Early Postoperative Morbidity After Chronic Subdural Hematoma: Predictive Usefulness of the Physiological and Operative Severity Score for Enumeration of Mortality and Morbidity, American College of Surgeons National Surgical Quality Improvement Program, and American Society of Anesthesiologists Grade in a Prospective Cohort

Abstract

Although chronic subdural hematoma (CSDH) is generally benign, long-term survival (LTS) after CSDH is poor in a significant subgroup. This dichotomy has been compared to fractured neck of femur. However, although early postoperative mortality (within 30 days of CSDH) is well recorded with CSDH and similar to fractured neck of femur (4%-8%), scant accurate data exist regarding early postoperative morbidity (POMB). POMB, which prolongs length of stay (LOS) after major nonneurosurgery, is associated with decreased LTS. One recent CSDH study suggested a POMB standard of 10% i.e., notably less than with fractured neck of femur (45%). POMB was recorded in a novel prospective single-center cohort after CSDH. The POSSUM (Physiological and Operative Severity Score for Enumeration of Mortality and Morbidity), American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) score, and American Society of Anesthesiologists (ASA) grade were assessed as tools for potentially predicting POMB. Receiver operating characteristic (ROC) curves were calculated. Early postoperative mortality (within 30 days of CSDH) occurred in 3 of 114 patients (3%). Seventy-one POMB events occurred in 54 of 114 patients (47%), with 27 of 54 (50%) having a Clavien-Dindo grade ≥2. Most POMB was neurologic (n= 47/71, 66%). Age (P= 0.01), Glasgow Coma Scale (GCS) score (P= 0.001), Markwalder grade (P= 0.01), hypertension (P= 0.047), and/or ≥1 preexistent comorbidity (P= 0.041) were predictive. LOS (P= 0.01) and discharge modified Rankin Scale score (P < 0.001) were significantly associated. Predicted and observed POMB with POSSUM were significantly disparate (χ2= 15.23; P= 0.001): POSSUM area under ROC (AUROC= 0.611) was also nondiscriminatory. ACS-NSQIP (χ2= 18.51; P < 0.001; AUROC= 0.629) and ASA grades (P= 0.25) were also nonpredictive. POMB was frequently disabling, mostly neurologic, and as frequent and diverse as with fractured neck of femur. POMB was significantly correlated with LOS and discharge modified Rankin Scale score. Surprisingly, POSSUM, ACS-NSQIP, and ASA grades were not predictive and would not aid consent. Simple parameters (age, Glasgow Coma Scale, Markwalder grade, hypertension, and/or ≥1 other comorbidity) were instead predictive. Longitudinal follow-up will determine whether POMB affects LTS. CSDH, like fractured neck of femur, is distinct.