrest Target temperature management Withdrawal Sedation