The overall CIP incidence was 3.3% (48 out of 1450 patients) with a continuous increase in the annual CIP rate (1.4% in 1998 to 5.5% in 2003). CIP patients had higher APACHE II (17 ± 9 vs 21 ± 8; P = 0.002) and SAPS II scores (44 ± 22 vs 53 ± 16; P = 0.01), a higher incidence of mechanical ventilation (1000/1402 vs 48/48; P = 0.0001) and renal support (266/1402 vs 22/48; P = 0.0001), as well as a longer duration of mechanical ventilation (median 4 vs 30 days; P = 0.0001), renal support (median 4 vs 11 days; P = 0.0001) and ICU stay (median 5 vs 36 days; P = 0.0001). Furthermore a higher bicarbonate on admission was noted. In the multivariate analysis, only high bicarbonate on admission (P = 0.0002) and renal support (P = 0.0001) were independent risk factors for the development of CIP. Evaluating factors associated with CIP (as a cause or as a consequence), high bicarbonate (P = 0.0016), duration of ICU stay (P = 0.0001) and duration of renal support (P = 0.043) were independently associated with CIP.