Matt Harmon

203 Summary ARDS for example, increased dead space in associated with increased mortality. 17 TTM at 36°C may therefore be preferable in patients with pulmonary aspiration following cardiac arrest, who are at high risk for lung injury. In chapter six we explored the effects of hypo- and hypercarbia on neurologic outcome, but found no relationship between PaCO2 and neurologic outcome. There are two RCT’s and one observational study that support these findings 18,19 , although other observational studies have been inconsistent showing both negative and beneficial effects of hypo- and hypercarbia. 20-23 These findings do not necessarily support specific carbon dioxide targets post cardiac arrest. Therefore, carbon dioxide levels should be titrated to the specific needs of patients. In general, prospective clinical trials on mechanical ventilation in ICU patients have largely excluded patients with cardiac arrest 24 , despite this population being at risk for lung injury. The studies presented in this thesis these results should lead to recommendations on optimal mechanical ventilation strategies specifically for patients with cardiac arrest. 24 In chapter seven we described the effect of TTM on the microbiological profile of infectious complications in patients with cardiac arrest. We found an 11% incidence of bacteremia in these patients. 25 In this study, nosocomial infection was most often due to gram-negative bacteria, although Staphylococcus aureus was the most commonly cultured micro-organism. The results from this study can help guide empiric antibiotic treatment as inappropriate antibiotic therapy occurs in a significant proportion of cardiac arrest patient and is associated with increased ICU-stay. 25 Subsequently, we investigated the association between antibiotic prophylaxis and nosocomial infections. We found that antibiotic prophylaxis was associated with a decreased incidence of pneumonia and bacteremia. In line with this finding, a large RCT has shown that prophylactic antibiotic treatment with amoxicillin–clavulanate reduces early ventilator-associated pneumonia in patients admitted to the ICU after cardiac arrest. 26 We suggest antibiotic prophylaxis as a standard practice in patients with cardiac arrest. Based on our results, a cephalosporin of the 2 nd or 3 rd generation may be a reasonable empiric approach. However, antibiotic prophylaxis selection should also be based on local resistance patterns. Sites in this study were predominantly from northern European countries, which have notably different antibiotic resistance patterns compared to southern European countries. 27 Also, there is a paucity of data on the relationship between nosocomial pneumonia and associated bacteremia and our results can aid in the epidemiologic understanding of bacteremia in mechanically ventilated patients. 28 Taken together, studies examining the characteristics of TTM treatment in cardiac arrest are imperative as they serve to improve our understanding of TTM and adjacent therapies. TTM is complex and substitutes a combination of multiple