Ventilator-associated pneumonia caused by Pseudomonas aeruginosaand respiratory colonization by Candida spp

Introduction

This study aims to test the association of an increased mortality in critically ill patients with ventilator-associated pneumonia (VAP) caused by Pseudomonas aeruginosa in patients with a previous respiratory tract colonization by Candida spp. compared with that of patients with a VAP by P. aeruginosa without Candida spp. isolation.

Methods

A retrospective study on all 5,236 critically ills patients admitted to the ICU of a university hospital from 2001 to 2008, of which 1,097 received mechanical ventilation and in whom Pseudomonas and/or Candida were isolated in quantitative cultures from the Mini-BAL [1].

Results

P. aeruginosa and Candida spp. were present at the same time in 295 patients (P-C group), P. aeruginosa only in 92 patients (P group) and Candida spp. only in the remaining 710 patients (C group). SAPS II was 44.27 ± 14.8 (mean ± SD), 39.07 ± 14.61 and 39.07 ± 14.61, respectively, for P-C, P and C groups. The SAPS II score of the C group was significantly higher than the P group (P < 0.05), the SAPS II score of the C group was higher than the P-C group (P > 0.05), and the SAPS II score of the P group was lower than the P-C group (P > 0.05). The population with Candida spp. isolation alone was older (70.25 years vs 63.17 (group P-C) and 60.22 (group P), P < 0.05). The group with Pseudomonas associated with Candida spp. had a mortality rate higher than the P group (57.96% vs 6.05%, P < 0.05). The length of stay in the ICU of patients with Candida spp. and P. aeruginosa was not different from the group who had P. aeruginosa alone (26.22 ± 31.80 vs 29.15 ± 25.66, P > 0.05). Duration of hospitalization in the group with only P. aeruginosa was longer than the other two groups (79.38 days vs 51.85 of the group P-C and 28.40 of group C, P < 0.05).

Conclusions

Candida colonization seems to increase the risk for Pseudomonas infection [2]. Patients who developed VAP due to P. aeruginosa with previous colonization of the respiratory tract by Candida spp. were older, with a higher SAPS II score and had a high mortality.