Outcome and mortality risk factors of patients presenting to the ICU with severe sepsis and septic shock

Introduction

This study investigated clinical characteristic, outcome and risk factors for hospital mortality of patients who were admitted with severe sepsis and septic shock to the ICU in single tertiary referral university teaching hospital in Thailand.

Methods

A retrospective analysis of prospectively collected data of patients with an ICU admission between 1 July 2004 and 30 June 2006.

Results

A total of 390 patients, with a mean age of 55.5 ± 19 years, were admitted during the study period. Three hundred and three (77.7%) of these patients had septic shock. The mean APACHE II score was 26.8 ± 9.4. Overall ICU and hospital mortality rates were 39.2% and 49.7%, respectively. Comorbid diseases were found in 157 patients (40.3%), the most common being hemotologic malignancy (15.4%), immunocompromised (7.4%) and AIDS (4.9%). One hundred and seventy-three patients (44.4%) had a community-acquired infection. Respiratory tract infection was the most common site of infection (50%). Positive blood cultures were found in 106 (27.5%) patients and there were positive cultures in all 241 (61.8%) patients. The most common organisms were Klebsiella pneumoniae (19.9%), Escherichia coli (14.5%) and Pseudomonas species (9.8%). Acute respiratory distress syndrome (ARDS) had been identified in 80 patients (20.5%). Septic patients with ARDS had significant higher mortality than those patients without ARDS (68.8% vs 31.3%, P < 0.001, respectively). A pulmonary artery catheter was used in 31 (7.9%) patients. In a multivariate analysis, ARDS (OR, 2.59; 95% CI, 1.29–5.12, P = 0.007), pulmonary artery catheter placement (OR, 4.12; 95% CI, 1.21–14.08, P = 0.024), comorbid diseases (OR, 1.85; 95% CI, 1.03–3.33, P = 0.04), hospital-acquired infection (OR, 2.12; 95% CI, 1.21–3.17, P = 0.009), APACHE II score (OR, 1.10 per point increase; 95% CI, 1.05–1.16, P < 0.001) and maximum LOD score (OR, 1.34 per point increase; 95% CI, 1.21–1.49, P < 0.001) were independent risk factors for hospital mortality.

Conclusion

This study identifies that outcome for patients with severe sepsis and septic shock is closely related to ARDS, pulmonary artery catheter placement, hospital-acquired infection and high severity score. These groups of patients require special attention to reduce mortality.