Delayed awakening after cardiac arrest: prevalence and risk factors in the Parisian registry.
OBJECTIVE
Although prolonged unconsciousness after cardiac arrest (CA) is a sign of poor neurological outcome, limited evidence shows that a late recovery may occur in a minority of patients. We investigated the prevalence and the predictive factors of delayed awakening in comatose CA survivors treated with targeted temperature management (TTM).


METHODS
Retrospective analysis of the Parisian Region Out-of-Hospital CA Registry (2008-2013). In adult comatose CA survivors treated with TTM, sedated with midazolam and fentanyl, time to awakening was measured starting from discontinuation of sedation at the end of rewarming. Awakening was defined as delayed when it occurred after more than 48 h.


RESULTS
A total of 326 patients (71 % male, mean age 59 ± 16 years) were included, among whom 194 awoke. Delayed awakening occurred in 56/194 (29 %) patients, at a median time of 93 h (IQR 70-117) from discontinuation of sedation. In 5/56 (9 %) late awakeners, pupillary reflex and motor response were both absent 48 h after sedation discontinuation. In multivariate analysis, age over 59 years (OR 2.1, 95 % CI 1.0-4.3), post-resuscitation shock (OR 2.6 [1.3-5.2]), and renal insufficiency at admission (OR 3.1 [1.4-6.8]) were associated with significantly higher rates of delayed awakening.


CONCLUSIONS
Delayed awakening is common among patients recovering from coma after CA. Renal insufficiency, older age, and post-resuscitation shock were independent predictors of delayed awakening. Presence of unfavorable neurological signs at 48 h after rewarming from TTM and discontinuation of sedation did not rule out recovery of consciousness in late awakeners.
Medical ICU, Cochin Hospital, AP-HP, 27 rue du Faubourg Saint-Jacques, 75014, Paris, France.
Marine
M
Paul
Medical ICU, Cochin Hospital, AP-HP, 27 rue du Faubourg Saint-Jacques, 75014, Paris, France.|Paris Cardiovascular Research Center, INSERM U970, Paris, France.|Université Paris-Descartes-Sorbonne-Paris-Cité, Paris, France.|Paris Sudden Death Expertise Center, Paris, France.
Wulfran
W
Bougouin
Medical ICU, Cochin Hospital, AP-HP, 27 rue du Faubourg Saint-Jacques, 75014, Paris, France.|Paris Cardiovascular Research Center, INSERM U970, Paris, France.|Université Paris-Descartes-Sorbonne-Paris-Cité, Paris, France.|Paris Sudden Death Expertise Center, Paris, France.
Guillaume
G
Geri
Paris Cardiovascular Research Center, INSERM U970, Paris, France.|Université Paris-Descartes-Sorbonne-Paris-Cité, Paris, France.|Paris Sudden Death Expertise Center, Paris, France.|Emergency Department, Cochin-Hotel-Dieu Hospital, APHP, Paris, France.
Florence
F
Dumas
Medical ICU, Cochin Hospital, AP-HP, 27 rue du Faubourg Saint-Jacques, 75014, Paris, France.|Université Paris-Descartes-Sorbonne-Paris-Cité, Paris, France.
Benoit
B
Champigneulle
Paris Cardiovascular Research Center, INSERM U970, Paris, France.|Paris Sudden Death Expertise Center, Paris, France.|ICU, Mignot Hospital, Le Chesnay, France.
Stéphane
S
Legriel
Medical ICU, Cochin Hospital, AP-HP, 27 rue du Faubourg Saint-Jacques, 75014, Paris, France.|Université Paris-Descartes-Sorbonne-Paris-Cité, Paris, France.
Julien
J
Charpentier
Medical ICU, Cochin Hospital, AP-HP, 27 rue du Faubourg Saint-Jacques, 75014, Paris, France.|Université Paris-Descartes-Sorbonne-Paris-Cité, Paris, France.
Jean-Paul
JP
Mira
Department of Anaesthesiology and Intensive Care, Catholic University School of Medicine, Rome, Italy.
Claudio
C
Sandroni
Medical ICU, Cochin Hospital, AP-HP, 27 rue du Faubourg Saint-Jacques, 75014, Paris, France. alain.cariou@cch.aphp.fr.|Paris Cardiovascular Research Center, INSERM U970, Paris, France. alain.cariou@cch.aphp.fr.|Université Paris-Descartes-Sorbonne-Paris-Cité, Paris, France. alain.cariou@cch.aphp.fr.|Paris Sudden Death Expertise Center, Paris, France. alain.cariou@cch.aphp.fr.
Alain
A
Cariou
D000367:Age Factors; D005260:Female; D005283:Fentanyl / Q000627:therapeutic use; D006323:Heart Arrest / Q000188:drug therapy / Q000401:mortality / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008874:Midazolam / Q000627:therapeutic use; D008875:Middle Aged; D010297:Paris; D015995:Prevalence; D012189:Retrospective Studies; D012307:Risk Factors; D013997:Time Factors
D008874:Midazolam; D005283:Fentanyl
Cardiac arrest; Prognosis; Therapeutic hypothermia