Splenic volume in severe sepsis is associated with disease severity and pneumococcal infection

Aim A small spleen, which is occasionally found in patients with pneumococcal sepsis, may increase pneumococcal susceptibility because of splenic malfunction. However, a small spleen may also originate from severe disease. We carried out a retrospective study to evaluate the association between splenic volume and severe pneumococcal sepsis or disease severity. Methods We reviewed the medical records of 23 patients with severe pneumococcal sepsis treated at our institution between January 2004 and September 2015 (pneumococcal group) and 61 patients with severe non-pneumococcal bacteremia treated between April 2011 and September 2015 (control group). Splenic volume measured by abdominal computed tomography on admission was compared between the two groups. Correlations between Acute Physiology and Chronic Health Evaluation (APACHE) II scores and splenic volume on admission and the change in splenic volume from the non-septic state to admission were also determined. Results Splenic volume on admission was significantly smaller (P = 0.001) and a small spleen was more frequent (P < 0.001) in the pneumococcal group. The APACHE II score was negatively correlated with splenic volume on admission (r = −0.46, P < 0.001) and the change in splenic volume (r = −0.44, P = 0.004). Pneumococcal infection (odds ratio 13.1, 95% confidence interval 2.6–65.7; P = 0.002) and APACHE II score (odds ratio 1.2, 95% confidence interval 1.1–1.3; P = 0.002) were independently associated with small spleen. Conclusion Splenic volume decreased with increasing severity of severe sepsis. A small spleen was also associated with severe pneumococcal infection.