Base excess and early mortality in patients admitted to the general intensive care unit at a university hospital in Fortaleza

Introduction

Base excess is considered an indicator of injury, shock and adequate resuscitation. We looked to establish a relation between base excess and serum bicarbonate obtained on admission to the ICU and the prognostics of patients.

Methods

A retrospective study with analysis of 110 patients admitted consecutively to the ICU, during the period June–December 2006.

Figure 1

Results

Of the 110 patients, there was a predominance of women and mean age 54.2 ± 18.7 years. The length of stay in the ICU was 6.5 ± 7.4 days and the mean APACHE II index, at the first 24 hours of admission, was 21.0 ± 8.1 points. Most patients survived (71.9%), 9.3% died during the first 48 hours in the ICU and 18.6% after 48 hours from admission to this unit. The standardized mortality ratio was 0.715. Patients with early mortality, during the first 48 hours in the ICU, had lower base excess (-7.75 ± 8.33 vs -3.17 ± 5.43) and serum bicarbonate (16.7 ± 6.2 vs 20.9 ± 5.6) than survivors (P < 0.05). Patients with permanence in the ICU up to 7 days and patients that stayed in this unit for more than 7 days had similar base excess and serum bicarbonate (-3.24 ± 5.37 vs -2.98 ± 5.72 and 20.9 ± 5.3 vs 20.9 ± 6.3) (P > 0.05).

Conclusion

Serum bicarbonate and base excess were associated with early mortality during the ICU stay. However, these parameters did not correlate with ICU length of stay.