A low prognostic nutritional index is associated with chronic subdural hematoma recurrence

Chronic subdural hematoma (CSDH) is a common neurosurgical condition. Inflammation has been found to play an essential role in the formation of CSDHs, and the prognostic nutritional index (PNI), a nutritional and inflammatory baseline marker, plays a role in predicting the prognosis of many diseases. We aimed to identify the relationship between PNI and CSDH recurrence. This study retrospectively analyzed 261 CSDH patients who underwent burr hole evacuation in Beijing Tiantan Hospital from August 2013 to March 2018. The PNI was calculated as 5 ∗ lymphocyte count (109/L) + serum albumin concentration (g/L), and these markers were obtained from the peripheral blood test on the day of discharge from the hospital. Recurrence was defined as operated hematoma enlargement accompanied by newly emerging neurological disorders. The comparison of baseline characteristics demonstrated that patients with bilateral hematoma and low levels of albumin, lymphocytes, and PNI were more likely to be recurrent. After adjusting for age, sex, and other important variables, decreased PNI levels were associated with an increased risk of CSDH (OR, 0.803, 95% CI: 0.715-0.902, p = 0.001). The addition of PNI to conventional risk factors significantly improved the risk prediction of CSDH (net reclassification index: 71.12%, p = 0.001; integrated discrimination index: 10.94%, p = 0.006). A low PNI level is associated with an increased risk of CSDH recurrence. As an easily obtainable nutritional and inflammatory marker, PNI may play a significant role in predicting the recurrence of CSDH patients.