Abnormal liver function tests are associated with increased mortality in both cardiothoracic and general intensive care

Introduction

The objective of this study was to identify differences in liver function tests (LFT) between patients admitted to a general ICU (GICU) and a cardiothoracic ICU (CTICU), and the effect on mortality. Liver dysfunction (LD) in critically ill patients is common and is associated with increased mortality and prolonged ICU stay [1]. Patients undergoing cardiothoracic surgery are anecdotally at increased risk of LD as a consequence of haemodynamic instability.

Methods

A retrospective study of all first admissions to the CTICU and the GICU between 1 October 2006 and 31 March 2007 was performed. LFT were obtained from the Chemical Pathology Department. Patient demographics and mortality were established from the hospital electronic patient record.

Results

A total of 481 patients were admitted to the CTICU and 661 to the GICU. Compared with the GICU, patients admitted to the CTICU were older (66.9 vs. 59.7 years, P < 0.05), more likely to be male (71% vs. 58%, P < 0.05) and more likely to survive (30-day mortality 8.5% vs. 22%; P < 0.05). At the time of admission, albumin was <35 g/dl in 94% of patients and declined thereafter. Excluding albumin, LFT were entirely normal in 50% and 54% on admission to the GICU and the CTICU. Abnormal LFT on admission were associated with increased mortality (Table 1).

Table 1 Abnormal LFT on admission to the ICU and associated 30-day mortality

Conclusion

Abnormal LFT are common in critically ill patients on admission to the ICU. Patients with subtle LD on admission are at increased risk of mortality in both groups. An abnormal bilirubin has a greater impact in patients admitted to the CTICU than the GICU.