Bacteremia, APACHE II and need for renal replacement therapy are independent predictors of mortality in critically ill transplanted patients with cirrhosis

Introduction

Our objective was to determine what physiological and biochemical factors predict development of bacteremia in transplanted cirrhotic patients (TP) and, upon diagnosis of bacteremia, what is the natural history of bacteremic patients (BTP) versus controls (TP).

Methods

Data collected prospectively and entered into a dedicated physiology database for all transplanted cirrhotic patients admitted to a specialist liver intensive therapy unit (LITU) were examined from January 2003 to July 2005 for incidence of bacteremia and survival.

Results

In total, 362 patients were transplanted for decompensated cirrhosis (64% elective, 36% in-hospital). Thirty-eight (10%) suffered bacteremia (BTP) while 324 (90%) patients did not (TP). Forty-nine per cent of isolates were Gram-positive organisms, 45% Gram-negatives and 6% fungemia. Median time to first bacteremia was 11.5 days. On admission (univariate), BTP patients had significantly higher APACHE II scores (23 vs 11, P < 0.001), worse acidosis (pH 7.27 vs 7.35, P < 0.001) and greater degrees of encephalopathy (GCS 12 vs 15, P < 0.001). During their LITU course BTP patients had significantly greater requirements for renal replacement therapy (RRT) (68% vs 17%, P < 0.001), mechanical ventilation (median 15 days vs 2 days, P < 0.001) and a longer median LITU stay (21 vs 3 days, P < 0.001). Survival to hospital discharge was worse in the BTP group (55% vs 95%, P < 0.001). Multivariate analysis (logistical regression) was performed modelling with APACHE II. APACHE II (odds ratio 1.06), bacteremia (4.01) and requirement for RRT pre or post transplant (12.5) were independent predictors of mortality. The APACHE II model performed well (AUROC 0.817).

Conclusions

In transplanted cirrhotic patients, bacteremia was associated with increased severity of illness on admission, greater requirements for organ support and independently adversely impacted on survival. Higher APACHE II score and the requirement of RRT during LITU stay were also independently predictive of mortality.