midazolam are given in the same proportion [12]. To date, there are no recommendations for the first choice sedative drug in this setting. Compared to midazolam, pharmacokinetics of propofol is not altered by hypothermia. Moreover, its antioxidant properties could be of clinical interest to mitigate the post-resuscitation syndrome [24]. Sufentanil is the most commonly used opioid during therapeutic hypothermia after cardiac arrest in France, whereas worldwide, fentanyl is the first choice. However, fentanyl has been shown to accumulate during hypothermia [25]. There is no data available concerning the pharmacokinetics of sufentanil during hypothermia. As it is metabolized by the same cytochrome, hypothermia may also increase its half-life. It is advisable to give NMBA during therapeutic hypothermia and this recommendation is followed by 97% of French ICUs. This percentage is higher than the 79% reported in the rest of the world by Chamorro et al [23]. The most commonly used NMBA in France is cisatracurium whereas pancuronium is the first choice worldwide. This difference can be explained by the withdrawal of pancuronium from the French market and cisatracurium is supposed to be the only NMBA authorized in ICUs in France. Similarly to the sedative drugs, the question of the best NMBA is still unanswered. However, the recent report of a better outcome with the use of cisatracurium in patients with ARDS could partly explain the easy use of cisatracurium in ICU setting [26]. Prognostic factors are frequently used, mostly neurological examination and EEG studies and to a lesser extent biomarkers and evoked potentials. Guidelines concerning the use of prognostic factors were made before the era of therapeutic hypothermia [27]. Since this treatment is recommended after out of hospital cardiac arrest, the validity of these factors is questioned [28]. Indeed, hypothermia prolongs sedation as it impairs the metabolism of the most common sedative and analgesic drugs such as midazolam and fentanyl. A recent study failed to find a clinical difference between hypothermic and non-hypothermic patients regarding the time of awakening, but the infusion regimen of sedative drugs was very low compared to previous reports [23,29]. Currently, the use of prognostic factors raises crucial questions. The first concern is the cost of these additional tests as resources are becoming scarce in most ICUs. The second concern is ethical with possible premature withdrawal of life sustaining therapies. Further References 1. de Vreede-Swagemakers JJ, Gorgels AP, Dubois-Arbouw WI, van Ree JW, Daemen MJ, et al. (1997) Out-of-hospital cardiac arrest in the 1990’s: a population-based study in the Maastricht area on incidence, characteristics and survival. J Am Coll Cardiol 30: 1500–5. 2. Gueugniaud PY, David JS, Chanzy E, Hubert H, Dubien PY, et al. (2008) Vasopressin and epinephrine vs. epinephrine alone in cardiopulmonary resuscitation. New Engl J Med 359: 21–30. 3. Nolan JP, Laver SR, Welch CA, Harrison DA, Gupta V, Rowan K (2007) Outcome following admission to UK intensive care units after cardiac arrest: a secondary analysis of the ICNARC Case Mix Programme Database. Anaesthesia 62: 1207–16. 4. Bernard SA, Gray TW, Buist MD, Jones BM, Silvester W, et al. (2002) Treatment of comatose survivors of the out-of-hospital cardiac arrest with induced hypothermia. N Engl J Med 346: 557–63. 5. The hypothermia after cardiac arrest study group (2002) Mild therapeutic hypothermia to improve the neurologic outcome after cardiac arrest. N Engl J Med 346: 549–56. 6. Hachimi-Idrissi S, Corne L, Ebinger G, Michotte Y, Huyghens L (2001) Mild hypothermia induced by a helmet device: a clinical feasibility study. Resuscitation 51: 275–281. 7. Oddo M, Schaller MD, Feihl F, Ribordy V, Liaudet L (2006) From evidence to clinical practice: Effective implementation of therapeutic hypothermia to improve patient outcome after cardiac arrest. Crit Care Med 34: 1865–1873. 