Factors associated with pneumonia in post–cardiac arrest patients receiving therapeutic hypothermia

Early-onset pneumonia after out-of-hospital cardiac arrest

“…62 Nevertheless, a high percentage of MRSA has been reported in the case of EOP. 6,28 The low reported incidence of anaerobic organisms in EOP is in agreement with more recent studies describing the microbiology of community-acquired aspiration syndrome. 60,62e64 However, it is unclear if the low incidence of anaerobic bacteria isolation results from a really low presence, a lack of Early-onset pneumonia after cardiac arrest growth in the microbiological lab, or difficulties to isolate these species.…”

“…36 Moreover, the enhanced risk of pneumonia seems to be temperatureindependent, since a recent randomized study comparing a targeted temperature of 33 versus 36 C after OHCA revealed more cases of pneumonia in the 33 C group (52%) than in the 36 C group (46%), but this difference did not reach statistical significance (p Z 0.089). 30 Finally, in a smaller study by Woo et al 28 the development of pneumonia in patients treated with therapeutic hypothermia after OHCA was not associated with any factor relevant to temperature modulation including target body temperature and cooling method. However, this study also did not distinguish early and late-onset pneumonia.…”

“…However, early and late-onset pneumonia were collectively analyzed. 28 Finally, the occurrence of EOP after cardiac arrest does not seem to be influenced by demographic characteristics, cause of the arrest or first recorded cardiac rhythm. 27 …”

“…Indeed, all incidences used to concern around one third of the patients, 7,8 whereas they now concern around half of them in the largest series. 6,27,28,30,36 Table 1 summarizes the incidence of EOP in the main studies focusing on pneumonia after OHCA. Although the use of different diagnostic criteria hinders any attempt for general conclusions, the introduction of therapeutic hypothermia is accompanied by a trend towards an increased frequency of pneumonia after cardiac arrest.…”

“…As expected, the microbiological pattern is influenced by the country where the study has been performed, with Asian series reporting for instance a high rate of non-fermenting Gram-negative bacilli. 28 EOP is polymicrobial in up to one half of the cases, while in about one third of the cases, no microorganism is isolated, although other criteria strongly suggest a pneumonia diagnosis. 6,27 Likewise, lack of bacteriological documentation has been also reported in a significant percentage of cases with community-acquired aspiration pneumonitis, ranging from 40 to 79%.…”