There was a higher frequency of ARDS (84.2% vs 17.6%, respectively; p < 0.001) and DIC (57.9% vs 8.1%, respectively; p < 0.001) in the CAP-AB group than in the HAP-AB group. The frequency of shock requiring inotropic support (CAP-AB group, 57.9%; HAP-AB group, 43.2%; p = 0.307), the requirement of mechanical ventilation (CAP-AB group, 63.2%; HAP-AB group, 66.2%; p = 0.79), and acute renal failure requiring dialysis (CAP-AB group, 15.8%; HAP-AB group, 6.8%; p = 0.35) was not significantly different. The CAP-AB group had a significantly worse prognosis compared to the HAP-AB group, with a higher 30-day mortality rate in the CAP-AB group (57.8% vs 35.4%, respectively; p < 0.001) [Fig 1]. other
The following parameters were found to be associated with higher mortality in the CAP-AB group: presence of AB bacteremia (p = 0.040); platelet count of < 120 X 109 cells/L (p = 0.026); pH < 7.35 on presentation (p = 0.047); and the presence of DIC (p = 0.004). Unexpectedly, adequate empirical antibiotic therapy within first 12 h of diagnosis was not associated with improved survival in the CAP-AB group (3 of 6 patients died [50%]) when compared to patients who received inadequate coverage (7 of 13 patients died [54%]; p = 0.879 [log-rank test]). A subgroup analysis was performed including only CAP-AB patients who survived the initial 48 h (13 patients), so that the antibiotics administered initially would have adequate time to act. Again, patients treated with adequate initial antibiotics had no significant difference in mortality (one of four patients died [25%]) from patients treated with inadequate initial antibiotics (three of nine patients died [33.3%]; p = 0.598 [log-rank test]). Five of eight CAP-AB patients (62.5%) who received a combination of third-generation cephalosporins and aminoglycosides survived, vs 4 of 11 patients (36.4%) who did not receive this combination and survived (p = 0.337 [log-rank test]). In four patients, the antibiotics used were changed based on susceptibility results, and three of those patients survived. Other factors, including age, APACHE II score, and Charlson comorbidity score, were not associated with poor survival in the CAP-AB group. Multivariate analysis was not performed due to the small number of patients.
Figure 1. Survival curve for CAP-AB and HAP-AB patients.