8. Dumas F, Grimaldi D, Zuber B, Fichet J, Charpentier J, et al. (2011) Is hypothermia after cardiac arrest effective in both shockable and nonshockable patients?: insights from a large registry. Circulation 123: 877–86. Therapeutic Hypothermia in France recommendations are urgently needed to clarify the use of the prognostic factors after cardiac arrest treated by hypothermia. While offering novel insight, our study has to be interpreted with caution. The first caveat is the percentage of ICUs answering of only 37%, questioning the validity of our results. Rates of answer of previous surveys on therapeutic hypothermia after cardiac arrest range from 17 to 98.4% [11,12]. The type of survey could explain this apparent difference as a survey delivered by post has a higher percentage of answer than a survey delivered by e- mail [30]. Actually, the percentage of answers of our study is higher compared to the study using the same type of survey [10,11]. Another limit of our study lies in the type of a self- declaration survey. There is probably a discrepancy between what is declared and what is done in ‘‘real-life’’. An audit realized by a trained staff in the different units could diminish this potential bias. Last, our study was focused on therapeutic hypothermia. But recently, percutaneous coronary intervention (PCI) has been reported to improve outcome after out of hospital cardiac arrest [31]. Data concerning its practice was not included in the questionnaire so it was impossible to report the combination of both therapies. Further studies are needed to evaluate the practice of a postresuscitation care bundle and its effect on outcome after out of hospital cardiac arrest. Conclusions Despite a low response rate of the survey, practice of therapeutic hypothermia after cardiac arrest follows the international guide- lines in France. Prognostic factors are widely used but their value in the era of therapeutic hypothermia is still debated. Supporting Information Questionnaire S1 File sent by e-mail to the head of the ICUs for the purpose of the survey. (DOC) Author Contributions Conceived and designed the experiments: JCO FC JYL ML SJ JMC BA CI. Performed the experiments: JCO FC. Analyzed the data: JCO FC JYL ML SJ JMC BA CI. Wrote the paper: JCO FC JYL ML SJ JMC BA CI. 9. Nolan JP, Soar J, Zideman DA, Biarent D, Bossaert LL, et al. (2010) European Resuscitation Council Guidelines for Resuscitation 2010 Section 1. Executive summary. Resuscitation 81: 1219–76. 10. Abella BS, Rhee JW, Huang KN, Vanden Hoek TL, Becker LB (2005) Induced hypothermia is underused after resuscitation from cardiac arrest: a current practice survey. Resuscitation 64: 181–6. 11. Merchant RM, Soar J, Skrifvars MB, Silfvast T, Ederson TT, et al. (2006) Therapeutic hypothermia utilization among physicians after resuscitation from cardiac arrest. Crit Care Med 34: 1935–40. 12. Laver SR, Padkin A, Atalla A, Nolan JP (2006) Therapeutic hypothermia after cardiac arrest: a survey of practice in intensive care units in the United Kingdom. Anaesthesia 61: 873–7. 13. Wolfrum S, Radke PW, Pischon T, Willich SN, Schunkert H, et al. (2007) Mild therapeutic hypothermia after cardiac arrest - a nationwide survey on the implementation of the ILCOR guidelines in German intensive care units. Resuscitation 72: 207–13. 14. Bianchin A, Pellizzato N, Martano L, Castioni CA (2009) Therapeutic hypothermia in Italian intensive care units: a national survey. Minerva Anestesiol 75: 357–62. 15. Kalhan R, Mikkelsen M, Dedhiya P, Christie J, Gaughan C, et al. (2006) Underuse of lung protective ventilation: analysis of potential factors to explain physician behavior. Crit Care Med 34: 300–6. 16. Lefrant JY, Muller L, Raillard A, Jung B, Beaudroit L, et al. (2010) Reduction of the severe sepsis or septic shock associated mortality by reinforcement of the recommendations bundle: a multicenter study. Ann Fr Anesth Reanim 29: 621– 8. PLOS ONE | www.plosone.org 4 September 2012 | Volume 7 | Issue 9 | e45284