Matt Harmon

179 Chapter nine Background Infectious complications are common in cardiac arrest patients and may contribute to mortality. 1-5 The high rate of nosocomial infections may be due to an impaired immune response following cardiac arrest. 6 There is a debate whether induced hypothermia may further hamper the body’s ability to adequately respond to infections. 7 One study suggests that hypothermia is associated with an increased incidence of pneumonia within the first 3 days following cardiac arrest. 1 In particular, a higher incidence of infections due to gram-negative organisms was found. 1 In contrast, we recently showed that there were no differences between risk of infection in patients randomized to targeted temperature management at 33°C versus 36°C. 5 Discrepancies between studies may be explained by difficulties in diagnosis of infections during temperature management strategies, not only due to temperature modulation but also due to systemic inflammatory reaction following a cardiac arrest. Difficulties in diagnosing infection may result in delay in initiation of antibiotic treatment 8,9 with subsequent increased duration of ICU- and hospital- stay. 10 This may prompt the question whether the use of prophylactic antibiotics may reduce infectious complications in cardiac arrest patients. In retrospective analyses, antibiotic use in the first 7 days following cardiac arrest was associated with improved survival 8 and a four-fold reduction of pneumonia. 11 The Targeted Temperature Management (TTM) was a randomized clinical trial in which the impact of temperature on neurological outcome was assessed. In this substudy, we describe the microbiological profile of nosocomial infections in patients with cardiac arrest and examined the impact of TTM33 compared to TTM36 on this profile. Also, the association between prophylactic antibiotics and the incidence of infectious complications was investigated. We hypothesized that use of prophylactic antibiotic use would be associated with less infectious complications in cardiac arrest patients. Methods Patients This is posthoc analysis of the TTM cohort, that following informed consent from next of kin included adult (≥18 years) unconscious patients (Glasgow Coma Scale <8) resuscitated from cardiac arrest of a presumed cardiac cause with return of spontaneous circulation with a duration of at least 20 minutes. Inclusion occurred at 36 centers in Europe and Australia. Further details on the exclusion criteria, trial protocol and main results were published previously. 12